I am done

rl/Lib/site-packages/mpmath/__init__.py

@@ -0,0 +1,468 @@
+__version__ = '1.3.0'
+
+from .usertools import monitor, timing
+
+from .ctx_fp import FPContext
+from .ctx_mp import MPContext
+from .ctx_iv import MPIntervalContext
+
+fp = FPContext()
+mp = MPContext()
+iv = MPIntervalContext()
+
+fp._mp = mp
+mp._mp = mp
+iv._mp = mp
+mp._fp = fp
+fp._fp = fp
+mp._iv = iv
+fp._iv = iv
+iv._iv = iv
+
+# XXX: extremely bad pickle hack
+from . import ctx_mp as _ctx_mp
+_ctx_mp._mpf_module.mpf = mp.mpf
+_ctx_mp._mpf_module.mpc = mp.mpc
+
+make_mpf = mp.make_mpf
+make_mpc = mp.make_mpc
+
+extraprec = mp.extraprec
+extradps = mp.extradps
+workprec = mp.workprec
+workdps = mp.workdps
+autoprec = mp.autoprec
+maxcalls = mp.maxcalls
+memoize = mp.memoize
+
+mag = mp.mag
+
+bernfrac = mp.bernfrac
+
+qfrom = mp.qfrom
+mfrom = mp.mfrom
+kfrom = mp.kfrom
+taufrom = mp.taufrom
+qbarfrom = mp.qbarfrom
+ellipfun = mp.ellipfun
+jtheta = mp.jtheta
+kleinj = mp.kleinj
+eta = mp.eta
+
+qp = mp.qp
+qhyper = mp.qhyper
+qgamma = mp.qgamma
+qfac = mp.qfac
+
+nint_distance = mp.nint_distance
+
+plot = mp.plot
+cplot = mp.cplot
+splot = mp.splot
+
+odefun = mp.odefun
+
+jacobian = mp.jacobian
+findroot = mp.findroot
+multiplicity = mp.multiplicity
+
+isinf = mp.isinf
+isnan = mp.isnan
+isnormal = mp.isnormal
+isint = mp.isint
+isfinite = mp.isfinite
+almosteq = mp.almosteq
+nan = mp.nan
+rand = mp.rand
+
+absmin = mp.absmin
+absmax = mp.absmax
+
+fraction = mp.fraction
+
+linspace = mp.linspace
+arange = mp.arange
+
+mpmathify = convert = mp.convert
+mpc = mp.mpc
+
+mpi = iv._mpi
+
+nstr = mp.nstr
+nprint = mp.nprint
+chop = mp.chop
+
+fneg = mp.fneg
+fadd = mp.fadd
+fsub = mp.fsub
+fmul = mp.fmul
+fdiv = mp.fdiv
+fprod = mp.fprod
+
+quad = mp.quad
+quadgl = mp.quadgl
+quadts = mp.quadts
+quadosc = mp.quadosc
+quadsubdiv = mp.quadsubdiv
+
+invertlaplace = mp.invertlaplace
+invlaptalbot = mp.invlaptalbot
+invlapstehfest = mp.invlapstehfest
+invlapdehoog = mp.invlapdehoog
+
+pslq = mp.pslq
+identify = mp.identify
+findpoly = mp.findpoly
+
+richardson = mp.richardson
+shanks = mp.shanks
+levin = mp.levin
+cohen_alt = mp.cohen_alt
+nsum = mp.nsum
+nprod = mp.nprod
+difference = mp.difference
+diff = mp.diff
+diffs = mp.diffs
+diffs_prod = mp.diffs_prod
+diffs_exp = mp.diffs_exp
+diffun = mp.diffun
+differint = mp.differint
+taylor = mp.taylor
+pade = mp.pade
+polyval = mp.polyval
+polyroots = mp.polyroots
+fourier = mp.fourier
+fourierval = mp.fourierval
+sumem = mp.sumem
+sumap = mp.sumap
+chebyfit = mp.chebyfit
+limit = mp.limit
+
+matrix = mp.matrix
+eye = mp.eye
+diag = mp.diag
+zeros = mp.zeros
+ones = mp.ones
+hilbert = mp.hilbert
+randmatrix = mp.randmatrix
+swap_row = mp.swap_row
+extend = mp.extend
+norm = mp.norm
+mnorm = mp.mnorm
+
+lu_solve = mp.lu_solve
+lu = mp.lu
+qr = mp.qr
+unitvector = mp.unitvector
+inverse = mp.inverse
+residual = mp.residual
+qr_solve = mp.qr_solve
+cholesky = mp.cholesky
+cholesky_solve = mp.cholesky_solve
+det = mp.det
+cond = mp.cond
+hessenberg = mp.hessenberg
+schur = mp.schur
+eig = mp.eig
+eig_sort = mp.eig_sort
+eigsy = mp.eigsy
+eighe = mp.eighe
+eigh = mp.eigh
+svd_r = mp.svd_r
+svd_c = mp.svd_c
+svd = mp.svd
+gauss_quadrature = mp.gauss_quadrature
+
+expm = mp.expm
+sqrtm = mp.sqrtm
+powm = mp.powm
+logm = mp.logm
+sinm = mp.sinm
+cosm = mp.cosm
+
+mpf = mp.mpf
+j = mp.j
+exp = mp.exp
+expj = mp.expj
+expjpi = mp.expjpi
+ln = mp.ln
+im = mp.im
+re = mp.re
+inf = mp.inf
+ninf = mp.ninf
+sign = mp.sign
+
+eps = mp.eps
+pi = mp.pi
+ln2 = mp.ln2
+ln10 = mp.ln10
+phi = mp.phi
+e = mp.e
+euler = mp.euler
+catalan = mp.catalan
+khinchin = mp.khinchin
+glaisher = mp.glaisher
+apery = mp.apery
+degree = mp.degree
+twinprime = mp.twinprime
+mertens = mp.mertens
+
+ldexp = mp.ldexp
+frexp = mp.frexp
+
+fsum = mp.fsum
+fdot = mp.fdot
+
+sqrt = mp.sqrt
+cbrt = mp.cbrt
+exp = mp.exp
+ln = mp.ln
+log = mp.log
+log10 = mp.log10
+power = mp.power
+cos = mp.cos
+sin = mp.sin
+tan = mp.tan
+cosh = mp.cosh
+sinh = mp.sinh
+tanh = mp.tanh
+acos = mp.acos
+asin = mp.asin
+atan = mp.atan
+asinh = mp.asinh
+acosh = mp.acosh
+atanh = mp.atanh
+sec = mp.sec
+csc = mp.csc
+cot = mp.cot
+sech = mp.sech
+csch = mp.csch
+coth = mp.coth
+asec = mp.asec
+acsc = mp.acsc
+acot = mp.acot
+asech = mp.asech
+acsch = mp.acsch
+acoth = mp.acoth
+cospi = mp.cospi
+sinpi = mp.sinpi
+sinc = mp.sinc
+sincpi = mp.sincpi
+cos_sin = mp.cos_sin
+cospi_sinpi = mp.cospi_sinpi
+fabs = mp.fabs
+re = mp.re
+im = mp.im
+conj = mp.conj
+floor = mp.floor
+ceil = mp.ceil
+nint = mp.nint
+frac = mp.frac
+root = mp.root
+nthroot = mp.nthroot
+hypot = mp.hypot
+fmod = mp.fmod
+ldexp = mp.ldexp
+frexp = mp.frexp
+sign = mp.sign
+arg = mp.arg
+phase = mp.phase
+polar = mp.polar
+rect = mp.rect
+degrees = mp.degrees
+radians = mp.radians
+atan2 = mp.atan2
+fib = mp.fib
+fibonacci = mp.fibonacci
+lambertw = mp.lambertw
+zeta = mp.zeta
+altzeta = mp.altzeta
+gamma = mp.gamma
+rgamma = mp.rgamma
+factorial = mp.factorial
+fac = mp.fac
+fac2 = mp.fac2
+beta = mp.beta
+betainc = mp.betainc
+psi = mp.psi
+#psi0 = mp.psi0
+#psi1 = mp.psi1
+#psi2 = mp.psi2
+#psi3 = mp.psi3
+polygamma = mp.polygamma
+digamma = mp.digamma
+#trigamma = mp.trigamma
+#tetragamma = mp.tetragamma
+#pentagamma = mp.pentagamma
+harmonic = mp.harmonic
+bernoulli = mp.bernoulli
+bernfrac = mp.bernfrac
+stieltjes = mp.stieltjes
+hurwitz = mp.hurwitz
+dirichlet = mp.dirichlet
+bernpoly = mp.bernpoly
+eulerpoly = mp.eulerpoly
+eulernum = mp.eulernum
+polylog = mp.polylog
+clsin = mp.clsin
+clcos = mp.clcos
+gammainc = mp.gammainc
+gammaprod = mp.gammaprod
+binomial = mp.binomial
+rf = mp.rf
+ff = mp.ff
+hyper = mp.hyper
+hyp0f1 = mp.hyp0f1
+hyp1f1 = mp.hyp1f1
+hyp1f2 = mp.hyp1f2
+hyp2f1 = mp.hyp2f1
+hyp2f2 = mp.hyp2f2
+hyp2f0 = mp.hyp2f0
+hyp2f3 = mp.hyp2f3
+hyp3f2 = mp.hyp3f2
+hyperu = mp.hyperu
+hypercomb = mp.hypercomb
+meijerg = mp.meijerg
+appellf1 = mp.appellf1
+appellf2 = mp.appellf2
+appellf3 = mp.appellf3
+appellf4 = mp.appellf4
+hyper2d = mp.hyper2d
+bihyper = mp.bihyper
+erf = mp.erf
+erfc = mp.erfc
+erfi = mp.erfi
+erfinv = mp.erfinv
+npdf = mp.npdf
+ncdf = mp.ncdf
+expint = mp.expint
+e1 = mp.e1
+ei = mp.ei
+li = mp.li
+ci = mp.ci
+si = mp.si
+chi = mp.chi
+shi = mp.shi
+fresnels = mp.fresnels
+fresnelc = mp.fresnelc
+airyai = mp.airyai
+airybi = mp.airybi
+airyaizero = mp.airyaizero
+airybizero = mp.airybizero
+scorergi = mp.scorergi
+scorerhi = mp.scorerhi
+ellipk = mp.ellipk
+ellipe = mp.ellipe
+ellipf = mp.ellipf
+ellippi = mp.ellippi
+elliprc = mp.elliprc
+elliprj = mp.elliprj
+elliprf = mp.elliprf
+elliprd = mp.elliprd
+elliprg = mp.elliprg
+agm = mp.agm
+jacobi = mp.jacobi
+chebyt = mp.chebyt
+chebyu = mp.chebyu
+legendre = mp.legendre
+legenp = mp.legenp
+legenq = mp.legenq
+hermite = mp.hermite
+pcfd = mp.pcfd
+pcfu = mp.pcfu
+pcfv = mp.pcfv
+pcfw = mp.pcfw
+gegenbauer = mp.gegenbauer
+laguerre = mp.laguerre
+spherharm = mp.spherharm
+besselj = mp.besselj
+j0 = mp.j0
+j1 = mp.j1
+besseli = mp.besseli
+bessely = mp.bessely
+besselk = mp.besselk
+besseljzero = mp.besseljzero
+besselyzero = mp.besselyzero
+hankel1 = mp.hankel1
+hankel2 = mp.hankel2
+struveh = mp.struveh
+struvel = mp.struvel
+angerj = mp.angerj
+webere = mp.webere
+lommels1 = mp.lommels1
+lommels2 = mp.lommels2
+whitm = mp.whitm
+whitw = mp.whitw
+ber = mp.ber
+bei = mp.bei
+ker = mp.ker
+kei = mp.kei
+coulombc = mp.coulombc
+coulombf = mp.coulombf
+coulombg = mp.coulombg
+barnesg = mp.barnesg
+superfac = mp.superfac
+hyperfac = mp.hyperfac
+loggamma = mp.loggamma
+siegeltheta = mp.siegeltheta
+siegelz = mp.siegelz
+grampoint = mp.grampoint
+zetazero = mp.zetazero
+riemannr = mp.riemannr
+primepi = mp.primepi
+primepi2 = mp.primepi2
+primezeta = mp.primezeta
+bell = mp.bell
+polyexp = mp.polyexp
+expm1 = mp.expm1
+log1p = mp.log1p
+powm1 = mp.powm1
+unitroots = mp.unitroots
+cyclotomic = mp.cyclotomic
+mangoldt = mp.mangoldt
+secondzeta = mp.secondzeta
+nzeros = mp.nzeros
+backlunds = mp.backlunds
+lerchphi = mp.lerchphi
+stirling1 = mp.stirling1
+stirling2 = mp.stirling2
+squarew = mp.squarew
+trianglew = mp.trianglew
+sawtoothw = mp.sawtoothw
+unit_triangle = mp.unit_triangle
+sigmoid = mp.sigmoid
+
+# be careful when changing this name, don't use test*!
+def runtests():
+    """
+    Run all mpmath tests and print output.
+    """
+    import os.path
+    from inspect import getsourcefile
+    from .tests import runtests as tests
+    testdir = os.path.dirname(os.path.abspath(getsourcefile(tests)))
+    importdir = os.path.abspath(testdir + '/../..')
+    tests.testit(importdir, testdir)
+
+def doctests(filter=[]):
+    import sys
+    from timeit import default_timer as clock
+    for i, arg in enumerate(sys.argv):
+        if '__init__.py' in arg:
+            filter = [sn for sn in sys.argv[i+1:] if not sn.startswith("-")]
+            break
+    import doctest
+    globs = globals().copy()
+    for obj in globs: #sorted(globs.keys()):
+        if filter:
+            if not sum([pat in obj for pat in filter]):
+                continue
+        sys.stdout.write(str(obj) + " ")
+        sys.stdout.flush()
+        t1 = clock()
+        doctest.run_docstring_examples(globs[obj], {}, verbose=("-v" in sys.argv))
+        t2 = clock()
+        print(round(t2-t1, 3))
+
+if __name__ == '__main__':
+    doctests()

rl/Lib/site-packages/mpmath/calculus/__init__.py

@@ -0,0 +1,6 @@
+from . import calculus
+# XXX: hack to set methods
+from . import approximation
+from . import differentiation
+from . import extrapolation
+from . import polynomials

rl/Lib/site-packages/mpmath/calculus/approximation.py

@@ -0,0 +1,246 @@
+from ..libmp.backend import xrange
+from .calculus import defun
+
+#----------------------------------------------------------------------------#
+#                              Approximation methods                         #
+#----------------------------------------------------------------------------#
+
+# The Chebyshev approximation formula is given at:
+# http://mathworld.wolfram.com/ChebyshevApproximationFormula.html
+
+# The only major changes in the following code is that we return the
+# expanded polynomial coefficients instead of Chebyshev coefficients,
+# and that we automatically transform [a,b] -> [-1,1] and back
+# for convenience.
+
+# Coefficient in Chebyshev approximation
+def chebcoeff(ctx,f,a,b,j,N):
+    s = ctx.mpf(0)
+    h = ctx.mpf(0.5)
+    for k in range(1, N+1):
+        t = ctx.cospi((k-h)/N)
+        s += f(t*(b-a)*h + (b+a)*h) * ctx.cospi(j*(k-h)/N)
+    return 2*s/N
+
+# Generate Chebyshev polynomials T_n(ax+b) in expanded form
+def chebT(ctx, a=1, b=0):
+    Tb = [1]
+    yield Tb
+    Ta = [b, a]
+    while 1:
+        yield Ta
+        # Recurrence: T[n+1](ax+b) = 2*(ax+b)*T[n](ax+b) - T[n-1](ax+b)
+        Tmp = [0] + [2*a*t for t in Ta]
+        for i, c in enumerate(Ta): Tmp[i] += 2*b*c
+        for i, c in enumerate(Tb): Tmp[i] -= c
+        Ta, Tb = Tmp, Ta
+
+@defun
+def chebyfit(ctx, f, interval, N, error=False):
+    r"""
+    Computes a polynomial of degree `N-1` that approximates the
+    given function `f` on the interval `[a, b]`. With ``error=True``,
+    :func:`~mpmath.chebyfit` also returns an accurate estimate of the
+    maximum absolute error; that is, the maximum value of
+    `|f(x) - P(x)|` for `x \in [a, b]`.
+
+    :func:`~mpmath.chebyfit` uses the Chebyshev approximation formula,
+    which gives a nearly optimal solution: that is, the maximum
+    error of the approximating polynomial is very close to
+    the smallest possible for any polynomial of the same degree.
+
+    Chebyshev approximation is very useful if one needs repeated
+    evaluation of an expensive function, such as function defined
+    implicitly by an integral or a differential equation. (For
+    example, it could be used to turn a slow mpmath function
+    into a fast machine-precision version of the same.)
+
+    **Examples**
+
+    Here we use :func:`~mpmath.chebyfit` to generate a low-degree approximation
+    of `f(x) = \cos(x)`, valid on the interval `[1, 2]`::
+
+        >>> from mpmath import *
+        >>> mp.dps = 15; mp.pretty = True
+        >>> poly, err = chebyfit(cos, [1, 2], 5, error=True)
+        >>> nprint(poly)
+        [0.00291682, 0.146166, -0.732491, 0.174141, 0.949553]
+        >>> nprint(err, 12)
+        1.61351758081e-5
+
+    The polynomial can be evaluated using ``polyval``::
+
+        >>> nprint(polyval(poly, 1.6), 12)
+        -0.0291858904138
+        >>> nprint(cos(1.6), 12)
+        -0.0291995223013
+
+    Sampling the true error at 1000 points shows that the error
+    estimate generated by ``chebyfit`` is remarkably good::
+
+        >>> error = lambda x: abs(cos(x) - polyval(poly, x))
+        >>> nprint(max([error(1+n/1000.) for n in range(1000)]), 12)
+        1.61349954245e-5
+
+    **Choice of degree**
+
+    The degree `N` can be set arbitrarily high, to obtain an
+    arbitrarily good approximation. As a rule of thumb, an
+    `N`-term Chebyshev approximation is good to `N/(b-a)` decimal
+    places on a unit interval (although this depends on how
+    well-behaved `f` is). The cost grows accordingly: ``chebyfit``
+    evaluates the function `(N^2)/2` times to compute the
+    coefficients and an additional `N` times to estimate the error.
+
+    **Possible issues**
+
+    One should be careful to use a sufficiently high working
+    precision both when calling ``chebyfit`` and when evaluating
+    the resulting polynomial, as the polynomial is sometimes
+    ill-conditioned. It is for example difficult to reach
+    15-digit accuracy when evaluating the polynomial using
+    machine precision floats, no matter the theoretical
+    accuracy of the polynomial. (The option to return the
+    coefficients in Chebyshev form should be made available
+    in the future.)
+
+    It is important to note the Chebyshev approximation works
+    poorly if `f` is not smooth. A function containing singularities,
+    rapid oscillation, etc can be approximated more effectively by
+    multiplying it by a weight function that cancels out the
+    nonsmooth features, or by dividing the interval into several
+    segments.
+    """
+    a, b = ctx._as_points(interval)
+    orig = ctx.prec
+    try:
+        ctx.prec = orig + int(N**0.5) + 20
+        c = [chebcoeff(ctx,f,a,b,k,N) for k in range(N)]
+        d = [ctx.zero] * N
+        d[0] = -c[0]/2
+        h = ctx.mpf(0.5)
+        T = chebT(ctx, ctx.mpf(2)/(b-a), ctx.mpf(-1)*(b+a)/(b-a))
+        for (k, Tk) in zip(range(N), T):
+            for i in range(len(Tk)):
+                d[i] += c[k]*Tk[i]
+        d = d[::-1]
+        # Estimate maximum error
+        err = ctx.zero
+        for k in range(N):
+            x = ctx.cos(ctx.pi*k/N) * (b-a)*h + (b+a)*h
+            err = max(err, abs(f(x) - ctx.polyval(d, x)))
+    finally:
+        ctx.prec = orig
+    if error:
+        return d, +err
+    else:
+        return d
+
+@defun
+def fourier(ctx, f, interval, N):
+    r"""
+    Computes the Fourier series of degree `N` of the given function
+    on the interval `[a, b]`. More precisely, :func:`~mpmath.fourier` returns
+    two lists `(c, s)` of coefficients (the cosine series and sine
+    series, respectively), such that
+
+    .. math ::
+
+        f(x) \sim \sum_{k=0}^N
+            c_k \cos(k m x) + s_k \sin(k m x)
+
+    where `m = 2 \pi / (b-a)`.
+
+    Note that many texts define the first coefficient as `2 c_0` instead
+    of `c_0`. The easiest way to evaluate the computed series correctly
+    is to pass it to :func:`~mpmath.fourierval`.
+
+    **Examples**
+
+    The function `f(x) = x` has a simple Fourier series on the standard
+    interval `[-\pi, \pi]`. The cosine coefficients are all zero (because
+    the function has odd symmetry), and the sine coefficients are
+    rational numbers::
+
+        >>> from mpmath import *
+        >>> mp.dps = 15; mp.pretty = True
+        >>> c, s = fourier(lambda x: x, [-pi, pi], 5)
+        >>> nprint(c)
+        [0.0, 0.0, 0.0, 0.0, 0.0, 0.0]
+        >>> nprint(s)
+        [0.0, 2.0, -1.0, 0.666667, -0.5, 0.4]
+
+    This computes a Fourier series of a nonsymmetric function on
+    a nonstandard interval::
+
+        >>> I = [-1, 1.5]
+        >>> f = lambda x: x**2 - 4*x + 1
+        >>> cs = fourier(f, I, 4)
+        >>> nprint(cs[0])
+        [0.583333, 1.12479, -1.27552, 0.904708, -0.441296]
+        >>> nprint(cs[1])
+        [0.0, -2.6255, 0.580905, 0.219974, -0.540057]
+
+    It is instructive to plot a function along with its truncated
+    Fourier series::
+
+        >>> plot([f, lambda x: fourierval(cs, I, x)], I) #doctest: +SKIP
+
+    Fourier series generally converge slowly (and may not converge
+    pointwise). For example, if `f(x) = \cosh(x)`, a 10-term Fourier
+    series gives an `L^2` error corresponding to 2-digit accuracy::
+
+        >>> I = [-1, 1]
+        >>> cs = fourier(cosh, I, 9)
+        >>> g = lambda x: (cosh(x) - fourierval(cs, I, x))**2
+        >>> nprint(sqrt(quad(g, I)))
+        0.00467963
+
+    :func:`~mpmath.fourier` uses numerical quadrature. For nonsmooth functions,
+    the accuracy (and speed) can be improved by including all singular
+    points in the interval specification::
+
+        >>> nprint(fourier(abs, [-1, 1], 0), 10)
+        ([0.5000441648], [0.0])
+        >>> nprint(fourier(abs, [-1, 0, 1], 0), 10)
+        ([0.5], [0.0])
+
+    """
+    interval = ctx._as_points(interval)
+    a = interval[0]
+    b = interval[-1]
+    L = b-a
+    cos_series = []
+    sin_series = []
+    cutoff = ctx.eps*10
+    for n in xrange(N+1):
+        m = 2*n*ctx.pi/L
+        an = 2*ctx.quadgl(lambda t: f(t)*ctx.cos(m*t), interval)/L
+        bn = 2*ctx.quadgl(lambda t: f(t)*ctx.sin(m*t), interval)/L
+        if n == 0:
+            an /= 2
+        if abs(an) < cutoff: an = ctx.zero
+        if abs(bn) < cutoff: bn = ctx.zero
+        cos_series.append(an)
+        sin_series.append(bn)
+    return cos_series, sin_series
+
+@defun
+def fourierval(ctx, series, interval, x):
+    """
+    Evaluates a Fourier series (in the format computed by
+    by :func:`~mpmath.fourier` for the given interval) at the point `x`.
+
+    The series should be a pair `(c, s)` where `c` is the
+    cosine series and `s` is the sine series. The two lists
+    need not have the same length.
+    """
+    cs, ss = series
+    ab = ctx._as_points(interval)
+    a = interval[0]
+    b = interval[-1]
+    m = 2*ctx.pi/(ab[-1]-ab[0])
+    s = ctx.zero
+    s += ctx.fsum(cs[n]*ctx.cos(m*n*x) for n in xrange(len(cs)) if cs[n])
+    s += ctx.fsum(ss[n]*ctx.sin(m*n*x) for n in xrange(len(ss)) if ss[n])
+    return s

rl/Lib/site-packages/mpmath/calculus/calculus.py

@@ -0,0 +1,6 @@
+class CalculusMethods(object):
+    pass
+
+def defun(f):
+    setattr(CalculusMethods, f.__name__, f)
+    return f

rl/Lib/site-packages/mpmath/calculus/differentiation.py

@@ -0,0 +1,647 @@
+from ..libmp.backend import xrange
+from .calculus import defun
+
+try:
+    iteritems = dict.iteritems
+except AttributeError:
+    iteritems = dict.items
+
+#----------------------------------------------------------------------------#
+#                                Differentiation                             #
+#----------------------------------------------------------------------------#
+
+@defun
+def difference(ctx, s, n):
+    r"""
+    Given a sequence `(s_k)` containing at least `n+1` items, returns the
+    `n`-th forward difference,
+
+    .. math ::
+
+        \Delta^n = \sum_{k=0}^{\infty} (-1)^{k+n} {n \choose k} s_k.
+    """
+    n = int(n)
+    d = ctx.zero
+    b = (-1) ** (n & 1)
+    for k in xrange(n+1):
+        d += b * s[k]
+        b = (b * (k-n)) // (k+1)
+    return d
+
+def hsteps(ctx, f, x, n, prec, **options):
+    singular = options.get('singular')
+    addprec = options.get('addprec', 10)
+    direction = options.get('direction', 0)
+    workprec = (prec+2*addprec) * (n+1)
+    orig = ctx.prec
+    try:
+        ctx.prec = workprec
+        h = options.get('h')
+        if h is None:
+            if options.get('relative'):
+                hextramag = int(ctx.mag(x))
+            else:
+                hextramag = 0
+            h = ctx.ldexp(1, -prec-addprec-hextramag)
+        else:
+            h = ctx.convert(h)
+        # Directed: steps x, x+h, ... x+n*h
+        direction = options.get('direction', 0)
+        if direction:
+            h *= ctx.sign(direction)
+            steps = xrange(n+1)
+            norm = h
+        # Central: steps x-n*h, x-(n-2)*h ..., x, ..., x+(n-2)*h, x+n*h
+        else:
+            steps = xrange(-n, n+1, 2)
+            norm = (2*h)
+        # Perturb
+        if singular:
+            x += 0.5*h
+        values = [f(x+k*h) for k in steps]
+        return values, norm, workprec
+    finally:
+        ctx.prec = orig
+
+
+@defun
+def diff(ctx, f, x, n=1, **options):
+    r"""
+    Numerically computes the derivative of `f`, `f'(x)`, or generally for
+    an integer `n \ge 0`, the `n`-th derivative `f^{(n)}(x)`.
+    A few basic examples are::
+
+        >>> from mpmath import *
+        >>> mp.dps = 15; mp.pretty = True
+        >>> diff(lambda x: x**2 + x, 1.0)
+        3.0
+        >>> diff(lambda x: x**2 + x, 1.0, 2)
+        2.0
+        >>> diff(lambda x: x**2 + x, 1.0, 3)
+        0.0
+        >>> nprint([diff(exp, 3, n) for n in range(5)])   # exp'(x) = exp(x)
+        [20.0855, 20.0855, 20.0855, 20.0855, 20.0855]
+
+    Even more generally, given a tuple of arguments `(x_1, \ldots, x_k)`
+    and order `(n_1, \ldots, n_k)`, the partial derivative
+    `f^{(n_1,\ldots,n_k)}(x_1,\ldots,x_k)` is evaluated. For example::
+
+        >>> diff(lambda x,y: 3*x*y + 2*y - x, (0.25, 0.5), (0,1))
+        2.75
+        >>> diff(lambda x,y: 3*x*y + 2*y - x, (0.25, 0.5), (1,1))
+        3.0
+
+    **Options**
+
+    The following optional keyword arguments are recognized:
+
+    ``method``
+        Supported methods are ``'step'`` or ``'quad'``: derivatives may be
+        computed using either a finite difference with a small step
+        size `h` (default), or numerical quadrature.
+    ``direction``
+        Direction of finite difference: can be -1 for a left
+        difference, 0 for a central difference (default), or +1
+        for a right difference; more generally can be any complex number.
+    ``addprec``
+        Extra precision for `h` used to account for the function's
+        sensitivity to perturbations (default = 10).
+    ``relative``
+        Choose `h` relative to the magnitude of `x`, rather than an
+        absolute value; useful for large or tiny `x` (default = False).
+    ``h``
+        As an alternative to ``addprec`` and ``relative``, manually
+        select the step size `h`.
+    ``singular``
+        If True, evaluation exactly at the point `x` is avoided; this is
+        useful for differentiating functions with removable singularities.
+        Default = False.
+    ``radius``
+        Radius of integration contour (with ``method = 'quad'``).
+        Default = 0.25. A larger radius typically is faster and more
+        accurate, but it must be chosen so that `f` has no
+        singularities within the radius from the evaluation point.
+
+    A finite difference requires `n+1` function evaluations and must be
+    performed at `(n+1)` times the target precision. Accordingly, `f` must
+    support fast evaluation at high precision.
+
+    With integration, a larger number of function evaluations is
+    required, but not much extra precision is required. For high order
+    derivatives, this method may thus be faster if f is very expensive to
+    evaluate at high precision.
+
+    **Further examples**
+
+    The direction option is useful for computing left- or right-sided
+    derivatives of nonsmooth functions::
+
+        >>> diff(abs, 0, direction=0)
+        0.0
+        >>> diff(abs, 0, direction=1)
+        1.0
+        >>> diff(abs, 0, direction=-1)
+        -1.0
+
+    More generally, if the direction is nonzero, a right difference
+    is computed where the step size is multiplied by sign(direction).
+    For example, with direction=+j, the derivative from the positive
+    imaginary direction will be computed::
+
+        >>> diff(abs, 0, direction=j)
+        (0.0 - 1.0j)
+
+    With integration, the result may have a small imaginary part
+    even even if the result is purely real::
+
+        >>> diff(sqrt, 1, method='quad')    # doctest:+ELLIPSIS
+        (0.5 - 4.59...e-26j)
+        >>> chop(_)
+        0.5
+
+    Adding precision to obtain an accurate value::
+
+        >>> diff(cos, 1e-30)
+        0.0
+        >>> diff(cos, 1e-30, h=0.0001)
+        -9.99999998328279e-31
+        >>> diff(cos, 1e-30, addprec=100)
+        -1.0e-30
+
+    """
+    partial = False
+    try:
+        orders = list(n)
+        x = list(x)
+        partial = True
+    except TypeError:
+        pass
+    if partial:
+        x = [ctx.convert(_) for _ in x]
+        return _partial_diff(ctx, f, x, orders, options)
+    method = options.get('method', 'step')
+    if n == 0 and method != 'quad' and not options.get('singular'):
+        return f(ctx.convert(x))
+    prec = ctx.prec
+    try:
+        if method == 'step':
+            values, norm, workprec = hsteps(ctx, f, x, n, prec, **options)
+            ctx.prec = workprec
+            v = ctx.difference(values, n) / norm**n
+        elif method == 'quad':
+            ctx.prec += 10
+            radius = ctx.convert(options.get('radius', 0.25))
+            def g(t):
+                rei = radius*ctx.expj(t)
+                z = x + rei
+                return f(z) / rei**n
+            d = ctx.quadts(g, [0, 2*ctx.pi])
+            v = d * ctx.factorial(n) / (2*ctx.pi)
+        else:
+            raise ValueError("unknown method: %r" % method)
+    finally:
+        ctx.prec = prec
+    return +v
+
+def _partial_diff(ctx, f, xs, orders, options):
+    if not orders:
+        return f()
+    if not sum(orders):
+        return f(*xs)
+    i = 0
+    for i in range(len(orders)):
+        if orders[i]:
+            break
+    order = orders[i]
+    def fdiff_inner(*f_args):
+        def inner(t):
+            return f(*(f_args[:i] + (t,) + f_args[i+1:]))
+        return ctx.diff(inner, f_args[i], order, **options)
+    orders[i] = 0
+    return _partial_diff(ctx, fdiff_inner, xs, orders, options)
+
+@defun
+def diffs(ctx, f, x, n=None, **options):
+    r"""
+    Returns a generator that yields the sequence of derivatives
+
+    .. math ::
+
+        f(x), f'(x), f''(x), \ldots, f^{(k)}(x), \ldots
+
+    With ``method='step'``, :func:`~mpmath.diffs` uses only `O(k)`
+    function evaluations to generate the first `k` derivatives,
+    rather than the roughly `O(k^2)` evaluations
+    required if one calls :func:`~mpmath.diff` `k` separate times.
+
+    With `n < \infty`, the generator stops as soon as the
+    `n`-th derivative has been generated. If the exact number of
+    needed derivatives is known in advance, this is further
+    slightly more efficient.
+
+    Options are the same as for :func:`~mpmath.diff`.
+
+    **Examples**
+
+        >>> from mpmath import *
+        >>> mp.dps = 15
+        >>> nprint(list(diffs(cos, 1, 5)))
+        [0.540302, -0.841471, -0.540302, 0.841471, 0.540302, -0.841471]
+        >>> for i, d in zip(range(6), diffs(cos, 1)):
+        ...     print("%s %s" % (i, d))
+        ...
+        0 0.54030230586814
+        1 -0.841470984807897
+        2 -0.54030230586814
+        3 0.841470984807897
+        4 0.54030230586814
+        5 -0.841470984807897
+
+    """
+    if n is None:
+        n = ctx.inf
+    else:
+        n = int(n)
+    if options.get('method', 'step') != 'step':
+        k = 0
+        while k < n + 1:
+            yield ctx.diff(f, x, k, **options)
+            k += 1
+        return
+    singular = options.get('singular')
+    if singular:
+        yield ctx.diff(f, x, 0, singular=True)
+    else:
+        yield f(ctx.convert(x))
+    if n < 1:
+        return
+    if n == ctx.inf:
+        A, B = 1, 2
+    else:
+        A, B = 1, n+1
+    while 1:
+        callprec = ctx.prec
+        y, norm, workprec = hsteps(ctx, f, x, B, callprec, **options)
+        for k in xrange(A, B):
+            try:
+                ctx.prec = workprec
+                d = ctx.difference(y, k) / norm**k
+            finally:
+                ctx.prec = callprec
+            yield +d
+            if k >= n:
+                return
+        A, B = B, int(A*1.4+1)
+        B = min(B, n)
+
+def iterable_to_function(gen):
+    gen = iter(gen)
+    data = []
+    def f(k):
+        for i in xrange(len(data), k+1):
+            data.append(next(gen))
+        return data[k]
+    return f
+
+@defun
+def diffs_prod(ctx, factors):
+    r"""
+    Given a list of `N` iterables or generators yielding
+    `f_k(x), f'_k(x), f''_k(x), \ldots` for `k = 1, \ldots, N`,
+    generate `g(x), g'(x), g''(x), \ldots` where
+    `g(x) = f_1(x) f_2(x) \cdots f_N(x)`.
+
+    At high precision and for large orders, this is typically more efficient
+    than numerical differentiation if the derivatives of each `f_k(x)`
+    admit direct computation.
+
+    Note: This function does not increase the working precision internally,
+    so guard digits may have to be added externally for full accuracy.
+
+    **Examples**
+
+        >>> from mpmath import *
+        >>> mp.dps = 15; mp.pretty = True
+        >>> f = lambda x: exp(x)*cos(x)*sin(x)
+        >>> u = diffs(f, 1)
+        >>> v = mp.diffs_prod([diffs(exp,1), diffs(cos,1), diffs(sin,1)])
+        >>> next(u); next(v)
+        1.23586333600241
+        1.23586333600241
+        >>> next(u); next(v)
+        0.104658952245596
+        0.104658952245596
+        >>> next(u); next(v)
+        -5.96999877552086
+        -5.96999877552086
+        >>> next(u); next(v)
+        -12.4632923122697
+        -12.4632923122697
+
+    """
+    N = len(factors)
+    if N == 1:
+        for c in factors[0]:
+            yield c
+    else:
+        u = iterable_to_function(ctx.diffs_prod(factors[:N//2]))
+        v = iterable_to_function(ctx.diffs_prod(factors[N//2:]))
+        n = 0
+        while 1:
+            #yield sum(binomial(n,k)*u(n-k)*v(k) for k in xrange(n+1))
+            s = u(n) * v(0)
+            a = 1
+            for k in xrange(1,n+1):
+                a = a * (n-k+1) // k
+                s += a * u(n-k) * v(k)
+            yield s
+            n += 1
+
+def dpoly(n, _cache={}):
+    """
+    nth differentiation polynomial for exp (Faa di Bruno's formula).
+
+    TODO: most exponents are zero, so maybe a sparse representation
+    would be better.
+    """
+    if n in _cache:
+        return _cache[n]
+    if not _cache:
+        _cache[0] = {(0,):1}
+    R = dpoly(n-1)
+    R = dict((c+(0,),v) for (c,v) in iteritems(R))
+    Ra = {}
+    for powers, count in iteritems(R):
+        powers1 = (powers[0]+1,) + powers[1:]
+        if powers1 in Ra:
+            Ra[powers1] += count
+        else:
+            Ra[powers1] = count
+    for powers, count in iteritems(R):
+        if not sum(powers):
+            continue
+        for k,p in enumerate(powers):
+            if p:
+                powers2 = powers[:k] + (p-1,powers[k+1]+1) + powers[k+2:]
+                if powers2 in Ra:
+                    Ra[powers2] += p*count
+                else:
+                    Ra[powers2] = p*count
+    _cache[n] = Ra
+    return _cache[n]
+
+@defun
+def diffs_exp(ctx, fdiffs):
+    r"""
+    Given an iterable or generator yielding `f(x), f'(x), f''(x), \ldots`
+    generate `g(x), g'(x), g''(x), \ldots` where `g(x) = \exp(f(x))`.
+
+    At high precision and for large orders, this is typically more efficient
+    than numerical differentiation if the derivatives of `f(x)`
+    admit direct computation.
+
+    Note: This function does not increase the working precision internally,
+    so guard digits may have to be added externally for full accuracy.
+
+    **Examples**
+
+    The derivatives of the gamma function can be computed using
+    logarithmic differentiation::
+
+        >>> from mpmath import *
+        >>> mp.dps = 15; mp.pretty = True
+        >>>
+        >>> def diffs_loggamma(x):
+        ...     yield loggamma(x)
+        ...     i = 0
+        ...     while 1:
+        ...         yield psi(i,x)
+        ...         i += 1
+        ...
+        >>> u = diffs_exp(diffs_loggamma(3))
+        >>> v = diffs(gamma, 3)
+        >>> next(u); next(v)
+        2.0
+        2.0
+        >>> next(u); next(v)
+        1.84556867019693
+        1.84556867019693
+        >>> next(u); next(v)
+        2.49292999190269
+        2.49292999190269
+        >>> next(u); next(v)
+        3.44996501352367
+        3.44996501352367
+
+    """
+    fn = iterable_to_function(fdiffs)
+    f0 = ctx.exp(fn(0))
+    yield f0
+    i = 1
+    while 1:
+        s = ctx.mpf(0)
+        for powers, c in iteritems(dpoly(i)):
+            s += c*ctx.fprod(fn(k+1)**p for (k,p) in enumerate(powers) if p)
+        yield s * f0
+        i += 1
+
+@defun
+def differint(ctx, f, x, n=1, x0=0):
+    r"""
+    Calculates the Riemann-Liouville differintegral, or fractional
+    derivative, defined by
+
+    .. math ::
+
+        \,_{x_0}{\mathbb{D}}^n_xf(x) = \frac{1}{\Gamma(m-n)} \frac{d^m}{dx^m}
+        \int_{x_0}^{x}(x-t)^{m-n-1}f(t)dt
+
+    where `f` is a given (presumably well-behaved) function,
+    `x` is the evaluation point, `n` is the order, and `x_0` is
+    the reference point of integration (`m` is an arbitrary
+    parameter selected automatically).
+
+    With `n = 1`, this is just the standard derivative `f'(x)`; with `n = 2`,
+    the second derivative `f''(x)`, etc. With `n = -1`, it gives
+    `\int_{x_0}^x f(t) dt`, with `n = -2`
+    it gives `\int_{x_0}^x \left( \int_{x_0}^t f(u) du \right) dt`, etc.
+
+    As `n` is permitted to be any number, this operator generalizes
+    iterated differentiation and iterated integration to a single
+    operator with a continuous order parameter.
+
+    **Examples**
+
+    There is an exact formula for the fractional derivative of a
+    monomial `x^p`, which may be used as a reference. For example,
+    the following gives a half-derivative (order 0.5)::
+
+        >>> from mpmath import *
+        >>> mp.dps = 15; mp.pretty = True
+        >>> x = mpf(3); p = 2; n = 0.5
+        >>> differint(lambda t: t**p, x, n)
+        7.81764019044672
+        >>> gamma(p+1)/gamma(p-n+1) * x**(p-n)
+        7.81764019044672
+
+    Another useful test function is the exponential function, whose
+    integration / differentiation formula easy generalizes
+    to arbitrary order. Here we first compute a third derivative,
+    and then a triply nested integral. (The reference point `x_0`
+    is set to `-\infty` to avoid nonzero endpoint terms.)::
+
+        >>> differint(lambda x: exp(pi*x), -1.5, 3)
+        0.278538406900792
+        >>> exp(pi*-1.5) * pi**3
+        0.278538406900792
+        >>> differint(lambda x: exp(pi*x), 3.5, -3, -inf)
+        1922.50563031149
+        >>> exp(pi*3.5) / pi**3
+        1922.50563031149
+
+    However, for noninteger `n`, the differentiation formula for the
+    exponential function must be modified to give the same result as the
+    Riemann-Liouville differintegral::
+
+        >>> x = mpf(3.5)
+        >>> c = pi
+        >>> n = 1+2*j
+        >>> differint(lambda x: exp(c*x), x, n)
+        (-123295.005390743 + 140955.117867654j)
+        >>> x**(-n) * exp(c)**x * (x*c)**n * gammainc(-n, 0, x*c) / gamma(-n)
+        (-123295.005390743 + 140955.117867654j)
+
+
+    """
+    m = max(int(ctx.ceil(ctx.re(n)))+1, 1)
+    r = m-n-1
+    g = lambda x: ctx.quad(lambda t: (x-t)**r * f(t), [x0, x])
+    return ctx.diff(g, x, m) / ctx.gamma(m-n)
+
+@defun
+def diffun(ctx, f, n=1, **options):
+    r"""
+    Given a function `f`, returns a function `g(x)` that evaluates the nth
+    derivative `f^{(n)}(x)`::
+
+        >>> from mpmath import *
+        >>> mp.dps = 15; mp.pretty = True
+        >>> cos2 = diffun(sin)
+        >>> sin2 = diffun(sin, 4)
+        >>> cos(1.3), cos2(1.3)
+        (0.267498828624587, 0.267498828624587)
+        >>> sin(1.3), sin2(1.3)
+        (0.963558185417193, 0.963558185417193)
+
+    The function `f` must support arbitrary precision evaluation.
+    See :func:`~mpmath.diff` for additional details and supported
+    keyword options.
+    """
+    if n == 0:
+        return f
+    def g(x):
+        return ctx.diff(f, x, n, **options)
+    return g
+
+@defun
+def taylor(ctx, f, x, n, **options):
+    r"""
+    Produces a degree-`n` Taylor polynomial around the point `x` of the
+    given function `f`. The coefficients are returned as a list.
+
+        >>> from mpmath import *
+        >>> mp.dps = 15; mp.pretty = True
+        >>> nprint(chop(taylor(sin, 0, 5)))
+        [0.0, 1.0, 0.0, -0.166667, 0.0, 0.00833333]
+
+    The coefficients are computed using high-order numerical
+    differentiation. The function must be possible to evaluate
+    to arbitrary precision. See :func:`~mpmath.diff` for additional details
+    and supported keyword options.
+
+    Note that to evaluate the Taylor polynomial as an approximation
+    of `f`, e.g. with :func:`~mpmath.polyval`, the coefficients must be reversed,
+    and the point of the Taylor expansion must be subtracted from
+    the argument:
+
+        >>> p = taylor(exp, 2.0, 10)
+        >>> polyval(p[::-1], 2.5 - 2.0)
+        12.1824939606092
+        >>> exp(2.5)
+        12.1824939607035
+
+    """
+    gen = enumerate(ctx.diffs(f, x, n, **options))
+    if options.get("chop", True):
+        return [ctx.chop(d)/ctx.factorial(i) for i, d in gen]
+    else:
+        return [d/ctx.factorial(i) for i, d in gen]
+
+@defun
+def pade(ctx, a, L, M):
+    r"""
+    Computes a Pade approximation of degree `(L, M)` to a function.
+    Given at least `L+M+1` Taylor coefficients `a` approximating
+    a function `A(x)`, :func:`~mpmath.pade` returns coefficients of
+    polynomials `P, Q` satisfying
+
+    .. math ::
+
+        P = \sum_{k=0}^L p_k x^k
+
+        Q = \sum_{k=0}^M q_k x^k
+
+        Q_0 = 1
+
+        A(x) Q(x) = P(x) + O(x^{L+M+1})
+
+    `P(x)/Q(x)` can provide a good approximation to an analytic function
+    beyond the radius of convergence of its Taylor series (example
+    from G.A. Baker 'Essentials of Pade Approximants' Academic Press,
+    Ch.1A)::
+
+        >>> from mpmath import *
+        >>> mp.dps = 15; mp.pretty = True
+        >>> one = mpf(1)
+        >>> def f(x):
+        ...     return sqrt((one + 2*x)/(one + x))
+        ...
+        >>> a = taylor(f, 0, 6)
+        >>> p, q = pade(a, 3, 3)
+        >>> x = 10
+        >>> polyval(p[::-1], x)/polyval(q[::-1], x)
+        1.38169105566806
+        >>> f(x)
+        1.38169855941551
+
+    """
+    # To determine L+1 coefficients of P and M coefficients of Q
+    # L+M+1 coefficients of A must be provided
+    if len(a) < L+M+1:
+        raise ValueError("L+M+1 Coefficients should be provided")
+
+    if M == 0:
+        if L == 0:
+            return [ctx.one], [ctx.one]
+        else:
+            return a[:L+1], [ctx.one]
+
+    # Solve first
+    # a[L]*q[1] + ... + a[L-M+1]*q[M] = -a[L+1]
+    # ...
+    # a[L+M-1]*q[1] + ... + a[L]*q[M] = -a[L+M]
+    A = ctx.matrix(M)
+    for j in range(M):
+        for i in range(min(M, L+j+1)):
+            A[j, i] = a[L+j-i]
+    v = -ctx.matrix(a[(L+1):(L+M+1)])
+    x = ctx.lu_solve(A, v)
+    q = [ctx.one] + list(x)
+    # compute p
+    p = [0]*(L+1)
+    for i in range(L+1):
+        s = a[i]
+        for j in range(1, min(M,i) + 1):
+            s += q[j]*a[i-j]
+        p[i] = s
+    return p, q

rl/Lib/site-packages/mpmath/calculus/inverselaplace.py

@@ -0,0 +1,973 @@
+# contributed to mpmath by Kristopher L. Kuhlman, February 2017
+# contributed to mpmath by Guillermo Navas-Palencia, February 2022
+
+class InverseLaplaceTransform(object):
+    r"""
+    Inverse Laplace transform methods are implemented using this
+    class, in order to simplify the code and provide a common
+    infrastructure.
+
+    Implement a custom inverse Laplace transform algorithm by
+    subclassing :class:`InverseLaplaceTransform` and implementing the
+    appropriate methods. The subclass can then be used by
+    :func:`~mpmath.invertlaplace` by passing it as the *method*
+    argument.
+    """
+
+    def __init__(self, ctx):
+        self.ctx = ctx
+
+    def calc_laplace_parameter(self, t, **kwargs):
+        r"""
+        Determine the vector of Laplace parameter values needed for an
+        algorithm, this will depend on the choice of algorithm (de
+        Hoog is default), the algorithm-specific parameters passed (or
+        default ones), and desired time.
+        """
+        raise NotImplementedError
+
+    def calc_time_domain_solution(self, fp):
+        r"""
+        Compute the time domain solution, after computing the
+        Laplace-space function evaluations at the abscissa required
+        for the algorithm. Abscissa computed for one algorithm are
+        typically not useful for another algorithm.
+        """
+        raise NotImplementedError
+
+
+class FixedTalbot(InverseLaplaceTransform):
+
+    def calc_laplace_parameter(self, t, **kwargs):
+        r"""The "fixed" Talbot method deforms the Bromwich contour towards
+        `-\infty` in the shape of a parabola. Traditionally the Talbot
+        algorithm has adjustable parameters, but the "fixed" version
+        does not. The `r` parameter could be passed in as a parameter,
+        if you want to override the default given by (Abate & Valko,
+        2004).
+
+        The Laplace parameter is sampled along a parabola opening
+        along the negative imaginary axis, with the base of the
+        parabola along the real axis at
+        `p=\frac{r}{t_\mathrm{max}}`. As the number of terms used in
+        the approximation (degree) grows, the abscissa required for
+        function evaluation tend towards `-\infty`, requiring high
+        precision to prevent overflow.  If any poles, branch cuts or
+        other singularities exist such that the deformed Bromwich
+        contour lies to the left of the singularity, the method will
+        fail.
+
+        **Optional arguments**
+
+        :class:`~mpmath.calculus.inverselaplace.FixedTalbot.calc_laplace_parameter`
+        recognizes the following keywords
+
+        *tmax*
+            maximum time associated with vector of times
+            (typically just the time requested)
+        *degree*
+            integer order of approximation (M = number of terms)
+        *r*
+            abscissa for `p_0` (otherwise computed using rule
+            of thumb `2M/5`)
+
+        The working precision will be increased according to a rule of
+        thumb. If 'degree' is not specified, the working precision and
+        degree are chosen to hopefully achieve the dps of the calling
+        context. If 'degree' is specified, the working precision is
+        chosen to achieve maximum resulting precision for the
+        specified degree.
+
+        .. math ::
+
+            p_0=\frac{r}{t}
+
+        .. math ::
+
+            p_i=\frac{i r \pi}{Mt_\mathrm{max}}\left[\cot\left(
+            \frac{i\pi}{M}\right) + j \right] \qquad 1\le i <M
+
+        where `j=\sqrt{-1}`, `r=2M/5`, and `t_\mathrm{max}` is the
+        maximum specified time.
+
+        """
+
+        # required
+        # ------------------------------
+        # time of desired approximation
+        self.t = self.ctx.convert(t)
+
+        # optional
+        # ------------------------------
+        # maximum time desired (used for scaling) default is requested
+        # time.
+        self.tmax = self.ctx.convert(kwargs.get('tmax', self.t))
+
+        # empirical relationships used here based on a linear fit of
+        # requested and delivered dps for exponentially decaying time
+        # functions for requested dps up to 512.
+
+        if 'degree' in kwargs:
+            self.degree = kwargs['degree']
+            self.dps_goal = self.degree
+        else:
+            self.dps_goal = int(1.72*self.ctx.dps)
+            self.degree = max(12, int(1.38*self.dps_goal))
+
+        M = self.degree
+
+        # this is adjusting the dps of the calling context hopefully
+        # the caller doesn't monkey around with it between calling
+        # this routine and calc_time_domain_solution()
+        self.dps_orig = self.ctx.dps
+        self.ctx.dps = self.dps_goal
+
+        # Abate & Valko rule of thumb for r parameter
+        self.r = kwargs.get('r', self.ctx.fraction(2, 5)*M)
+
+        self.theta = self.ctx.linspace(0.0, self.ctx.pi, M+1)
+
+        self.cot_theta = self.ctx.matrix(M, 1)
+        self.cot_theta[0] = 0  # not used
+
+        # all but time-dependent part of p
+        self.delta = self.ctx.matrix(M, 1)
+        self.delta[0] = self.r
+
+        for i in range(1, M):
+            self.cot_theta[i] = self.ctx.cot(self.theta[i])
+            self.delta[i] = self.r*self.theta[i]*(self.cot_theta[i] + 1j)
+
+        self.p = self.ctx.matrix(M, 1)
+        self.p = self.delta/self.tmax
+
+        # NB: p is complex (mpc)
+
+    def calc_time_domain_solution(self, fp, t, manual_prec=False):
+        r"""The fixed Talbot time-domain solution is computed from the
+        Laplace-space function evaluations using
+
+        .. math ::
+
+            f(t,M)=\frac{2}{5t}\sum_{k=0}^{M-1}\Re \left[
+            \gamma_k \bar{f}(p_k)\right]
+
+        where
+
+        .. math ::
+
+            \gamma_0 = \frac{1}{2}e^{r}\bar{f}(p_0)
+
+        .. math ::
+
+            \gamma_k = e^{tp_k}\left\lbrace 1 + \frac{jk\pi}{M}\left[1 +
+            \cot \left( \frac{k \pi}{M} \right)^2 \right] - j\cot\left(
+            \frac{k \pi}{M}\right)\right \rbrace \qquad 1\le k<M.
+
+        Again, `j=\sqrt{-1}`.
+
+        Before calling this function, call
+        :class:`~mpmath.calculus.inverselaplace.FixedTalbot.calc_laplace_parameter`
+        to set the parameters and compute the required coefficients.
+
+        **References**
+
+        1. Abate, J., P. Valko (2004). Multi-precision Laplace
+           transform inversion. *International Journal for Numerical
+           Methods in Engineering* 60:979-993,
+           http://dx.doi.org/10.1002/nme.995
+        2. Talbot, A. (1979). The accurate numerical inversion of
+           Laplace transforms. *IMA Journal of Applied Mathematics*
+           23(1):97, http://dx.doi.org/10.1093/imamat/23.1.97
+        """
+
+        # required
+        # ------------------------------
+        self.t = self.ctx.convert(t)
+
+        # assume fp was computed from p matrix returned from
+        # calc_laplace_parameter(), so is already a list or matrix of
+        # mpmath 'mpc' types
+
+        # these were computed in previous call to
+        # calc_laplace_parameter()
+        theta = self.theta
+        delta = self.delta
+        M = self.degree
+        p = self.p
+        r = self.r
+
+        ans = self.ctx.matrix(M, 1)
+        ans[0] = self.ctx.exp(delta[0])*fp[0]/2
+
+        for i in range(1, M):
+            ans[i] = self.ctx.exp(delta[i])*fp[i]*(
+                1 + 1j*theta[i]*(1 + self.cot_theta[i]**2) -
+                1j*self.cot_theta[i])
+
+        result = self.ctx.fraction(2, 5)*self.ctx.fsum(ans)/self.t
+
+        # setting dps back to value when calc_laplace_parameter was
+        # called, unless flag is set.
+        if not manual_prec:
+            self.ctx.dps = self.dps_orig
+
+        return result.real
+
+
+# ****************************************
+
+class Stehfest(InverseLaplaceTransform):
+
+    def calc_laplace_parameter(self, t, **kwargs):
+        r"""
+        The Gaver-Stehfest method is a discrete approximation of the
+        Widder-Post inversion algorithm, rather than a direct
+        approximation of the Bromwich contour integral.
+
+        The method abscissa along the real axis, and therefore has
+        issues inverting oscillatory functions (which have poles in
+        pairs away from the real axis).
+
+        The working precision will be increased according to a rule of
+        thumb. If 'degree' is not specified, the working precision and
+        degree are chosen to hopefully achieve the dps of the calling
+        context. If 'degree' is specified, the working precision is
+        chosen to achieve maximum resulting precision for the
+        specified degree.
+
+        .. math ::
+
+            p_k = \frac{k \log 2}{t} \qquad 1 \le k \le M
+        """
+
+        # required
+        # ------------------------------
+        # time of desired approximation
+        self.t = self.ctx.convert(t)
+
+        # optional
+        # ------------------------------
+
+        # empirical relationships used here based on a linear fit of
+        # requested and delivered dps for exponentially decaying time
+        # functions for requested dps up to 512.
+
+        if 'degree' in kwargs:
+            self.degree = kwargs['degree']
+            self.dps_goal = int(1.38*self.degree)
+        else:
+            self.dps_goal = int(2.93*self.ctx.dps)
+            self.degree = max(16, self.dps_goal)
+
+        # _coeff routine requires even degree
+        if self.degree % 2 > 0:
+            self.degree += 1
+
+        M = self.degree
+
+        # this is adjusting the dps of the calling context
+        # hopefully the caller doesn't monkey around with it
+        # between calling this routine and calc_time_domain_solution()
+        self.dps_orig = self.ctx.dps
+        self.ctx.dps = self.dps_goal
+
+        self.V = self._coeff()
+        self.p = self.ctx.matrix(self.ctx.arange(1, M+1))*self.ctx.ln2/self.t
+
+        # NB: p is real (mpf)
+
+    def _coeff(self):
+        r"""Salzer summation weights (aka, "Stehfest coefficients")
+        only depend on the approximation order (M) and the precision"""
+
+        M = self.degree
+        M2 = int(M/2)  # checked earlier that M is even
+
+        V = self.ctx.matrix(M, 1)
+
+        # Salzer summation weights
+        # get very large in magnitude and oscillate in sign,
+        # if the precision is not high enough, there will be
+        # catastrophic cancellation
+        for k in range(1, M+1):
+            z = self.ctx.matrix(min(k, M2)+1, 1)
+            for j in range(int((k+1)/2), min(k, M2)+1):
+                z[j] = (self.ctx.power(j, M2)*self.ctx.fac(2*j)/
+                        (self.ctx.fac(M2-j)*self.ctx.fac(j)*
+                         self.ctx.fac(j-1)*self.ctx.fac(k-j)*
+                         self.ctx.fac(2*j-k)))
+            V[k-1] = self.ctx.power(-1, k+M2)*self.ctx.fsum(z)
+
+        return V
+
+    def calc_time_domain_solution(self, fp, t, manual_prec=False):
+        r"""Compute time-domain Stehfest algorithm solution.
+
+        .. math ::
+
+            f(t,M) = \frac{\log 2}{t} \sum_{k=1}^{M} V_k \bar{f}\left(
+            p_k \right)
+
+        where
+
+        .. math ::
+
+            V_k = (-1)^{k + N/2} \sum^{\min(k,N/2)}_{i=\lfloor(k+1)/2 \rfloor}
+            \frac{i^{\frac{N}{2}}(2i)!}{\left(\frac{N}{2}-i \right)! \, i! \,
+            \left(i-1 \right)! \, \left(k-i\right)! \, \left(2i-k \right)!}
+
+        As the degree increases, the abscissa (`p_k`) only increase
+        linearly towards `\infty`, but the Stehfest coefficients
+        (`V_k`) alternate in sign and increase rapidly in sign,
+        requiring high precision to prevent overflow or loss of
+        significance when evaluating the sum.
+
+        **References**
+
+        1. Widder, D. (1941). *The Laplace Transform*. Princeton.
+        2. Stehfest, H. (1970). Algorithm 368: numerical inversion of
+           Laplace transforms. *Communications of the ACM* 13(1):47-49,
+           http://dx.doi.org/10.1145/361953.361969
+
+        """
+
+        # required
+        self.t = self.ctx.convert(t)
+
+        # assume fp was computed from p matrix returned from
+        # calc_laplace_parameter(), so is already
+        # a list or matrix of mpmath 'mpf' types
+
+        result = self.ctx.fdot(self.V, fp)*self.ctx.ln2/self.t
+
+        # setting dps back to value when calc_laplace_parameter was called
+        if not manual_prec:
+            self.ctx.dps = self.dps_orig
+
+        # ignore any small imaginary part
+        return result.real
+
+
+# ****************************************
+
+class deHoog(InverseLaplaceTransform):
+
+    def calc_laplace_parameter(self, t, **kwargs):
+        r"""the de Hoog, Knight & Stokes algorithm is an
+        accelerated form of the Fourier series numerical
+        inverse Laplace transform algorithms.
+
+        .. math ::
+
+            p_k = \gamma + \frac{jk}{T} \qquad 0 \le k < 2M+1
+
+        where
+
+        .. math ::
+
+            \gamma = \alpha - \frac{\log \mathrm{tol}}{2T},
+
+        `j=\sqrt{-1}`, `T = 2t_\mathrm{max}` is a scaled time,
+        `\alpha=10^{-\mathrm{dps\_goal}}` is the real part of the
+        rightmost pole or singularity, which is chosen based on the
+        desired accuracy (assuming the rightmost singularity is 0),
+        and `\mathrm{tol}=10\alpha` is the desired tolerance, which is
+        chosen in relation to `\alpha`.`
+
+        When increasing the degree, the abscissa increase towards
+        `j\infty`, but more slowly than the fixed Talbot
+        algorithm. The de Hoog et al. algorithm typically does better
+        with oscillatory functions of time, and less well-behaved
+        functions. The method tends to be slower than the Talbot and
+        Stehfest algorithsm, especially so at very high precision
+        (e.g., `>500` digits precision).
+
+        """
+
+        # required
+        # ------------------------------
+        self.t = self.ctx.convert(t)
+
+        # optional
+        # ------------------------------
+        self.tmax = kwargs.get('tmax', self.t)
+
+        # empirical relationships used here based on a linear fit of
+        # requested and delivered dps for exponentially decaying time
+        # functions for requested dps up to 512.
+
+        if 'degree' in kwargs:
+            self.degree = kwargs['degree']
+            self.dps_goal = int(1.38*self.degree)
+        else:
+            self.dps_goal = int(self.ctx.dps*1.36)
+            self.degree = max(10, self.dps_goal)
+
+        # 2*M+1 terms in approximation
+        M = self.degree
+
+        # adjust alpha component of abscissa of convergence for higher
+        # precision
+        tmp = self.ctx.power(10.0, -self.dps_goal)
+        self.alpha = self.ctx.convert(kwargs.get('alpha', tmp))
+
+        # desired tolerance (here simply related to alpha)
+        self.tol = self.ctx.convert(kwargs.get('tol', self.alpha*10.0))
+        self.np = 2*self.degree+1  # number of terms in approximation
+
+        # this is adjusting the dps of the calling context
+        # hopefully the caller doesn't monkey around with it
+        # between calling this routine and calc_time_domain_solution()
+        self.dps_orig = self.ctx.dps
+        self.ctx.dps = self.dps_goal
+
+        # scaling factor (likely tun-able, but 2 is typical)
+        self.scale = kwargs.get('scale', 2)
+        self.T = self.ctx.convert(kwargs.get('T', self.scale*self.tmax))
+
+        self.p = self.ctx.matrix(2*M+1, 1)
+        self.gamma = self.alpha - self.ctx.log(self.tol)/(self.scale*self.T)
+        self.p = (self.gamma + self.ctx.pi*
+                  self.ctx.matrix(self.ctx.arange(self.np))/self.T*1j)
+
+        # NB: p is complex (mpc)
+
+    def calc_time_domain_solution(self, fp, t, manual_prec=False):
+        r"""Calculate time-domain solution for
+        de Hoog, Knight & Stokes algorithm.
+
+        The un-accelerated Fourier series approach is:
+
+        .. math ::
+
+            f(t,2M+1) = \frac{e^{\gamma t}}{T} \sum_{k=0}^{2M}{}^{'}
+            \Re\left[\bar{f}\left( p_k \right)
+            e^{i\pi t/T} \right],
+
+        where the prime on the summation indicates the first term is halved.
+
+        This simplistic approach requires so many function evaluations
+        that it is not practical. Non-linear acceleration is
+        accomplished via Pade-approximation and an analytic expression
+        for the remainder of the continued fraction. See the original
+        paper (reference 2 below) a detailed description of the
+        numerical approach.
+
+        **References**
+
+        1. Davies, B. (2005). *Integral Transforms and their
+           Applications*, Third Edition. Springer.
+        2. de Hoog, F., J. Knight, A. Stokes (1982). An improved
+           method for numerical inversion of Laplace transforms. *SIAM
+           Journal of Scientific and Statistical Computing* 3:357-366,
+           http://dx.doi.org/10.1137/0903022
+
+        """
+
+        M = self.degree
+        np = self.np
+        T = self.T
+
+        self.t = self.ctx.convert(t)
+
+        # would it be useful to try re-using
+        # space between e&q and A&B?
+        e = self.ctx.zeros(np, M+1)
+        q = self.ctx.matrix(2*M, M)
+        d = self.ctx.matrix(np, 1)
+        A = self.ctx.zeros(np+1, 1)
+        B = self.ctx.ones(np+1, 1)
+
+        # initialize Q-D table
+        e[:, 0] = 0.0 + 0j
+        q[0, 0] = fp[1]/(fp[0]/2)
+        for i in range(1, 2*M):
+            q[i, 0] = fp[i+1]/fp[i]
+
+        # rhombus rule for filling triangular Q-D table (e & q)
+        for r in range(1, M+1):
+            # start with e, column 1, 0:2*M-2
+            mr = 2*(M-r) + 1
+            e[0:mr, r] = q[1:mr+1, r-1] - q[0:mr, r-1] + e[1:mr+1, r-1]
+            if not r == M:
+                rq = r+1
+                mr = 2*(M-rq)+1 + 2
+                for i in range(mr):
+                    q[i, rq-1] = q[i+1, rq-2]*e[i+1, rq-1]/e[i, rq-1]
+
+        # build up continued fraction coefficients (d)
+        d[0] = fp[0]/2
+        for r in range(1, M+1):
+            d[2*r-1] = -q[0, r-1]  # even terms
+            d[2*r]   = -e[0, r]    # odd terms
+
+        # seed A and B for recurrence
+        A[0] = 0.0 + 0.0j
+        A[1] = d[0]
+        B[0:2] = 1.0 + 0.0j
+
+        # base of the power series
+        z = self.ctx.expjpi(self.t/T)  # i*pi is already in fcn
+
+        # coefficients of Pade approximation (A & B)
+        # using recurrence for all but last term
+        for i in range(1, 2*M):
+            A[i+1] = A[i] + d[i]*A[i-1]*z
+            B[i+1] = B[i] + d[i]*B[i-1]*z
+
+        # "improved remainder" to continued fraction
+        brem = (1 + (d[2*M-1] - d[2*M])*z)/2
+        # powm1(x,y) computes x^y - 1 more accurately near zero
+        rem = brem*self.ctx.powm1(1 + d[2*M]*z/brem,
+                                  self.ctx.fraction(1, 2))
+
+        # last term of recurrence using new remainder
+        A[np] = A[2*M] + rem*A[2*M-1]
+        B[np] = B[2*M] + rem*B[2*M-1]
+
+        # diagonal Pade approximation
+        # F=A/B represents accelerated trapezoid rule
+        result = self.ctx.exp(self.gamma*self.t)/T*(A[np]/B[np]).real
+
+        # setting dps back to value when calc_laplace_parameter was called
+        if not manual_prec:
+            self.ctx.dps = self.dps_orig
+
+        return result
+
+
+# ****************************************
+
+class Cohen(InverseLaplaceTransform):
+
+    def calc_laplace_parameter(self, t, **kwargs):
+        r"""The Cohen algorithm accelerates the convergence of the nearly
+        alternating series resulting from the application of the trapezoidal
+        rule to the Bromwich contour inversion integral.
+
+        .. math ::
+
+            p_k = \frac{\gamma}{2 t} + \frac{\pi i k}{t} \qquad 0 \le k < M
+
+        where
+
+        .. math ::
+
+            \gamma = \frac{2}{3} (d + \log(10) + \log(2 t)),
+
+        `d = \mathrm{dps\_goal}`, which is chosen based on the desired
+        accuracy using the method developed in [1] to improve numerical
+        stability. The Cohen algorithm shows robustness similar to the de Hoog
+        et al. algorithm, but it is faster than the fixed Talbot algorithm.
+
+        **Optional arguments**
+
+        *degree*
+            integer order of the approximation (M = number of terms)
+        *alpha*
+            abscissa for `p_0` (controls the discretization error)
+
+        The working precision will be increased according to a rule of
+        thumb. If 'degree' is not specified, the working precision and
+        degree are chosen to hopefully achieve the dps of the calling
+        context. If 'degree' is specified, the working precision is
+        chosen to achieve maximum resulting precision for the
+        specified degree.
+
+        **References**
+
+        1. P. Glasserman, J. Ruiz-Mata (2006). Computing the credit loss
+        distribution in the Gaussian copula model: a comparison of methods.
+        *Journal of Credit Risk* 2(4):33-66, 10.21314/JCR.2006.057
+
+        """
+        self.t = self.ctx.convert(t)
+
+        if 'degree' in kwargs:
+            self.degree = kwargs['degree']
+            self.dps_goal = int(1.5 * self.degree)
+        else:
+            self.dps_goal = int(self.ctx.dps * 1.74)
+            self.degree = max(22, int(1.31 * self.dps_goal))
+
+        M = self.degree + 1
+
+        # this is adjusting the dps of the calling context hopefully
+        # the caller doesn't monkey around with it between calling
+        # this routine and calc_time_domain_solution()
+        self.dps_orig = self.ctx.dps
+        self.ctx.dps = self.dps_goal
+
+        ttwo = 2 * self.t
+        tmp = self.ctx.dps * self.ctx.log(10) + self.ctx.log(ttwo)
+        tmp = self.ctx.fraction(2, 3) * tmp
+        self.alpha = self.ctx.convert(kwargs.get('alpha', tmp))
+
+        # all but time-dependent part of p
+        a_t = self.alpha / ttwo
+        p_t = self.ctx.pi * 1j / self.t
+
+        self.p = self.ctx.matrix(M, 1)
+        self.p[0] = a_t
+
+        for i in range(1, M):
+            self.p[i] = a_t + i * p_t
+
+    def calc_time_domain_solution(self, fp, t, manual_prec=False):
+        r"""Calculate time-domain solution for Cohen algorithm.
+
+        The accelerated nearly alternating series is:
+
+        .. math ::
+
+            f(t, M) = \frac{e^{\gamma / 2}}{t} \left[\frac{1}{2}
+            \Re\left(\bar{f}\left(\frac{\gamma}{2t}\right) \right) -
+            \sum_{k=0}^{M-1}\frac{c_{M,k}}{d_M}\Re\left(\bar{f}
+            \left(\frac{\gamma + 2(k+1) \pi i}{2t}\right)\right)\right],
+
+        where coefficients `\frac{c_{M, k}}{d_M}` are described in [1].
+
+        1. H. Cohen, F. Rodriguez Villegas, D. Zagier (2000). Convergence
+        acceleration of alternating series. *Experiment. Math* 9(1):3-12
+
+        """
+        self.t = self.ctx.convert(t)
+
+        n = self.degree
+        M = n + 1
+
+        A = self.ctx.matrix(M, 1)
+        for i in range(M):
+            A[i] = fp[i].real
+
+        d = (3 + self.ctx.sqrt(8)) ** n
+        d = (d + 1 / d) / 2
+        b = -self.ctx.one
+        c = -d
+        s = 0
+
+        for k in range(n):
+            c = b - c
+            s = s + c * A[k + 1]
+            b = 2 * (k + n) * (k - n) * b / ((2 * k + 1) * (k + self.ctx.one))
+
+        result = self.ctx.exp(self.alpha / 2) / self.t * (A[0] / 2 - s / d)
+
+        # setting dps back to value when calc_laplace_parameter was
+        # called, unless flag is set.
+        if not manual_prec:
+            self.ctx.dps = self.dps_orig
+
+        return result
+
+
+# ****************************************
+
+class LaplaceTransformInversionMethods(object):
+    def __init__(ctx, *args, **kwargs):
+        ctx._fixed_talbot = FixedTalbot(ctx)
+        ctx._stehfest = Stehfest(ctx)
+        ctx._de_hoog = deHoog(ctx)
+        ctx._cohen = Cohen(ctx)
+
+    def invertlaplace(ctx, f, t, **kwargs):
+        r"""Computes the numerical inverse Laplace transform for a
+        Laplace-space function at a given time.  The function being
+        evaluated is assumed to be a real-valued function of time.
+
+        The user must supply a Laplace-space function `\bar{f}(p)`,
+        and a desired time at which to estimate the time-domain
+        solution `f(t)`.
+
+        A few basic examples of Laplace-space functions with known
+        inverses (see references [1,2]) :
+
+        .. math ::
+
+            \mathcal{L}\left\lbrace f(t) \right\rbrace=\bar{f}(p)
+
+        .. math ::
+
+            \mathcal{L}^{-1}\left\lbrace \bar{f}(p) \right\rbrace = f(t)
+
+        .. math ::
+
+            \bar{f}(p) = \frac{1}{(p+1)^2}
+
+        .. math ::
+
+            f(t) = t e^{-t}
+
+        >>> from mpmath import *
+        >>> mp.dps = 15; mp.pretty = True
+        >>> tt = [0.001, 0.01, 0.1, 1, 10]
+        >>> fp = lambda p: 1/(p+1)**2
+        >>> ft = lambda t: t*exp(-t)
+        >>> ft(tt[0]),ft(tt[0])-invertlaplace(fp,tt[0],method='talbot')
+        (0.000999000499833375, 8.57923043561212e-20)
+        >>> ft(tt[1]),ft(tt[1])-invertlaplace(fp,tt[1],method='talbot')
+        (0.00990049833749168, 3.27007646698047e-19)
+        >>> ft(tt[2]),ft(tt[2])-invertlaplace(fp,tt[2],method='talbot')
+        (0.090483741803596, -1.75215800052168e-18)
+        >>> ft(tt[3]),ft(tt[3])-invertlaplace(fp,tt[3],method='talbot')
+        (0.367879441171442, 1.2428864009344e-17)
+        >>> ft(tt[4]),ft(tt[4])-invertlaplace(fp,tt[4],method='talbot')
+        (0.000453999297624849, 4.04513489306658e-20)
+
+        The methods also work for higher precision:
+
+        >>> mp.dps = 100; mp.pretty = True
+        >>> nstr(ft(tt[0]),15),nstr(ft(tt[0])-invertlaplace(fp,tt[0],method='talbot'),15)
+        ('0.000999000499833375', '-4.96868310693356e-105')
+        >>> nstr(ft(tt[1]),15),nstr(ft(tt[1])-invertlaplace(fp,tt[1],method='talbot'),15)
+        ('0.00990049833749168', '1.23032291513122e-104')
+
+        .. math ::
+
+            \bar{f}(p) = \frac{1}{p^2+1}
+
+        .. math ::
+
+            f(t) = \mathrm{J}_0(t)
+
+        >>> mp.dps = 15; mp.pretty = True
+        >>> fp = lambda p: 1/sqrt(p*p + 1)
+        >>> ft = lambda t: besselj(0,t)
+        >>> ft(tt[0]),ft(tt[0])-invertlaplace(fp,tt[0],method='dehoog')
+        (0.999999750000016, -6.09717765032273e-18)
+        >>> ft(tt[1]),ft(tt[1])-invertlaplace(fp,tt[1],method='dehoog')
+        (0.99997500015625, -5.61756281076169e-17)
+
+        .. math ::
+
+            \bar{f}(p) = \frac{\log p}{p}
+
+        .. math ::
+
+            f(t) = -\gamma -\log t
+
+        >>> mp.dps = 15; mp.pretty = True
+        >>> fp = lambda p: log(p)/p
+        >>> ft = lambda t: -euler-log(t)
+        >>> ft(tt[0]),ft(tt[0])-invertlaplace(fp,tt[0],method='stehfest')
+        (6.3305396140806, -1.92126634837863e-16)
+        >>> ft(tt[1]),ft(tt[1])-invertlaplace(fp,tt[1],method='stehfest')
+        (4.02795452108656, -4.81486093200704e-16)
+
+        **Options**
+
+        :func:`~mpmath.invertlaplace` recognizes the following optional
+        keywords valid for all methods:
+
+        *method*
+            Chooses numerical inverse Laplace transform algorithm
+            (described below).
+        *degree*
+            Number of terms used in the approximation
+
+        **Algorithms**
+
+        Mpmath implements four numerical inverse Laplace transform
+        algorithms, attributed to: Talbot, Stehfest, and de Hoog,
+        Knight and Stokes. These can be selected by using
+        *method='talbot'*, *method='stehfest'*, *method='dehoog'* or
+        *method='cohen'* or by passing the classes *method=FixedTalbot*,
+        *method=Stehfest*, *method=deHoog*, or *method=Cohen*. The functions
+        :func:`~mpmath.invlaptalbot`, :func:`~mpmath.invlapstehfest`,
+        :func:`~mpmath.invlapdehoog`, and :func:`~mpmath.invlapcohen`
+        are also available as shortcuts.
+
+        All four algorithms implement a heuristic balance between the
+        requested precision and the precision used internally for the
+        calculations. This has been tuned for a typical exponentially
+        decaying function and precision up to few hundred decimal
+        digits.
+
+        The Laplace transform converts the variable time (i.e., along
+        a line) into a parameter given by the right half of the
+        complex `p`-plane.  Singularities, poles, and branch cuts in
+        the complex `p`-plane contain all the information regarding
+        the time behavior of the corresponding function. Any numerical
+        method must therefore sample `p`-plane "close enough" to the
+        singularities to accurately characterize them, while not
+        getting too close to have catastrophic cancellation, overflow,
+        or underflow issues. Most significantly, if one or more of the
+        singularities in the `p`-plane is not on the left side of the
+        Bromwich contour, its effects will be left out of the computed
+        solution, and the answer will be completely wrong.
+
+        *Talbot*
+
+        The fixed Talbot method is high accuracy and fast, but the
+        method can catastrophically fail for certain classes of time-domain
+        behavior, including a Heaviside step function for positive
+        time (e.g., `H(t-2)`), or some oscillatory behaviors. The
+        Talbot method usually has adjustable parameters, but the
+        "fixed" variety implemented here does not. This method
+        deforms the Bromwich integral contour in the shape of a
+        parabola towards `-\infty`, which leads to problems
+        when the solution has a decaying exponential in it (e.g., a
+        Heaviside step function is equivalent to multiplying by a
+        decaying exponential in Laplace space).
+
+        *Stehfest*
+
+        The Stehfest algorithm only uses abscissa along the real axis
+        of the complex `p`-plane to estimate the time-domain
+        function. Oscillatory time-domain functions have poles away
+        from the real axis, so this method does not work well with
+        oscillatory functions, especially high-frequency ones. This
+        method also depends on summation of terms in a series that
+        grows very large, and will have catastrophic cancellation
+        during summation if the working precision is too low.
+
+        *de Hoog et al.*
+
+        The de Hoog, Knight, and Stokes method is essentially a
+        Fourier-series quadrature-type approximation to the Bromwich
+        contour integral, with non-linear series acceleration and an
+        analytical expression for the remainder term. This method is
+        typically one of the most robust. This method also involves the
+        greatest amount of overhead, so it is typically the slowest of the
+        four methods at high precision.
+
+        *Cohen*
+
+        The Cohen method is a trapezoidal rule approximation to the Bromwich
+        contour integral, with linear acceleration for alternating
+        series. This method is as robust as the de Hoog et al method and the
+        fastest of the four methods at high precision, and is therefore the
+        default method.
+
+        **Singularities**
+
+        All numerical inverse Laplace transform methods have problems
+        at large time when the Laplace-space function has poles,
+        singularities, or branch cuts to the right of the origin in
+        the complex plane. For simple poles in `\bar{f}(p)` at the
+        `p`-plane origin, the time function is constant in time (e.g.,
+        `\mathcal{L}\left\lbrace 1 \right\rbrace=1/p` has a pole at
+        `p=0`). A pole in `\bar{f}(p)` to the left of the origin is a
+        decreasing function of time (e.g., `\mathcal{L}\left\lbrace
+        e^{-t/2} \right\rbrace=1/(p+1/2)` has a pole at `p=-1/2`), and
+        a pole to the right of the origin leads to an increasing
+        function in time (e.g., `\mathcal{L}\left\lbrace t e^{t/4}
+        \right\rbrace = 1/(p-1/4)^2` has a pole at `p=1/4`).  When
+        singularities occur off the real `p` axis, the time-domain
+        function is oscillatory. For example `\mathcal{L}\left\lbrace
+        \mathrm{J}_0(t) \right\rbrace=1/\sqrt{p^2+1}` has a branch cut
+        starting at `p=j=\sqrt{-1}` and is a decaying oscillatory
+        function, This range of behaviors is illustrated in Duffy [3]
+        Figure 4.10.4, p. 228.
+
+        In general as `p \rightarrow \infty` `t \rightarrow 0` and
+        vice-versa. All numerical inverse Laplace transform methods
+        require their abscissa to shift closer to the origin for
+        larger times. If the abscissa shift left of the rightmost
+        singularity in the Laplace domain, the answer will be
+        completely wrong (the effect of singularities to the right of
+        the Bromwich contour are not included in the results).
+
+        For example, the following exponentially growing function has
+        a pole at `p=3`:
+
+        .. math ::
+
+            \bar{f}(p)=\frac{1}{p^2-9}
+
+        .. math ::
+
+            f(t)=\frac{1}{3}\sinh 3t
+
+        >>> mp.dps = 15; mp.pretty = True
+        >>> fp = lambda p: 1/(p*p-9)
+        >>> ft = lambda t: sinh(3*t)/3
+        >>> tt = [0.01,0.1,1.0,10.0]
+        >>> ft(tt[0]),invertlaplace(fp,tt[0],method='talbot')
+        (0.0100015000675014, 0.0100015000675014)
+        >>> ft(tt[1]),invertlaplace(fp,tt[1],method='talbot')
+        (0.101506764482381, 0.101506764482381)
+        >>> ft(tt[2]),invertlaplace(fp,tt[2],method='talbot')
+        (3.33929164246997, 3.33929164246997)
+        >>> ft(tt[3]),invertlaplace(fp,tt[3],method='talbot')
+        (1781079096920.74, -1.61331069624091e-14)
+
+        **References**
+
+        1. [DLMF]_ section 1.14 (http://dlmf.nist.gov/1.14T4)
+        2. Cohen, A.M. (2007). Numerical Methods for Laplace Transform
+           Inversion, Springer.
+        3. Duffy, D.G. (1998). Advanced Engineering Mathematics, CRC Press.
+
+        **Numerical Inverse Laplace Transform Reviews**
+
+        1. Bellman, R., R.E. Kalaba, J.A. Lockett (1966). *Numerical
+           inversion of the Laplace transform: Applications to Biology,
+           Economics, Engineering, and Physics*. Elsevier.
+        2. Davies, B., B. Martin (1979). Numerical inversion of the
+           Laplace transform: a survey and comparison of methods. *Journal
+           of Computational Physics* 33:1-32,
+           http://dx.doi.org/10.1016/0021-9991(79)90025-1
+        3. Duffy, D.G. (1993). On the numerical inversion of Laplace
+           transforms: Comparison of three new methods on characteristic
+           problems from applications. *ACM Transactions on Mathematical
+           Software* 19(3):333-359, http://dx.doi.org/10.1145/155743.155788
+        4. Kuhlman, K.L., (2013). Review of Inverse Laplace Transform
+           Algorithms for Laplace-Space Numerical Approaches, *Numerical
+           Algorithms*, 63(2):339-355.
+           http://dx.doi.org/10.1007/s11075-012-9625-3
+
+        """
+
+        rule = kwargs.get('method', 'cohen')
+        if type(rule) is str:
+            lrule = rule.lower()
+            if lrule == 'talbot':
+                rule = ctx._fixed_talbot
+            elif lrule == 'stehfest':
+                rule = ctx._stehfest
+            elif lrule == 'dehoog':
+                rule = ctx._de_hoog
+            elif rule == 'cohen':
+                rule = ctx._cohen
+            else:
+                raise ValueError("unknown invlap algorithm: %s" % rule)
+        else:
+            rule = rule(ctx)
+
+        # determine the vector of Laplace-space parameter
+        # needed for the requested method and desired time
+        rule.calc_laplace_parameter(t, **kwargs)
+
+        # compute the Laplace-space function evalutations
+        # at the required abscissa.
+        fp = [f(p) for p in rule.p]
+
+        # compute the time-domain solution from the
+        # Laplace-space function evaluations
+        return rule.calc_time_domain_solution(fp, t)
+
+    # shortcuts for the above function for specific methods
+    def invlaptalbot(ctx, *args, **kwargs):
+        kwargs['method'] = 'talbot'
+        return ctx.invertlaplace(*args, **kwargs)
+
+    def invlapstehfest(ctx, *args, **kwargs):
+        kwargs['method'] = 'stehfest'
+        return ctx.invertlaplace(*args, **kwargs)
+
+    def invlapdehoog(ctx, *args, **kwargs):
+        kwargs['method'] = 'dehoog'
+        return ctx.invertlaplace(*args, **kwargs)
+
+    def invlapcohen(ctx, *args, **kwargs):
+        kwargs['method'] = 'cohen'
+        return ctx.invertlaplace(*args, **kwargs)
+
+
+# ****************************************
+
+if __name__ == '__main__':
+    import doctest
+    doctest.testmod()

rl/Lib/site-packages/mpmath/calculus/odes.py

@@ -0,0 +1,288 @@
+from bisect import bisect
+from ..libmp.backend import xrange
+
+class ODEMethods(object):
+    pass
+
+def ode_taylor(ctx, derivs, x0, y0, tol_prec, n):
+    h = tol = ctx.ldexp(1, -tol_prec)
+    dim = len(y0)
+    xs = [x0]
+    ys = [y0]
+    x = x0
+    y = y0
+    orig = ctx.prec
+    try:
+        ctx.prec = orig*(1+n)
+        # Use n steps with Euler's method to get
+        # evaluation points for derivatives
+        for i in range(n):
+            fxy = derivs(x, y)
+            y = [y[i]+h*fxy[i] for i in xrange(len(y))]
+            x += h
+            xs.append(x)
+            ys.append(y)
+        # Compute derivatives
+        ser = [[] for d in range(dim)]
+        for j in range(n+1):
+            s = [0]*dim
+            b = (-1) ** (j & 1)
+            k = 1
+            for i in range(j+1):
+                for d in range(dim):
+                    s[d] += b * ys[i][d]
+                b = (b * (j-k+1)) // (-k)
+                k += 1
+            scale = h**(-j) / ctx.fac(j)
+            for d in range(dim):
+                s[d] = s[d] * scale
+                ser[d].append(s[d])
+    finally:
+        ctx.prec = orig
+    # Estimate radius for which we can get full accuracy.
+    # XXX: do this right for zeros
+    radius = ctx.one
+    for ts in ser:
+        if ts[-1]:
+            radius = min(radius, ctx.nthroot(tol/abs(ts[-1]), n))
+    radius /= 2  # XXX
+    return ser, x0+radius
+
+def odefun(ctx, F, x0, y0, tol=None, degree=None, method='taylor', verbose=False):
+    r"""
+    Returns a function `y(x) = [y_0(x), y_1(x), \ldots, y_n(x)]`
+    that is a numerical solution of the `n+1`-dimensional first-order
+    ordinary differential equation (ODE) system
+
+    .. math ::
+
+        y_0'(x) = F_0(x, [y_0(x), y_1(x), \ldots, y_n(x)])
+
+        y_1'(x) = F_1(x, [y_0(x), y_1(x), \ldots, y_n(x)])
+
+        \vdots
+
+        y_n'(x) = F_n(x, [y_0(x), y_1(x), \ldots, y_n(x)])
+
+    The derivatives are specified by the vector-valued function
+    *F* that evaluates
+    `[y_0', \ldots, y_n'] = F(x, [y_0, \ldots, y_n])`.
+    The initial point `x_0` is specified by the scalar argument *x0*,
+    and the initial value `y(x_0) =  [y_0(x_0), \ldots, y_n(x_0)]` is
+    specified by the vector argument *y0*.
+
+    For convenience, if the system is one-dimensional, you may optionally
+    provide just a scalar value for *y0*. In this case, *F* should accept
+    a scalar *y* argument and return a scalar. The solution function
+    *y* will return scalar values instead of length-1 vectors.
+
+    Evaluation of the solution function `y(x)` is permitted
+    for any `x \ge x_0`.
+
+    A high-order ODE can be solved by transforming it into first-order
+    vector form. This transformation is described in standard texts
+    on ODEs. Examples will also be given below.
+
+    **Options, speed and accuracy**
+
+    By default, :func:`~mpmath.odefun` uses a high-order Taylor series
+    method. For reasonably well-behaved problems, the solution will
+    be fully accurate to within the working precision. Note that
+    *F* must be possible to evaluate to very high precision
+    for the generation of Taylor series to work.
+
+    To get a faster but less accurate solution, you can set a large
+    value for *tol* (which defaults roughly to *eps*). If you just
+    want to plot the solution or perform a basic simulation,
+    *tol = 0.01* is likely sufficient.
+
+    The *degree* argument controls the degree of the solver (with
+    *method='taylor'*, this is the degree of the Taylor series
+    expansion). A higher degree means that a longer step can be taken
+    before a new local solution must be generated from *F*,
+    meaning that fewer steps are required to get from `x_0` to a given
+    `x_1`. On the other hand, a higher degree also means that each
+    local solution becomes more expensive (i.e., more evaluations of
+    *F* are required per step, and at higher precision).
+
+    The optimal setting therefore involves a tradeoff. Generally,
+    decreasing the *degree* for Taylor series is likely to give faster
+    solution at low precision, while increasing is likely to be better
+    at higher precision.
+
+    The function
+    object returned by :func:`~mpmath.odefun` caches the solutions at all step
+    points and uses polynomial interpolation between step points.
+    Therefore, once `y(x_1)` has been evaluated for some `x_1`,
+    `y(x)` can be evaluated very quickly for any `x_0 \le x \le x_1`.
+    and continuing the evaluation up to `x_2 > x_1` is also fast.
+
+    **Examples of first-order ODEs**
+
+    We will solve the standard test problem `y'(x) = y(x), y(0) = 1`
+    which has explicit solution `y(x) = \exp(x)`::
+
+        >>> from mpmath import *
+        >>> mp.dps = 15; mp.pretty = True
+        >>> f = odefun(lambda x, y: y, 0, 1)
+        >>> for x in [0, 1, 2.5]:
+        ...     print((f(x), exp(x)))
+        ...
+        (1.0, 1.0)
+        (2.71828182845905, 2.71828182845905)
+        (12.1824939607035, 12.1824939607035)
+
+    The solution with high precision::
+
+        >>> mp.dps = 50
+        >>> f = odefun(lambda x, y: y, 0, 1)
+        >>> f(1)
+        2.7182818284590452353602874713526624977572470937
+        >>> exp(1)
+        2.7182818284590452353602874713526624977572470937
+
+    Using the more general vectorized form, the test problem
+    can be input as (note that *f* returns a 1-element vector)::
+
+        >>> mp.dps = 15
+        >>> f = odefun(lambda x, y: [y[0]], 0, [1])
+        >>> f(1)
+        [2.71828182845905]
+
+    :func:`~mpmath.odefun` can solve nonlinear ODEs, which are generally
+    impossible (and at best difficult) to solve analytically. As
+    an example of a nonlinear ODE, we will solve `y'(x) = x \sin(y(x))`
+    for `y(0) = \pi/2`. An exact solution happens to be known
+    for this problem, and is given by
+    `y(x) = 2 \tan^{-1}\left(\exp\left(x^2/2\right)\right)`::
+
+        >>> f = odefun(lambda x, y: x*sin(y), 0, pi/2)
+        >>> for x in [2, 5, 10]:
+        ...     print((f(x), 2*atan(exp(mpf(x)**2/2))))
+        ...
+        (2.87255666284091, 2.87255666284091)
+        (3.14158520028345, 3.14158520028345)
+        (3.14159265358979, 3.14159265358979)
+
+    If `F` is independent of `y`, an ODE can be solved using direct
+    integration. We can therefore obtain a reference solution with
+    :func:`~mpmath.quad`::
+
+        >>> f = lambda x: (1+x**2)/(1+x**3)
+        >>> g = odefun(lambda x, y: f(x), pi, 0)
+        >>> g(2*pi)
+        0.72128263801696
+        >>> quad(f, [pi, 2*pi])
+        0.72128263801696
+
+    **Examples of second-order ODEs**
+
+    We will solve the harmonic oscillator equation `y''(x) + y(x) = 0`.
+    To do this, we introduce the helper functions `y_0 = y, y_1 = y_0'`
+    whereby the original equation can be written as `y_1' + y_0' = 0`. Put
+    together, we get the first-order, two-dimensional vector ODE
+
+    .. math ::
+
+        \begin{cases}
+        y_0' = y_1 \\
+        y_1' = -y_0
+        \end{cases}
+
+    To get a well-defined IVP, we need two initial values. With
+    `y(0) = y_0(0) = 1` and `-y'(0) = y_1(0) = 0`, the problem will of
+    course be solved by `y(x) = y_0(x) = \cos(x)` and
+    `-y'(x) = y_1(x) = \sin(x)`. We check this::
+
+        >>> f = odefun(lambda x, y: [-y[1], y[0]], 0, [1, 0])
+        >>> for x in [0, 1, 2.5, 10]:
+        ...     nprint(f(x), 15)
+        ...     nprint([cos(x), sin(x)], 15)
+        ...     print("---")
+        ...
+        [1.0, 0.0]
+        [1.0, 0.0]
+        ---
+        [0.54030230586814, 0.841470984807897]
+        [0.54030230586814, 0.841470984807897]
+        ---
+        [-0.801143615546934, 0.598472144103957]
+        [-0.801143615546934, 0.598472144103957]
+        ---
+        [-0.839071529076452, -0.54402111088937]
+        [-0.839071529076452, -0.54402111088937]
+        ---
+
+    Note that we get both the sine and the cosine solutions
+    simultaneously.
+
+    **TODO**
+
+    * Better automatic choice of degree and step size
+    * Make determination of Taylor series convergence radius
+      more robust
+    * Allow solution for `x < x_0`
+    * Allow solution for complex `x`
+    * Test for difficult (ill-conditioned) problems
+    * Implement Runge-Kutta and other algorithms
+
+    """
+    if tol:
+        tol_prec = int(-ctx.log(tol, 2))+10
+    else:
+        tol_prec = ctx.prec+10
+    degree = degree or (3 + int(3*ctx.dps/2.))
+    workprec = ctx.prec + 40
+    try:
+        len(y0)
+        return_vector = True
+    except TypeError:
+        F_ = F
+        F = lambda x, y: [F_(x, y[0])]
+        y0 = [y0]
+        return_vector = False
+    ser, xb = ode_taylor(ctx, F, x0, y0, tol_prec, degree)
+    series_boundaries = [x0, xb]
+    series_data = [(ser, x0, xb)]
+    # We will be working with vectors of Taylor series
+    def mpolyval(ser, a):
+        return [ctx.polyval(s[::-1], a) for s in ser]
+    # Find nearest expansion point; compute if necessary
+    def get_series(x):
+        if x < x0:
+            raise ValueError
+        n = bisect(series_boundaries, x)
+        if n < len(series_boundaries):
+            return series_data[n-1]
+        while 1:
+            ser, xa, xb = series_data[-1]
+            if verbose:
+                print("Computing Taylor series for [%f, %f]" % (xa, xb))
+            y = mpolyval(ser, xb-xa)
+            xa = xb
+            ser, xb = ode_taylor(ctx, F, xb, y, tol_prec, degree)
+            series_boundaries.append(xb)
+            series_data.append((ser, xa, xb))
+            if x <= xb:
+                return series_data[-1]
+    # Evaluation function
+    def interpolant(x):
+        x = ctx.convert(x)
+        orig = ctx.prec
+        try:
+            ctx.prec = workprec
+            ser, xa, xb = get_series(x)
+            y = mpolyval(ser, x-xa)
+        finally:
+            ctx.prec = orig
+        if return_vector:
+            return [+yk for yk in y]
+        else:
+            return +y[0]
+    return interpolant
+
+ODEMethods.odefun = odefun
+
+if __name__ == "__main__":
+    import doctest
+    doctest.testmod()

rl/Lib/site-packages/mpmath/calculus/polynomials.py

@@ -0,0 +1,213 @@
+from ..libmp.backend import xrange
+from .calculus import defun
+
+#----------------------------------------------------------------------------#
+#                                Polynomials                                 #
+#----------------------------------------------------------------------------#
+
+# XXX: extra precision
+@defun
+def polyval(ctx, coeffs, x, derivative=False):
+    r"""
+    Given coefficients `[c_n, \ldots, c_2, c_1, c_0]` and a number `x`,
+    :func:`~mpmath.polyval` evaluates the polynomial
+
+    .. math ::
+
+        P(x) = c_n x^n + \ldots + c_2 x^2 + c_1 x + c_0.
+
+    If *derivative=True* is set, :func:`~mpmath.polyval` simultaneously
+    evaluates `P(x)` with the derivative, `P'(x)`, and returns the
+    tuple `(P(x), P'(x))`.
+
+        >>> from mpmath import *
+        >>> mp.pretty = True
+        >>> polyval([3, 0, 2], 0.5)
+        2.75
+        >>> polyval([3, 0, 2], 0.5, derivative=True)
+        (2.75, 3.0)
+
+    The coefficients and the evaluation point may be any combination
+    of real or complex numbers.
+    """
+    if not coeffs:
+        return ctx.zero
+    p = ctx.convert(coeffs[0])
+    q = ctx.zero
+    for c in coeffs[1:]:
+        if derivative:
+            q = p + x*q
+        p = c + x*p
+    if derivative:
+        return p, q
+    else:
+        return p
+
+@defun
+def polyroots(ctx, coeffs, maxsteps=50, cleanup=True, extraprec=10,
+        error=False, roots_init=None):
+    """
+    Computes all roots (real or complex) of a given polynomial.
+
+    The roots are returned as a sorted list, where real roots appear first
+    followed by complex conjugate roots as adjacent elements. The polynomial
+    should be given as a list of coefficients, in the format used by
+    :func:`~mpmath.polyval`. The leading coefficient must be nonzero.
+
+    With *error=True*, :func:`~mpmath.polyroots` returns a tuple *(roots, err)*
+    where *err* is an estimate of the maximum error among the computed roots.
+
+    **Examples**
+
+    Finding the three real roots of `x^3 - x^2 - 14x + 24`::
+
+        >>> from mpmath import *
+        >>> mp.dps = 15; mp.pretty = True
+        >>> nprint(polyroots([1,-1,-14,24]), 4)
+        [-4.0, 2.0, 3.0]
+
+    Finding the two complex conjugate roots of `4x^2 + 3x + 2`, with an
+    error estimate::
+
+        >>> roots, err = polyroots([4,3,2], error=True)
+        >>> for r in roots:
+        ...     print(r)
+        ...
+        (-0.375 + 0.59947894041409j)
+        (-0.375 - 0.59947894041409j)
+        >>>
+        >>> err
+        2.22044604925031e-16
+        >>>
+        >>> polyval([4,3,2], roots[0])
+        (2.22044604925031e-16 + 0.0j)
+        >>> polyval([4,3,2], roots[1])
+        (2.22044604925031e-16 + 0.0j)
+
+    The following example computes all the 5th roots of unity; that is,
+    the roots of `x^5 - 1`::
+
+        >>> mp.dps = 20
+        >>> for r in polyroots([1, 0, 0, 0, 0, -1]):
+        ...     print(r)
+        ...
+        1.0
+        (-0.8090169943749474241 + 0.58778525229247312917j)
+        (-0.8090169943749474241 - 0.58778525229247312917j)
+        (0.3090169943749474241 + 0.95105651629515357212j)
+        (0.3090169943749474241 - 0.95105651629515357212j)
+
+    **Precision and conditioning**
+
+    The roots are computed to the current working precision accuracy. If this
+    accuracy cannot be achieved in ``maxsteps`` steps, then a
+    ``NoConvergence`` exception is raised. The algorithm internally is using
+    the current working precision extended by ``extraprec``. If
+    ``NoConvergence`` was raised, that is caused either by not having enough
+    extra precision to achieve convergence (in which case increasing
+    ``extraprec`` should fix the problem) or too low ``maxsteps`` (in which
+    case increasing ``maxsteps`` should fix the problem), or a combination of
+    both.
+
+    The user should always do a convergence study with regards to
+    ``extraprec`` to ensure accurate results. It is possible to get
+    convergence to a wrong answer with too low ``extraprec``.
+
+    Provided there are no repeated roots, :func:`~mpmath.polyroots` can
+    typically compute all roots of an arbitrary polynomial to high precision::
+
+        >>> mp.dps = 60
+        >>> for r in polyroots([1, 0, -10, 0, 1]):
+        ...     print(r)
+        ...
+        -3.14626436994197234232913506571557044551247712918732870123249
+        -0.317837245195782244725757617296174288373133378433432554879127
+        0.317837245195782244725757617296174288373133378433432554879127
+        3.14626436994197234232913506571557044551247712918732870123249
+        >>>
+        >>> sqrt(3) + sqrt(2)
+        3.14626436994197234232913506571557044551247712918732870123249
+        >>> sqrt(3) - sqrt(2)
+        0.317837245195782244725757617296174288373133378433432554879127
+
+    **Algorithm**
+
+    :func:`~mpmath.polyroots` implements the Durand-Kerner method [1], which
+    uses complex arithmetic to locate all roots simultaneously.
+    The Durand-Kerner method can be viewed as approximately performing
+    simultaneous Newton iteration for all the roots. In particular,
+    the convergence to simple roots is quadratic, just like Newton's
+    method.
+
+    Although all roots are internally calculated using complex arithmetic, any
+    root found to have an imaginary part smaller than the estimated numerical
+    error is truncated to a real number (small real parts are also chopped).
+    Real roots are placed first in the returned list, sorted by value. The
+    remaining complex roots are sorted by their real parts so that conjugate
+    roots end up next to each other.
+
+    **References**
+
+    1. http://en.wikipedia.org/wiki/Durand-Kerner_method
+
+    """
+    if len(coeffs) <= 1:
+        if not coeffs or not coeffs[0]:
+            raise ValueError("Input to polyroots must not be the zero polynomial")
+        # Constant polynomial with no roots
+        return []
+
+    orig = ctx.prec
+    tol = +ctx.eps
+    with ctx.extraprec(extraprec):
+        deg = len(coeffs) - 1
+        # Must be monic
+        lead = ctx.convert(coeffs[0])
+        if lead == 1:
+            coeffs = [ctx.convert(c) for c in coeffs]
+        else:
+            coeffs = [c/lead for c in coeffs]
+        f = lambda x: ctx.polyval(coeffs, x)
+        if roots_init is None:
+            roots = [ctx.mpc((0.4+0.9j)**n) for n in xrange(deg)]
+        else:
+            roots = [None]*deg;
+            deg_init = min(deg, len(roots_init))
+            roots[:deg_init] = list(roots_init[:deg_init])
+            roots[deg_init:] = [ctx.mpc((0.4+0.9j)**n) for n
+                                in xrange(deg_init,deg)]
+        err = [ctx.one for n in xrange(deg)]
+        # Durand-Kerner iteration until convergence
+        for step in xrange(maxsteps):
+            if abs(max(err)) < tol:
+                break
+            for i in xrange(deg):
+                p = roots[i]
+                x = f(p)
+                for j in range(deg):
+                    if i != j:
+                        try:
+                            x /= (p-roots[j])
+                        except ZeroDivisionError:
+                            continue
+                roots[i] = p - x
+                err[i] = abs(x)
+        if abs(max(err)) >= tol:
+            raise ctx.NoConvergence("Didn't converge in maxsteps=%d steps." \
+                    % maxsteps)
+        # Remove small real or imaginary parts
+        if cleanup:
+            for i in xrange(deg):
+                if abs(roots[i]) < tol:
+                    roots[i] = ctx.zero
+                elif abs(ctx._im(roots[i])) < tol:
+                    roots[i] = roots[i].real
+                elif abs(ctx._re(roots[i])) < tol:
+                    roots[i] = roots[i].imag * 1j
+        roots.sort(key=lambda x: (abs(ctx._im(x)), ctx._re(x)))
+    if error:
+        err = max(err)
+        err = max(err, ctx.ldexp(1, -orig+1))
+        return [+r for r in roots], +err
+    else:
+        return [+r for r in roots]

rl/Lib/site-packages/mpmath/ctx_base.py

@@ -0,0 +1,494 @@
+from operator import gt, lt
+
+from .libmp.backend import xrange
+
+from .functions.functions import SpecialFunctions
+from .functions.rszeta import RSCache
+from .calculus.quadrature import QuadratureMethods
+from .calculus.inverselaplace import LaplaceTransformInversionMethods
+from .calculus.calculus import CalculusMethods
+from .calculus.optimization import OptimizationMethods
+from .calculus.odes import ODEMethods
+from .matrices.matrices import MatrixMethods
+from .matrices.calculus import MatrixCalculusMethods
+from .matrices.linalg import LinearAlgebraMethods
+from .matrices.eigen import Eigen
+from .identification import IdentificationMethods
+from .visualization import VisualizationMethods
+
+from . import libmp
+
+class Context(object):
+    pass
+
+class StandardBaseContext(Context,
+    SpecialFunctions,
+    RSCache,
+    QuadratureMethods,
+    LaplaceTransformInversionMethods,
+    CalculusMethods,
+    MatrixMethods,
+    MatrixCalculusMethods,
+    LinearAlgebraMethods,
+    Eigen,
+    IdentificationMethods,
+    OptimizationMethods,
+    ODEMethods,
+    VisualizationMethods):
+
+    NoConvergence = libmp.NoConvergence
+    ComplexResult = libmp.ComplexResult
+
+    def __init__(ctx):
+        ctx._aliases = {}
+        # Call those that need preinitialization (e.g. for wrappers)
+        SpecialFunctions.__init__(ctx)
+        RSCache.__init__(ctx)
+        QuadratureMethods.__init__(ctx)
+        LaplaceTransformInversionMethods.__init__(ctx)
+        CalculusMethods.__init__(ctx)
+        MatrixMethods.__init__(ctx)
+
+    def _init_aliases(ctx):
+        for alias, value in ctx._aliases.items():
+            try:
+                setattr(ctx, alias, getattr(ctx, value))
+            except AttributeError:
+                pass
+
+    _fixed_precision = False
+
+    # XXX
+    verbose = False
+
+    def warn(ctx, msg):
+        print("Warning:", msg)
+
+    def bad_domain(ctx, msg):
+        raise ValueError(msg)
+
+    def _re(ctx, x):
+        if hasattr(x, "real"):
+            return x.real
+        return x
+
+    def _im(ctx, x):
+        if hasattr(x, "imag"):
+            return x.imag
+        return ctx.zero
+
+    def _as_points(ctx, x):
+        return x
+
+    def fneg(ctx, x, **kwargs):
+        return -ctx.convert(x)
+
+    def fadd(ctx, x, y, **kwargs):
+        return ctx.convert(x)+ctx.convert(y)
+
+    def fsub(ctx, x, y, **kwargs):
+        return ctx.convert(x)-ctx.convert(y)
+
+    def fmul(ctx, x, y, **kwargs):
+        return ctx.convert(x)*ctx.convert(y)
+
+    def fdiv(ctx, x, y, **kwargs):
+        return ctx.convert(x)/ctx.convert(y)
+
+    def fsum(ctx, args, absolute=False, squared=False):
+        if absolute:
+            if squared:
+                return sum((abs(x)**2 for x in args), ctx.zero)
+            return sum((abs(x) for x in args), ctx.zero)
+        if squared:
+            return sum((x**2 for x in args), ctx.zero)
+        return sum(args, ctx.zero)
+
+    def fdot(ctx, xs, ys=None, conjugate=False):
+        if ys is not None:
+            xs = zip(xs, ys)
+        if conjugate:
+            cf = ctx.conj
+            return sum((x*cf(y) for (x,y) in xs), ctx.zero)
+        else:
+            return sum((x*y for (x,y) in xs), ctx.zero)
+
+    def fprod(ctx, args):
+        prod = ctx.one
+        for arg in args:
+            prod *= arg
+        return prod
+
+    def nprint(ctx, x, n=6, **kwargs):
+        """
+        Equivalent to ``print(nstr(x, n))``.
+        """
+        print(ctx.nstr(x, n, **kwargs))
+
+    def chop(ctx, x, tol=None):
+        """
+        Chops off small real or imaginary parts, or converts
+        numbers close to zero to exact zeros. The input can be a
+        single number or an iterable::
+
+            >>> from mpmath import *
+            >>> mp.dps = 15; mp.pretty = False
+            >>> chop(5+1e-10j, tol=1e-9)
+            mpf('5.0')
+            >>> nprint(chop([1.0, 1e-20, 3+1e-18j, -4, 2]))
+            [1.0, 0.0, 3.0, -4.0, 2.0]
+
+        The tolerance defaults to ``100*eps``.
+        """
+        if tol is None:
+            tol = 100*ctx.eps
+        try:
+            x = ctx.convert(x)
+            absx = abs(x)
+            if abs(x) < tol:
+                return ctx.zero
+            if ctx._is_complex_type(x):
+                #part_tol = min(tol, absx*tol)
+                part_tol = max(tol, absx*tol)
+                if abs(x.imag) < part_tol:
+                    return x.real
+                if abs(x.real) < part_tol:
+                    return ctx.mpc(0, x.imag)
+        except TypeError:
+            if isinstance(x, ctx.matrix):
+                return x.apply(lambda a: ctx.chop(a, tol))
+            if hasattr(x, "__iter__"):
+                return [ctx.chop(a, tol) for a in x]
+        return x
+
+    def almosteq(ctx, s, t, rel_eps=None, abs_eps=None):
+        r"""
+        Determine whether the difference between `s` and `t` is smaller
+        than a given epsilon, either relatively or absolutely.
+
+        Both a maximum relative difference and a maximum difference
+        ('epsilons') may be specified. The absolute difference is
+        defined as `|s-t|` and the relative difference is defined
+        as `|s-t|/\max(|s|, |t|)`.
+
+        If only one epsilon is given, both are set to the same value.
+        If none is given, both epsilons are set to `2^{-p+m}` where
+        `p` is the current working precision and `m` is a small
+        integer. The default setting typically allows :func:`~mpmath.almosteq`
+        to be used to check for mathematical equality
+        in the presence of small rounding errors.
+
+        **Examples**
+
+            >>> from mpmath import *
+            >>> mp.dps = 15
+            >>> almosteq(3.141592653589793, 3.141592653589790)
+            True
+            >>> almosteq(3.141592653589793, 3.141592653589700)
+            False
+            >>> almosteq(3.141592653589793, 3.141592653589700, 1e-10)
+            True
+            >>> almosteq(1e-20, 2e-20)
+            True
+            >>> almosteq(1e-20, 2e-20, rel_eps=0, abs_eps=0)
+            False
+
+        """
+        t = ctx.convert(t)
+        if abs_eps is None and rel_eps is None:
+            rel_eps = abs_eps = ctx.ldexp(1, -ctx.prec+4)
+        if abs_eps is None:
+            abs_eps = rel_eps
+        elif rel_eps is None:
+            rel_eps = abs_eps
+        diff = abs(s-t)
+        if diff <= abs_eps:
+            return True
+        abss = abs(s)
+        abst = abs(t)
+        if abss < abst:
+            err = diff/abst
+        else:
+            err = diff/abss
+        return err <= rel_eps
+
+    def arange(ctx, *args):
+        r"""
+        This is a generalized version of Python's :func:`~mpmath.range` function
+        that accepts fractional endpoints and step sizes and
+        returns a list of ``mpf`` instances. Like :func:`~mpmath.range`,
+        :func:`~mpmath.arange` can be called with 1, 2 or 3 arguments:
+
+        ``arange(b)``
+            `[0, 1, 2, \ldots, x]`
+        ``arange(a, b)``
+            `[a, a+1, a+2, \ldots, x]`
+        ``arange(a, b, h)``
+            `[a, a+h, a+h, \ldots, x]`
+
+        where `b-1 \le x < b` (in the third case, `b-h \le x < b`).
+
+        Like Python's :func:`~mpmath.range`, the endpoint is not included. To
+        produce ranges where the endpoint is included, :func:`~mpmath.linspace`
+        is more convenient.
+
+        **Examples**
+
+            >>> from mpmath import *
+            >>> mp.dps = 15; mp.pretty = False
+            >>> arange(4)
+            [mpf('0.0'), mpf('1.0'), mpf('2.0'), mpf('3.0')]
+            >>> arange(1, 2, 0.25)
+            [mpf('1.0'), mpf('1.25'), mpf('1.5'), mpf('1.75')]
+            >>> arange(1, -1, -0.75)
+            [mpf('1.0'), mpf('0.25'), mpf('-0.5')]
+
+        """
+        if not len(args) <= 3:
+            raise TypeError('arange expected at most 3 arguments, got %i'
+                            % len(args))
+        if not len(args) >= 1:
+            raise TypeError('arange expected at least 1 argument, got %i'
+                            % len(args))
+        # set default
+        a = 0
+        dt = 1
+        # interpret arguments
+        if len(args) == 1:
+            b = args[0]
+        elif len(args) >= 2:
+            a = args[0]
+            b = args[1]
+        if len(args) == 3:
+            dt = args[2]
+        a, b, dt = ctx.mpf(a), ctx.mpf(b), ctx.mpf(dt)
+        assert a + dt != a, 'dt is too small and would cause an infinite loop'
+        # adapt code for sign of dt
+        if a > b:
+            if dt > 0:
+                return []
+            op = gt
+        else:
+            if dt < 0:
+                return []
+            op = lt
+        # create list
+        result = []
+        i = 0
+        t = a
+        while 1:
+            t = a + dt*i
+            i += 1
+            if op(t, b):
+                result.append(t)
+            else:
+                break
+        return result
+
+    def linspace(ctx, *args, **kwargs):
+        """
+        ``linspace(a, b, n)`` returns a list of `n` evenly spaced
+        samples from `a` to `b`. The syntax ``linspace(mpi(a,b), n)``
+        is also valid.
+
+        This function is often more convenient than :func:`~mpmath.arange`
+        for partitioning an interval into subintervals, since
+        the endpoint is included::
+
+            >>> from mpmath import *
+            >>> mp.dps = 15; mp.pretty = False
+            >>> linspace(1, 4, 4)
+            [mpf('1.0'), mpf('2.0'), mpf('3.0'), mpf('4.0')]
+
+        You may also provide the keyword argument ``endpoint=False``::
+
+            >>> linspace(1, 4, 4, endpoint=False)
+            [mpf('1.0'), mpf('1.75'), mpf('2.5'), mpf('3.25')]
+
+        """
+        if len(args) == 3:
+            a = ctx.mpf(args[0])
+            b = ctx.mpf(args[1])
+            n = int(args[2])
+        elif len(args) == 2:
+            assert hasattr(args[0], '_mpi_')
+            a = args[0].a
+            b = args[0].b
+            n = int(args[1])
+        else:
+            raise TypeError('linspace expected 2 or 3 arguments, got %i' \
+                            % len(args))
+        if n < 1:
+            raise ValueError('n must be greater than 0')
+        if not 'endpoint' in kwargs or kwargs['endpoint']:
+            if n == 1:
+                return [ctx.mpf(a)]
+            step = (b - a) / ctx.mpf(n - 1)
+            y = [i*step + a for i in xrange(n)]
+            y[-1] = b
+        else:
+            step = (b - a) / ctx.mpf(n)
+            y = [i*step + a for i in xrange(n)]
+        return y
+
+    def cos_sin(ctx, z, **kwargs):
+        return ctx.cos(z, **kwargs), ctx.sin(z, **kwargs)
+
+    def cospi_sinpi(ctx, z, **kwargs):
+        return ctx.cospi(z, **kwargs), ctx.sinpi(z, **kwargs)
+
+    def _default_hyper_maxprec(ctx, p):
+        return int(1000 * p**0.25 + 4*p)
+
+    _gcd = staticmethod(libmp.gcd)
+    list_primes = staticmethod(libmp.list_primes)
+    isprime = staticmethod(libmp.isprime)
+    bernfrac = staticmethod(libmp.bernfrac)
+    moebius = staticmethod(libmp.moebius)
+    _ifac = staticmethod(libmp.ifac)
+    _eulernum = staticmethod(libmp.eulernum)
+    _stirling1 = staticmethod(libmp.stirling1)
+    _stirling2 = staticmethod(libmp.stirling2)
+
+    def sum_accurately(ctx, terms, check_step=1):
+        prec = ctx.prec
+        try:
+            extraprec = 10
+            while 1:
+                ctx.prec = prec + extraprec + 5
+                max_mag = ctx.ninf
+                s = ctx.zero
+                k = 0
+                for term in terms():
+                    s += term
+                    if (not k % check_step) and term:
+                        term_mag = ctx.mag(term)
+                        max_mag = max(max_mag, term_mag)
+                        sum_mag = ctx.mag(s)
+                        if sum_mag - term_mag > ctx.prec:
+                            break
+                    k += 1
+                cancellation = max_mag - sum_mag
+                if cancellation != cancellation:
+                    break
+                if cancellation < extraprec or ctx._fixed_precision:
+                    break
+                extraprec += min(ctx.prec, cancellation)
+            return s
+        finally:
+            ctx.prec = prec
+
+    def mul_accurately(ctx, factors, check_step=1):
+        prec = ctx.prec
+        try:
+            extraprec = 10
+            while 1:
+                ctx.prec = prec + extraprec + 5
+                max_mag = ctx.ninf
+                one = ctx.one
+                s = one
+                k = 0
+                for factor in factors():
+                    s *= factor
+                    term = factor - one
+                    if (not k % check_step):
+                        term_mag = ctx.mag(term)
+                        max_mag = max(max_mag, term_mag)
+                        sum_mag = ctx.mag(s-one)
+                        #if sum_mag - term_mag > ctx.prec:
+                        #    break
+                        if -term_mag > ctx.prec:
+                            break
+                    k += 1
+                cancellation = max_mag - sum_mag
+                if cancellation != cancellation:
+                    break
+                if cancellation < extraprec or ctx._fixed_precision:
+                    break
+                extraprec += min(ctx.prec, cancellation)
+            return s
+        finally:
+            ctx.prec = prec
+
+    def power(ctx, x, y):
+        r"""Converts `x` and `y` to mpmath numbers and evaluates
+        `x^y = \exp(y \log(x))`::
+
+            >>> from mpmath import *
+            >>> mp.dps = 30; mp.pretty = True
+            >>> power(2, 0.5)
+            1.41421356237309504880168872421
+
+        This shows the leading few digits of a large Mersenne prime
+        (performing the exact calculation ``2**43112609-1`` and
+        displaying the result in Python would be very slow)::
+
+            >>> power(2, 43112609)-1
+            3.16470269330255923143453723949e+12978188
+        """
+        return ctx.convert(x) ** ctx.convert(y)
+
+    def _zeta_int(ctx, n):
+        return ctx.zeta(n)
+
+    def maxcalls(ctx, f, N):
+        """
+        Return a wrapped copy of *f* that raises ``NoConvergence`` when *f*
+        has been called more than *N* times::
+
+            >>> from mpmath import *
+            >>> mp.dps = 15
+            >>> f = maxcalls(sin, 10)
+            >>> print(sum(f(n) for n in range(10)))
+            1.95520948210738
+            >>> f(10) # doctest: +IGNORE_EXCEPTION_DETAIL
+            Traceback (most recent call last):
+              ...
+            NoConvergence: maxcalls: function evaluated 10 times
+
+        """
+        counter = [0]
+        def f_maxcalls_wrapped(*args, **kwargs):
+            counter[0] += 1
+            if counter[0] > N:
+                raise ctx.NoConvergence("maxcalls: function evaluated %i times" % N)
+            return f(*args, **kwargs)
+        return f_maxcalls_wrapped
+
+    def memoize(ctx, f):
+        """
+        Return a wrapped copy of *f* that caches computed values, i.e.
+        a memoized copy of *f*. Values are only reused if the cached precision
+        is equal to or higher than the working precision::
+
+            >>> from mpmath import *
+            >>> mp.dps = 15; mp.pretty = True
+            >>> f = memoize(maxcalls(sin, 1))
+            >>> f(2)
+            0.909297426825682
+            >>> f(2)
+            0.909297426825682
+            >>> mp.dps = 25
+            >>> f(2) # doctest: +IGNORE_EXCEPTION_DETAIL
+            Traceback (most recent call last):
+              ...
+            NoConvergence: maxcalls: function evaluated 1 times
+
+        """
+        f_cache = {}
+        def f_cached(*args, **kwargs):
+            if kwargs:
+                key = args, tuple(kwargs.items())
+            else:
+                key = args
+            prec = ctx.prec
+            if key in f_cache:
+                cprec, cvalue = f_cache[key]
+                if cprec >= prec:
+                    return +cvalue
+            value = f(*args, **kwargs)
+            f_cache[key] = (prec, value)
+            return value
+        f_cached.__name__ = f.__name__
+        f_cached.__doc__ = f.__doc__
+        return f_cached

rl/Lib/site-packages/mpmath/ctx_fp.py

@@ -0,0 +1,253 @@
+from .ctx_base import StandardBaseContext
+
+import math
+import cmath
+from . import math2
+
+from . import function_docs
+
+from .libmp import mpf_bernoulli, to_float, int_types
+from . import libmp
+
+class FPContext(StandardBaseContext):
+    """
+    Context for fast low-precision arithmetic (53-bit precision, giving at most
+    about 15-digit accuracy), using Python's builtin float and complex.
+    """
+
+    def __init__(ctx):
+        StandardBaseContext.__init__(ctx)
+
+        # Override SpecialFunctions implementation
+        ctx.loggamma = math2.loggamma
+        ctx._bernoulli_cache = {}
+        ctx.pretty = False
+
+        ctx._init_aliases()
+
+    _mpq = lambda cls, x: float(x[0])/x[1]
+
+    NoConvergence = libmp.NoConvergence
+
+    def _get_prec(ctx): return 53
+    def _set_prec(ctx, p): return
+    def _get_dps(ctx): return 15
+    def _set_dps(ctx, p): return
+
+    _fixed_precision = True
+
+    prec = property(_get_prec, _set_prec)
+    dps = property(_get_dps, _set_dps)
+
+    zero = 0.0
+    one = 1.0
+    eps = math2.EPS
+    inf = math2.INF
+    ninf = math2.NINF
+    nan = math2.NAN
+    j = 1j
+
+    # Called by SpecialFunctions.__init__()
+    @classmethod
+    def _wrap_specfun(cls, name, f, wrap):
+        if wrap:
+            def f_wrapped(ctx, *args, **kwargs):
+                convert = ctx.convert
+                args = [convert(a) for a in args]
+                return f(ctx, *args, **kwargs)
+        else:
+            f_wrapped = f
+        f_wrapped.__doc__ = function_docs.__dict__.get(name, f.__doc__)
+        setattr(cls, name, f_wrapped)
+
+    def bernoulli(ctx, n):
+        cache = ctx._bernoulli_cache
+        if n in cache:
+            return cache[n]
+        cache[n] = to_float(mpf_bernoulli(n, 53, 'n'), strict=True)
+        return cache[n]
+
+    pi = math2.pi
+    e = math2.e
+    euler = math2.euler
+    sqrt2 = 1.4142135623730950488
+    sqrt5 = 2.2360679774997896964
+    phi = 1.6180339887498948482
+    ln2 = 0.69314718055994530942
+    ln10 = 2.302585092994045684
+    euler = 0.57721566490153286061
+    catalan = 0.91596559417721901505
+    khinchin = 2.6854520010653064453
+    apery = 1.2020569031595942854
+    glaisher = 1.2824271291006226369
+
+    absmin = absmax = abs
+
+    def is_special(ctx, x):
+        return x - x != 0.0
+
+    def isnan(ctx, x):
+        return x != x
+
+    def isinf(ctx, x):
+        return abs(x) == math2.INF
+
+    def isnormal(ctx, x):
+        if x:
+            return x - x == 0.0
+        return False
+
+    def isnpint(ctx, x):
+        if type(x) is complex:
+            if x.imag:
+                return False
+            x = x.real
+        return x <= 0.0 and round(x) == x
+
+    mpf = float
+    mpc = complex
+
+    def convert(ctx, x):
+        try:
+            return float(x)
+        except:
+            return complex(x)
+
+    power = staticmethod(math2.pow)
+    sqrt = staticmethod(math2.sqrt)
+    exp = staticmethod(math2.exp)
+    ln = log = staticmethod(math2.log)
+    cos = staticmethod(math2.cos)
+    sin = staticmethod(math2.sin)
+    tan = staticmethod(math2.tan)
+    cos_sin = staticmethod(math2.cos_sin)
+    acos = staticmethod(math2.acos)
+    asin = staticmethod(math2.asin)
+    atan = staticmethod(math2.atan)
+    cosh = staticmethod(math2.cosh)
+    sinh = staticmethod(math2.sinh)
+    tanh = staticmethod(math2.tanh)
+    gamma = staticmethod(math2.gamma)
+    rgamma = staticmethod(math2.rgamma)
+    fac = factorial = staticmethod(math2.factorial)
+    floor = staticmethod(math2.floor)
+    ceil = staticmethod(math2.ceil)
+    cospi = staticmethod(math2.cospi)
+    sinpi = staticmethod(math2.sinpi)
+    cbrt = staticmethod(math2.cbrt)
+    _nthroot = staticmethod(math2.nthroot)
+    _ei = staticmethod(math2.ei)
+    _e1 = staticmethod(math2.e1)
+    _zeta = _zeta_int = staticmethod(math2.zeta)
+
+    # XXX: math2
+    def arg(ctx, z):
+        z = complex(z)
+        return math.atan2(z.imag, z.real)
+
+    def expj(ctx, x):
+        return ctx.exp(ctx.j*x)
+
+    def expjpi(ctx, x):
+        return ctx.exp(ctx.j*ctx.pi*x)
+
+    ldexp = math.ldexp
+    frexp = math.frexp
+
+    def mag(ctx, z):
+        if z:
+            return ctx.frexp(abs(z))[1]
+        return ctx.ninf
+
+    def isint(ctx, z):
+        if hasattr(z, "imag"):   # float/int don't have .real/.imag in py2.5
+            if z.imag:
+                return False
+            z = z.real
+        try:
+            return z == int(z)
+        except:
+            return False
+
+    def nint_distance(ctx, z):
+        if hasattr(z, "imag"):   # float/int don't have .real/.imag in py2.5
+            n = round(z.real)
+        else:
+            n = round(z)
+        if n == z:
+            return n, ctx.ninf
+        return n, ctx.mag(abs(z-n))
+
+    def _convert_param(ctx, z):
+        if type(z) is tuple:
+            p, q = z
+            return ctx.mpf(p) / q, 'R'
+        if hasattr(z, "imag"):    # float/int don't have .real/.imag in py2.5
+            intz = int(z.real)
+        else:
+            intz = int(z)
+        if z == intz:
+            return intz, 'Z'
+        return z, 'R'
+
+    def _is_real_type(ctx, z):
+        return isinstance(z, float) or isinstance(z, int_types)
+
+    def _is_complex_type(ctx, z):
+        return isinstance(z, complex)
+
+    def hypsum(ctx, p, q, types, coeffs, z, maxterms=6000, **kwargs):
+        coeffs = list(coeffs)
+        num = range(p)
+        den = range(p,p+q)
+        tol = ctx.eps
+        s = t = 1.0
+        k = 0
+        while 1:
+            for i in num: t *= (coeffs[i]+k)
+            for i in den: t /= (coeffs[i]+k)
+            k += 1; t /= k; t *= z; s += t
+            if abs(t) < tol:
+                return s
+            if k > maxterms:
+                raise ctx.NoConvergence
+
+    def atan2(ctx, x, y):
+        return math.atan2(x, y)
+
+    def psi(ctx, m, z):
+        m = int(m)
+        if m == 0:
+            return ctx.digamma(z)
+        return (-1)**(m+1) * ctx.fac(m) * ctx.zeta(m+1, z)
+
+    digamma = staticmethod(math2.digamma)
+
+    def harmonic(ctx, x):
+        x = ctx.convert(x)
+        if x == 0 or x == 1:
+            return x
+        return ctx.digamma(x+1) + ctx.euler
+
+    nstr = str
+
+    def to_fixed(ctx, x, prec):
+        return int(math.ldexp(x, prec))
+
+    def rand(ctx):
+        import random
+        return random.random()
+
+    _erf = staticmethod(math2.erf)
+    _erfc = staticmethod(math2.erfc)
+
+    def sum_accurately(ctx, terms, check_step=1):
+        s = ctx.zero
+        k = 0
+        for term in terms():
+            s += term
+            if (not k % check_step) and term:
+                if abs(term) <= 1e-18*abs(s):
+                    break
+            k += 1
+        return s

rl/Lib/site-packages/mpmath/ctx_iv.py

@@ -0,0 +1,551 @@
+import operator
+
+from . import libmp
+
+from .libmp.backend import basestring
+
+from .libmp import (
+    int_types, MPZ_ONE,
+    prec_to_dps, dps_to_prec, repr_dps,
+    round_floor, round_ceiling,
+    fzero, finf, fninf, fnan,
+    mpf_le, mpf_neg,
+    from_int, from_float, from_str, from_rational,
+    mpi_mid, mpi_delta, mpi_str,
+    mpi_abs, mpi_pos, mpi_neg, mpi_add, mpi_sub,
+    mpi_mul, mpi_div, mpi_pow_int, mpi_pow,
+    mpi_from_str,
+    mpci_pos, mpci_neg, mpci_add, mpci_sub, mpci_mul, mpci_div, mpci_pow,
+    mpci_abs, mpci_pow, mpci_exp, mpci_log,
+    ComplexResult,
+    mpf_hash, mpc_hash)
+from .matrices.matrices import _matrix
+
+mpi_zero = (fzero, fzero)
+
+from .ctx_base import StandardBaseContext
+
+new = object.__new__
+
+def convert_mpf_(x, prec, rounding):
+    if hasattr(x, "_mpf_"): return x._mpf_
+    if isinstance(x, int_types): return from_int(x, prec, rounding)
+    if isinstance(x, float): return from_float(x, prec, rounding)
+    if isinstance(x, basestring): return from_str(x, prec, rounding)
+    raise NotImplementedError
+
+
+class ivmpf(object):
+    """
+    Interval arithmetic class. Precision is controlled by iv.prec.
+    """
+
+    def __new__(cls, x=0):
+        return cls.ctx.convert(x)
+
+    def cast(self, cls, f_convert):
+        a, b = self._mpi_
+        if a == b:
+            return cls(f_convert(a))
+        raise ValueError
+
+    def __int__(self):
+        return self.cast(int, libmp.to_int)
+
+    def __float__(self):
+        return self.cast(float, libmp.to_float)
+
+    def __complex__(self):
+        return self.cast(complex, libmp.to_float)
+
+    def __hash__(self):
+        a, b = self._mpi_
+        if a == b:
+            return mpf_hash(a)
+        else:
+            return hash(self._mpi_)
+
+    @property
+    def real(self): return self
+
+    @property
+    def imag(self): return self.ctx.zero
+
+    def conjugate(self): return self
+
+    @property
+    def a(self):
+        a, b = self._mpi_
+        return self.ctx.make_mpf((a, a))
+
+    @property
+    def b(self):
+        a, b = self._mpi_
+        return self.ctx.make_mpf((b, b))
+
+    @property
+    def mid(self):
+        ctx = self.ctx
+        v = mpi_mid(self._mpi_, ctx.prec)
+        return ctx.make_mpf((v, v))
+
+    @property
+    def delta(self):
+        ctx = self.ctx
+        v = mpi_delta(self._mpi_, ctx.prec)
+        return ctx.make_mpf((v,v))
+
+    @property
+    def _mpci_(self):
+        return self._mpi_, mpi_zero
+
+    def _compare(*args):
+        raise TypeError("no ordering relation is defined for intervals")
+
+    __gt__ = _compare
+    __le__ = _compare
+    __gt__ = _compare
+    __ge__ = _compare
+
+    def __contains__(self, t):
+        t = self.ctx.mpf(t)
+        return (self.a <= t.a) and (t.b <= self.b)
+
+    def __str__(self):
+        return mpi_str(self._mpi_, self.ctx.prec)
+
+    def __repr__(self):
+        if self.ctx.pretty:
+            return str(self)
+        a, b = self._mpi_
+        n = repr_dps(self.ctx.prec)
+        a = libmp.to_str(a, n)
+        b = libmp.to_str(b, n)
+        return "mpi(%r, %r)" % (a, b)
+
+    def _compare(s, t, cmpfun):
+        if not hasattr(t, "_mpi_"):
+            try:
+                t = s.ctx.convert(t)
+            except:
+                return NotImplemented
+        return cmpfun(s._mpi_, t._mpi_)
+
+    def __eq__(s, t): return s._compare(t, libmp.mpi_eq)
+    def __ne__(s, t): return s._compare(t, libmp.mpi_ne)
+    def __lt__(s, t): return s._compare(t, libmp.mpi_lt)
+    def __le__(s, t): return s._compare(t, libmp.mpi_le)
+    def __gt__(s, t): return s._compare(t, libmp.mpi_gt)
+    def __ge__(s, t): return s._compare(t, libmp.mpi_ge)
+
+    def __abs__(self):
+        return self.ctx.make_mpf(mpi_abs(self._mpi_, self.ctx.prec))
+    def __pos__(self):
+        return self.ctx.make_mpf(mpi_pos(self._mpi_, self.ctx.prec))
+    def __neg__(self):
+        return self.ctx.make_mpf(mpi_neg(self._mpi_, self.ctx.prec))
+
+    def ae(s, t, rel_eps=None, abs_eps=None):
+        return s.ctx.almosteq(s, t, rel_eps, abs_eps)
+
+class ivmpc(object):
+
+    def __new__(cls, re=0, im=0):
+        re = cls.ctx.convert(re)
+        im = cls.ctx.convert(im)
+        y = new(cls)
+        y._mpci_ = re._mpi_, im._mpi_
+        return y
+
+    def __hash__(self):
+        (a, b), (c,d) = self._mpci_
+        if a == b and c == d:
+            return mpc_hash((a, c))
+        else:
+            return hash(self._mpci_)
+
+    def __repr__(s):
+        if s.ctx.pretty:
+            return str(s)
+        return "iv.mpc(%s, %s)" % (repr(s.real), repr(s.imag))
+
+    def __str__(s):
+        return "(%s + %s*j)" % (str(s.real), str(s.imag))
+
+    @property
+    def a(self):
+        (a, b), (c,d) = self._mpci_
+        return self.ctx.make_mpf((a, a))
+
+    @property
+    def b(self):
+        (a, b), (c,d) = self._mpci_
+        return self.ctx.make_mpf((b, b))
+
+    @property
+    def c(self):
+        (a, b), (c,d) = self._mpci_
+        return self.ctx.make_mpf((c, c))
+
+    @property
+    def d(self):
+        (a, b), (c,d) = self._mpci_
+        return self.ctx.make_mpf((d, d))
+
+    @property
+    def real(s):
+        return s.ctx.make_mpf(s._mpci_[0])
+
+    @property
+    def imag(s):
+        return s.ctx.make_mpf(s._mpci_[1])
+
+    def conjugate(s):
+        a, b = s._mpci_
+        return s.ctx.make_mpc((a, mpf_neg(b)))
+
+    def overlap(s, t):
+        t = s.ctx.convert(t)
+        real_overlap = (s.a <= t.a <= s.b) or (s.a <= t.b <= s.b) or (t.a <= s.a <= t.b) or (t.a <= s.b <= t.b)
+        imag_overlap = (s.c <= t.c <= s.d) or (s.c <= t.d <= s.d) or (t.c <= s.c <= t.d) or (t.c <= s.d <= t.d)
+        return real_overlap and imag_overlap
+
+    def __contains__(s, t):
+        t = s.ctx.convert(t)
+        return t.real in s.real and t.imag in s.imag
+
+    def _compare(s, t, ne=False):
+        if not isinstance(t, s.ctx._types):
+            try:
+                t = s.ctx.convert(t)
+            except:
+                return NotImplemented
+        if hasattr(t, '_mpi_'):
+            tval = t._mpi_, mpi_zero
+        elif hasattr(t, '_mpci_'):
+            tval = t._mpci_
+        if ne:
+            return s._mpci_ != tval
+        return s._mpci_ == tval
+
+    def __eq__(s, t): return s._compare(t)
+    def __ne__(s, t): return s._compare(t, True)
+
+    def __lt__(s, t): raise TypeError("complex intervals cannot be ordered")
+    __le__ = __gt__ = __ge__ = __lt__
+
+    def __neg__(s): return s.ctx.make_mpc(mpci_neg(s._mpci_, s.ctx.prec))
+    def __pos__(s): return s.ctx.make_mpc(mpci_pos(s._mpci_, s.ctx.prec))
+    def __abs__(s): return s.ctx.make_mpf(mpci_abs(s._mpci_, s.ctx.prec))
+
+    def ae(s, t, rel_eps=None, abs_eps=None):
+        return s.ctx.almosteq(s, t, rel_eps, abs_eps)
+
+def _binary_op(f_real, f_complex):
+    def g_complex(ctx, sval, tval):
+        return ctx.make_mpc(f_complex(sval, tval, ctx.prec))
+    def g_real(ctx, sval, tval):
+        try:
+            return ctx.make_mpf(f_real(sval, tval, ctx.prec))
+        except ComplexResult:
+            sval = (sval, mpi_zero)
+            tval = (tval, mpi_zero)
+            return g_complex(ctx, sval, tval)
+    def lop_real(s, t):
+        if isinstance(t, _matrix): return NotImplemented
+        ctx = s.ctx
+        if not isinstance(t, ctx._types): t = ctx.convert(t)
+        if hasattr(t, "_mpi_"): return g_real(ctx, s._mpi_, t._mpi_)
+        if hasattr(t, "_mpci_"): return g_complex(ctx, (s._mpi_, mpi_zero), t._mpci_)
+        return NotImplemented
+    def rop_real(s, t):
+        ctx = s.ctx
+        if not isinstance(t, ctx._types): t = ctx.convert(t)
+        if hasattr(t, "_mpi_"): return g_real(ctx, t._mpi_, s._mpi_)
+        if hasattr(t, "_mpci_"): return g_complex(ctx, t._mpci_, (s._mpi_, mpi_zero))
+        return NotImplemented
+    def lop_complex(s, t):
+        if isinstance(t, _matrix): return NotImplemented
+        ctx = s.ctx
+        if not isinstance(t, s.ctx._types):
+            try:
+                t = s.ctx.convert(t)
+            except (ValueError, TypeError):
+                return NotImplemented
+        return g_complex(ctx, s._mpci_, t._mpci_)
+    def rop_complex(s, t):
+        ctx = s.ctx
+        if not isinstance(t, s.ctx._types):
+            t = s.ctx.convert(t)
+        return g_complex(ctx, t._mpci_, s._mpci_)
+    return lop_real, rop_real, lop_complex, rop_complex
+
+ivmpf.__add__, ivmpf.__radd__, ivmpc.__add__, ivmpc.__radd__ = _binary_op(mpi_add, mpci_add)
+ivmpf.__sub__, ivmpf.__rsub__, ivmpc.__sub__, ivmpc.__rsub__ = _binary_op(mpi_sub, mpci_sub)
+ivmpf.__mul__, ivmpf.__rmul__, ivmpc.__mul__, ivmpc.__rmul__ = _binary_op(mpi_mul, mpci_mul)
+ivmpf.__div__, ivmpf.__rdiv__, ivmpc.__div__, ivmpc.__rdiv__ = _binary_op(mpi_div, mpci_div)
+ivmpf.__pow__, ivmpf.__rpow__, ivmpc.__pow__, ivmpc.__rpow__ = _binary_op(mpi_pow, mpci_pow)
+
+ivmpf.__truediv__ = ivmpf.__div__; ivmpf.__rtruediv__ = ivmpf.__rdiv__
+ivmpc.__truediv__ = ivmpc.__div__; ivmpc.__rtruediv__ = ivmpc.__rdiv__
+
+class ivmpf_constant(ivmpf):
+    def __new__(cls, f):
+        self = new(cls)
+        self._f = f
+        return self
+    def _get_mpi_(self):
+        prec = self.ctx._prec[0]
+        a = self._f(prec, round_floor)
+        b = self._f(prec, round_ceiling)
+        return a, b
+    _mpi_ = property(_get_mpi_)
+
+class MPIntervalContext(StandardBaseContext):
+
+    def __init__(ctx):
+        ctx.mpf = type('ivmpf', (ivmpf,), {})
+        ctx.mpc = type('ivmpc', (ivmpc,), {})
+        ctx._types = (ctx.mpf, ctx.mpc)
+        ctx._constant = type('ivmpf_constant', (ivmpf_constant,), {})
+        ctx._prec = [53]
+        ctx._set_prec(53)
+        ctx._constant._ctxdata = ctx.mpf._ctxdata = ctx.mpc._ctxdata = [ctx.mpf, new, ctx._prec]
+        ctx._constant.ctx = ctx.mpf.ctx = ctx.mpc.ctx = ctx
+        ctx.pretty = False
+        StandardBaseContext.__init__(ctx)
+        ctx._init_builtins()
+
+    def _mpi(ctx, a, b=None):
+        if b is None:
+            return ctx.mpf(a)
+        return ctx.mpf((a,b))
+
+    def _init_builtins(ctx):
+        ctx.one = ctx.mpf(1)
+        ctx.zero = ctx.mpf(0)
+        ctx.inf = ctx.mpf('inf')
+        ctx.ninf = -ctx.inf
+        ctx.nan = ctx.mpf('nan')
+        ctx.j = ctx.mpc(0,1)
+        ctx.exp = ctx._wrap_mpi_function(libmp.mpi_exp, libmp.mpci_exp)
+        ctx.sqrt = ctx._wrap_mpi_function(libmp.mpi_sqrt)
+        ctx.ln = ctx._wrap_mpi_function(libmp.mpi_log, libmp.mpci_log)
+        ctx.cos = ctx._wrap_mpi_function(libmp.mpi_cos, libmp.mpci_cos)
+        ctx.sin = ctx._wrap_mpi_function(libmp.mpi_sin, libmp.mpci_sin)
+        ctx.tan = ctx._wrap_mpi_function(libmp.mpi_tan)
+        ctx.gamma = ctx._wrap_mpi_function(libmp.mpi_gamma, libmp.mpci_gamma)
+        ctx.loggamma = ctx._wrap_mpi_function(libmp.mpi_loggamma, libmp.mpci_loggamma)
+        ctx.rgamma = ctx._wrap_mpi_function(libmp.mpi_rgamma, libmp.mpci_rgamma)
+        ctx.factorial = ctx._wrap_mpi_function(libmp.mpi_factorial, libmp.mpci_factorial)
+        ctx.fac = ctx.factorial
+
+        ctx.eps = ctx._constant(lambda prec, rnd: (0, MPZ_ONE, 1-prec, 1))
+        ctx.pi = ctx._constant(libmp.mpf_pi)
+        ctx.e = ctx._constant(libmp.mpf_e)
+        ctx.ln2 = ctx._constant(libmp.mpf_ln2)
+        ctx.ln10 = ctx._constant(libmp.mpf_ln10)
+        ctx.phi = ctx._constant(libmp.mpf_phi)
+        ctx.euler = ctx._constant(libmp.mpf_euler)
+        ctx.catalan = ctx._constant(libmp.mpf_catalan)
+        ctx.glaisher = ctx._constant(libmp.mpf_glaisher)
+        ctx.khinchin = ctx._constant(libmp.mpf_khinchin)
+        ctx.twinprime = ctx._constant(libmp.mpf_twinprime)
+
+    def _wrap_mpi_function(ctx, f_real, f_complex=None):
+        def g(x, **kwargs):
+            if kwargs:
+                prec = kwargs.get('prec', ctx._prec[0])
+            else:
+                prec = ctx._prec[0]
+            x = ctx.convert(x)
+            if hasattr(x, "_mpi_"):
+                return ctx.make_mpf(f_real(x._mpi_, prec))
+            if hasattr(x, "_mpci_"):
+                return ctx.make_mpc(f_complex(x._mpci_, prec))
+            raise ValueError
+        return g
+
+    @classmethod
+    def _wrap_specfun(cls, name, f, wrap):
+        if wrap:
+            def f_wrapped(ctx, *args, **kwargs):
+                convert = ctx.convert
+                args = [convert(a) for a in args]
+                prec = ctx.prec
+                try:
+                    ctx.prec += 10
+                    retval = f(ctx, *args, **kwargs)
+                finally:
+                    ctx.prec = prec
+                return +retval
+        else:
+            f_wrapped = f
+        setattr(cls, name, f_wrapped)
+
+    def _set_prec(ctx, n):
+        ctx._prec[0] = max(1, int(n))
+        ctx._dps = prec_to_dps(n)
+
+    def _set_dps(ctx, n):
+        ctx._prec[0] = dps_to_prec(n)
+        ctx._dps = max(1, int(n))
+
+    prec = property(lambda ctx: ctx._prec[0], _set_prec)
+    dps = property(lambda ctx: ctx._dps, _set_dps)
+
+    def make_mpf(ctx, v):
+        a = new(ctx.mpf)
+        a._mpi_ = v
+        return a
+
+    def make_mpc(ctx, v):
+        a = new(ctx.mpc)
+        a._mpci_ = v
+        return a
+
+    def _mpq(ctx, pq):
+        p, q = pq
+        a = libmp.from_rational(p, q, ctx.prec, round_floor)
+        b = libmp.from_rational(p, q, ctx.prec, round_ceiling)
+        return ctx.make_mpf((a, b))
+
+    def convert(ctx, x):
+        if isinstance(x, (ctx.mpf, ctx.mpc)):
+            return x
+        if isinstance(x, ctx._constant):
+            return +x
+        if isinstance(x, complex) or hasattr(x, "_mpc_"):
+            re = ctx.convert(x.real)
+            im = ctx.convert(x.imag)
+            return ctx.mpc(re,im)
+        if isinstance(x, basestring):
+            v = mpi_from_str(x, ctx.prec)
+            return ctx.make_mpf(v)
+        if hasattr(x, "_mpi_"):
+            a, b = x._mpi_
+        else:
+            try:
+                a, b = x
+            except (TypeError, ValueError):
+                a = b = x
+            if hasattr(a, "_mpi_"):
+                a = a._mpi_[0]
+            else:
+                a = convert_mpf_(a, ctx.prec, round_floor)
+            if hasattr(b, "_mpi_"):
+                b = b._mpi_[1]
+            else:
+                b = convert_mpf_(b, ctx.prec, round_ceiling)
+        if a == fnan or b == fnan:
+            a = fninf
+            b = finf
+        assert mpf_le(a, b), "endpoints must be properly ordered"
+        return ctx.make_mpf((a, b))
+
+    def nstr(ctx, x, n=5, **kwargs):
+        x = ctx.convert(x)
+        if hasattr(x, "_mpi_"):
+            return libmp.mpi_to_str(x._mpi_, n, **kwargs)
+        if hasattr(x, "_mpci_"):
+            re = libmp.mpi_to_str(x._mpci_[0], n, **kwargs)
+            im = libmp.mpi_to_str(x._mpci_[1], n, **kwargs)
+            return "(%s + %s*j)" % (re, im)
+
+    def mag(ctx, x):
+        x = ctx.convert(x)
+        if isinstance(x, ctx.mpc):
+            return max(ctx.mag(x.real), ctx.mag(x.imag)) + 1
+        a, b = libmp.mpi_abs(x._mpi_)
+        sign, man, exp, bc = b
+        if man:
+            return exp+bc
+        if b == fzero:
+            return ctx.ninf
+        if b == fnan:
+            return ctx.nan
+        return ctx.inf
+
+    def isnan(ctx, x):
+        return False
+
+    def isinf(ctx, x):
+        return x == ctx.inf
+
+    def isint(ctx, x):
+        x = ctx.convert(x)
+        a, b = x._mpi_
+        if a == b:
+            sign, man, exp, bc = a
+            if man:
+                return exp >= 0
+            return a == fzero
+        return None
+
+    def ldexp(ctx, x, n):
+        a, b = ctx.convert(x)._mpi_
+        a = libmp.mpf_shift(a, n)
+        b = libmp.mpf_shift(b, n)
+        return ctx.make_mpf((a,b))
+
+    def absmin(ctx, x):
+        return abs(ctx.convert(x)).a
+
+    def absmax(ctx, x):
+        return abs(ctx.convert(x)).b
+
+    def atan2(ctx, y, x):
+        y = ctx.convert(y)._mpi_
+        x = ctx.convert(x)._mpi_
+        return ctx.make_mpf(libmp.mpi_atan2(y,x,ctx.prec))
+
+    def _convert_param(ctx, x):
+        if isinstance(x, libmp.int_types):
+            return x, 'Z'
+        if isinstance(x, tuple):
+            p, q = x
+            return (ctx.mpf(p) / ctx.mpf(q), 'R')
+        x = ctx.convert(x)
+        if isinstance(x, ctx.mpf):
+            return x, 'R'
+        if isinstance(x, ctx.mpc):
+            return x, 'C'
+        raise ValueError
+
+    def _is_real_type(ctx, z):
+        return isinstance(z, ctx.mpf) or isinstance(z, int_types)
+
+    def _is_complex_type(ctx, z):
+        return isinstance(z, ctx.mpc)
+
+    def hypsum(ctx, p, q, types, coeffs, z, maxterms=6000, **kwargs):
+        coeffs = list(coeffs)
+        num = range(p)
+        den = range(p,p+q)
+        #tol = ctx.eps
+        s = t = ctx.one
+        k = 0
+        while 1:
+            for i in num: t *= (coeffs[i]+k)
+            for i in den: t /= (coeffs[i]+k)
+            k += 1; t /= k; t *= z; s += t
+            if t == 0:
+                return s
+            #if abs(t) < tol:
+            #    return s
+            if k > maxterms:
+                raise ctx.NoConvergence
+
+
+# Register with "numbers" ABC
+#     We do not subclass, hence we do not use the @abstractmethod checks. While
+#     this is less invasive it may turn out that we do not actually support
+#     parts of the expected interfaces.  See
+#     http://docs.python.org/2/library/numbers.html for list of abstract
+#     methods.
+try:
+    import numbers
+    numbers.Complex.register(ivmpc)
+    numbers.Real.register(ivmpf)
+except ImportError:
+    pass

rl/Lib/site-packages/mpmath/functions/__init__.py

@@ -0,0 +1,14 @@
+from . import functions
+# Hack to update methods
+from . import factorials
+from . import hypergeometric
+from . import expintegrals
+from . import bessel
+from . import orthogonal
+from . import theta
+from . import elliptic
+from . import signals
+from . import zeta
+from . import rszeta
+from . import zetazeros
+from . import qfunctions

rl/Lib/site-packages/mpmath/functions/expintegrals.py

@@ -0,0 +1,425 @@
+from .functions import defun, defun_wrapped
+
+@defun_wrapped
+def _erf_complex(ctx, z):
+    z2 = ctx.square_exp_arg(z, -1)
+    #z2 = -z**2
+    v = (2/ctx.sqrt(ctx.pi))*z * ctx.hyp1f1((1,2),(3,2), z2)
+    if not ctx._re(z):
+        v = ctx._im(v)*ctx.j
+    return v
+
+@defun_wrapped
+def _erfc_complex(ctx, z):
+    if ctx.re(z) > 2:
+        z2 = ctx.square_exp_arg(z)
+        nz2 = ctx.fneg(z2, exact=True)
+        v = ctx.exp(nz2)/ctx.sqrt(ctx.pi) * ctx.hyperu((1,2),(1,2), z2)
+    else:
+        v = 1 - ctx._erf_complex(z)
+    if not ctx._re(z):
+        v = 1+ctx._im(v)*ctx.j
+    return v
+
+@defun
+def erf(ctx, z):
+    z = ctx.convert(z)
+    if ctx._is_real_type(z):
+        try:
+            return ctx._erf(z)
+        except NotImplementedError:
+            pass
+    if ctx._is_complex_type(z) and not z.imag:
+        try:
+            return type(z)(ctx._erf(z.real))
+        except NotImplementedError:
+            pass
+    return ctx._erf_complex(z)
+
+@defun
+def erfc(ctx, z):
+    z = ctx.convert(z)
+    if ctx._is_real_type(z):
+        try:
+            return ctx._erfc(z)
+        except NotImplementedError:
+            pass
+    if ctx._is_complex_type(z) and not z.imag:
+        try:
+            return type(z)(ctx._erfc(z.real))
+        except NotImplementedError:
+            pass
+    return ctx._erfc_complex(z)
+
+@defun
+def square_exp_arg(ctx, z, mult=1, reciprocal=False):
+    prec = ctx.prec*4+20
+    if reciprocal:
+        z2 = ctx.fmul(z, z, prec=prec)
+        z2 = ctx.fdiv(ctx.one, z2, prec=prec)
+    else:
+        z2 = ctx.fmul(z, z, prec=prec)
+    if mult != 1:
+        z2 = ctx.fmul(z2, mult, exact=True)
+    return z2
+
+@defun_wrapped
+def erfi(ctx, z):
+    if not z:
+        return z
+    z2 = ctx.square_exp_arg(z)
+    v = (2/ctx.sqrt(ctx.pi)*z) * ctx.hyp1f1((1,2), (3,2), z2)
+    if not ctx._re(z):
+        v = ctx._im(v)*ctx.j
+    return v
+
+@defun_wrapped
+def erfinv(ctx, x):
+    xre = ctx._re(x)
+    if (xre != x) or (xre < -1) or (xre > 1):
+        return ctx.bad_domain("erfinv(x) is defined only for -1 <= x <= 1")
+    x = xre
+    #if ctx.isnan(x): return x
+    if not x: return x
+    if x == 1: return ctx.inf
+    if x == -1: return ctx.ninf
+    if abs(x) < 0.9:
+        a = 0.53728*x**3 + 0.813198*x
+    else:
+        # An asymptotic formula
+        u = ctx.ln(2/ctx.pi/(abs(x)-1)**2)
+        a = ctx.sign(x) * ctx.sqrt(u - ctx.ln(u))/ctx.sqrt(2)
+    ctx.prec += 10
+    return ctx.findroot(lambda t: ctx.erf(t)-x, a)
+
+@defun_wrapped
+def npdf(ctx, x, mu=0, sigma=1):
+    sigma = ctx.convert(sigma)
+    return ctx.exp(-(x-mu)**2/(2*sigma**2)) / (sigma*ctx.sqrt(2*ctx.pi))
+
+@defun_wrapped
+def ncdf(ctx, x, mu=0, sigma=1):
+    a = (x-mu)/(sigma*ctx.sqrt(2))
+    if a < 0:
+        return ctx.erfc(-a)/2
+    else:
+        return (1+ctx.erf(a))/2
+
+@defun_wrapped
+def betainc(ctx, a, b, x1=0, x2=1, regularized=False):
+    if x1 == x2:
+        v = 0
+    elif not x1:
+        if x1 == 0 and x2 == 1:
+            v = ctx.beta(a, b)
+        else:
+            v = x2**a * ctx.hyp2f1(a, 1-b, a+1, x2) / a
+    else:
+        m, d = ctx.nint_distance(a)
+        if m <= 0:
+            if d < -ctx.prec:
+                h = +ctx.eps
+                ctx.prec *= 2
+                a += h
+            elif d < -4:
+                ctx.prec -= d
+        s1 = x2**a * ctx.hyp2f1(a,1-b,a+1,x2)
+        s2 = x1**a * ctx.hyp2f1(a,1-b,a+1,x1)
+        v = (s1 - s2) / a
+    if regularized:
+        v /= ctx.beta(a,b)
+    return v
+
+@defun
+def gammainc(ctx, z, a=0, b=None, regularized=False):
+    regularized = bool(regularized)
+    z = ctx.convert(z)
+    if a is None:
+        a = ctx.zero
+        lower_modified = False
+    else:
+        a = ctx.convert(a)
+        lower_modified = a != ctx.zero
+    if b is None:
+        b = ctx.inf
+        upper_modified = False
+    else:
+        b = ctx.convert(b)
+        upper_modified = b != ctx.inf
+    # Complete gamma function
+    if not (upper_modified or lower_modified):
+        if regularized:
+            if ctx.re(z) < 0:
+                return ctx.inf
+            elif ctx.re(z) > 0:
+                return ctx.one
+            else:
+                return ctx.nan
+        return ctx.gamma(z)
+    if a == b:
+        return ctx.zero
+    # Standardize
+    if ctx.re(a) > ctx.re(b):
+        return -ctx.gammainc(z, b, a, regularized)
+    # Generalized gamma
+    if upper_modified and lower_modified:
+        return +ctx._gamma3(z, a, b, regularized)
+    # Upper gamma
+    elif lower_modified:
+        return ctx._upper_gamma(z, a, regularized)
+    # Lower gamma
+    elif upper_modified:
+        return ctx._lower_gamma(z, b, regularized)
+
+@defun
+def _lower_gamma(ctx, z, b, regularized=False):
+    # Pole
+    if ctx.isnpint(z):
+        return type(z)(ctx.inf)
+    G = [z] * regularized
+    negb = ctx.fneg(b, exact=True)
+    def h(z):
+        T1 = [ctx.exp(negb), b, z], [1, z, -1], [], G, [1], [1+z], b
+        return (T1,)
+    return ctx.hypercomb(h, [z])
+
+@defun
+def _upper_gamma(ctx, z, a, regularized=False):
+    # Fast integer case, when available
+    if ctx.isint(z):
+        try:
+            if regularized:
+                # Gamma pole
+                if ctx.isnpint(z):
+                    return type(z)(ctx.zero)
+                orig = ctx.prec
+                try:
+                    ctx.prec += 10
+                    return ctx._gamma_upper_int(z, a) / ctx.gamma(z)
+                finally:
+                    ctx.prec = orig
+            else:
+                return ctx._gamma_upper_int(z, a)
+        except NotImplementedError:
+            pass
+    # hypercomb is unable to detect the exact zeros, so handle them here
+    if z == 2 and a == -1:
+        return (z+a)*0
+    if z == 3 and (a == -1-1j or a == -1+1j):
+        return (z+a)*0
+    nega = ctx.fneg(a, exact=True)
+    G = [z] * regularized
+    # Use 2F0 series when possible; fall back to lower gamma representation
+    try:
+        def h(z):
+            r = z-1
+            return [([ctx.exp(nega), a], [1, r], [], G, [1, -r], [], 1/nega)]
+        return ctx.hypercomb(h, [z], force_series=True)
+    except ctx.NoConvergence:
+        def h(z):
+            T1 = [], [1, z-1], [z], G, [], [], 0
+            T2 = [-ctx.exp(nega), a, z], [1, z, -1], [], G, [1], [1+z], a
+            return T1, T2
+        return ctx.hypercomb(h, [z])
+
+@defun
+def _gamma3(ctx, z, a, b, regularized=False):
+    pole = ctx.isnpint(z)
+    if regularized and pole:
+        return ctx.zero
+    try:
+        ctx.prec += 15
+        # We don't know in advance whether it's better to write as a difference
+        # of lower or upper gamma functions, so try both
+        T1 = ctx.gammainc(z, a, regularized=regularized)
+        T2 = ctx.gammainc(z, b, regularized=regularized)
+        R = T1 - T2
+        if ctx.mag(R) - max(ctx.mag(T1), ctx.mag(T2)) > -10:
+            return R
+        if not pole:
+            T1 = ctx.gammainc(z, 0, b, regularized=regularized)
+            T2 = ctx.gammainc(z, 0, a, regularized=regularized)
+            R = T1 - T2
+            # May be ok, but should probably at least print a warning
+            # about possible cancellation
+            if 1: #ctx.mag(R) - max(ctx.mag(T1), ctx.mag(T2)) > -10:
+                return R
+    finally:
+        ctx.prec -= 15
+    raise NotImplementedError
+
+@defun_wrapped
+def expint(ctx, n, z):
+    if ctx.isint(n) and ctx._is_real_type(z):
+        try:
+            return ctx._expint_int(n, z)
+        except NotImplementedError:
+            pass
+    if ctx.isnan(n) or ctx.isnan(z):
+        return z*n
+    if z == ctx.inf:
+        return 1/z
+    if z == 0:
+        # integral from 1 to infinity of t^n
+        if ctx.re(n) <= 1:
+            # TODO: reasonable sign of infinity
+            return type(z)(ctx.inf)
+        else:
+            return ctx.one/(n-1)
+    if n == 0:
+        return ctx.exp(-z)/z
+    if n == -1:
+        return ctx.exp(-z)*(z+1)/z**2
+    return z**(n-1) * ctx.gammainc(1-n, z)
+
+@defun_wrapped
+def li(ctx, z, offset=False):
+    if offset:
+        if z == 2:
+            return ctx.zero
+        return ctx.ei(ctx.ln(z)) - ctx.ei(ctx.ln2)
+    if not z:
+        return z
+    if z == 1:
+        return ctx.ninf
+    return ctx.ei(ctx.ln(z))
+
+@defun
+def ei(ctx, z):
+    try:
+        return ctx._ei(z)
+    except NotImplementedError:
+        return ctx._ei_generic(z)
+
+@defun_wrapped
+def _ei_generic(ctx, z):
+    # Note: the following is currently untested because mp and fp
+    # both use special-case ei code
+    if z == ctx.inf:
+        return z
+    if z == ctx.ninf:
+        return ctx.zero
+    if ctx.mag(z) > 1:
+        try:
+            r = ctx.one/z
+            v = ctx.exp(z)*ctx.hyper([1,1],[],r,
+                maxterms=ctx.prec, force_series=True)/z
+            im = ctx._im(z)
+            if im > 0:
+                v += ctx.pi*ctx.j
+            if im < 0:
+                v -= ctx.pi*ctx.j
+            return v
+        except ctx.NoConvergence:
+            pass
+    v = z*ctx.hyp2f2(1,1,2,2,z) + ctx.euler
+    if ctx._im(z):
+        v += 0.5*(ctx.log(z) - ctx.log(ctx.one/z))
+    else:
+        v += ctx.log(abs(z))
+    return v
+
+@defun
+def e1(ctx, z):
+    try:
+        return ctx._e1(z)
+    except NotImplementedError:
+        return ctx.expint(1, z)
+
+@defun
+def ci(ctx, z):
+    try:
+        return ctx._ci(z)
+    except NotImplementedError:
+        return ctx._ci_generic(z)
+
+@defun_wrapped
+def _ci_generic(ctx, z):
+    if ctx.isinf(z):
+        if z == ctx.inf: return ctx.zero
+        if z == ctx.ninf: return ctx.pi*1j
+    jz = ctx.fmul(ctx.j,z,exact=True)
+    njz = ctx.fneg(jz,exact=True)
+    v = 0.5*(ctx.ei(jz) + ctx.ei(njz))
+    zreal = ctx._re(z)
+    zimag = ctx._im(z)
+    if zreal == 0:
+        if zimag > 0: v += ctx.pi*0.5j
+        if zimag < 0: v -= ctx.pi*0.5j
+    if zreal < 0:
+        if zimag >= 0: v += ctx.pi*1j
+        if zimag <  0: v -= ctx.pi*1j
+    if ctx._is_real_type(z) and zreal > 0:
+        v = ctx._re(v)
+    return v
+
+@defun
+def si(ctx, z):
+    try:
+        return ctx._si(z)
+    except NotImplementedError:
+        return ctx._si_generic(z)
+
+@defun_wrapped
+def _si_generic(ctx, z):
+    if ctx.isinf(z):
+        if z == ctx.inf: return 0.5*ctx.pi
+        if z == ctx.ninf: return -0.5*ctx.pi
+    # Suffers from cancellation near 0
+    if ctx.mag(z) >= -1:
+        jz = ctx.fmul(ctx.j,z,exact=True)
+        njz = ctx.fneg(jz,exact=True)
+        v = (-0.5j)*(ctx.ei(jz) - ctx.ei(njz))
+        zreal = ctx._re(z)
+        if zreal > 0:
+            v -= 0.5*ctx.pi
+        if zreal < 0:
+            v += 0.5*ctx.pi
+        if ctx._is_real_type(z):
+            v = ctx._re(v)
+        return v
+    else:
+        return z*ctx.hyp1f2((1,2),(3,2),(3,2),-0.25*z*z)
+
+@defun_wrapped
+def chi(ctx, z):
+    nz = ctx.fneg(z, exact=True)
+    v = 0.5*(ctx.ei(z) + ctx.ei(nz))
+    zreal = ctx._re(z)
+    zimag = ctx._im(z)
+    if zimag > 0:
+        v += ctx.pi*0.5j
+    elif zimag < 0:
+        v -= ctx.pi*0.5j
+    elif zreal < 0:
+        v += ctx.pi*1j
+    return v
+
+@defun_wrapped
+def shi(ctx, z):
+    # Suffers from cancellation near 0
+    if ctx.mag(z) >= -1:
+        nz = ctx.fneg(z, exact=True)
+        v = 0.5*(ctx.ei(z) - ctx.ei(nz))
+        zimag = ctx._im(z)
+        if zimag > 0: v -= 0.5j*ctx.pi
+        if zimag < 0: v += 0.5j*ctx.pi
+        return v
+    else:
+        return z * ctx.hyp1f2((1,2),(3,2),(3,2),0.25*z*z)
+
+@defun_wrapped
+def fresnels(ctx, z):
+    if z == ctx.inf:
+        return ctx.mpf(0.5)
+    if z == ctx.ninf:
+        return ctx.mpf(-0.5)
+    return ctx.pi*z**3/6*ctx.hyp1f2((3,4),(3,2),(7,4),-ctx.pi**2*z**4/16)
+
+@defun_wrapped
+def fresnelc(ctx, z):
+    if z == ctx.inf:
+        return ctx.mpf(0.5)
+    if z == ctx.ninf:
+        return ctx.mpf(-0.5)
+    return z*ctx.hyp1f2((1,4),(1,2),(5,4),-ctx.pi**2*z**4/16)

rl/Lib/site-packages/mpmath/functions/factorials.py

@@ -0,0 +1,187 @@
+from ..libmp.backend import xrange
+from .functions import defun, defun_wrapped
+
+@defun
+def gammaprod(ctx, a, b, _infsign=False):
+    a = [ctx.convert(x) for x in a]
+    b = [ctx.convert(x) for x in b]
+    poles_num = []
+    poles_den = []
+    regular_num = []
+    regular_den = []
+    for x in a: [regular_num, poles_num][ctx.isnpint(x)].append(x)
+    for x in b: [regular_den, poles_den][ctx.isnpint(x)].append(x)
+    # One more pole in numerator or denominator gives 0 or inf
+    if len(poles_num) < len(poles_den): return ctx.zero
+    if len(poles_num) > len(poles_den):
+        # Get correct sign of infinity for x+h, h -> 0 from above
+        # XXX: hack, this should be done properly
+        if _infsign:
+            a = [x and x*(1+ctx.eps) or x+ctx.eps for x in poles_num]
+            b = [x and x*(1+ctx.eps) or x+ctx.eps for x in poles_den]
+            return ctx.sign(ctx.gammaprod(a+regular_num,b+regular_den)) * ctx.inf
+        else:
+            return ctx.inf
+    # All poles cancel
+    # lim G(i)/G(j) = (-1)**(i+j) * gamma(1-j) / gamma(1-i)
+    p = ctx.one
+    orig = ctx.prec
+    try:
+        ctx.prec = orig + 15
+        while poles_num:
+            i = poles_num.pop()
+            j = poles_den.pop()
+            p *= (-1)**(i+j) * ctx.gamma(1-j) / ctx.gamma(1-i)
+        for x in regular_num: p *= ctx.gamma(x)
+        for x in regular_den: p /= ctx.gamma(x)
+    finally:
+        ctx.prec = orig
+    return +p
+
+@defun
+def beta(ctx, x, y):
+    x = ctx.convert(x)
+    y = ctx.convert(y)
+    if ctx.isinf(y):
+        x, y = y, x
+    if ctx.isinf(x):
+        if x == ctx.inf and not ctx._im(y):
+            if y == ctx.ninf:
+                return ctx.nan
+            if y > 0:
+                return ctx.zero
+            if ctx.isint(y):
+                return ctx.nan
+            if y < 0:
+                return ctx.sign(ctx.gamma(y)) * ctx.inf
+        return ctx.nan
+    xy = ctx.fadd(x, y, prec=2*ctx.prec)
+    return ctx.gammaprod([x, y], [xy])
+
+@defun
+def binomial(ctx, n, k):
+    n1 = ctx.fadd(n, 1, prec=2*ctx.prec)
+    k1 = ctx.fadd(k, 1, prec=2*ctx.prec)
+    nk1 = ctx.fsub(n1, k, prec=2*ctx.prec)
+    return ctx.gammaprod([n1], [k1, nk1])
+
+@defun
+def rf(ctx, x, n):
+    xn = ctx.fadd(x, n, prec=2*ctx.prec)
+    return ctx.gammaprod([xn], [x])
+
+@defun
+def ff(ctx, x, n):
+    x1 = ctx.fadd(x, 1, prec=2*ctx.prec)
+    xn1 = ctx.fadd(ctx.fsub(x, n, prec=2*ctx.prec), 1, prec=2*ctx.prec)
+    return ctx.gammaprod([x1], [xn1])
+
+@defun_wrapped
+def fac2(ctx, x):
+    if ctx.isinf(x):
+        if x == ctx.inf:
+            return x
+        return ctx.nan
+    return 2**(x/2)*(ctx.pi/2)**((ctx.cospi(x)-1)/4)*ctx.gamma(x/2+1)
+
+@defun_wrapped
+def barnesg(ctx, z):
+    if ctx.isinf(z):
+        if z == ctx.inf:
+            return z
+        return ctx.nan
+    if ctx.isnan(z):
+        return z
+    if (not ctx._im(z)) and ctx._re(z) <= 0 and ctx.isint(ctx._re(z)):
+        return z*0
+    # Account for size (would not be needed if computing log(G))
+    if abs(z) > 5:
+        ctx.dps += 2*ctx.log(abs(z),2)
+    # Reflection formula
+    if ctx.re(z) < -ctx.dps:
+        w = 1-z
+        pi2 = 2*ctx.pi
+        u = ctx.expjpi(2*w)
+        v = ctx.j*ctx.pi/12 - ctx.j*ctx.pi*w**2/2 + w*ctx.ln(1-u) - \
+            ctx.j*ctx.polylog(2, u)/pi2
+        v = ctx.barnesg(2-z)*ctx.exp(v)/pi2**w
+        if ctx._is_real_type(z):
+            v = ctx._re(v)
+        return v
+    # Estimate terms for asymptotic expansion
+    # TODO: fixme, obviously
+    N = ctx.dps // 2 + 5
+    G = 1
+    while abs(z) < N or ctx.re(z) < 1:
+        G /= ctx.gamma(z)
+        z += 1
+    z -= 1
+    s = ctx.mpf(1)/12
+    s -= ctx.log(ctx.glaisher)
+    s += z*ctx.log(2*ctx.pi)/2
+    s += (z**2/2-ctx.mpf(1)/12)*ctx.log(z)
+    s -= 3*z**2/4
+    z2k = z2 = z**2
+    for k in xrange(1, N+1):
+        t = ctx.bernoulli(2*k+2) / (4*k*(k+1)*z2k)
+        if abs(t) < ctx.eps:
+            #print k, N      # check how many terms were needed
+            break
+        z2k *= z2
+        s += t
+    #if k == N:
+    #    print "warning: series for barnesg failed to converge", ctx.dps
+    return G*ctx.exp(s)
+
+@defun
+def superfac(ctx, z):
+    return ctx.barnesg(z+2)
+
+@defun_wrapped
+def hyperfac(ctx, z):
+    # XXX: estimate needed extra bits accurately
+    if z == ctx.inf:
+        return z
+    if abs(z) > 5:
+        extra = 4*int(ctx.log(abs(z),2))
+    else:
+        extra = 0
+    ctx.prec += extra
+    if not ctx._im(z) and ctx._re(z) < 0 and ctx.isint(ctx._re(z)):
+        n = int(ctx.re(z))
+        h = ctx.hyperfac(-n-1)
+        if ((n+1)//2) & 1:
+            h = -h
+        if ctx._is_complex_type(z):
+            return h + 0j
+        return h
+    zp1 = z+1
+    # Wrong branch cut
+    #v = ctx.gamma(zp1)**z
+    #ctx.prec -= extra
+    #return v / ctx.barnesg(zp1)
+    v = ctx.exp(z*ctx.loggamma(zp1))
+    ctx.prec -= extra
+    return v / ctx.barnesg(zp1)
+
+'''
+@defun
+def psi0(ctx, z):
+    """Shortcut for psi(0,z) (the digamma function)"""
+    return ctx.psi(0, z)
+
+@defun
+def psi1(ctx, z):
+    """Shortcut for psi(1,z) (the trigamma function)"""
+    return ctx.psi(1, z)
+
+@defun
+def psi2(ctx, z):
+    """Shortcut for psi(2,z) (the tetragamma function)"""
+    return ctx.psi(2, z)
+
+@defun
+def psi3(ctx, z):
+    """Shortcut for psi(3,z) (the pentagamma function)"""
+    return ctx.psi(3, z)
+'''

rl/Lib/site-packages/mpmath/functions/functions.py

@@ -0,0 +1,645 @@
+from ..libmp.backend import xrange
+
+class SpecialFunctions(object):
+    """
+    This class implements special functions using high-level code.
+
+    Elementary and some other functions (e.g. gamma function, basecase
+    hypergeometric series) are assumed to be predefined by the context as
+    "builtins" or "low-level" functions.
+    """
+    defined_functions = {}
+
+    # The series for the Jacobi theta functions converge for |q| < 1;
+    # in the current implementation they throw a ValueError for
+    # abs(q) > THETA_Q_LIM
+    THETA_Q_LIM = 1 - 10**-7
+
+    def __init__(self):
+        cls = self.__class__
+        for name in cls.defined_functions:
+            f, wrap = cls.defined_functions[name]
+            cls._wrap_specfun(name, f, wrap)
+
+        self.mpq_1 = self._mpq((1,1))
+        self.mpq_0 = self._mpq((0,1))
+        self.mpq_1_2 = self._mpq((1,2))
+        self.mpq_3_2 = self._mpq((3,2))
+        self.mpq_1_4 = self._mpq((1,4))
+        self.mpq_1_16 = self._mpq((1,16))
+        self.mpq_3_16 = self._mpq((3,16))
+        self.mpq_5_2 = self._mpq((5,2))
+        self.mpq_3_4 = self._mpq((3,4))
+        self.mpq_7_4 = self._mpq((7,4))
+        self.mpq_5_4 = self._mpq((5,4))
+        self.mpq_1_3 = self._mpq((1,3))
+        self.mpq_2_3 = self._mpq((2,3))
+        self.mpq_4_3 = self._mpq((4,3))
+        self.mpq_1_6 = self._mpq((1,6))
+        self.mpq_5_6 = self._mpq((5,6))
+        self.mpq_5_3 = self._mpq((5,3))
+
+        self._misc_const_cache = {}
+
+        self._aliases.update({
+            'phase' : 'arg',
+            'conjugate' : 'conj',
+            'nthroot' : 'root',
+            'polygamma' : 'psi',
+            'hurwitz' : 'zeta',
+            #'digamma' : 'psi0',
+            #'trigamma' : 'psi1',
+            #'tetragamma' : 'psi2',
+            #'pentagamma' : 'psi3',
+            'fibonacci' : 'fib',
+            'factorial' : 'fac',
+        })
+
+        self.zetazero_memoized = self.memoize(self.zetazero)
+
+    # Default -- do nothing
+    @classmethod
+    def _wrap_specfun(cls, name, f, wrap):
+        setattr(cls, name, f)
+
+    # Optional fast versions of common functions in common cases.
+    # If not overridden, default (generic hypergeometric series)
+    # implementations will be used
+    def _besselj(ctx, n, z): raise NotImplementedError
+    def _erf(ctx, z): raise NotImplementedError
+    def _erfc(ctx, z): raise NotImplementedError
+    def _gamma_upper_int(ctx, z, a): raise NotImplementedError
+    def _expint_int(ctx, n, z): raise NotImplementedError
+    def _zeta(ctx, s): raise NotImplementedError
+    def _zetasum_fast(ctx, s, a, n, derivatives, reflect): raise NotImplementedError
+    def _ei(ctx, z): raise NotImplementedError
+    def _e1(ctx, z): raise NotImplementedError
+    def _ci(ctx, z): raise NotImplementedError
+    def _si(ctx, z): raise NotImplementedError
+    def _altzeta(ctx, s): raise NotImplementedError
+
+def defun_wrapped(f):
+    SpecialFunctions.defined_functions[f.__name__] = f, True
+    return f
+
+def defun(f):
+    SpecialFunctions.defined_functions[f.__name__] = f, False
+    return f
+
+def defun_static(f):
+    setattr(SpecialFunctions, f.__name__, f)
+    return f
+
+@defun_wrapped
+def cot(ctx, z): return ctx.one / ctx.tan(z)
+
+@defun_wrapped
+def sec(ctx, z): return ctx.one / ctx.cos(z)
+
+@defun_wrapped
+def csc(ctx, z): return ctx.one / ctx.sin(z)
+
+@defun_wrapped
+def coth(ctx, z): return ctx.one / ctx.tanh(z)
+
+@defun_wrapped
+def sech(ctx, z): return ctx.one / ctx.cosh(z)
+
+@defun_wrapped
+def csch(ctx, z): return ctx.one / ctx.sinh(z)
+
+@defun_wrapped
+def acot(ctx, z):
+    if not z:
+        return ctx.pi * 0.5
+    else:
+        return ctx.atan(ctx.one / z)
+
+@defun_wrapped
+def asec(ctx, z): return ctx.acos(ctx.one / z)
+
+@defun_wrapped
+def acsc(ctx, z): return ctx.asin(ctx.one / z)
+
+@defun_wrapped
+def acoth(ctx, z):
+    if not z:
+        return ctx.pi * 0.5j
+    else:
+        return ctx.atanh(ctx.one / z)
+
+
+@defun_wrapped
+def asech(ctx, z): return ctx.acosh(ctx.one / z)
+
+@defun_wrapped
+def acsch(ctx, z): return ctx.asinh(ctx.one / z)
+
+@defun
+def sign(ctx, x):
+    x = ctx.convert(x)
+    if not x or ctx.isnan(x):
+        return x
+    if ctx._is_real_type(x):
+        if x > 0:
+            return ctx.one
+        else:
+            return -ctx.one
+    return x / abs(x)
+
+@defun
+def agm(ctx, a, b=1):
+    if b == 1:
+        return ctx.agm1(a)
+    a = ctx.convert(a)
+    b = ctx.convert(b)
+    return ctx._agm(a, b)
+
+@defun_wrapped
+def sinc(ctx, x):
+    if ctx.isinf(x):
+        return 1/x
+    if not x:
+        return x+1
+    return ctx.sin(x)/x
+
+@defun_wrapped
+def sincpi(ctx, x):
+    if ctx.isinf(x):
+        return 1/x
+    if not x:
+        return x+1
+    return ctx.sinpi(x)/(ctx.pi*x)
+
+# TODO: tests; improve implementation
+@defun_wrapped
+def expm1(ctx, x):
+    if not x:
+        return ctx.zero
+    # exp(x) - 1 ~ x
+    if ctx.mag(x) < -ctx.prec:
+        return x + 0.5*x**2
+    # TODO: accurately eval the smaller of the real/imag parts
+    return ctx.sum_accurately(lambda: iter([ctx.exp(x),-1]),1)
+
+@defun_wrapped
+def log1p(ctx, x):
+    if not x:
+        return ctx.zero
+    if ctx.mag(x) < -ctx.prec:
+        return x - 0.5*x**2
+    return ctx.log(ctx.fadd(1, x, prec=2*ctx.prec))
+
+@defun_wrapped
+def powm1(ctx, x, y):
+    mag = ctx.mag
+    one = ctx.one
+    w = x**y - one
+    M = mag(w)
+    # Only moderate cancellation
+    if M > -8:
+        return w
+    # Check for the only possible exact cases
+    if not w:
+        if (not y) or (x in (1, -1, 1j, -1j) and ctx.isint(y)):
+            return w
+    x1 = x - one
+    magy = mag(y)
+    lnx = ctx.ln(x)
+    # Small y: x^y - 1 ~ log(x)*y + O(log(x)^2 * y^2)
+    if magy + mag(lnx) < -ctx.prec:
+        return lnx*y + (lnx*y)**2/2
+    # TODO: accurately eval the smaller of the real/imag part
+    return ctx.sum_accurately(lambda: iter([x**y, -1]), 1)
+
+@defun
+def _rootof1(ctx, k, n):
+    k = int(k)
+    n = int(n)
+    k %= n
+    if not k:
+        return ctx.one
+    elif 2*k == n:
+        return -ctx.one
+    elif 4*k == n:
+        return ctx.j
+    elif 4*k == 3*n:
+        return -ctx.j
+    return ctx.expjpi(2*ctx.mpf(k)/n)
+
+@defun
+def root(ctx, x, n, k=0):
+    n = int(n)
+    x = ctx.convert(x)
+    if k:
+        # Special case: there is an exact real root
+        if (n & 1 and 2*k == n-1) and (not ctx.im(x)) and (ctx.re(x) < 0):
+            return -ctx.root(-x, n)
+        # Multiply by root of unity
+        prec = ctx.prec
+        try:
+            ctx.prec += 10
+            v = ctx.root(x, n, 0) * ctx._rootof1(k, n)
+        finally:
+            ctx.prec = prec
+        return +v
+    return ctx._nthroot(x, n)
+
+@defun
+def unitroots(ctx, n, primitive=False):
+    gcd = ctx._gcd
+    prec = ctx.prec
+    try:
+        ctx.prec += 10
+        if primitive:
+            v = [ctx._rootof1(k,n) for k in range(n) if gcd(k,n) == 1]
+        else:
+            # TODO: this can be done *much* faster
+            v = [ctx._rootof1(k,n) for k in range(n)]
+    finally:
+        ctx.prec = prec
+    return [+x for x in v]
+
+@defun
+def arg(ctx, x):
+    x = ctx.convert(x)
+    re = ctx._re(x)
+    im = ctx._im(x)
+    return ctx.atan2(im, re)
+
+@defun
+def fabs(ctx, x):
+    return abs(ctx.convert(x))
+
+@defun
+def re(ctx, x):
+    x = ctx.convert(x)
+    if hasattr(x, "real"):    # py2.5 doesn't have .real/.imag for all numbers
+        return x.real
+    return x
+
+@defun
+def im(ctx, x):
+    x = ctx.convert(x)
+    if hasattr(x, "imag"):    # py2.5 doesn't have .real/.imag for all numbers
+        return x.imag
+    return ctx.zero
+
+@defun
+def conj(ctx, x):
+    x = ctx.convert(x)
+    try:
+        return x.conjugate()
+    except AttributeError:
+        return x
+
+@defun
+def polar(ctx, z):
+    return (ctx.fabs(z), ctx.arg(z))
+
+@defun_wrapped
+def rect(ctx, r, phi):
+    return r * ctx.mpc(*ctx.cos_sin(phi))
+
+@defun
+def log(ctx, x, b=None):
+    if b is None:
+        return ctx.ln(x)
+    wp = ctx.prec + 20
+    return ctx.ln(x, prec=wp) / ctx.ln(b, prec=wp)
+
+@defun
+def log10(ctx, x):
+    return ctx.log(x, 10)
+
+@defun
+def fmod(ctx, x, y):
+    return ctx.convert(x) % ctx.convert(y)
+
+@defun
+def degrees(ctx, x):
+    return x / ctx.degree
+
+@defun
+def radians(ctx, x):
+    return x * ctx.degree
+
+def _lambertw_special(ctx, z, k):
+    # W(0,0) = 0; all other branches are singular
+    if not z:
+        if not k:
+            return z
+        return ctx.ninf + z
+    if z == ctx.inf:
+        if k == 0:
+            return z
+        else:
+            return z + 2*k*ctx.pi*ctx.j
+    if z == ctx.ninf:
+        return (-z) + (2*k+1)*ctx.pi*ctx.j
+    # Some kind of nan or complex inf/nan?
+    return ctx.ln(z)
+
+import math
+import cmath
+
+def _lambertw_approx_hybrid(z, k):
+    imag_sign = 0
+    if hasattr(z, "imag"):
+        x = float(z.real)
+        y = z.imag
+        if y:
+            imag_sign = (-1) ** (y < 0)
+        y = float(y)
+    else:
+        x = float(z)
+        y = 0.0
+        imag_sign = 0
+    # hack to work regardless of whether Python supports -0.0
+    if not y:
+        y = 0.0
+    z = complex(x,y)
+    if k == 0:
+        if -4.0 < y < 4.0 and -1.0 < x < 2.5:
+            if imag_sign:
+                # Taylor series in upper/lower half-plane
+                if y > 1.00: return (0.876+0.645j) + (0.118-0.174j)*(z-(0.75+2.5j))
+                if y > 0.25: return (0.505+0.204j) + (0.375-0.132j)*(z-(0.75+0.5j))
+                if y < -1.00: return (0.876-0.645j) + (0.118+0.174j)*(z-(0.75-2.5j))
+                if y < -0.25: return (0.505-0.204j) + (0.375+0.132j)*(z-(0.75-0.5j))
+            # Taylor series near -1
+            if x < -0.5:
+                if imag_sign >= 0:
+                    return (-0.318+1.34j) + (-0.697-0.593j)*(z+1)
+                else:
+                    return (-0.318-1.34j) + (-0.697+0.593j)*(z+1)
+            # return real type
+            r = -0.367879441171442
+            if (not imag_sign) and x > r:
+                z = x
+            # Singularity near -1/e
+            if x < -0.2:
+                return -1 + 2.33164398159712*(z-r)**0.5 - 1.81218788563936*(z-r)
+            # Taylor series near 0
+            if x < 0.5: return z
+            # Simple linear approximation
+            return 0.2 + 0.3*z
+        if (not imag_sign) and x > 0.0:
+            L1 = math.log(x); L2 = math.log(L1)
+        else:
+            L1 = cmath.log(z); L2 = cmath.log(L1)
+    elif k == -1:
+        # return real type
+        r = -0.367879441171442
+        if (not imag_sign) and r < x < 0.0:
+            z = x
+        if (imag_sign >= 0) and y < 0.1 and -0.6 < x < -0.2:
+            return -1 - 2.33164398159712*(z-r)**0.5 - 1.81218788563936*(z-r)
+        if (not imag_sign) and -0.2 <= x < 0.0:
+            L1 = math.log(-x)
+            return L1 - math.log(-L1)
+        else:
+            if imag_sign == -1 and (not y) and x < 0.0:
+                L1 = cmath.log(z) - 3.1415926535897932j
+            else:
+                L1 = cmath.log(z) - 6.2831853071795865j
+            L2 = cmath.log(L1)
+    return L1 - L2 + L2/L1 + L2*(L2-2)/(2*L1**2)
+
+def _lambertw_series(ctx, z, k, tol):
+    """
+    Return rough approximation for W_k(z) from an asymptotic series,
+    sufficiently accurate for the Halley iteration to converge to
+    the correct value.
+    """
+    magz = ctx.mag(z)
+    if (-10 < magz < 900) and (-1000 < k < 1000):
+        # Near the branch point at -1/e
+        if magz < 1 and abs(z+0.36787944117144) < 0.05:
+            if k == 0 or (k == -1 and ctx._im(z) >= 0) or \
+                         (k == 1  and ctx._im(z) < 0):
+                delta = ctx.sum_accurately(lambda: [z, ctx.exp(-1)])
+                cancellation = -ctx.mag(delta)
+                ctx.prec += cancellation
+                # Use series given in Corless et al.
+                p = ctx.sqrt(2*(ctx.e*z+1))
+                ctx.prec -= cancellation
+                u = {0:ctx.mpf(-1), 1:ctx.mpf(1)}
+                a = {0:ctx.mpf(2), 1:ctx.mpf(-1)}
+                if k != 0:
+                    p = -p
+                s = ctx.zero
+                # The series converges, so we could use it directly, but unless
+                # *extremely* close, it is better to just use the first few
+                # terms to get a good approximation for the iteration
+                for l in xrange(max(2,cancellation)):
+                    if l not in u:
+                        a[l] = ctx.fsum(u[j]*u[l+1-j] for j in xrange(2,l))
+                        u[l] = (l-1)*(u[l-2]/2+a[l-2]/4)/(l+1)-a[l]/2-u[l-1]/(l+1)
+                    term = u[l] * p**l
+                    s += term
+                    if ctx.mag(term) < -tol:
+                        return s, True
+                    l += 1
+                ctx.prec += cancellation//2
+                return s, False
+        if k == 0 or k == -1:
+            return _lambertw_approx_hybrid(z, k), False
+    if k == 0:
+        if magz < -1:
+            return z*(1-z), False
+        L1 = ctx.ln(z)
+        L2 = ctx.ln(L1)
+    elif k == -1 and (not ctx._im(z)) and (-0.36787944117144 < ctx._re(z) < 0):
+        L1 = ctx.ln(-z)
+        return L1 - ctx.ln(-L1), False
+    else:
+        # This holds both as z -> 0 and z -> inf.
+        # Relative error is O(1/log(z)).
+        L1 = ctx.ln(z) + 2j*ctx.pi*k
+        L2 = ctx.ln(L1)
+    return L1 - L2 + L2/L1 + L2*(L2-2)/(2*L1**2), False
+
+@defun
+def lambertw(ctx, z, k=0):
+    z = ctx.convert(z)
+    k = int(k)
+    if not ctx.isnormal(z):
+        return _lambertw_special(ctx, z, k)
+    prec = ctx.prec
+    ctx.prec += 20 + ctx.mag(k or 1)
+    wp = ctx.prec
+    tol = wp - 5
+    w, done = _lambertw_series(ctx, z, k, tol)
+    if not done:
+        # Use Halley iteration to solve w*exp(w) = z
+        two = ctx.mpf(2)
+        for i in xrange(100):
+            ew = ctx.exp(w)
+            wew = w*ew
+            wewz = wew-z
+            wn = w - wewz/(wew+ew-(w+two)*wewz/(two*w+two))
+            if ctx.mag(wn-w) <= ctx.mag(wn) - tol:
+                w = wn
+                break
+            else:
+                w = wn
+        if i == 100:
+            ctx.warn("Lambert W iteration failed to converge for z = %s" % z)
+    ctx.prec = prec
+    return +w
+
+@defun_wrapped
+def bell(ctx, n, x=1):
+    x = ctx.convert(x)
+    if not n:
+        if ctx.isnan(x):
+            return x
+        return type(x)(1)
+    if ctx.isinf(x) or ctx.isinf(n) or ctx.isnan(x) or ctx.isnan(n):
+        return x**n
+    if n == 1: return x
+    if n == 2: return x*(x+1)
+    if x == 0: return ctx.sincpi(n)
+    return _polyexp(ctx, n, x, True) / ctx.exp(x)
+
+def _polyexp(ctx, n, x, extra=False):
+    def _terms():
+        if extra:
+            yield ctx.sincpi(n)
+        t = x
+        k = 1
+        while 1:
+            yield k**n * t
+            k += 1
+            t = t*x/k
+    return ctx.sum_accurately(_terms, check_step=4)
+
+@defun_wrapped
+def polyexp(ctx, s, z):
+    if ctx.isinf(z) or ctx.isinf(s) or ctx.isnan(z) or ctx.isnan(s):
+        return z**s
+    if z == 0: return z*s
+    if s == 0: return ctx.expm1(z)
+    if s == 1: return ctx.exp(z)*z
+    if s == 2: return ctx.exp(z)*z*(z+1)
+    return _polyexp(ctx, s, z)
+
+@defun_wrapped
+def cyclotomic(ctx, n, z):
+    n = int(n)
+    if n < 0:
+        raise ValueError("n cannot be negative")
+    p = ctx.one
+    if n == 0:
+        return p
+    if n == 1:
+        return z - p
+    if n == 2:
+        return z + p
+    # Use divisor product representation. Unfortunately, this sometimes
+    # includes singularities for roots of unity, which we have to cancel out.
+    # Matching zeros/poles pairwise, we have (1-z^a)/(1-z^b) ~ a/b + O(z-1).
+    a_prod = 1
+    b_prod = 1
+    num_zeros = 0
+    num_poles = 0
+    for d in range(1,n+1):
+        if not n % d:
+            w = ctx.moebius(n//d)
+            # Use powm1 because it is important that we get 0 only
+            # if it really is exactly 0
+            b = -ctx.powm1(z, d)
+            if b:
+                p *= b**w
+            else:
+                if w == 1:
+                    a_prod *= d
+                    num_zeros += 1
+                elif w == -1:
+                    b_prod *= d
+                    num_poles += 1
+    #print n, num_zeros, num_poles
+    if num_zeros:
+        if num_zeros > num_poles:
+            p *= 0
+        else:
+            p *= a_prod
+            p /= b_prod
+    return p
+
+@defun
+def mangoldt(ctx, n):
+    r"""
+    Evaluates the von Mangoldt function `\Lambda(n) = \log p`
+    if `n = p^k` a power of a prime, and `\Lambda(n) = 0` otherwise.
+
+    **Examples**
+
+        >>> from mpmath import *
+        >>> mp.dps = 25; mp.pretty = True
+        >>> [mangoldt(n) for n in range(-2,3)]
+        [0.0, 0.0, 0.0, 0.0, 0.6931471805599453094172321]
+        >>> mangoldt(6)
+        0.0
+        >>> mangoldt(7)
+        1.945910149055313305105353
+        >>> mangoldt(8)
+        0.6931471805599453094172321
+        >>> fsum(mangoldt(n) for n in range(101))
+        94.04531122935739224600493
+        >>> fsum(mangoldt(n) for n in range(10001))
+        10013.39669326311478372032
+
+    """
+    n = int(n)
+    if n < 2:
+        return ctx.zero
+    if n % 2 == 0:
+        # Must be a power of two
+        if n & (n-1) == 0:
+            return +ctx.ln2
+        else:
+            return ctx.zero
+    # TODO: the following could be generalized into a perfect
+    # power testing function
+    # ---
+    # Look for a small factor
+    for p in (3,5,7,11,13,17,19,23,29,31):
+        if not n % p:
+            q, r = n // p, 0
+            while q > 1:
+                q, r = divmod(q, p)
+                if r:
+                    return ctx.zero
+            return ctx.ln(p)
+    if ctx.isprime(n):
+        return ctx.ln(n)
+    # Obviously, we could use arbitrary-precision arithmetic for this...
+    if n > 10**30:
+        raise NotImplementedError
+    k = 2
+    while 1:
+        p = int(n**(1./k) + 0.5)
+        if p < 2:
+            return ctx.zero
+        if p ** k == n:
+            if ctx.isprime(p):
+                return ctx.ln(p)
+        k += 1
+
+@defun
+def stirling1(ctx, n, k, exact=False):
+    v = ctx._stirling1(int(n), int(k))
+    if exact:
+        return int(v)
+    else:
+        return ctx.mpf(v)
+
+@defun
+def stirling2(ctx, n, k, exact=False):
+    v = ctx._stirling2(int(n), int(k))
+    if exact:
+        return int(v)
+    else:
+        return ctx.mpf(v)

rl/Lib/site-packages/mpmath/functions/orthogonal.py

@@ -0,0 +1,493 @@
+from .functions import defun, defun_wrapped
+
+def _hermite_param(ctx, n, z, parabolic_cylinder):
+    """
+    Combined calculation of the Hermite polynomial H_n(z) (and its
+    generalization to complex n) and the parabolic cylinder
+    function D.
+    """
+    n, ntyp = ctx._convert_param(n)
+    z = ctx.convert(z)
+    q = -ctx.mpq_1_2
+    # For re(z) > 0, 2F0 -- http://functions.wolfram.com/
+    #     HypergeometricFunctions/HermiteHGeneral/06/02/0009/
+    # Otherwise, there is a reflection formula
+    # 2F0 + http://functions.wolfram.com/HypergeometricFunctions/
+    #           HermiteHGeneral/16/01/01/0006/
+    #
+    # TODO:
+    # An alternative would be to use
+    # http://functions.wolfram.com/HypergeometricFunctions/
+    #     HermiteHGeneral/06/02/0006/
+    #
+    # Also, the 1F1 expansion
+    # http://functions.wolfram.com/HypergeometricFunctions/
+    #     HermiteHGeneral/26/01/02/0001/
+    # should probably be used for tiny z
+    if not z:
+        T1 = [2, ctx.pi], [n, 0.5], [], [q*(n-1)], [], [], 0
+        if parabolic_cylinder:
+            T1[1][0] += q*n
+        return T1,
+    can_use_2f0 = ctx.isnpint(-n) or ctx.re(z) > 0 or \
+        (ctx.re(z) == 0 and ctx.im(z) > 0)
+    expprec = ctx.prec*4 + 20
+    if parabolic_cylinder:
+        u = ctx.fmul(ctx.fmul(z,z,prec=expprec), -0.25, exact=True)
+        w = ctx.fmul(z, ctx.sqrt(0.5,prec=expprec), prec=expprec)
+    else:
+        w = z
+    w2 = ctx.fmul(w, w, prec=expprec)
+    rw2 = ctx.fdiv(1, w2, prec=expprec)
+    nrw2 = ctx.fneg(rw2, exact=True)
+    nw = ctx.fneg(w, exact=True)
+    if can_use_2f0:
+        T1 = [2, w], [n, n], [], [], [q*n, q*(n-1)], [], nrw2
+        terms = [T1]
+    else:
+        T1 = [2, nw], [n, n], [], [], [q*n, q*(n-1)], [], nrw2
+        T2 = [2, ctx.pi, nw], [n+2, 0.5, 1], [], [q*n], [q*(n-1)], [1-q], w2
+        terms = [T1,T2]
+    # Multiply by prefactor for D_n
+    if parabolic_cylinder:
+        expu = ctx.exp(u)
+        for i in range(len(terms)):
+            terms[i][1][0] += q*n
+            terms[i][0].append(expu)
+            terms[i][1].append(1)
+    return tuple(terms)
+
+@defun
+def hermite(ctx, n, z, **kwargs):
+    return ctx.hypercomb(lambda: _hermite_param(ctx, n, z, 0), [], **kwargs)
+
+@defun
+def pcfd(ctx, n, z, **kwargs):
+    r"""
+    Gives the parabolic cylinder function in Whittaker's notation
+    `D_n(z) = U(-n-1/2, z)` (see :func:`~mpmath.pcfu`).
+    It solves the differential equation
+
+    .. math ::
+
+        y'' + \left(n + \frac{1}{2} - \frac{1}{4} z^2\right) y = 0.
+
+    and can be represented in terms of Hermite polynomials
+    (see :func:`~mpmath.hermite`) as
+
+    .. math ::
+
+        D_n(z) = 2^{-n/2} e^{-z^2/4} H_n\left(\frac{z}{\sqrt{2}}\right).
+
+    **Plots**
+
+    .. literalinclude :: /plots/pcfd.py
+    .. image :: /plots/pcfd.png
+
+    **Examples**
+
+        >>> from mpmath import *
+        >>> mp.dps = 25; mp.pretty = True
+        >>> pcfd(0,0); pcfd(1,0); pcfd(2,0); pcfd(3,0)
+        1.0
+        0.0
+        -1.0
+        0.0
+        >>> pcfd(4,0); pcfd(-3,0)
+        3.0
+        0.6266570686577501256039413
+        >>> pcfd('1/2', 2+3j)
+        (-5.363331161232920734849056 - 3.858877821790010714163487j)
+        >>> pcfd(2, -10)
+        1.374906442631438038871515e-9
+
+    Verifying the differential equation::
+
+        >>> n = mpf(2.5)
+        >>> y = lambda z: pcfd(n,z)
+        >>> z = 1.75
+        >>> chop(diff(y,z,2) + (n+0.5-0.25*z**2)*y(z))
+        0.0
+
+    Rational Taylor series expansion when `n` is an integer::
+
+        >>> taylor(lambda z: pcfd(5,z), 0, 7)
+        [0.0, 15.0, 0.0, -13.75, 0.0, 3.96875, 0.0, -0.6015625]
+
+    """
+    return ctx.hypercomb(lambda: _hermite_param(ctx, n, z, 1), [], **kwargs)
+
+@defun
+def pcfu(ctx, a, z, **kwargs):
+    r"""
+    Gives the parabolic cylinder function `U(a,z)`, which may be
+    defined for `\Re(z) > 0` in terms of the confluent
+    U-function (see :func:`~mpmath.hyperu`) by
+
+    .. math ::
+
+        U(a,z) = 2^{-\frac{1}{4}-\frac{a}{2}} e^{-\frac{1}{4} z^2}
+            U\left(\frac{a}{2}+\frac{1}{4},
+            \frac{1}{2}, \frac{1}{2}z^2\right)
+
+    or, for arbitrary `z`,
+
+    .. math ::
+
+        e^{-\frac{1}{4}z^2} U(a,z) =
+            U(a,0) \,_1F_1\left(-\tfrac{a}{2}+\tfrac{1}{4};
+            \tfrac{1}{2}; -\tfrac{1}{2}z^2\right) +
+            U'(a,0) z \,_1F_1\left(-\tfrac{a}{2}+\tfrac{3}{4};
+            \tfrac{3}{2}; -\tfrac{1}{2}z^2\right).
+
+    **Examples**
+
+    Connection to other functions::
+
+        >>> from mpmath import *
+        >>> mp.dps = 25; mp.pretty = True
+        >>> z = mpf(3)
+        >>> pcfu(0.5,z)
+        0.03210358129311151450551963
+        >>> sqrt(pi/2)*exp(z**2/4)*erfc(z/sqrt(2))
+        0.03210358129311151450551963
+        >>> pcfu(0.5,-z)
+        23.75012332835297233711255
+        >>> sqrt(pi/2)*exp(z**2/4)*erfc(-z/sqrt(2))
+        23.75012332835297233711255
+        >>> pcfu(0.5,-z)
+        23.75012332835297233711255
+        >>> sqrt(pi/2)*exp(z**2/4)*erfc(-z/sqrt(2))
+        23.75012332835297233711255
+
+    """
+    n, _ = ctx._convert_param(a)
+    return ctx.pcfd(-n-ctx.mpq_1_2, z)
+
+@defun
+def pcfv(ctx, a, z, **kwargs):
+    r"""
+    Gives the parabolic cylinder function `V(a,z)`, which can be
+    represented in terms of :func:`~mpmath.pcfu` as
+
+    .. math ::
+
+        V(a,z) = \frac{\Gamma(a+\tfrac{1}{2}) (U(a,-z)-\sin(\pi a) U(a,z)}{\pi}.
+
+    **Examples**
+
+    Wronskian relation between `U` and `V`::
+
+        >>> from mpmath import *
+        >>> mp.dps = 25; mp.pretty = True
+        >>> a, z = 2, 3
+        >>> pcfu(a,z)*diff(pcfv,(a,z),(0,1))-diff(pcfu,(a,z),(0,1))*pcfv(a,z)
+        0.7978845608028653558798921
+        >>> sqrt(2/pi)
+        0.7978845608028653558798921
+        >>> a, z = 2.5, 3
+        >>> pcfu(a,z)*diff(pcfv,(a,z),(0,1))-diff(pcfu,(a,z),(0,1))*pcfv(a,z)
+        0.7978845608028653558798921
+        >>> a, z = 0.25, -1
+        >>> pcfu(a,z)*diff(pcfv,(a,z),(0,1))-diff(pcfu,(a,z),(0,1))*pcfv(a,z)
+        0.7978845608028653558798921
+        >>> a, z = 2+1j, 2+3j
+        >>> chop(pcfu(a,z)*diff(pcfv,(a,z),(0,1))-diff(pcfu,(a,z),(0,1))*pcfv(a,z))
+        0.7978845608028653558798921
+
+    """
+    n, ntype = ctx._convert_param(a)
+    z = ctx.convert(z)
+    q = ctx.mpq_1_2
+    r = ctx.mpq_1_4
+    if ntype == 'Q' and ctx.isint(n*2):
+        # Faster for half-integers
+        def h():
+            jz = ctx.fmul(z, -1j, exact=True)
+            T1terms = _hermite_param(ctx, -n-q, z, 1)
+            T2terms = _hermite_param(ctx, n-q, jz, 1)
+            for T in T1terms:
+                T[0].append(1j)
+                T[1].append(1)
+                T[3].append(q-n)
+            u = ctx.expjpi((q*n-r)) * ctx.sqrt(2/ctx.pi)
+            for T in T2terms:
+                T[0].append(u)
+                T[1].append(1)
+            return T1terms + T2terms
+        v = ctx.hypercomb(h, [], **kwargs)
+        if ctx._is_real_type(n) and ctx._is_real_type(z):
+            v = ctx._re(v)
+        return v
+    else:
+        def h(n):
+            w = ctx.square_exp_arg(z, -0.25)
+            u = ctx.square_exp_arg(z, 0.5)
+            e = ctx.exp(w)
+            l = [ctx.pi, q, ctx.exp(w)]
+            Y1 = l, [-q, n*q+r, 1], [r-q*n], [], [q*n+r], [q], u
+            Y2 = l + [z], [-q, n*q-r, 1, 1], [1-r-q*n], [], [q*n+1-r], [1+q], u
+            c, s = ctx.cospi_sinpi(r+q*n)
+            Y1[0].append(s)
+            Y2[0].append(c)
+            for Y in (Y1, Y2):
+                Y[1].append(1)
+                Y[3].append(q-n)
+            return Y1, Y2
+        return ctx.hypercomb(h, [n], **kwargs)
+
+
+@defun
+def pcfw(ctx, a, z, **kwargs):
+    r"""
+    Gives the parabolic cylinder function `W(a,z)` defined in (DLMF 12.14).
+
+    **Examples**
+
+    Value at the origin::
+
+        >>> from mpmath import *
+        >>> mp.dps = 25; mp.pretty = True
+        >>> a = mpf(0.25)
+        >>> pcfw(a,0)
+        0.9722833245718180765617104
+        >>> power(2,-0.75)*sqrt(abs(gamma(0.25+0.5j*a)/gamma(0.75+0.5j*a)))
+        0.9722833245718180765617104
+        >>> diff(pcfw,(a,0),(0,1))
+        -0.5142533944210078966003624
+        >>> -power(2,-0.25)*sqrt(abs(gamma(0.75+0.5j*a)/gamma(0.25+0.5j*a)))
+        -0.5142533944210078966003624
+
+    """
+    n, _ = ctx._convert_param(a)
+    z = ctx.convert(z)
+    def terms():
+        phi2 = ctx.arg(ctx.gamma(0.5 + ctx.j*n))
+        phi2 = (ctx.loggamma(0.5+ctx.j*n) - ctx.loggamma(0.5-ctx.j*n))/2j
+        rho = ctx.pi/8 + 0.5*phi2
+        # XXX: cancellation computing k
+        k = ctx.sqrt(1 + ctx.exp(2*ctx.pi*n)) - ctx.exp(ctx.pi*n)
+        C = ctx.sqrt(k/2) * ctx.exp(0.25*ctx.pi*n)
+        yield C * ctx.expj(rho) * ctx.pcfu(ctx.j*n, z*ctx.expjpi(-0.25))
+        yield C * ctx.expj(-rho) * ctx.pcfu(-ctx.j*n, z*ctx.expjpi(0.25))
+    v = ctx.sum_accurately(terms)
+    if ctx._is_real_type(n) and ctx._is_real_type(z):
+        v = ctx._re(v)
+    return v
+
+"""
+Even/odd PCFs. Useful?
+
+@defun
+def pcfy1(ctx, a, z, **kwargs):
+    a, _ = ctx._convert_param(n)
+    z = ctx.convert(z)
+    def h():
+        w = ctx.square_exp_arg(z)
+        w1 = ctx.fmul(w, -0.25, exact=True)
+        w2 = ctx.fmul(w, 0.5, exact=True)
+        e = ctx.exp(w1)
+        return [e], [1], [], [], [ctx.mpq_1_2*a+ctx.mpq_1_4], [ctx.mpq_1_2], w2
+    return ctx.hypercomb(h, [], **kwargs)
+
+@defun
+def pcfy2(ctx, a, z, **kwargs):
+    a, _ = ctx._convert_param(n)
+    z = ctx.convert(z)
+    def h():
+        w = ctx.square_exp_arg(z)
+        w1 = ctx.fmul(w, -0.25, exact=True)
+        w2 = ctx.fmul(w, 0.5, exact=True)
+        e = ctx.exp(w1)
+        return [e, z], [1, 1], [], [], [ctx.mpq_1_2*a+ctx.mpq_3_4], \
+            [ctx.mpq_3_2], w2
+    return ctx.hypercomb(h, [], **kwargs)
+"""
+
+@defun_wrapped
+def gegenbauer(ctx, n, a, z, **kwargs):
+    # Special cases: a+0.5, a*2 poles
+    if ctx.isnpint(a):
+        return 0*(z+n)
+    if ctx.isnpint(a+0.5):
+        # TODO: something else is required here
+        # E.g.: gegenbauer(-2, -0.5, 3) == -12
+        if ctx.isnpint(n+1):
+            raise NotImplementedError("Gegenbauer function with two limits")
+        def h(a):
+            a2 = 2*a
+            T = [], [], [n+a2], [n+1, a2], [-n, n+a2], [a+0.5], 0.5*(1-z)
+            return [T]
+        return ctx.hypercomb(h, [a], **kwargs)
+    def h(n):
+        a2 = 2*a
+        T = [], [], [n+a2], [n+1, a2], [-n, n+a2], [a+0.5], 0.5*(1-z)
+        return [T]
+    return ctx.hypercomb(h, [n], **kwargs)
+
+@defun_wrapped
+def jacobi(ctx, n, a, b, x, **kwargs):
+    if not ctx.isnpint(a):
+        def h(n):
+            return (([], [], [a+n+1], [n+1, a+1], [-n, a+b+n+1], [a+1], (1-x)*0.5),)
+        return ctx.hypercomb(h, [n], **kwargs)
+    if not ctx.isint(b):
+        def h(n, a):
+            return (([], [], [-b], [n+1, -b-n], [-n, a+b+n+1], [b+1], (x+1)*0.5),)
+        return ctx.hypercomb(h, [n, a], **kwargs)
+    # XXX: determine appropriate limit
+    return ctx.binomial(n+a,n) * ctx.hyp2f1(-n,1+n+a+b,a+1,(1-x)/2, **kwargs)
+
+@defun_wrapped
+def laguerre(ctx, n, a, z, **kwargs):
+    # XXX: limits, poles
+    #if ctx.isnpint(n):
+    #    return 0*(a+z)
+    def h(a):
+        return (([], [], [a+n+1], [a+1, n+1], [-n], [a+1], z),)
+    return ctx.hypercomb(h, [a], **kwargs)
+
+@defun_wrapped
+def legendre(ctx, n, x, **kwargs):
+    if ctx.isint(n):
+        n = int(n)
+        # Accuracy near zeros
+        if (n + (n < 0)) & 1:
+            if not x:
+                return x
+            mag = ctx.mag(x)
+            if mag < -2*ctx.prec-10:
+                return x
+            if mag < -5:
+                ctx.prec += -mag
+    return ctx.hyp2f1(-n,n+1,1,(1-x)/2, **kwargs)
+
+@defun
+def legenp(ctx, n, m, z, type=2, **kwargs):
+    # Legendre function, 1st kind
+    n = ctx.convert(n)
+    m = ctx.convert(m)
+    # Faster
+    if not m:
+        return ctx.legendre(n, z, **kwargs)
+    # TODO: correct evaluation at singularities
+    if type == 2:
+        def h(n,m):
+            g = m*0.5
+            T = [1+z, 1-z], [g, -g], [], [1-m], [-n, n+1], [1-m], 0.5*(1-z)
+            return (T,)
+        return ctx.hypercomb(h, [n,m], **kwargs)
+    if type == 3:
+        def h(n,m):
+            g = m*0.5
+            T = [z+1, z-1], [g, -g], [], [1-m], [-n, n+1], [1-m], 0.5*(1-z)
+            return (T,)
+        return ctx.hypercomb(h, [n,m], **kwargs)
+    raise ValueError("requires type=2 or type=3")
+
+@defun
+def legenq(ctx, n, m, z, type=2, **kwargs):
+    # Legendre function, 2nd kind
+    n = ctx.convert(n)
+    m = ctx.convert(m)
+    z = ctx.convert(z)
+    if z in (1, -1):
+        #if ctx.isint(m):
+        #    return ctx.nan
+        #return ctx.inf  # unsigned
+        return ctx.nan
+    if type == 2:
+        def h(n, m):
+            cos, sin = ctx.cospi_sinpi(m)
+            s = 2 * sin / ctx.pi
+            c = cos
+            a = 1+z
+            b = 1-z
+            u = m/2
+            w = (1-z)/2
+            T1 = [s, c, a, b], [-1, 1, u, -u], [], [1-m], \
+                [-n, n+1], [1-m], w
+            T2 = [-s, a, b], [-1, -u, u], [n+m+1], [n-m+1, m+1], \
+                [-n, n+1], [m+1], w
+            return T1, T2
+        return ctx.hypercomb(h, [n, m], **kwargs)
+    if type == 3:
+        # The following is faster when there only is a single series
+        # Note: not valid for -1 < z < 0 (?)
+        if abs(z) > 1:
+            def h(n, m):
+                T1 = [ctx.expjpi(m), 2, ctx.pi, z, z-1, z+1], \
+                     [1, -n-1, 0.5, -n-m-1, 0.5*m, 0.5*m], \
+                     [n+m+1], [n+1.5], \
+                     [0.5*(2+n+m), 0.5*(1+n+m)], [n+1.5], z**(-2)
+                return [T1]
+            return ctx.hypercomb(h, [n, m], **kwargs)
+        else:
+            # not valid for 1 < z < inf ?
+            def h(n, m):
+                s = 2 * ctx.sinpi(m) / ctx.pi
+                c = ctx.expjpi(m)
+                a = 1+z
+                b = z-1
+                u = m/2
+                w = (1-z)/2
+                T1 = [s, c, a, b], [-1, 1, u, -u], [], [1-m], \
+                    [-n, n+1], [1-m], w
+                T2 = [-s, c, a, b], [-1, 1, -u, u], [n+m+1], [n-m+1, m+1], \
+                    [-n, n+1], [m+1], w
+                return T1, T2
+            return ctx.hypercomb(h, [n, m], **kwargs)
+    raise ValueError("requires type=2 or type=3")
+
+@defun_wrapped
+def chebyt(ctx, n, x, **kwargs):
+    if (not x) and ctx.isint(n) and int(ctx._re(n)) % 2 == 1:
+        return x * 0
+    return ctx.hyp2f1(-n,n,(1,2),(1-x)/2, **kwargs)
+
+@defun_wrapped
+def chebyu(ctx, n, x, **kwargs):
+    if (not x) and ctx.isint(n) and int(ctx._re(n)) % 2 == 1:
+        return x * 0
+    return (n+1) * ctx.hyp2f1(-n, n+2, (3,2), (1-x)/2, **kwargs)
+
+@defun
+def spherharm(ctx, l, m, theta, phi, **kwargs):
+    l = ctx.convert(l)
+    m = ctx.convert(m)
+    theta = ctx.convert(theta)
+    phi = ctx.convert(phi)
+    l_isint = ctx.isint(l)
+    l_natural = l_isint and l >= 0
+    m_isint = ctx.isint(m)
+    if l_isint and l < 0 and m_isint:
+        return ctx.spherharm(-(l+1), m, theta, phi, **kwargs)
+    if theta == 0 and m_isint and m < 0:
+        return ctx.zero * 1j
+    if l_natural and m_isint:
+        if abs(m) > l:
+            return ctx.zero * 1j
+        # http://functions.wolfram.com/Polynomials/
+        #     SphericalHarmonicY/26/01/02/0004/
+        def h(l,m):
+            absm = abs(m)
+            C = [-1, ctx.expj(m*phi),
+                 (2*l+1)*ctx.fac(l+absm)/ctx.pi/ctx.fac(l-absm),
+                 ctx.sin(theta)**2,
+                 ctx.fac(absm), 2]
+            P = [0.5*m*(ctx.sign(m)+1), 1, 0.5, 0.5*absm, -1, -absm-1]
+            return ((C, P, [], [], [absm-l, l+absm+1], [absm+1],
+                ctx.sin(0.5*theta)**2),)
+    else:
+        # http://functions.wolfram.com/HypergeometricFunctions/
+        #     SphericalHarmonicYGeneral/26/01/02/0001/
+        def h(l,m):
+            if ctx.isnpint(l-m+1) or ctx.isnpint(l+m+1) or ctx.isnpint(1-m):
+                return (([0], [-1], [], [], [], [], 0),)
+            cos, sin = ctx.cos_sin(0.5*theta)
+            C = [0.5*ctx.expj(m*phi), (2*l+1)/ctx.pi,
+                 ctx.gamma(l-m+1), ctx.gamma(l+m+1),
+                 cos**2, sin**2]
+            P = [1, 0.5, 0.5, -0.5, 0.5*m, -0.5*m]
+            return ((C, P, [], [1-m], [-l,l+1], [1-m], sin**2),)
+    return ctx.hypercomb(h, [l,m], **kwargs)

rl/Lib/site-packages/mpmath/functions/qfunctions.py

@@ -0,0 +1,280 @@
+from .functions import defun, defun_wrapped
+
+@defun
+def qp(ctx, a, q=None, n=None, **kwargs):
+    r"""
+    Evaluates the q-Pochhammer symbol (or q-rising factorial)
+
+    .. math ::
+
+        (a; q)_n = \prod_{k=0}^{n-1} (1-a q^k)
+
+    where `n = \infty` is permitted if `|q| < 1`. Called with two arguments,
+    ``qp(a,q)`` computes `(a;q)_{\infty}`; with a single argument, ``qp(q)``
+    computes `(q;q)_{\infty}`. The special case
+
+    .. math ::
+
+        \phi(q) = (q; q)_{\infty} = \prod_{k=1}^{\infty} (1-q^k) =
+            \sum_{k=-\infty}^{\infty} (-1)^k q^{(3k^2-k)/2}
+
+    is also known as the Euler function, or (up to a factor `q^{-1/24}`)
+    the Dedekind eta function.
+
+    **Examples**
+
+    If `n` is a positive integer, the function amounts to a finite product::
+
+        >>> from mpmath import *
+        >>> mp.dps = 25; mp.pretty = True
+        >>> qp(2,3,5)
+        -725305.0
+        >>> fprod(1-2*3**k for k in range(5))
+        -725305.0
+        >>> qp(2,3,0)
+        1.0
+
+    Complex arguments are allowed::
+
+        >>> qp(2-1j, 0.75j)
+        (0.4628842231660149089976379 + 4.481821753552703090628793j)
+
+    The regular Pochhammer symbol `(a)_n` is obtained in the
+    following limit as `q \to 1`::
+
+        >>> a, n = 4, 7
+        >>> limit(lambda q: qp(q**a,q,n) / (1-q)**n, 1)
+        604800.0
+        >>> rf(a,n)
+        604800.0
+
+    The Taylor series of the reciprocal Euler function gives
+    the partition function `P(n)`, i.e. the number of ways of writing
+    `n` as a sum of positive integers::
+
+        >>> taylor(lambda q: 1/qp(q), 0, 10)
+        [1.0, 1.0, 2.0, 3.0, 5.0, 7.0, 11.0, 15.0, 22.0, 30.0, 42.0]
+
+    Special values include::
+
+        >>> qp(0)
+        1.0
+        >>> findroot(diffun(qp), -0.4)   # location of maximum
+        -0.4112484791779547734440257
+        >>> qp(_)
+        1.228348867038575112586878
+
+    The q-Pochhammer symbol is related to the Jacobi theta functions.
+    For example, the following identity holds::
+
+        >>> q = mpf(0.5)    # arbitrary
+        >>> qp(q)
+        0.2887880950866024212788997
+        >>> root(3,-2)*root(q,-24)*jtheta(2,pi/6,root(q,6))
+        0.2887880950866024212788997
+
+    """
+    a = ctx.convert(a)
+    if n is None:
+        n = ctx.inf
+    else:
+        n = ctx.convert(n)
+    if n < 0:
+        raise ValueError("n cannot be negative")
+    if q is None:
+        q = a
+    else:
+        q = ctx.convert(q)
+    if n == 0:
+        return ctx.one + 0*(a+q)
+    infinite = (n == ctx.inf)
+    same = (a == q)
+    if infinite:
+        if abs(q) >= 1:
+            if same and (q == -1 or q == 1):
+                return ctx.zero * q
+            raise ValueError("q-function only defined for |q| < 1")
+        elif q == 0:
+            return ctx.one - a
+    maxterms = kwargs.get('maxterms', 50*ctx.prec)
+    if infinite and same:
+        # Euler's pentagonal theorem
+        def terms():
+            t = 1
+            yield t
+            k = 1
+            x1 = q
+            x2 = q**2
+            while 1:
+                yield (-1)**k * x1
+                yield (-1)**k * x2
+                x1 *= q**(3*k+1)
+                x2 *= q**(3*k+2)
+                k += 1
+                if k > maxterms:
+                    raise ctx.NoConvergence
+        return ctx.sum_accurately(terms)
+    # return ctx.nprod(lambda k: 1-a*q**k, [0,n-1])
+    def factors():
+        k = 0
+        r = ctx.one
+        while 1:
+            yield 1 - a*r
+            r *= q
+            k += 1
+            if k >= n:
+                return
+            if k > maxterms:
+                raise ctx.NoConvergence
+    return ctx.mul_accurately(factors)
+
+@defun_wrapped
+def qgamma(ctx, z, q, **kwargs):
+    r"""
+    Evaluates the q-gamma function
+
+    .. math ::
+
+        \Gamma_q(z) = \frac{(q; q)_{\infty}}{(q^z; q)_{\infty}} (1-q)^{1-z}.
+
+
+    **Examples**
+
+    Evaluation for real and complex arguments::
+
+        >>> from mpmath import *
+        >>> mp.dps = 25; mp.pretty = True
+        >>> qgamma(4,0.75)
+        4.046875
+        >>> qgamma(6,6)
+        121226245.0
+        >>> qgamma(3+4j, 0.5j)
+        (0.1663082382255199834630088 + 0.01952474576025952984418217j)
+
+    The q-gamma function satisfies a functional equation similar
+    to that of the ordinary gamma function::
+
+        >>> q = mpf(0.25)
+        >>> z = mpf(2.5)
+        >>> qgamma(z+1,q)
+        1.428277424823760954685912
+        >>> (1-q**z)/(1-q)*qgamma(z,q)
+        1.428277424823760954685912
+
+    """
+    if abs(q) > 1:
+        return ctx.qgamma(z,1/q)*q**((z-2)*(z-1)*0.5)
+    return ctx.qp(q, q, None, **kwargs) / \
+        ctx.qp(q**z, q, None, **kwargs) * (1-q)**(1-z)
+
+@defun_wrapped
+def qfac(ctx, z, q, **kwargs):
+    r"""
+    Evaluates the q-factorial,
+
+    .. math ::
+
+        [n]_q! = (1+q)(1+q+q^2)\cdots(1+q+\cdots+q^{n-1})
+
+    or more generally
+
+    .. math ::
+
+        [z]_q! = \frac{(q;q)_z}{(1-q)^z}.
+
+    **Examples**
+
+        >>> from mpmath import *
+        >>> mp.dps = 25; mp.pretty = True
+        >>> qfac(0,0)
+        1.0
+        >>> qfac(4,3)
+        2080.0
+        >>> qfac(5,6)
+        121226245.0
+        >>> qfac(1+1j, 2+1j)
+        (0.4370556551322672478613695 + 0.2609739839216039203708921j)
+
+    """
+    if ctx.isint(z) and ctx._re(z) > 0:
+        n = int(ctx._re(z))
+        return ctx.qp(q, q, n, **kwargs) / (1-q)**n
+    return ctx.qgamma(z+1, q, **kwargs)
+
+@defun
+def qhyper(ctx, a_s, b_s, q, z, **kwargs):
+    r"""
+    Evaluates the basic hypergeometric series or hypergeometric q-series
+
+    .. math ::
+
+        \,_r\phi_s \left[\begin{matrix}
+            a_1 & a_2 & \ldots & a_r \\
+            b_1 & b_2 & \ldots & b_s
+        \end{matrix} ; q,z \right] =
+        \sum_{n=0}^\infty
+        \frac{(a_1;q)_n, \ldots, (a_r;q)_n}
+             {(b_1;q)_n, \ldots, (b_s;q)_n}
+        \left((-1)^n q^{n\choose 2}\right)^{1+s-r}
+        \frac{z^n}{(q;q)_n}
+
+    where `(a;q)_n` denotes the q-Pochhammer symbol (see :func:`~mpmath.qp`).
+
+    **Examples**
+
+    Evaluation works for real and complex arguments::
+
+        >>> from mpmath import *
+        >>> mp.dps = 25; mp.pretty = True
+        >>> qhyper([0.5], [2.25], 0.25, 4)
+        -0.1975849091263356009534385
+        >>> qhyper([0.5], [2.25], 0.25-0.25j, 4)
+        (2.806330244925716649839237 + 3.568997623337943121769938j)
+        >>> qhyper([1+j], [2,3+0.5j], 0.25, 3+4j)
+        (9.112885171773400017270226 - 1.272756997166375050700388j)
+
+    Comparing with a summation of the defining series, using
+    :func:`~mpmath.nsum`::
+
+        >>> b, q, z = 3, 0.25, 0.5
+        >>> qhyper([], [b], q, z)
+        0.6221136748254495583228324
+        >>> nsum(lambda n: z**n / qp(q,q,n)/qp(b,q,n) * q**(n*(n-1)), [0,inf])
+        0.6221136748254495583228324
+
+    """
+    #a_s = [ctx._convert_param(a)[0] for a in a_s]
+    #b_s = [ctx._convert_param(b)[0] for b in b_s]
+    #q = ctx._convert_param(q)[0]
+    a_s = [ctx.convert(a) for a in a_s]
+    b_s = [ctx.convert(b) for b in b_s]
+    q = ctx.convert(q)
+    z = ctx.convert(z)
+    r = len(a_s)
+    s = len(b_s)
+    d = 1+s-r
+    maxterms = kwargs.get('maxterms', 50*ctx.prec)
+    def terms():
+        t = ctx.one
+        yield t
+        qk = 1
+        k = 0
+        x = 1
+        while 1:
+            for a in a_s:
+                p = 1 - a*qk
+                t *= p
+            for b in b_s:
+                p = 1 - b*qk
+                if not p:
+                    raise ValueError
+                t /= p
+            t *= z
+            x *= (-1)**d * qk ** d
+            qk *= q
+            t /= (1 - qk)
+            k += 1
+            yield t * x
+            if k > maxterms:
+                raise ctx.NoConvergence
+    return ctx.sum_accurately(terms)

rl/Lib/site-packages/mpmath/functions/signals.py

@@ -0,0 +1,32 @@
+from .functions import defun_wrapped
+
+@defun_wrapped
+def squarew(ctx, t, amplitude=1, period=1):
+    P = period
+    A = amplitude
+    return A*((-1)**ctx.floor(2*t/P))
+
+@defun_wrapped
+def trianglew(ctx, t, amplitude=1, period=1):
+    A = amplitude
+    P = period
+
+    return 2*A*(0.5 - ctx.fabs(1 - 2*ctx.frac(t/P + 0.25)))
+
+@defun_wrapped
+def sawtoothw(ctx, t, amplitude=1, period=1):
+    A = amplitude
+    P = period
+    return A*ctx.frac(t/P)
+
+@defun_wrapped
+def unit_triangle(ctx, t, amplitude=1):
+    A = amplitude
+    if t <= -1 or t >= 1:
+        return ctx.zero
+    return A*(-ctx.fabs(t) + 1)
+
+@defun_wrapped
+def sigmoid(ctx, t, amplitude=1):
+    A = amplitude
+    return A / (1 + ctx.exp(-t))

rl/Lib/site-packages/mpmath/identification.py

@@ -0,0 +1,844 @@
+"""
+Implements the PSLQ algorithm for integer relation detection,
+and derivative algorithms for constant recognition.
+"""
+
+from .libmp.backend import xrange
+from .libmp import int_types, sqrt_fixed
+
+# round to nearest integer (can be done more elegantly...)
+def round_fixed(x, prec):
+    return ((x + (1<<(prec-1))) >> prec) << prec
+
+class IdentificationMethods(object):
+    pass
+
+
+def pslq(ctx, x, tol=None, maxcoeff=1000, maxsteps=100, verbose=False):
+    r"""
+    Given a vector of real numbers `x = [x_0, x_1, ..., x_n]`, ``pslq(x)``
+    uses the PSLQ algorithm to find a list of integers
+    `[c_0, c_1, ..., c_n]` such that
+
+    .. math ::
+
+        |c_1 x_1 + c_2 x_2 + ... + c_n x_n| < \mathrm{tol}
+
+    and such that `\max |c_k| < \mathrm{maxcoeff}`. If no such vector
+    exists, :func:`~mpmath.pslq` returns ``None``. The tolerance defaults to
+    3/4 of the working precision.
+
+    **Examples**
+
+    Find rational approximations for `\pi`::
+
+        >>> from mpmath import *
+        >>> mp.dps = 15; mp.pretty = True
+        >>> pslq([-1, pi], tol=0.01)
+        [22, 7]
+        >>> pslq([-1, pi], tol=0.001)
+        [355, 113]
+        >>> mpf(22)/7; mpf(355)/113; +pi
+        3.14285714285714
+        3.14159292035398
+        3.14159265358979
+
+    Pi is not a rational number with denominator less than 1000::
+
+        >>> pslq([-1, pi])
+        >>>
+
+    To within the standard precision, it can however be approximated
+    by at least one rational number with denominator less than `10^{12}`::
+
+        >>> p, q = pslq([-1, pi], maxcoeff=10**12)
+        >>> print(p); print(q)
+        238410049439
+        75888275702
+        >>> mpf(p)/q
+        3.14159265358979
+
+    The PSLQ algorithm can be applied to long vectors. For example,
+    we can investigate the rational (in)dependence of integer square
+    roots::
+
+        >>> mp.dps = 30
+        >>> pslq([sqrt(n) for n in range(2, 5+1)])
+        >>>
+        >>> pslq([sqrt(n) for n in range(2, 6+1)])
+        >>>
+        >>> pslq([sqrt(n) for n in range(2, 8+1)])
+        [2, 0, 0, 0, 0, 0, -1]
+
+    **Machin formulas**
+
+    A famous formula for `\pi` is Machin's,
+
+    .. math ::
+
+        \frac{\pi}{4} = 4 \operatorname{acot} 5 - \operatorname{acot} 239
+
+    There are actually infinitely many formulas of this type. Two
+    others are
+
+    .. math ::
+
+        \frac{\pi}{4} = \operatorname{acot} 1
+
+        \frac{\pi}{4} = 12 \operatorname{acot} 49 + 32 \operatorname{acot} 57
+            + 5 \operatorname{acot} 239 + 12 \operatorname{acot} 110443
+
+    We can easily verify the formulas using the PSLQ algorithm::
+
+        >>> mp.dps = 30
+        >>> pslq([pi/4, acot(1)])
+        [1, -1]
+        >>> pslq([pi/4, acot(5), acot(239)])
+        [1, -4, 1]
+        >>> pslq([pi/4, acot(49), acot(57), acot(239), acot(110443)])
+        [1, -12, -32, 5, -12]
+
+    We could try to generate a custom Machin-like formula by running
+    the PSLQ algorithm with a few inverse cotangent values, for example
+    acot(2), acot(3) ... acot(10). Unfortunately, there is a linear
+    dependence among these values, resulting in only that dependence
+    being detected, with a zero coefficient for `\pi`::
+
+        >>> pslq([pi] + [acot(n) for n in range(2,11)])
+        [0, 1, -1, 0, 0, 0, -1, 0, 0, 0]
+
+    We get better luck by removing linearly dependent terms::
+
+        >>> pslq([pi] + [acot(n) for n in range(2,11) if n not in (3, 5)])
+        [1, -8, 0, 0, 4, 0, 0, 0]
+
+    In other words, we found the following formula::
+
+        >>> 8*acot(2) - 4*acot(7)
+        3.14159265358979323846264338328
+        >>> +pi
+        3.14159265358979323846264338328
+
+    **Algorithm**
+
+    This is a fairly direct translation to Python of the pseudocode given by
+    David Bailey, "The PSLQ Integer Relation Algorithm":
+    http://www.cecm.sfu.ca/organics/papers/bailey/paper/html/node3.html
+
+    The present implementation uses fixed-point instead of floating-point
+    arithmetic, since this is significantly (about 7x) faster.
+    """
+
+    n = len(x)
+    if n < 2:
+        raise ValueError("n cannot be less than 2")
+
+    # At too low precision, the algorithm becomes meaningless
+    prec = ctx.prec
+    if prec < 53:
+        raise ValueError("prec cannot be less than 53")
+
+    if verbose and prec // max(2,n) < 5:
+        print("Warning: precision for PSLQ may be too low")
+
+    target = int(prec * 0.75)
+
+    if tol is None:
+        tol = ctx.mpf(2)**(-target)
+    else:
+        tol = ctx.convert(tol)
+
+    extra = 60
+    prec += extra
+
+    if verbose:
+        print("PSLQ using prec %i and tol %s" % (prec, ctx.nstr(tol)))
+
+    tol = ctx.to_fixed(tol, prec)
+    assert tol
+
+    # Convert to fixed-point numbers. The dummy None is added so we can
+    # use 1-based indexing. (This just allows us to be consistent with
+    # Bailey's indexing. The algorithm is 100 lines long, so debugging
+    # a single wrong index can be painful.)
+    x = [None] + [ctx.to_fixed(ctx.mpf(xk), prec) for xk in x]
+
+    # Sanity check on magnitudes
+    minx = min(abs(xx) for xx in x[1:])
+    if not minx:
+        raise ValueError("PSLQ requires a vector of nonzero numbers")
+    if minx < tol//100:
+        if verbose:
+            print("STOPPING: (one number is too small)")
+        return None
+
+    g = sqrt_fixed((4<<prec)//3, prec)
+    A = {}
+    B = {}
+    H = {}
+    # Initialization
+    # step 1
+    for i in xrange(1, n+1):
+        for j in xrange(1, n+1):
+            A[i,j] = B[i,j] = (i==j) << prec
+            H[i,j] = 0
+    # step 2
+    s = [None] + [0] * n
+    for k in xrange(1, n+1):
+        t = 0
+        for j in xrange(k, n+1):
+            t += (x[j]**2 >> prec)
+        s[k] = sqrt_fixed(t, prec)
+    t = s[1]
+    y = x[:]
+    for k in xrange(1, n+1):
+        y[k] = (x[k] << prec) // t
+        s[k] = (s[k] << prec) // t
+    # step 3
+    for i in xrange(1, n+1):
+        for j in xrange(i+1, n):
+            H[i,j] = 0
+        if i <= n-1:
+            if s[i]:
+                H[i,i] = (s[i+1] << prec) // s[i]
+            else:
+                H[i,i] = 0
+        for j in range(1, i):
+            sjj1 = s[j]*s[j+1]
+            if sjj1:
+                H[i,j] = ((-y[i]*y[j])<<prec)//sjj1
+            else:
+                H[i,j] = 0
+    # step 4
+    for i in xrange(2, n+1):
+        for j in xrange(i-1, 0, -1):
+            #t = floor(H[i,j]/H[j,j] + 0.5)
+            if H[j,j]:
+                t = round_fixed((H[i,j] << prec)//H[j,j], prec)
+            else:
+                #t = 0
+                continue
+            y[j] = y[j] + (t*y[i] >> prec)
+            for k in xrange(1, j+1):
+                H[i,k] = H[i,k] - (t*H[j,k] >> prec)
+            for k in xrange(1, n+1):
+                A[i,k] = A[i,k] - (t*A[j,k] >> prec)
+                B[k,j] = B[k,j] + (t*B[k,i] >> prec)
+    # Main algorithm
+    for REP in range(maxsteps):
+        # Step 1
+        m = -1
+        szmax = -1
+        for i in range(1, n):
+            h = H[i,i]
+            sz = (g**i * abs(h)) >> (prec*(i-1))
+            if sz > szmax:
+                m = i
+                szmax = sz
+        # Step 2
+        y[m], y[m+1] = y[m+1], y[m]
+        for i in xrange(1,n+1): H[m,i], H[m+1,i] = H[m+1,i], H[m,i]
+        for i in xrange(1,n+1): A[m,i], A[m+1,i] = A[m+1,i], A[m,i]
+        for i in xrange(1,n+1): B[i,m], B[i,m+1] = B[i,m+1], B[i,m]
+        # Step 3
+        if m <= n - 2:
+            t0 = sqrt_fixed((H[m,m]**2 + H[m,m+1]**2)>>prec, prec)
+            # A zero element probably indicates that the precision has
+            # been exhausted. XXX: this could be spurious, due to
+            # using fixed-point arithmetic
+            if not t0:
+                break
+            t1 = (H[m,m] << prec) // t0
+            t2 = (H[m,m+1] << prec) // t0
+            for i in xrange(m, n+1):
+                t3 = H[i,m]
+                t4 = H[i,m+1]
+                H[i,m] = (t1*t3+t2*t4) >> prec
+                H[i,m+1] = (-t2*t3+t1*t4) >> prec
+        # Step 4
+        for i in xrange(m+1, n+1):
+            for j in xrange(min(i-1, m+1), 0, -1):
+                try:
+                    t = round_fixed((H[i,j] << prec)//H[j,j], prec)
+                # Precision probably exhausted
+                except ZeroDivisionError:
+                    break
+                y[j] = y[j] + ((t*y[i]) >> prec)
+                for k in xrange(1, j+1):
+                    H[i,k] = H[i,k] - (t*H[j,k] >> prec)
+                for k in xrange(1, n+1):
+                    A[i,k] = A[i,k] - (t*A[j,k] >> prec)
+                    B[k,j] = B[k,j] + (t*B[k,i] >> prec)
+        # Until a relation is found, the error typically decreases
+        # slowly (e.g. a factor 1-10) with each step TODO: we could
+        # compare err from two successive iterations. If there is a
+        # large drop (several orders of magnitude), that indicates a
+        # "high quality" relation was detected. Reporting this to
+        # the user somehow might be useful.
+        best_err = maxcoeff<<prec
+        for i in xrange(1, n+1):
+            err = abs(y[i])
+            # Maybe we are done?
+            if err < tol:
+                # We are done if the coefficients are acceptable
+                vec = [int(round_fixed(B[j,i], prec) >> prec) for j in \
+                range(1,n+1)]
+                if max(abs(v) for v in vec) < maxcoeff:
+                    if verbose:
+                        print("FOUND relation at iter %i/%i, error: %s" % \
+                            (REP, maxsteps, ctx.nstr(err / ctx.mpf(2)**prec, 1)))
+                    return vec
+            best_err = min(err, best_err)
+        # Calculate a lower bound for the norm. We could do this
+        # more exactly (using the Euclidean norm) but there is probably
+        # no practical benefit.
+        recnorm = max(abs(h) for h in H.values())
+        if recnorm:
+            norm = ((1 << (2*prec)) // recnorm) >> prec
+            norm //= 100
+        else:
+            norm = ctx.inf
+        if verbose:
+            print("%i/%i:  Error: %8s   Norm: %s" % \
+                (REP, maxsteps, ctx.nstr(best_err / ctx.mpf(2)**prec, 1), norm))
+        if norm >= maxcoeff:
+            break
+    if verbose:
+        print("CANCELLING after step %i/%i." % (REP, maxsteps))
+        print("Could not find an integer relation. Norm bound: %s" % norm)
+    return None
+
+def findpoly(ctx, x, n=1, **kwargs):
+    r"""
+    ``findpoly(x, n)`` returns the coefficients of an integer
+    polynomial `P` of degree at most `n` such that `P(x) \approx 0`.
+    If no polynomial having `x` as a root can be found,
+    :func:`~mpmath.findpoly` returns ``None``.
+
+    :func:`~mpmath.findpoly` works by successively calling :func:`~mpmath.pslq` with
+    the vectors `[1, x]`, `[1, x, x^2]`, `[1, x, x^2, x^3]`, ...,
+    `[1, x, x^2, .., x^n]` as input. Keyword arguments given to
+    :func:`~mpmath.findpoly` are forwarded verbatim to :func:`~mpmath.pslq`. In
+    particular, you can specify a tolerance for `P(x)` with ``tol``
+    and a maximum permitted coefficient size with ``maxcoeff``.
+
+    For large values of `n`, it is recommended to run :func:`~mpmath.findpoly`
+    at high precision; preferably 50 digits or more.
+
+    **Examples**
+
+    By default (degree `n = 1`), :func:`~mpmath.findpoly` simply finds a linear
+    polynomial with a rational root::
+
+        >>> from mpmath import *
+        >>> mp.dps = 15; mp.pretty = True
+        >>> findpoly(0.7)
+        [-10, 7]
+
+    The generated coefficient list is valid input to ``polyval`` and
+    ``polyroots``::
+
+        >>> nprint(polyval(findpoly(phi, 2), phi), 1)
+        -2.0e-16
+        >>> for r in polyroots(findpoly(phi, 2)):
+        ...     print(r)
+        ...
+        -0.618033988749895
+        1.61803398874989
+
+    Numbers of the form `m + n \sqrt p` for integers `(m, n, p)` are
+    solutions to quadratic equations. As we find here, `1+\sqrt 2`
+    is a root of the polynomial `x^2 - 2x - 1`::
+
+        >>> findpoly(1+sqrt(2), 2)
+        [1, -2, -1]
+        >>> findroot(lambda x: x**2 - 2*x - 1, 1)
+        2.4142135623731
+
+    Despite only containing square roots, the following number results
+    in a polynomial of degree 4::
+
+        >>> findpoly(sqrt(2)+sqrt(3), 4)
+        [1, 0, -10, 0, 1]
+
+    In fact, `x^4 - 10x^2 + 1` is the *minimal polynomial* of
+    `r = \sqrt 2 + \sqrt 3`, meaning that a rational polynomial of
+    lower degree having `r` as a root does not exist. Given sufficient
+    precision, :func:`~mpmath.findpoly` will usually find the correct
+    minimal polynomial of a given algebraic number.
+
+    **Non-algebraic numbers**
+
+    If :func:`~mpmath.findpoly` fails to find a polynomial with given
+    coefficient size and tolerance constraints, that means no such
+    polynomial exists.
+
+    We can verify that `\pi` is not an algebraic number of degree 3 with
+    coefficients less than 1000::
+
+        >>> mp.dps = 15
+        >>> findpoly(pi, 3)
+        >>>
+
+    It is always possible to find an algebraic approximation of a number
+    using one (or several) of the following methods:
+
+        1. Increasing the permitted degree
+        2. Allowing larger coefficients
+        3. Reducing the tolerance
+
+    One example of each method is shown below::
+
+        >>> mp.dps = 15
+        >>> findpoly(pi, 4)
+        [95, -545, 863, -183, -298]
+        >>> findpoly(pi, 3, maxcoeff=10000)
+        [836, -1734, -2658, -457]
+        >>> findpoly(pi, 3, tol=1e-7)
+        [-4, 22, -29, -2]
+
+    It is unknown whether Euler's constant is transcendental (or even
+    irrational). We can use :func:`~mpmath.findpoly` to check that if is
+    an algebraic number, its minimal polynomial must have degree
+    at least 7 and a coefficient of magnitude at least 1000000::
+
+        >>> mp.dps = 200
+        >>> findpoly(euler, 6, maxcoeff=10**6, tol=1e-100, maxsteps=1000)
+        >>>
+
+    Note that the high precision and strict tolerance is necessary
+    for such high-degree runs, since otherwise unwanted low-accuracy
+    approximations will be detected. It may also be necessary to set
+    maxsteps high to prevent a premature exit (before the coefficient
+    bound has been reached). Running with ``verbose=True`` to get an
+    idea what is happening can be useful.
+    """
+    x = ctx.mpf(x)
+    if n < 1:
+        raise ValueError("n cannot be less than 1")
+    if x == 0:
+        return [1, 0]
+    xs = [ctx.mpf(1)]
+    for i in range(1,n+1):
+        xs.append(x**i)
+        a = ctx.pslq(xs, **kwargs)
+        if a is not None:
+            return a[::-1]
+
+def fracgcd(p, q):
+    x, y = p, q
+    while y:
+        x, y = y, x % y
+    if x != 1:
+        p //= x
+        q //= x
+    if q == 1:
+        return p
+    return p, q
+
+def pslqstring(r, constants):
+    q = r[0]
+    r = r[1:]
+    s = []
+    for i in range(len(r)):
+        p = r[i]
+        if p:
+            z = fracgcd(-p,q)
+            cs = constants[i][1]
+            if cs == '1':
+                cs = ''
+            else:
+                cs = '*' + cs
+            if isinstance(z, int_types):
+                if z > 0: term = str(z) + cs
+                else:     term = ("(%s)" % z) + cs
+            else:
+                term = ("(%s/%s)" % z) + cs
+            s.append(term)
+    s = ' + '.join(s)
+    if '+' in s or '*' in s:
+        s = '(' + s + ')'
+    return s or '0'
+
+def prodstring(r, constants):
+    q = r[0]
+    r = r[1:]
+    num = []
+    den = []
+    for i in range(len(r)):
+        p = r[i]
+        if p:
+            z = fracgcd(-p,q)
+            cs = constants[i][1]
+            if isinstance(z, int_types):
+                if abs(z) == 1: t = cs
+                else:           t = '%s**%s' % (cs, abs(z))
+                ([num,den][z<0]).append(t)
+            else:
+                t = '%s**(%s/%s)' % (cs, abs(z[0]), z[1])
+                ([num,den][z[0]<0]).append(t)
+    num = '*'.join(num)
+    den = '*'.join(den)
+    if num and den: return "(%s)/(%s)" % (num, den)
+    if num: return num
+    if den: return "1/(%s)" % den
+
+def quadraticstring(ctx,t,a,b,c):
+    if c < 0:
+        a,b,c = -a,-b,-c
+    u1 = (-b+ctx.sqrt(b**2-4*a*c))/(2*c)
+    u2 = (-b-ctx.sqrt(b**2-4*a*c))/(2*c)
+    if abs(u1-t) < abs(u2-t):
+        if b:  s = '((%s+sqrt(%s))/%s)' % (-b,b**2-4*a*c,2*c)
+        else:  s = '(sqrt(%s)/%s)' % (-4*a*c,2*c)
+    else:
+        if b:  s = '((%s-sqrt(%s))/%s)' % (-b,b**2-4*a*c,2*c)
+        else:  s = '(-sqrt(%s)/%s)' % (-4*a*c,2*c)
+    return s
+
+# Transformation y = f(x,c), with inverse function x = f(y,c)
+# The third entry indicates whether the transformation is
+# redundant when c = 1
+transforms = [
+  (lambda ctx,x,c: x*c, '$y/$c', 0),
+  (lambda ctx,x,c: x/c, '$c*$y', 1),
+  (lambda ctx,x,c: c/x, '$c/$y', 0),
+  (lambda ctx,x,c: (x*c)**2, 'sqrt($y)/$c', 0),
+  (lambda ctx,x,c: (x/c)**2, '$c*sqrt($y)', 1),
+  (lambda ctx,x,c: (c/x)**2, '$c/sqrt($y)', 0),
+  (lambda ctx,x,c: c*x**2, 'sqrt($y)/sqrt($c)', 1),
+  (lambda ctx,x,c: x**2/c, 'sqrt($c)*sqrt($y)', 1),
+  (lambda ctx,x,c: c/x**2, 'sqrt($c)/sqrt($y)', 1),
+  (lambda ctx,x,c: ctx.sqrt(x*c), '$y**2/$c', 0),
+  (lambda ctx,x,c: ctx.sqrt(x/c), '$c*$y**2', 1),
+  (lambda ctx,x,c: ctx.sqrt(c/x), '$c/$y**2', 0),
+  (lambda ctx,x,c: c*ctx.sqrt(x), '$y**2/$c**2', 1),
+  (lambda ctx,x,c: ctx.sqrt(x)/c, '$c**2*$y**2', 1),
+  (lambda ctx,x,c: c/ctx.sqrt(x), '$c**2/$y**2', 1),
+  (lambda ctx,x,c: ctx.exp(x*c), 'log($y)/$c', 0),
+  (lambda ctx,x,c: ctx.exp(x/c), '$c*log($y)', 1),
+  (lambda ctx,x,c: ctx.exp(c/x), '$c/log($y)', 0),
+  (lambda ctx,x,c: c*ctx.exp(x), 'log($y/$c)', 1),
+  (lambda ctx,x,c: ctx.exp(x)/c, 'log($c*$y)', 1),
+  (lambda ctx,x,c: c/ctx.exp(x), 'log($c/$y)', 0),
+  (lambda ctx,x,c: ctx.ln(x*c), 'exp($y)/$c', 0),
+  (lambda ctx,x,c: ctx.ln(x/c), '$c*exp($y)', 1),
+  (lambda ctx,x,c: ctx.ln(c/x), '$c/exp($y)', 0),
+  (lambda ctx,x,c: c*ctx.ln(x), 'exp($y/$c)', 1),
+  (lambda ctx,x,c: ctx.ln(x)/c, 'exp($c*$y)', 1),
+  (lambda ctx,x,c: c/ctx.ln(x), 'exp($c/$y)', 0),
+]
+
+def identify(ctx, x, constants=[], tol=None, maxcoeff=1000, full=False,
+    verbose=False):
+    r"""
+    Given a real number `x`, ``identify(x)`` attempts to find an exact
+    formula for `x`. This formula is returned as a string. If no match
+    is found, ``None`` is returned. With ``full=True``, a list of
+    matching formulas is returned.
+
+    As a simple example, :func:`~mpmath.identify` will find an algebraic
+    formula for the golden ratio::
+
+        >>> from mpmath import *
+        >>> mp.dps = 15; mp.pretty = True
+        >>> identify(phi)
+        '((1+sqrt(5))/2)'
+
+    :func:`~mpmath.identify` can identify simple algebraic numbers and simple
+    combinations of given base constants, as well as certain basic
+    transformations thereof. More specifically, :func:`~mpmath.identify`
+    looks for the following:
+
+        1. Fractions
+        2. Quadratic algebraic numbers
+        3. Rational linear combinations of the base constants
+        4. Any of the above after first transforming `x` into `f(x)` where
+           `f(x)` is `1/x`, `\sqrt x`, `x^2`, `\log x` or `\exp x`, either
+           directly or with `x` or `f(x)` multiplied or divided by one of
+           the base constants
+        5. Products of fractional powers of the base constants and
+           small integers
+
+    Base constants can be given as a list of strings representing mpmath
+    expressions (:func:`~mpmath.identify` will ``eval`` the strings to numerical
+    values and use the original strings for the output), or as a dict of
+    formula:value pairs.
+
+    In order not to produce spurious results, :func:`~mpmath.identify` should
+    be used with high precision; preferably 50 digits or more.
+
+    **Examples**
+
+    Simple identifications can be performed safely at standard
+    precision. Here the default recognition of rational, algebraic,
+    and exp/log of algebraic numbers is demonstrated::
+
+        >>> mp.dps = 15
+        >>> identify(0.22222222222222222)
+        '(2/9)'
+        >>> identify(1.9662210973805663)
+        'sqrt(((24+sqrt(48))/8))'
+        >>> identify(4.1132503787829275)
+        'exp((sqrt(8)/2))'
+        >>> identify(0.881373587019543)
+        'log(((2+sqrt(8))/2))'
+
+    By default, :func:`~mpmath.identify` does not recognize `\pi`. At standard
+    precision it finds a not too useful approximation. At slightly
+    increased precision, this approximation is no longer accurate
+    enough and :func:`~mpmath.identify` more correctly returns ``None``::
+
+        >>> identify(pi)
+        '(2**(176/117)*3**(20/117)*5**(35/39))/(7**(92/117))'
+        >>> mp.dps = 30
+        >>> identify(pi)
+        >>>
+
+    Numbers such as `\pi`, and simple combinations of user-defined
+    constants, can be identified if they are provided explicitly::
+
+        >>> identify(3*pi-2*e, ['pi', 'e'])
+        '(3*pi + (-2)*e)'
+
+    Here is an example using a dict of constants. Note that the
+    constants need not be "atomic"; :func:`~mpmath.identify` can just
+    as well express the given number in terms of expressions
+    given by formulas::
+
+        >>> identify(pi+e, {'a':pi+2, 'b':2*e})
+        '((-2) + 1*a + (1/2)*b)'
+
+    Next, we attempt some identifications with a set of base constants.
+    It is necessary to increase the precision a bit.
+
+        >>> mp.dps = 50
+        >>> base = ['sqrt(2)','pi','log(2)']
+        >>> identify(0.25, base)
+        '(1/4)'
+        >>> identify(3*pi + 2*sqrt(2) + 5*log(2)/7, base)
+        '(2*sqrt(2) + 3*pi + (5/7)*log(2))'
+        >>> identify(exp(pi+2), base)
+        'exp((2 + 1*pi))'
+        >>> identify(1/(3+sqrt(2)), base)
+        '((3/7) + (-1/7)*sqrt(2))'
+        >>> identify(sqrt(2)/(3*pi+4), base)
+        'sqrt(2)/(4 + 3*pi)'
+        >>> identify(5**(mpf(1)/3)*pi*log(2)**2, base)
+        '5**(1/3)*pi*log(2)**2'
+
+    An example of an erroneous solution being found when too low
+    precision is used::
+
+        >>> mp.dps = 15
+        >>> identify(1/(3*pi-4*e+sqrt(8)), ['pi', 'e', 'sqrt(2)'])
+        '((11/25) + (-158/75)*pi + (76/75)*e + (44/15)*sqrt(2))'
+        >>> mp.dps = 50
+        >>> identify(1/(3*pi-4*e+sqrt(8)), ['pi', 'e', 'sqrt(2)'])
+        '1/(3*pi + (-4)*e + 2*sqrt(2))'
+
+    **Finding approximate solutions**
+
+    The tolerance ``tol`` defaults to 3/4 of the working precision.
+    Lowering the tolerance is useful for finding approximate matches.
+    We can for example try to generate approximations for pi::
+
+        >>> mp.dps = 15
+        >>> identify(pi, tol=1e-2)
+        '(22/7)'
+        >>> identify(pi, tol=1e-3)
+        '(355/113)'
+        >>> identify(pi, tol=1e-10)
+        '(5**(339/269))/(2**(64/269)*3**(13/269)*7**(92/269))'
+
+    With ``full=True``, and by supplying a few base constants,
+    ``identify`` can generate almost endless lists of approximations
+    for any number (the output below has been truncated to show only
+    the first few)::
+
+        >>> for p in identify(pi, ['e', 'catalan'], tol=1e-5, full=True):
+        ...     print(p)
+        ...  # doctest: +ELLIPSIS
+        e/log((6 + (-4/3)*e))
+        (3**3*5*e*catalan**2)/(2*7**2)
+        sqrt(((-13) + 1*e + 22*catalan))
+        log(((-6) + 24*e + 4*catalan)/e)
+        exp(catalan*((-1/5) + (8/15)*e))
+        catalan*(6 + (-6)*e + 15*catalan)
+        sqrt((5 + 26*e + (-3)*catalan))/e
+        e*sqrt(((-27) + 2*e + 25*catalan))
+        log(((-1) + (-11)*e + 59*catalan))
+        ((3/20) + (21/20)*e + (3/20)*catalan)
+        ...
+
+    The numerical values are roughly as close to `\pi` as permitted by the
+    specified tolerance:
+
+        >>> e/log(6-4*e/3)
+        3.14157719846001
+        >>> 135*e*catalan**2/98
+        3.14166950419369
+        >>> sqrt(e-13+22*catalan)
+        3.14158000062992
+        >>> log(24*e-6+4*catalan)-1
+        3.14158791577159
+
+    **Symbolic processing**
+
+    The output formula can be evaluated as a Python expression.
+    Note however that if fractions (like '2/3') are present in
+    the formula, Python's :func:`~mpmath.eval()` may erroneously perform
+    integer division. Note also that the output is not necessarily
+    in the algebraically simplest form::
+
+        >>> identify(sqrt(2))
+        '(sqrt(8)/2)'
+
+    As a solution to both problems, consider using SymPy's
+    :func:`~mpmath.sympify` to convert the formula into a symbolic expression.
+    SymPy can be used to pretty-print or further simplify the formula
+    symbolically::
+
+        >>> from sympy import sympify # doctest: +SKIP
+        >>> sympify(identify(sqrt(2))) # doctest: +SKIP
+        2**(1/2)
+
+    Sometimes :func:`~mpmath.identify` can simplify an expression further than
+    a symbolic algorithm::
+
+        >>> from sympy import simplify # doctest: +SKIP
+        >>> x = sympify('-1/(-3/2+(1/2)*5**(1/2))*(3/2-1/2*5**(1/2))**(1/2)') # doctest: +SKIP
+        >>> x # doctest: +SKIP
+        (3/2 - 5**(1/2)/2)**(-1/2)
+        >>> x = simplify(x) # doctest: +SKIP
+        >>> x # doctest: +SKIP
+        2/(6 - 2*5**(1/2))**(1/2)
+        >>> mp.dps = 30 # doctest: +SKIP
+        >>> x = sympify(identify(x.evalf(30))) # doctest: +SKIP
+        >>> x # doctest: +SKIP
+        1/2 + 5**(1/2)/2
+
+    (In fact, this functionality is available directly in SymPy as the
+    function :func:`~mpmath.nsimplify`, which is essentially a wrapper for
+    :func:`~mpmath.identify`.)
+
+    **Miscellaneous issues and limitations**
+
+    The input `x` must be a real number. All base constants must be
+    positive real numbers and must not be rationals or rational linear
+    combinations of each other.
+
+    The worst-case computation time grows quickly with the number of
+    base constants. Already with 3 or 4 base constants,
+    :func:`~mpmath.identify` may require several seconds to finish. To search
+    for relations among a large number of constants, you should
+    consider using :func:`~mpmath.pslq` directly.
+
+    The extended transformations are applied to x, not the constants
+    separately. As a result, ``identify`` will for example be able to
+    recognize ``exp(2*pi+3)`` with ``pi`` given as a base constant, but
+    not ``2*exp(pi)+3``. It will be able to recognize the latter if
+    ``exp(pi)`` is given explicitly as a base constant.
+
+    """
+
+    solutions = []
+
+    def addsolution(s):
+        if verbose: print("Found: ", s)
+        solutions.append(s)
+
+    x = ctx.mpf(x)
+
+    # Further along, x will be assumed positive
+    if x == 0:
+        if full: return ['0']
+        else:    return '0'
+    if x < 0:
+        sol = ctx.identify(-x, constants, tol, maxcoeff, full, verbose)
+        if sol is None:
+            return sol
+        if full:
+            return ["-(%s)"%s for s in sol]
+        else:
+            return "-(%s)" % sol
+
+    if tol:
+        tol = ctx.mpf(tol)
+    else:
+        tol = ctx.eps**0.7
+    M = maxcoeff
+
+    if constants:
+        if isinstance(constants, dict):
+            constants = [(ctx.mpf(v), name) for (name, v) in sorted(constants.items())]
+        else:
+            namespace = dict((name, getattr(ctx,name)) for name in dir(ctx))
+            constants = [(eval(p, namespace), p) for p in constants]
+    else:
+        constants = []
+
+    # We always want to find at least rational terms
+    if 1 not in [value for (name, value) in constants]:
+        constants = [(ctx.mpf(1), '1')] + constants
+
+    # PSLQ with simple algebraic and functional transformations
+    for ft, ftn, red in transforms:
+        for c, cn in constants:
+            if red and cn == '1':
+                continue
+            t = ft(ctx,x,c)
+            # Prevent exponential transforms from wreaking havoc
+            if abs(t) > M**2 or abs(t) < tol:
+                continue
+            # Linear combination of base constants
+            r = ctx.pslq([t] + [a[0] for a in constants], tol, M)
+            s = None
+            if r is not None and max(abs(uw) for uw in r) <= M and r[0]:
+                s = pslqstring(r, constants)
+            # Quadratic algebraic numbers
+            else:
+                q = ctx.pslq([ctx.one, t, t**2], tol, M)
+                if q is not None and len(q) == 3 and q[2]:
+                    aa, bb, cc = q
+                    if max(abs(aa),abs(bb),abs(cc)) <= M:
+                        s = quadraticstring(ctx,t,aa,bb,cc)
+            if s:
+                if cn == '1' and ('/$c' in ftn):
+                    s = ftn.replace('$y', s).replace('/$c', '')
+                else:
+                    s = ftn.replace('$y', s).replace('$c', cn)
+                addsolution(s)
+                if not full: return solutions[0]
+
+            if verbose:
+                print(".")
+
+    # Check for a direct multiplicative formula
+    if x != 1:
+        # Allow fractional powers of fractions
+        ilogs = [2,3,5,7]
+        # Watch out for existing fractional powers of fractions
+        logs = []
+        for a, s in constants:
+            if not sum(bool(ctx.findpoly(ctx.ln(a)/ctx.ln(i),1)) for i in ilogs):
+                logs.append((ctx.ln(a), s))
+        logs = [(ctx.ln(i),str(i)) for i in ilogs] + logs
+        r = ctx.pslq([ctx.ln(x)] + [a[0] for a in logs], tol, M)
+        if r is not None and max(abs(uw) for uw in r) <= M and r[0]:
+            addsolution(prodstring(r, logs))
+            if not full: return solutions[0]
+
+    if full:
+        return sorted(solutions, key=len)
+    else:
+        return None
+
+IdentificationMethods.pslq = pslq
+IdentificationMethods.findpoly = findpoly
+IdentificationMethods.identify = identify
+
+
+if __name__ == '__main__':
+    import doctest
+    doctest.testmod()

rl/Lib/site-packages/mpmath/libmp/__init__.py

@@ -0,0 +1,77 @@
+from .libmpf import (prec_to_dps, dps_to_prec, repr_dps,
+  round_down, round_up, round_floor, round_ceiling, round_nearest,
+  to_pickable, from_pickable, ComplexResult,
+  fzero, fnzero, fone, fnone, ftwo, ften, fhalf, fnan, finf, fninf,
+  math_float_inf, round_int, normalize, normalize1,
+  from_man_exp, from_int, to_man_exp, to_int, mpf_ceil, mpf_floor,
+  mpf_nint, mpf_frac,
+  from_float, from_npfloat, from_Decimal, to_float, from_rational, to_rational, to_fixed,
+  mpf_rand, mpf_eq, mpf_hash, mpf_cmp, mpf_lt, mpf_le, mpf_gt, mpf_ge,
+  mpf_pos, mpf_neg, mpf_abs, mpf_sign, mpf_add, mpf_sub, mpf_sum,
+  mpf_mul, mpf_mul_int, mpf_shift, mpf_frexp,
+  mpf_div, mpf_rdiv_int, mpf_mod, mpf_pow_int,
+  mpf_perturb,
+  to_digits_exp, to_str, str_to_man_exp, from_str, from_bstr, to_bstr,
+  mpf_sqrt, mpf_hypot)
+
+from .libmpc import (mpc_one, mpc_zero, mpc_two, mpc_half,
+  mpc_is_inf, mpc_is_infnan, mpc_to_str, mpc_to_complex, mpc_hash,
+  mpc_conjugate, mpc_is_nonzero, mpc_add, mpc_add_mpf,
+  mpc_sub, mpc_sub_mpf, mpc_pos, mpc_neg, mpc_shift, mpc_abs,
+  mpc_arg, mpc_floor, mpc_ceil,  mpc_nint, mpc_frac, mpc_mul, mpc_square,
+  mpc_mul_mpf, mpc_mul_imag_mpf, mpc_mul_int,
+  mpc_div, mpc_div_mpf, mpc_reciprocal, mpc_mpf_div,
+  complex_int_pow, mpc_pow, mpc_pow_mpf, mpc_pow_int,
+  mpc_sqrt, mpc_nthroot, mpc_cbrt, mpc_exp, mpc_log, mpc_cos, mpc_sin,
+  mpc_tan, mpc_cos_pi, mpc_sin_pi, mpc_cosh, mpc_sinh, mpc_tanh,
+  mpc_atan, mpc_acos, mpc_asin, mpc_asinh, mpc_acosh, mpc_atanh,
+  mpc_fibonacci, mpf_expj, mpf_expjpi, mpc_expj, mpc_expjpi,
+  mpc_cos_sin, mpc_cos_sin_pi)
+
+from .libelefun import (ln2_fixed, mpf_ln2, ln10_fixed, mpf_ln10,
+  pi_fixed, mpf_pi, e_fixed, mpf_e, phi_fixed, mpf_phi,
+  degree_fixed, mpf_degree,
+  mpf_pow, mpf_nthroot, mpf_cbrt, log_int_fixed, agm_fixed,
+  mpf_log, mpf_log_hypot, mpf_exp, mpf_cos_sin, mpf_cos, mpf_sin, mpf_tan,
+  mpf_cos_sin_pi, mpf_cos_pi, mpf_sin_pi, mpf_cosh_sinh,
+  mpf_cosh, mpf_sinh, mpf_tanh, mpf_atan, mpf_atan2, mpf_asin,
+  mpf_acos, mpf_asinh, mpf_acosh, mpf_atanh, mpf_fibonacci)
+
+from .libhyper import (NoConvergence, make_hyp_summator,
+  mpf_erf, mpf_erfc, mpf_ei, mpc_ei, mpf_e1, mpc_e1, mpf_expint,
+  mpf_ci_si, mpf_ci, mpf_si, mpc_ci, mpc_si, mpf_besseljn,
+  mpc_besseljn, mpf_agm, mpf_agm1, mpc_agm, mpc_agm1,
+  mpf_ellipk, mpc_ellipk, mpf_ellipe, mpc_ellipe)
+
+from .gammazeta import (catalan_fixed, mpf_catalan,
+  khinchin_fixed, mpf_khinchin, glaisher_fixed, mpf_glaisher,
+  apery_fixed, mpf_apery, euler_fixed, mpf_euler, mertens_fixed,
+  mpf_mertens, twinprime_fixed, mpf_twinprime,
+  mpf_bernoulli, bernfrac, mpf_gamma_int,
+  mpf_factorial, mpc_factorial, mpf_gamma, mpc_gamma,
+  mpf_loggamma, mpc_loggamma, mpf_rgamma, mpc_rgamma,
+  mpf_harmonic, mpc_harmonic, mpf_psi0, mpc_psi0,
+  mpf_psi, mpc_psi, mpf_zeta_int, mpf_zeta, mpc_zeta,
+  mpf_altzeta, mpc_altzeta, mpf_zetasum, mpc_zetasum)
+
+from .libmpi import (mpi_str,
+  mpi_from_str, mpi_to_str,
+  mpi_eq, mpi_ne,
+  mpi_lt, mpi_le, mpi_gt, mpi_ge,
+  mpi_add, mpi_sub, mpi_delta, mpi_mid,
+  mpi_pos, mpi_neg, mpi_abs, mpi_mul, mpi_div, mpi_exp,
+  mpi_log, mpi_sqrt, mpi_pow_int, mpi_pow, mpi_cos_sin,
+  mpi_cos, mpi_sin, mpi_tan, mpi_cot,
+  mpi_atan, mpi_atan2,
+  mpci_pos, mpci_neg, mpci_add, mpci_sub, mpci_mul, mpci_div, mpci_pow,
+  mpci_abs, mpci_pow, mpci_exp, mpci_log, mpci_cos, mpci_sin,
+  mpi_gamma, mpci_gamma, mpi_loggamma, mpci_loggamma,
+  mpi_rgamma, mpci_rgamma, mpi_factorial, mpci_factorial)
+
+from .libintmath import (trailing, bitcount, numeral, bin_to_radix,
+  isqrt, isqrt_small, isqrt_fast, sqrt_fixed, sqrtrem, ifib, ifac,
+  list_primes, isprime, moebius, gcd, eulernum, stirling1, stirling2)
+
+from .backend import (gmpy, sage, BACKEND, STRICT, MPZ, MPZ_TYPE,
+  MPZ_ZERO, MPZ_ONE, MPZ_TWO, MPZ_THREE, MPZ_FIVE, int_types,
+  HASH_MODULUS, HASH_BITS)

rl/Lib/site-packages/mpmath/libmp/backend.py

@@ -0,0 +1,115 @@
+import os
+import sys
+
+#----------------------------------------------------------------------------#
+# Support GMPY for high-speed large integer arithmetic.                      #
+#                                                                            #
+# To allow an external module to handle arithmetic, we need to make sure     #
+# that all high-precision variables are declared of the correct type. MPZ    #
+# is the constructor for the high-precision type. It defaults to Python's    #
+# long type but can be assinged another type, typically gmpy.mpz.            #
+#                                                                            #
+# MPZ must be used for the mantissa component of an mpf and must be used     #
+# for internal fixed-point operations.                                       #
+#                                                                            #
+# Side-effects                                                               #
+# 1) "is" cannot be used to test for special values. Must use "==".          #
+# 2) There are bugs in GMPY prior to v1.02 so we must use v1.03 or later.    #
+#----------------------------------------------------------------------------#
+
+# So we can import it from this module
+gmpy = None
+sage = None
+sage_utils = None
+
+if sys.version_info[0] < 3:
+    python3 = False
+else:
+    python3 = True
+
+BACKEND = 'python'
+
+if not python3:
+    MPZ = long
+    xrange = xrange
+    basestring = basestring
+
+    def exec_(_code_, _globs_=None, _locs_=None):
+        """Execute code in a namespace."""
+        if _globs_ is None:
+            frame = sys._getframe(1)
+            _globs_ = frame.f_globals
+            if _locs_ is None:
+                _locs_ = frame.f_locals
+            del frame
+        elif _locs_ is None:
+            _locs_ = _globs_
+        exec("""exec _code_ in _globs_, _locs_""")
+else:
+    MPZ = int
+    xrange = range
+    basestring = str
+
+    import builtins
+    exec_ = getattr(builtins, "exec")
+
+# Define constants for calculating hash on Python 3.2.
+if sys.version_info >= (3, 2):
+    HASH_MODULUS = sys.hash_info.modulus
+    if sys.hash_info.width == 32:
+        HASH_BITS = 31
+    else:
+        HASH_BITS = 61
+else:
+    HASH_MODULUS = None
+    HASH_BITS = None
+
+if 'MPMATH_NOGMPY' not in os.environ:
+    try:
+        try:
+            import gmpy2 as gmpy
+        except ImportError:
+            try:
+                import gmpy
+            except ImportError:
+                raise ImportError
+        if gmpy.version() >= '1.03':
+            BACKEND = 'gmpy'
+            MPZ = gmpy.mpz
+    except:
+        pass
+
+if ('MPMATH_NOSAGE' not in os.environ and 'SAGE_ROOT' in os.environ or
+        'MPMATH_SAGE' in os.environ):
+    try:
+        import sage.all
+        import sage.libs.mpmath.utils as _sage_utils
+        sage = sage.all
+        sage_utils = _sage_utils
+        BACKEND = 'sage'
+        MPZ = sage.Integer
+    except:
+        pass
+
+if 'MPMATH_STRICT' in os.environ:
+    STRICT = True
+else:
+    STRICT = False
+
+MPZ_TYPE = type(MPZ(0))
+MPZ_ZERO = MPZ(0)
+MPZ_ONE = MPZ(1)
+MPZ_TWO = MPZ(2)
+MPZ_THREE = MPZ(3)
+MPZ_FIVE = MPZ(5)
+
+try:
+    if BACKEND == 'python':
+        int_types = (int, long)
+    else:
+        int_types = (int, long, MPZ_TYPE)
+except NameError:
+    if BACKEND == 'python':
+        int_types = (int,)
+    else:
+        int_types = (int, MPZ_TYPE)

rl/Lib/site-packages/mpmath/libmp/libintmath.py

@@ -0,0 +1,584 @@
+"""
+Utility functions for integer math.
+
+TODO: rename, cleanup, perhaps move the gmpy wrapper code
+here from settings.py
+
+"""
+
+import math
+from bisect import bisect
+
+from .backend import xrange
+from .backend import BACKEND, gmpy, sage, sage_utils, MPZ, MPZ_ONE, MPZ_ZERO
+
+small_trailing = [0] * 256
+for j in range(1,8):
+    small_trailing[1<<j::1<<(j+1)] = [j] * (1<<(7-j))
+
+def giant_steps(start, target, n=2):
+    """
+    Return a list of integers ~=
+
+    [start, n*start, ..., target/n^2, target/n, target]
+
+    but conservatively rounded so that the quotient between two
+    successive elements is actually slightly less than n.
+
+    With n = 2, this describes suitable precision steps for a
+    quadratically convergent algorithm such as Newton's method;
+    with n = 3 steps for cubic convergence (Halley's method), etc.
+
+        >>> giant_steps(50,1000)
+        [66, 128, 253, 502, 1000]
+        >>> giant_steps(50,1000,4)
+        [65, 252, 1000]
+
+    """
+    L = [target]
+    while L[-1] > start*n:
+        L = L + [L[-1]//n + 2]
+    return L[::-1]
+
+def rshift(x, n):
+    """For an integer x, calculate x >> n with the fastest (floor)
+    rounding. Unlike the plain Python expression (x >> n), n is
+    allowed to be negative, in which case a left shift is performed."""
+    if n >= 0: return x >> n
+    else:      return x << (-n)
+
+def lshift(x, n):
+    """For an integer x, calculate x << n. Unlike the plain Python
+    expression (x << n), n is allowed to be negative, in which case a
+    right shift with default (floor) rounding is performed."""
+    if n >= 0: return x << n
+    else:      return x >> (-n)
+
+if BACKEND == 'sage':
+    import operator
+    rshift = operator.rshift
+    lshift = operator.lshift
+
+def python_trailing(n):
+    """Count the number of trailing zero bits in abs(n)."""
+    if not n:
+        return 0
+    low_byte = n & 0xff
+    if low_byte:
+        return small_trailing[low_byte]
+    t = 8
+    n >>= 8
+    while not n & 0xff:
+        n >>= 8
+        t += 8
+    return t + small_trailing[n & 0xff]
+
+if BACKEND == 'gmpy':
+    if gmpy.version() >= '2':
+        def gmpy_trailing(n):
+            """Count the number of trailing zero bits in abs(n) using gmpy."""
+            if n: return MPZ(n).bit_scan1()
+            else: return 0
+    else:
+        def gmpy_trailing(n):
+            """Count the number of trailing zero bits in abs(n) using gmpy."""
+            if n: return MPZ(n).scan1()
+            else: return 0
+
+# Small powers of 2
+powers = [1<<_ for _ in range(300)]
+
+def python_bitcount(n):
+    """Calculate bit size of the nonnegative integer n."""
+    bc = bisect(powers, n)
+    if bc != 300:
+        return bc
+    bc = int(math.log(n, 2)) - 4
+    return bc + bctable[n>>bc]
+
+def gmpy_bitcount(n):
+    """Calculate bit size of the nonnegative integer n."""
+    if n: return MPZ(n).numdigits(2)
+    else: return 0
+
+#def sage_bitcount(n):
+#    if n: return MPZ(n).nbits()
+#    else: return 0
+
+def sage_trailing(n):
+    return MPZ(n).trailing_zero_bits()
+
+if BACKEND == 'gmpy':
+    bitcount = gmpy_bitcount
+    trailing = gmpy_trailing
+elif BACKEND == 'sage':
+    sage_bitcount = sage_utils.bitcount
+    bitcount = sage_bitcount
+    trailing = sage_trailing
+else:
+    bitcount = python_bitcount
+    trailing = python_trailing
+
+if BACKEND == 'gmpy' and 'bit_length' in dir(gmpy):
+    bitcount = gmpy.bit_length
+
+# Used to avoid slow function calls as far as possible
+trailtable = [trailing(n) for n in range(256)]
+bctable = [bitcount(n) for n in range(1024)]
+
+# TODO: speed up for bases 2, 4, 8, 16, ...
+
+def bin_to_radix(x, xbits, base, bdigits):
+    """Changes radix of a fixed-point number; i.e., converts
+    x * 2**xbits to floor(x * 10**bdigits)."""
+    return x * (MPZ(base)**bdigits) >> xbits
+
+stddigits = '0123456789abcdefghijklmnopqrstuvwxyz'
+
+def small_numeral(n, base=10, digits=stddigits):
+    """Return the string numeral of a positive integer in an arbitrary
+    base. Most efficient for small input."""
+    if base == 10:
+        return str(n)
+    digs = []
+    while n:
+        n, digit = divmod(n, base)
+        digs.append(digits[digit])
+    return "".join(digs[::-1])
+
+def numeral_python(n, base=10, size=0, digits=stddigits):
+    """Represent the integer n as a string of digits in the given base.
+    Recursive division is used to make this function about 3x faster
+    than Python's str() for converting integers to decimal strings.
+
+    The 'size' parameters specifies the number of digits in n; this
+    number is only used to determine splitting points and need not be
+    exact."""
+    if n <= 0:
+        if not n:
+            return "0"
+        return "-" + numeral(-n, base, size, digits)
+    # Fast enough to do directly
+    if size < 250:
+        return small_numeral(n, base, digits)
+    # Divide in half
+    half = (size // 2) + (size & 1)
+    A, B = divmod(n, base**half)
+    ad = numeral(A, base, half, digits)
+    bd = numeral(B, base, half, digits).rjust(half, "0")
+    return ad + bd
+
+def numeral_gmpy(n, base=10, size=0, digits=stddigits):
+    """Represent the integer n as a string of digits in the given base.
+    Recursive division is used to make this function about 3x faster
+    than Python's str() for converting integers to decimal strings.
+
+    The 'size' parameters specifies the number of digits in n; this
+    number is only used to determine splitting points and need not be
+    exact."""
+    if n < 0:
+        return "-" + numeral(-n, base, size, digits)
+    # gmpy.digits() may cause a segmentation fault when trying to convert
+    # extremely large values to a string. The size limit may need to be
+    # adjusted on some platforms, but 1500000 works on Windows and Linux.
+    if size < 1500000:
+        return gmpy.digits(n, base)
+    # Divide in half
+    half = (size // 2) + (size & 1)
+    A, B = divmod(n, MPZ(base)**half)
+    ad = numeral(A, base, half, digits)
+    bd = numeral(B, base, half, digits).rjust(half, "0")
+    return ad + bd
+
+if BACKEND == "gmpy":
+    numeral = numeral_gmpy
+else:
+    numeral = numeral_python
+
+_1_800 = 1<<800
+_1_600 = 1<<600
+_1_400 = 1<<400
+_1_200 = 1<<200
+_1_100 = 1<<100
+_1_50 = 1<<50
+
+def isqrt_small_python(x):
+    """
+    Correctly (floor) rounded integer square root, using
+    division. Fast up to ~200 digits.
+    """
+    if not x:
+        return x
+    if x < _1_800:
+        # Exact with IEEE double precision arithmetic
+        if x < _1_50:
+            return int(x**0.5)
+        # Initial estimate can be any integer >= the true root; round up
+        r = int(x**0.5 * 1.00000000000001) + 1
+    else:
+        bc = bitcount(x)
+        n = bc//2
+        r = int((x>>(2*n-100))**0.5+2)<<(n-50)  # +2 is to round up
+    # The following iteration now precisely computes floor(sqrt(x))
+    # See e.g. Crandall & Pomerance, "Prime Numbers: A Computational
+    # Perspective"
+    while 1:
+        y = (r+x//r)>>1
+        if y >= r:
+            return r
+        r = y
+
+def isqrt_fast_python(x):
+    """
+    Fast approximate integer square root, computed using division-free
+    Newton iteration for large x. For random integers the result is almost
+    always correct (floor(sqrt(x))), but is 1 ulp too small with a roughly
+    0.1% probability. If x is very close to an exact square, the answer is
+    1 ulp wrong with high probability.
+
+    With 0 guard bits, the largest error over a set of 10^5 random
+    inputs of size 1-10^5 bits was 3 ulp. The use of 10 guard bits
+    almost certainly guarantees a max 1 ulp error.
+    """
+    # Use direct division-based iteration if sqrt(x) < 2^400
+    # Assume floating-point square root accurate to within 1 ulp, then:
+    # 0 Newton iterations good to 52 bits
+    # 1 Newton iterations good to 104 bits
+    # 2 Newton iterations good to 208 bits
+    # 3 Newton iterations good to 416 bits
+    if x < _1_800:
+        y = int(x**0.5)
+        if x >= _1_100:
+            y = (y + x//y) >> 1
+            if x >= _1_200:
+                y = (y + x//y) >> 1
+                if x >= _1_400:
+                    y = (y + x//y) >> 1
+        return y
+    bc = bitcount(x)
+    guard_bits = 10
+    x <<= 2*guard_bits
+    bc += 2*guard_bits
+    bc += (bc&1)
+    hbc = bc//2
+    startprec = min(50, hbc)
+    # Newton iteration for 1/sqrt(x), with floating-point starting value
+    r = int(2.0**(2*startprec) * (x >> (bc-2*startprec)) ** -0.5)
+    pp = startprec
+    for p in giant_steps(startprec, hbc):
+        # r**2, scaled from real size 2**(-bc) to 2**p
+        r2 = (r*r) >> (2*pp - p)
+        # x*r**2, scaled from real size ~1.0 to 2**p
+        xr2 = ((x >> (bc-p)) * r2) >> p
+        # New value of r, scaled from real size 2**(-bc/2) to 2**p
+        r = (r * ((3<<p) - xr2)) >> (pp+1)
+        pp = p
+    # (1/sqrt(x))*x = sqrt(x)
+    return (r*(x>>hbc)) >> (p+guard_bits)
+
+def sqrtrem_python(x):
+    """Correctly rounded integer (floor) square root with remainder."""
+    # to check cutoff:
+    # plot(lambda x: timing(isqrt, 2**int(x)), [0,2000])
+    if x < _1_600:
+        y = isqrt_small_python(x)
+        return y, x - y*y
+    y = isqrt_fast_python(x) + 1
+    rem = x - y*y
+    # Correct remainder
+    while rem < 0:
+        y -= 1
+        rem += (1+2*y)
+    else:
+        if rem:
+            while rem > 2*(1+y):
+                y += 1
+                rem -= (1+2*y)
+    return y, rem
+
+def isqrt_python(x):
+    """Integer square root with correct (floor) rounding."""
+    return sqrtrem_python(x)[0]
+
+def sqrt_fixed(x, prec):
+    return isqrt_fast(x<<prec)
+
+sqrt_fixed2 = sqrt_fixed
+
+if BACKEND == 'gmpy':
+    if gmpy.version() >= '2':
+        isqrt_small = isqrt_fast = isqrt = gmpy.isqrt
+        sqrtrem = gmpy.isqrt_rem
+    else:
+        isqrt_small = isqrt_fast = isqrt = gmpy.sqrt
+        sqrtrem = gmpy.sqrtrem
+elif BACKEND == 'sage':
+    isqrt_small = isqrt_fast = isqrt = \
+        getattr(sage_utils, "isqrt", lambda n: MPZ(n).isqrt())
+    sqrtrem = lambda n: MPZ(n).sqrtrem()
+else:
+    isqrt_small = isqrt_small_python
+    isqrt_fast = isqrt_fast_python
+    isqrt = isqrt_python
+    sqrtrem = sqrtrem_python
+
+
+def ifib(n, _cache={}):
+    """Computes the nth Fibonacci number as an integer, for
+    integer n."""
+    if n < 0:
+        return (-1)**(-n+1) * ifib(-n)
+    if n in _cache:
+        return _cache[n]
+    m = n
+    # Use Dijkstra's logarithmic algorithm
+    # The following implementation is basically equivalent to
+    # http://en.literateprograms.org/Fibonacci_numbers_(Scheme)
+    a, b, p, q = MPZ_ONE, MPZ_ZERO, MPZ_ZERO, MPZ_ONE
+    while n:
+        if n & 1:
+            aq = a*q
+            a, b = b*q+aq+a*p, b*p+aq
+            n -= 1
+        else:
+            qq = q*q
+            p, q = p*p+qq, qq+2*p*q
+            n >>= 1
+    if m < 250:
+        _cache[m] = b
+    return b
+
+MAX_FACTORIAL_CACHE = 1000
+
+def ifac(n, memo={0:1, 1:1}):
+    """Return n factorial (for integers n >= 0 only)."""
+    f = memo.get(n)
+    if f:
+        return f
+    k = len(memo)
+    p = memo[k-1]
+    MAX = MAX_FACTORIAL_CACHE
+    while k <= n:
+        p *= k
+        if k <= MAX:
+            memo[k] = p
+        k += 1
+    return p
+
+def ifac2(n, memo_pair=[{0:1}, {1:1}]):
+    """Return n!! (double factorial), integers n >= 0 only."""
+    memo = memo_pair[n&1]
+    f = memo.get(n)
+    if f:
+        return f
+    k = max(memo)
+    p = memo[k]
+    MAX = MAX_FACTORIAL_CACHE
+    while k < n:
+        k += 2
+        p *= k
+        if k <= MAX:
+            memo[k] = p
+    return p
+
+if BACKEND == 'gmpy':
+    ifac = gmpy.fac
+elif BACKEND == 'sage':
+    ifac = lambda n: int(sage.factorial(n))
+    ifib = sage.fibonacci
+
+def list_primes(n):
+    n = n + 1
+    sieve = list(xrange(n))
+    sieve[:2] = [0, 0]
+    for i in xrange(2, int(n**0.5)+1):
+        if sieve[i]:
+            for j in xrange(i**2, n, i):
+                sieve[j] = 0
+    return [p for p in sieve if p]
+
+if BACKEND == 'sage':
+    # Note: it is *VERY* important for performance that we convert
+    # the list to Python ints.
+    def list_primes(n):
+        return [int(_) for _ in sage.primes(n+1)]
+
+small_odd_primes = (3,5,7,11,13,17,19,23,29,31,37,41,43,47)
+small_odd_primes_set = set(small_odd_primes)
+
+def isprime(n):
+    """
+    Determines whether n is a prime number. A probabilistic test is
+    performed if n is very large. No special trick is used for detecting
+    perfect powers.
+
+        >>> sum(list_primes(100000))
+        454396537
+        >>> sum(n*isprime(n) for n in range(100000))
+        454396537
+
+    """
+    n = int(n)
+    if not n & 1:
+        return n == 2
+    if n < 50:
+        return n in small_odd_primes_set
+    for p in small_odd_primes:
+        if not n % p:
+            return False
+    m = n-1
+    s = trailing(m)
+    d = m >> s
+    def test(a):
+        x = pow(a,d,n)
+        if x == 1 or x == m:
+            return True
+        for r in xrange(1,s):
+            x = x**2 % n
+            if x == m:
+                return True
+        return False
+    # See http://primes.utm.edu/prove/prove2_3.html
+    if n < 1373653:
+        witnesses = [2,3]
+    elif n < 341550071728321:
+        witnesses = [2,3,5,7,11,13,17]
+    else:
+        witnesses = small_odd_primes
+    for a in witnesses:
+        if not test(a):
+            return False
+    return True
+
+def moebius(n):
+    """
+    Evaluates the Moebius function which is `mu(n) = (-1)^k` if `n`
+    is a product of `k` distinct primes and `mu(n) = 0` otherwise.
+
+    TODO: speed up using factorization
+    """
+    n = abs(int(n))
+    if n < 2:
+        return n
+    factors = []
+    for p in xrange(2, n+1):
+        if not (n % p):
+            if not (n % p**2):
+                return 0
+            if not sum(p % f for f in factors):
+                factors.append(p)
+    return (-1)**len(factors)
+
+def gcd(*args):
+    a = 0
+    for b in args:
+        if a:
+            while b:
+                a, b = b, a % b
+        else:
+            a = b
+    return a
+
+
+#  Comment by Juan Arias de Reyna:
+#
+#  I learn this method to compute EulerE[2n] from van de Lune.
+#
+#  We apply the formula   EulerE[2n] = (-1)^n 2**(-2n) sum_{j=0}^n a(2n,2j+1)
+#
+#  where the numbers a(n,j) vanish for  j > n+1 or j <= -1  and satisfies
+#
+#  a(0,-1) = a(0,0) = 0;  a(0,1)= 1; a(0,2) = a(0,3) = 0
+#
+#  a(n,j) = a(n-1,j)                              when n+j is even
+#  a(n,j) = (j-1) a(n-1,j-1) + (j+1) a(n-1,j+1)   when n+j is odd
+#
+#
+#  But we can use only one array unidimensional a(j) since to compute
+#  a(n,j) we only need to know a(n-1,k) where k and j are of different parity
+#  and we have not to conserve the used values.
+#
+#  We cached up the values of Euler numbers to sufficiently high order.
+#
+#  Important Observation: If we pretend to use the numbers
+#     EulerE[1], EulerE[2], ... , EulerE[n]
+#     it is convenient to compute first EulerE[n], since the algorithm
+#     computes first all
+#     the previous ones, and keeps them in the CACHE
+
+MAX_EULER_CACHE = 500
+
+def eulernum(m, _cache={0:MPZ_ONE}):
+    r"""
+    Computes the Euler numbers `E(n)`, which can be defined as
+    coefficients of the Taylor expansion of `1/cosh x`:
+
+    .. math ::
+
+        \frac{1}{\cosh x} = \sum_{n=0}^\infty \frac{E_n}{n!} x^n
+
+    Example::
+
+        >>> [int(eulernum(n)) for n in range(11)]
+        [1, 0, -1, 0, 5, 0, -61, 0, 1385, 0, -50521]
+        >>> [int(eulernum(n)) for n in range(11)]   # test cache
+        [1, 0, -1, 0, 5, 0, -61, 0, 1385, 0, -50521]
+
+    """
+    # for odd m > 1, the Euler numbers are zero
+    if m & 1:
+        return MPZ_ZERO
+    f = _cache.get(m)
+    if f:
+        return f
+    MAX = MAX_EULER_CACHE
+    n = m
+    a = [MPZ(_) for _ in [0,0,1,0,0,0]]
+    for  n in range(1, m+1):
+        for j in range(n+1, -1, -2):
+            a[j+1] = (j-1)*a[j] + (j+1)*a[j+2]
+        a.append(0)
+        suma = 0
+        for k in range(n+1, -1, -2):
+            suma += a[k+1]
+            if n <= MAX:
+                _cache[n] = ((-1)**(n//2))*(suma // 2**n)
+        if n == m:
+            return ((-1)**(n//2))*suma // 2**n
+
+def stirling1(n, k):
+    """
+    Stirling number of the first kind.
+    """
+    if n < 0 or k < 0:
+        raise ValueError
+    if k >= n:
+        return MPZ(n == k)
+    if k < 1:
+        return MPZ_ZERO
+    L = [MPZ_ZERO] * (k+1)
+    L[1] = MPZ_ONE
+    for m in xrange(2, n+1):
+        for j in xrange(min(k, m), 0, -1):
+            L[j] = (m-1) * L[j] + L[j-1]
+    return (-1)**(n+k) * L[k]
+
+def stirling2(n, k):
+    """
+    Stirling number of the second kind.
+    """
+    if n < 0 or k < 0:
+        raise ValueError
+    if k >= n:
+        return MPZ(n == k)
+    if k <= 1:
+        return MPZ(k == 1)
+    s = MPZ_ZERO
+    t = MPZ_ONE
+    for j in xrange(k+1):
+        if (k + j) & 1:
+            s -= t * MPZ(j)**n
+        else:
+            s += t * MPZ(j)**n
+        t = t * (k - j) // (j + 1)
+    return s // ifac(k)

rl/Lib/site-packages/mpmath/libmp/libmpc.py

@@ -0,0 +1,835 @@
+"""
+Low-level functions for complex arithmetic.
+"""
+
+import sys
+
+from .backend import MPZ, MPZ_ZERO, MPZ_ONE, MPZ_TWO, BACKEND
+
+from .libmpf import (\
+    round_floor, round_ceiling, round_down, round_up,
+    round_nearest, round_fast, bitcount,
+    bctable, normalize, normalize1, reciprocal_rnd, rshift, lshift, giant_steps,
+    negative_rnd,
+    to_str, to_fixed, from_man_exp, from_float, to_float, from_int, to_int,
+    fzero, fone, ftwo, fhalf, finf, fninf, fnan, fnone,
+    mpf_abs, mpf_pos, mpf_neg, mpf_add, mpf_sub, mpf_mul,
+    mpf_div, mpf_mul_int, mpf_shift, mpf_sqrt, mpf_hypot,
+    mpf_rdiv_int, mpf_floor, mpf_ceil, mpf_nint, mpf_frac,
+    mpf_sign, mpf_hash,
+    ComplexResult
+)
+
+from .libelefun import (\
+    mpf_pi, mpf_exp, mpf_log, mpf_cos_sin, mpf_cosh_sinh, mpf_tan, mpf_pow_int,
+    mpf_log_hypot,
+    mpf_cos_sin_pi, mpf_phi,
+    mpf_cos, mpf_sin, mpf_cos_pi, mpf_sin_pi,
+    mpf_atan, mpf_atan2, mpf_cosh, mpf_sinh, mpf_tanh,
+    mpf_asin, mpf_acos, mpf_acosh, mpf_nthroot, mpf_fibonacci
+)
+
+# An mpc value is a (real, imag) tuple
+mpc_one = fone, fzero
+mpc_zero = fzero, fzero
+mpc_two = ftwo, fzero
+mpc_half = (fhalf, fzero)
+
+_infs = (finf, fninf)
+_infs_nan = (finf, fninf, fnan)
+
+def mpc_is_inf(z):
+    """Check if either real or imaginary part is infinite"""
+    re, im = z
+    if re in _infs: return True
+    if im in _infs: return True
+    return False
+
+def mpc_is_infnan(z):
+    """Check if either real or imaginary part is infinite or nan"""
+    re, im = z
+    if re in _infs_nan: return True
+    if im in _infs_nan: return True
+    return False
+
+def mpc_to_str(z, dps, **kwargs):
+    re, im = z
+    rs = to_str(re, dps)
+    if im[0]:
+        return rs + " - " + to_str(mpf_neg(im), dps, **kwargs) + "j"
+    else:
+        return rs + " + " + to_str(im, dps, **kwargs) + "j"
+
+def mpc_to_complex(z, strict=False, rnd=round_fast):
+    re, im = z
+    return complex(to_float(re, strict, rnd), to_float(im, strict, rnd))
+
+def mpc_hash(z):
+    if sys.version_info >= (3, 2):
+        re, im = z
+        h = mpf_hash(re) + sys.hash_info.imag * mpf_hash(im)
+        # Need to reduce either module 2^32 or 2^64
+        h = h % (2**sys.hash_info.width)
+        return int(h)
+    else:
+        try:
+            return hash(mpc_to_complex(z, strict=True))
+        except OverflowError:
+            return hash(z)
+
+def mpc_conjugate(z, prec, rnd=round_fast):
+    re, im = z
+    return re, mpf_neg(im, prec, rnd)
+
+def mpc_is_nonzero(z):
+    return z != mpc_zero
+
+def mpc_add(z, w, prec, rnd=round_fast):
+    a, b = z
+    c, d = w
+    return mpf_add(a, c, prec, rnd), mpf_add(b, d, prec, rnd)
+
+def mpc_add_mpf(z, x, prec, rnd=round_fast):
+    a, b = z
+    return mpf_add(a, x, prec, rnd), b
+
+def mpc_sub(z, w, prec=0, rnd=round_fast):
+    a, b = z
+    c, d = w
+    return mpf_sub(a, c, prec, rnd), mpf_sub(b, d, prec, rnd)
+
+def mpc_sub_mpf(z, p, prec=0, rnd=round_fast):
+    a, b = z
+    return mpf_sub(a, p, prec, rnd), b
+
+def mpc_pos(z, prec, rnd=round_fast):
+    a, b = z
+    return mpf_pos(a, prec, rnd), mpf_pos(b, prec, rnd)
+
+def mpc_neg(z, prec=None, rnd=round_fast):
+    a, b = z
+    return mpf_neg(a, prec, rnd), mpf_neg(b, prec, rnd)
+
+def mpc_shift(z, n):
+    a, b = z
+    return mpf_shift(a, n), mpf_shift(b, n)
+
+def mpc_abs(z, prec, rnd=round_fast):
+    """Absolute value of a complex number, |a+bi|.
+    Returns an mpf value."""
+    a, b = z
+    return mpf_hypot(a, b, prec, rnd)
+
+def mpc_arg(z, prec, rnd=round_fast):
+    """Argument of a complex number. Returns an mpf value."""
+    a, b = z
+    return mpf_atan2(b, a, prec, rnd)
+
+def mpc_floor(z, prec, rnd=round_fast):
+    a, b = z
+    return mpf_floor(a, prec, rnd), mpf_floor(b, prec, rnd)
+
+def mpc_ceil(z, prec, rnd=round_fast):
+    a, b = z
+    return mpf_ceil(a, prec, rnd), mpf_ceil(b, prec, rnd)
+
+def mpc_nint(z, prec, rnd=round_fast):
+    a, b = z
+    return mpf_nint(a, prec, rnd), mpf_nint(b, prec, rnd)
+
+def mpc_frac(z, prec, rnd=round_fast):
+    a, b = z
+    return mpf_frac(a, prec, rnd), mpf_frac(b, prec, rnd)
+
+
+def mpc_mul(z, w, prec, rnd=round_fast):
+    """
+    Complex multiplication.
+
+    Returns the real and imaginary part of (a+bi)*(c+di), rounded to
+    the specified precision. The rounding mode applies to the real and
+    imaginary parts separately.
+    """
+    a, b = z
+    c, d = w
+    p = mpf_mul(a, c)
+    q = mpf_mul(b, d)
+    r = mpf_mul(a, d)
+    s = mpf_mul(b, c)
+    re = mpf_sub(p, q, prec, rnd)
+    im = mpf_add(r, s, prec, rnd)
+    return re, im
+
+def mpc_square(z, prec, rnd=round_fast):
+    # (a+b*I)**2 == a**2 - b**2 + 2*I*a*b
+    a, b = z
+    p = mpf_mul(a,a)
+    q = mpf_mul(b,b)
+    r = mpf_mul(a,b, prec, rnd)
+    re = mpf_sub(p, q, prec, rnd)
+    im = mpf_shift(r, 1)
+    return re, im
+
+def mpc_mul_mpf(z, p, prec, rnd=round_fast):
+    a, b = z
+    re = mpf_mul(a, p, prec, rnd)
+    im = mpf_mul(b, p, prec, rnd)
+    return re, im
+
+def mpc_mul_imag_mpf(z, x, prec, rnd=round_fast):
+    """
+    Multiply the mpc value z by I*x where x is an mpf value.
+    """
+    a, b = z
+    re = mpf_neg(mpf_mul(b, x, prec, rnd))
+    im = mpf_mul(a, x, prec, rnd)
+    return re, im
+
+def mpc_mul_int(z, n, prec, rnd=round_fast):
+    a, b = z
+    re = mpf_mul_int(a, n, prec, rnd)
+    im = mpf_mul_int(b, n, prec, rnd)
+    return re, im
+
+def mpc_div(z, w, prec, rnd=round_fast):
+    a, b = z
+    c, d = w
+    wp = prec + 10
+    # mag = c*c + d*d
+    mag = mpf_add(mpf_mul(c, c), mpf_mul(d, d), wp)
+    # (a*c+b*d)/mag, (b*c-a*d)/mag
+    t = mpf_add(mpf_mul(a,c), mpf_mul(b,d), wp)
+    u = mpf_sub(mpf_mul(b,c), mpf_mul(a,d), wp)
+    return mpf_div(t,mag,prec,rnd), mpf_div(u,mag,prec,rnd)
+
+def mpc_div_mpf(z, p, prec, rnd=round_fast):
+    """Calculate z/p where p is real"""
+    a, b = z
+    re = mpf_div(a, p, prec, rnd)
+    im = mpf_div(b, p, prec, rnd)
+    return re, im
+
+def mpc_reciprocal(z, prec, rnd=round_fast):
+    """Calculate 1/z efficiently"""
+    a, b = z
+    m = mpf_add(mpf_mul(a,a),mpf_mul(b,b),prec+10)
+    re = mpf_div(a, m, prec, rnd)
+    im = mpf_neg(mpf_div(b, m, prec, rnd))
+    return re, im
+
+def mpc_mpf_div(p, z, prec, rnd=round_fast):
+    """Calculate p/z where p is real efficiently"""
+    a, b = z
+    m = mpf_add(mpf_mul(a,a),mpf_mul(b,b), prec+10)
+    re = mpf_div(mpf_mul(a,p), m, prec, rnd)
+    im = mpf_div(mpf_neg(mpf_mul(b,p)), m, prec, rnd)
+    return re, im
+
+def complex_int_pow(a, b, n):
+    """Complex integer power: computes (a+b*I)**n exactly for
+    nonnegative n (a and b must be Python ints)."""
+    wre = 1
+    wim = 0
+    while n:
+        if n & 1:
+            wre, wim = wre*a - wim*b, wim*a + wre*b
+            n -= 1
+        a, b = a*a - b*b, 2*a*b
+        n //= 2
+    return wre, wim
+
+def mpc_pow(z, w, prec, rnd=round_fast):
+    if w[1] == fzero:
+        return mpc_pow_mpf(z, w[0], prec, rnd)
+    return mpc_exp(mpc_mul(mpc_log(z, prec+10), w, prec+10), prec, rnd)
+
+def mpc_pow_mpf(z, p, prec, rnd=round_fast):
+    psign, pman, pexp, pbc = p
+    if pexp >= 0:
+        return mpc_pow_int(z, (-1)**psign * (pman<<pexp), prec, rnd)
+    if pexp == -1:
+        sqrtz = mpc_sqrt(z, prec+10)
+        return mpc_pow_int(sqrtz, (-1)**psign * pman, prec, rnd)
+    return mpc_exp(mpc_mul_mpf(mpc_log(z, prec+10), p, prec+10), prec, rnd)
+
+def mpc_pow_int(z, n, prec, rnd=round_fast):
+    a, b = z
+    if b == fzero:
+        return mpf_pow_int(a, n, prec, rnd), fzero
+    if a == fzero:
+        v = mpf_pow_int(b, n, prec, rnd)
+        n %= 4
+        if n == 0:
+            return v, fzero
+        elif n == 1:
+            return fzero, v
+        elif n == 2:
+            return mpf_neg(v), fzero
+        elif n == 3:
+            return fzero, mpf_neg(v)
+    if n == 0: return mpc_one
+    if n == 1: return mpc_pos(z, prec, rnd)
+    if n == 2: return mpc_square(z, prec, rnd)
+    if n == -1: return mpc_reciprocal(z, prec, rnd)
+    if n < 0: return mpc_reciprocal(mpc_pow_int(z, -n, prec+4), prec, rnd)
+    asign, aman, aexp, abc = a
+    bsign, bman, bexp, bbc = b
+    if asign: aman = -aman
+    if bsign: bman = -bman
+    de = aexp - bexp
+    abs_de = abs(de)
+    exact_size = n*(abs_de + max(abc, bbc))
+    if exact_size < 10000:
+        if de > 0:
+            aman <<= de
+            aexp = bexp
+        else:
+            bman <<= (-de)
+            bexp = aexp
+        re, im = complex_int_pow(aman, bman, n)
+        re = from_man_exp(re, int(n*aexp), prec, rnd)
+        im = from_man_exp(im, int(n*bexp), prec, rnd)
+        return re, im
+    return mpc_exp(mpc_mul_int(mpc_log(z, prec+10), n, prec+10), prec, rnd)
+
+def mpc_sqrt(z, prec, rnd=round_fast):
+    """Complex square root (principal branch).
+
+    We have sqrt(a+bi) = sqrt((r+a)/2) + b/sqrt(2*(r+a))*i where
+    r = abs(a+bi), when a+bi is not a negative real number."""
+    a, b = z
+    if b == fzero:
+        if a == fzero:
+            return (a, b)
+        # When a+bi is a negative real number, we get a real sqrt times i
+        if a[0]:
+            im = mpf_sqrt(mpf_neg(a), prec, rnd)
+            return (fzero, im)
+        else:
+            re = mpf_sqrt(a, prec, rnd)
+            return (re, fzero)
+    wp = prec+20
+    if not a[0]:                               # case a positive
+        t  = mpf_add(mpc_abs((a, b), wp), a, wp)  # t = abs(a+bi) + a
+        u = mpf_shift(t, -1)                      # u = t/2
+        re = mpf_sqrt(u, prec, rnd)               # re = sqrt(u)
+        v = mpf_shift(t, 1)                       # v = 2*t
+        w  = mpf_sqrt(v, wp)                      # w = sqrt(v)
+        im = mpf_div(b, w, prec, rnd)             # im = b / w
+    else:                                      # case a negative
+        t = mpf_sub(mpc_abs((a, b), wp), a, wp)   # t = abs(a+bi) - a
+        u = mpf_shift(t, -1)                      # u = t/2
+        im = mpf_sqrt(u, prec, rnd)               # im = sqrt(u)
+        v = mpf_shift(t, 1)                       # v = 2*t
+        w  = mpf_sqrt(v, wp)                      # w = sqrt(v)
+        re = mpf_div(b, w, prec, rnd)             # re = b/w
+        if b[0]:
+            re = mpf_neg(re)
+            im = mpf_neg(im)
+    return re, im
+
+def mpc_nthroot_fixed(a, b, n, prec):
+    # a, b signed integers at fixed precision prec
+    start = 50
+    a1 = int(rshift(a, prec - n*start))
+    b1 = int(rshift(b, prec - n*start))
+    try:
+        r = (a1 + 1j * b1)**(1.0/n)
+        re = r.real
+        im = r.imag
+        re = MPZ(int(re))
+        im = MPZ(int(im))
+    except OverflowError:
+        a1 = from_int(a1, start)
+        b1 = from_int(b1, start)
+        fn = from_int(n)
+        nth = mpf_rdiv_int(1, fn, start)
+        re, im = mpc_pow((a1, b1), (nth, fzero), start)
+        re = to_int(re)
+        im = to_int(im)
+    extra = 10
+    prevp = start
+    extra1 = n
+    for p in giant_steps(start, prec+extra):
+        # this is slow for large n, unlike int_pow_fixed
+        re2, im2 = complex_int_pow(re, im, n-1)
+        re2 = rshift(re2, (n-1)*prevp - p - extra1)
+        im2 = rshift(im2, (n-1)*prevp - p - extra1)
+        r4 = (re2*re2 + im2*im2) >> (p + extra1)
+        ap = rshift(a, prec - p)
+        bp = rshift(b, prec - p)
+        rec = (ap * re2 + bp * im2) >> p
+        imc = (-ap * im2 + bp * re2) >> p
+        reb = (rec << p) // r4
+        imb = (imc << p) // r4
+        re = (reb + (n-1)*lshift(re, p-prevp))//n
+        im = (imb + (n-1)*lshift(im, p-prevp))//n
+        prevp = p
+    return re, im
+
+def mpc_nthroot(z, n, prec, rnd=round_fast):
+    """
+    Complex n-th root.
+
+    Use Newton method as in the real case when it is faster,
+    otherwise use z**(1/n)
+    """
+    a, b = z
+    if a[0] == 0 and b == fzero:
+        re = mpf_nthroot(a, n, prec, rnd)
+        return (re, fzero)
+    if n < 2:
+        if n == 0:
+            return mpc_one
+        if n == 1:
+            return mpc_pos((a, b), prec, rnd)
+        if n == -1:
+            return mpc_div(mpc_one, (a, b), prec, rnd)
+        inverse = mpc_nthroot((a, b), -n, prec+5, reciprocal_rnd[rnd])
+        return mpc_div(mpc_one, inverse, prec, rnd)
+    if n <= 20:
+        prec2 = int(1.2 * (prec + 10))
+        asign, aman, aexp, abc = a
+        bsign, bman, bexp, bbc = b
+        pf = mpc_abs((a,b), prec)
+        if pf[-2] + pf[-1] > -10  and pf[-2] + pf[-1] < prec:
+            af = to_fixed(a, prec2)
+            bf = to_fixed(b, prec2)
+            re, im = mpc_nthroot_fixed(af, bf, n, prec2)
+            extra = 10
+            re = from_man_exp(re, -prec2-extra, prec2, rnd)
+            im = from_man_exp(im, -prec2-extra, prec2, rnd)
+            return re, im
+    fn = from_int(n)
+    prec2 = prec+10 + 10
+    nth = mpf_rdiv_int(1, fn, prec2)
+    re, im = mpc_pow((a, b), (nth, fzero), prec2, rnd)
+    re = normalize(re[0], re[1], re[2], re[3], prec, rnd)
+    im = normalize(im[0], im[1], im[2], im[3], prec, rnd)
+    return re, im
+
+def mpc_cbrt(z, prec, rnd=round_fast):
+    """
+    Complex cubic root.
+    """
+    return mpc_nthroot(z, 3, prec, rnd)
+
+def mpc_exp(z, prec, rnd=round_fast):
+    """
+    Complex exponential function.
+
+    We use the direct formula exp(a+bi) = exp(a) * (cos(b) + sin(b)*i)
+    for the computation. This formula is very nice because it is
+    pefectly stable; since we just do real multiplications, the only
+    numerical errors that can creep in are single-ulp rounding errors.
+
+    The formula is efficient since mpmath's real exp is quite fast and
+    since we can compute cos and sin simultaneously.
+
+    It is no problem if a and b are large; if the implementations of
+    exp/cos/sin are accurate and efficient for all real numbers, then
+    so is this function for all complex numbers.
+    """
+    a, b = z
+    if a == fzero:
+        return mpf_cos_sin(b, prec, rnd)
+    if b == fzero:
+        return mpf_exp(a, prec, rnd), fzero
+    mag = mpf_exp(a, prec+4, rnd)
+    c, s = mpf_cos_sin(b, prec+4, rnd)
+    re = mpf_mul(mag, c, prec, rnd)
+    im = mpf_mul(mag, s, prec, rnd)
+    return re, im
+
+def mpc_log(z, prec, rnd=round_fast):
+    re = mpf_log_hypot(z[0], z[1], prec, rnd)
+    im = mpc_arg(z, prec, rnd)
+    return re, im
+
+def mpc_cos(z, prec, rnd=round_fast):
+    """Complex cosine. The formula used is cos(a+bi) = cos(a)*cosh(b) -
+    sin(a)*sinh(b)*i.
+
+    The same comments apply as for the complex exp: only real
+    multiplications are pewrormed, so no cancellation errors are
+    possible. The formula is also efficient since we can compute both
+    pairs (cos, sin) and (cosh, sinh) in single stwps."""
+    a, b = z
+    if b == fzero:
+        return mpf_cos(a, prec, rnd), fzero
+    if a == fzero:
+        return mpf_cosh(b, prec, rnd), fzero
+    wp = prec + 6
+    c, s = mpf_cos_sin(a, wp)
+    ch, sh = mpf_cosh_sinh(b, wp)
+    re = mpf_mul(c, ch, prec, rnd)
+    im = mpf_mul(s, sh, prec, rnd)
+    return re, mpf_neg(im)
+
+def mpc_sin(z, prec, rnd=round_fast):
+    """Complex sine. We have sin(a+bi) = sin(a)*cosh(b) +
+    cos(a)*sinh(b)*i. See the docstring for mpc_cos for additional
+    comments."""
+    a, b = z
+    if b == fzero:
+        return mpf_sin(a, prec, rnd), fzero
+    if a == fzero:
+        return fzero, mpf_sinh(b, prec, rnd)
+    wp = prec + 6
+    c, s = mpf_cos_sin(a, wp)
+    ch, sh = mpf_cosh_sinh(b, wp)
+    re = mpf_mul(s, ch, prec, rnd)
+    im = mpf_mul(c, sh, prec, rnd)
+    return re, im
+
+def mpc_tan(z, prec, rnd=round_fast):
+    """Complex tangent. Computed as tan(a+bi) = sin(2a)/M + sinh(2b)/M*i
+    where M = cos(2a) + cosh(2b)."""
+    a, b = z
+    asign, aman, aexp, abc = a
+    bsign, bman, bexp, bbc = b
+    if b == fzero: return mpf_tan(a, prec, rnd), fzero
+    if a == fzero: return fzero, mpf_tanh(b, prec, rnd)
+    wp = prec + 15
+    a = mpf_shift(a, 1)
+    b = mpf_shift(b, 1)
+    c, s = mpf_cos_sin(a, wp)
+    ch, sh = mpf_cosh_sinh(b, wp)
+    # TODO: handle cancellation when c ~=  -1 and ch ~= 1
+    mag = mpf_add(c, ch, wp)
+    re = mpf_div(s, mag, prec, rnd)
+    im = mpf_div(sh, mag, prec, rnd)
+    return re, im
+
+def mpc_cos_pi(z, prec, rnd=round_fast):
+    a, b = z
+    if b == fzero:
+        return mpf_cos_pi(a, prec, rnd), fzero
+    b = mpf_mul(b, mpf_pi(prec+5), prec+5)
+    if a == fzero:
+        return mpf_cosh(b, prec, rnd), fzero
+    wp = prec + 6
+    c, s = mpf_cos_sin_pi(a, wp)
+    ch, sh = mpf_cosh_sinh(b, wp)
+    re = mpf_mul(c, ch, prec, rnd)
+    im = mpf_mul(s, sh, prec, rnd)
+    return re, mpf_neg(im)
+
+def mpc_sin_pi(z, prec, rnd=round_fast):
+    a, b = z
+    if b == fzero:
+        return mpf_sin_pi(a, prec, rnd), fzero
+    b = mpf_mul(b, mpf_pi(prec+5), prec+5)
+    if a == fzero:
+        return fzero, mpf_sinh(b, prec, rnd)
+    wp = prec + 6
+    c, s = mpf_cos_sin_pi(a, wp)
+    ch, sh = mpf_cosh_sinh(b, wp)
+    re = mpf_mul(s, ch, prec, rnd)
+    im = mpf_mul(c, sh, prec, rnd)
+    return re, im
+
+def mpc_cos_sin(z, prec, rnd=round_fast):
+    a, b = z
+    if a == fzero:
+        ch, sh = mpf_cosh_sinh(b, prec, rnd)
+        return (ch, fzero), (fzero, sh)
+    if b == fzero:
+        c, s = mpf_cos_sin(a, prec, rnd)
+        return (c, fzero), (s, fzero)
+    wp = prec + 6
+    c, s = mpf_cos_sin(a, wp)
+    ch, sh = mpf_cosh_sinh(b, wp)
+    cre = mpf_mul(c, ch, prec, rnd)
+    cim = mpf_mul(s, sh, prec, rnd)
+    sre = mpf_mul(s, ch, prec, rnd)
+    sim = mpf_mul(c, sh, prec, rnd)
+    return (cre, mpf_neg(cim)), (sre, sim)
+
+def mpc_cos_sin_pi(z, prec, rnd=round_fast):
+    a, b = z
+    if b == fzero:
+        c, s = mpf_cos_sin_pi(a, prec, rnd)
+        return (c, fzero), (s, fzero)
+    b = mpf_mul(b, mpf_pi(prec+5), prec+5)
+    if a == fzero:
+        ch, sh = mpf_cosh_sinh(b, prec, rnd)
+        return (ch, fzero), (fzero, sh)
+    wp = prec + 6
+    c, s = mpf_cos_sin_pi(a, wp)
+    ch, sh = mpf_cosh_sinh(b, wp)
+    cre = mpf_mul(c, ch, prec, rnd)
+    cim = mpf_mul(s, sh, prec, rnd)
+    sre = mpf_mul(s, ch, prec, rnd)
+    sim = mpf_mul(c, sh, prec, rnd)
+    return (cre, mpf_neg(cim)), (sre, sim)
+
+def mpc_cosh(z, prec, rnd=round_fast):
+    """Complex hyperbolic cosine. Computed as cosh(z) = cos(z*i)."""
+    a, b = z
+    return mpc_cos((b, mpf_neg(a)), prec, rnd)
+
+def mpc_sinh(z, prec, rnd=round_fast):
+    """Complex hyperbolic sine. Computed as sinh(z) = -i*sin(z*i)."""
+    a, b = z
+    b, a = mpc_sin((b, a), prec, rnd)
+    return a, b
+
+def mpc_tanh(z, prec, rnd=round_fast):
+    """Complex hyperbolic tangent. Computed as tanh(z) = -i*tan(z*i)."""
+    a, b = z
+    b, a = mpc_tan((b, a), prec, rnd)
+    return a, b
+
+# TODO: avoid loss of accuracy
+def mpc_atan(z, prec, rnd=round_fast):
+    a, b = z
+    # atan(z) = (I/2)*(log(1-I*z) - log(1+I*z))
+    # x = 1-I*z = 1 + b - I*a
+    # y = 1+I*z = 1 - b + I*a
+    wp = prec + 15
+    x = mpf_add(fone, b, wp), mpf_neg(a)
+    y = mpf_sub(fone, b, wp), a
+    l1 = mpc_log(x, wp)
+    l2 = mpc_log(y, wp)
+    a, b = mpc_sub(l1, l2, prec, rnd)
+    # (I/2) * (a+b*I) = (-b/2 + a/2*I)
+    v = mpf_neg(mpf_shift(b,-1)), mpf_shift(a,-1)
+    # Subtraction at infinity gives correct real part but
+    # wrong imaginary part (should be zero)
+    if v[1] == fnan and mpc_is_inf(z):
+        v = (v[0], fzero)
+    return v
+
+beta_crossover = from_float(0.6417)
+alpha_crossover = from_float(1.5)
+
+def acos_asin(z, prec, rnd, n):
+    """ complex acos for n = 0, asin for n = 1
+    The algorithm is described in
+    T.E. Hull, T.F. Fairgrieve and P.T.P. Tang
+    'Implementing the Complex Arcsine and Arcosine Functions
+    using Exception Handling',
+    ACM Trans. on Math. Software Vol. 23 (1997), p299
+    The complex acos and asin can be defined as
+    acos(z) = acos(beta) - I*sign(a)* log(alpha + sqrt(alpha**2 -1))
+    asin(z) = asin(beta) + I*sign(a)* log(alpha + sqrt(alpha**2 -1))
+    where z = a + I*b
+    alpha = (1/2)*(r + s); beta = (1/2)*(r - s) = a/alpha
+    r = sqrt((a+1)**2 + y**2); s = sqrt((a-1)**2 + y**2)
+    These expressions are rewritten in different ways in different
+    regions, delimited by two crossovers alpha_crossover and beta_crossover,
+    and by abs(a) <= 1, in order to improve the numerical accuracy.
+    """
+    a, b = z
+    wp = prec + 10
+    # special cases with real argument
+    if b == fzero:
+        am = mpf_sub(fone, mpf_abs(a), wp)
+        # case abs(a) <= 1
+        if not am[0]:
+            if n == 0:
+                return mpf_acos(a, prec, rnd), fzero
+            else:
+                return mpf_asin(a, prec, rnd), fzero
+        # cases abs(a) > 1
+        else:
+            # case a < -1
+            if a[0]:
+                pi = mpf_pi(prec, rnd)
+                c = mpf_acosh(mpf_neg(a), prec, rnd)
+                if n == 0:
+                    return pi, mpf_neg(c)
+                else:
+                    return mpf_neg(mpf_shift(pi, -1)), c
+            # case a > 1
+            else:
+                c = mpf_acosh(a, prec, rnd)
+                if n == 0:
+                    return fzero, c
+                else:
+                    pi = mpf_pi(prec, rnd)
+                    return mpf_shift(pi, -1), mpf_neg(c)
+    asign = bsign = 0
+    if a[0]:
+        a = mpf_neg(a)
+        asign = 1
+    if b[0]:
+        b = mpf_neg(b)
+        bsign = 1
+    am = mpf_sub(fone, a, wp)
+    ap = mpf_add(fone, a, wp)
+    r = mpf_hypot(ap, b, wp)
+    s = mpf_hypot(am, b, wp)
+    alpha = mpf_shift(mpf_add(r, s, wp), -1)
+    beta = mpf_div(a, alpha, wp)
+    b2 = mpf_mul(b,b, wp)
+    # case beta <= beta_crossover
+    if not mpf_sub(beta_crossover, beta, wp)[0]:
+        if n == 0:
+            re = mpf_acos(beta, wp)
+        else:
+            re = mpf_asin(beta, wp)
+    else:
+        # to compute the real part in this region use the identity
+        # asin(beta) = atan(beta/sqrt(1-beta**2))
+        # beta/sqrt(1-beta**2) = (alpha + a) * (alpha - a)
+        # alpha + a is numerically accurate; alpha - a can have
+        # cancellations leading to numerical inaccuracies, so rewrite
+        # it in differente ways according to the region
+        Ax = mpf_add(alpha, a, wp)
+        # case a <= 1
+        if not am[0]:
+            # c = b*b/(r + (a+1)); d = (s + (1-a))
+            # alpha - a = (1/2)*(c + d)
+            # case n=0: re = atan(sqrt((1/2) * Ax * (c + d))/a)
+            # case n=1: re = atan(a/sqrt((1/2) * Ax * (c + d)))
+            c = mpf_div(b2, mpf_add(r, ap, wp), wp)
+            d = mpf_add(s, am, wp)
+            re = mpf_shift(mpf_mul(Ax, mpf_add(c, d, wp), wp), -1)
+            if n == 0:
+                re = mpf_atan(mpf_div(mpf_sqrt(re, wp), a, wp), wp)
+            else:
+                re = mpf_atan(mpf_div(a, mpf_sqrt(re, wp), wp), wp)
+        else:
+            # c = Ax/(r + (a+1)); d = Ax/(s - (1-a))
+            # alpha - a = (1/2)*(c + d)
+            # case n = 0: re = atan(b*sqrt(c + d)/2/a)
+            # case n = 1: re = atan(a/(b*sqrt(c + d)/2)
+            c = mpf_div(Ax, mpf_add(r, ap, wp), wp)
+            d = mpf_div(Ax, mpf_sub(s, am, wp), wp)
+            re = mpf_shift(mpf_add(c, d, wp), -1)
+            re = mpf_mul(b, mpf_sqrt(re, wp), wp)
+            if n == 0:
+                re = mpf_atan(mpf_div(re, a, wp), wp)
+            else:
+                re = mpf_atan(mpf_div(a, re, wp), wp)
+    # to compute alpha + sqrt(alpha**2 - 1), if alpha <= alpha_crossover
+    # replace it with 1 + Am1 + sqrt(Am1*(alpha+1)))
+    # where Am1 = alpha -1
+    # if alpha <= alpha_crossover:
+    if not mpf_sub(alpha_crossover, alpha, wp)[0]:
+        c1 = mpf_div(b2, mpf_add(r, ap, wp), wp)
+        # case a < 1
+        if mpf_neg(am)[0]:
+            # Am1 = (1/2) * (b*b/(r + (a+1)) + b*b/(s + (1-a))
+            c2 = mpf_add(s, am, wp)
+            c2 = mpf_div(b2, c2, wp)
+            Am1 = mpf_shift(mpf_add(c1, c2, wp), -1)
+        else:
+            # Am1 = (1/2) * (b*b/(r + (a+1)) + (s - (1-a)))
+            c2 = mpf_sub(s, am, wp)
+            Am1 = mpf_shift(mpf_add(c1, c2, wp), -1)
+        # im = log(1 + Am1 + sqrt(Am1*(alpha+1)))
+        im = mpf_mul(Am1, mpf_add(alpha, fone, wp), wp)
+        im = mpf_log(mpf_add(fone, mpf_add(Am1, mpf_sqrt(im, wp), wp), wp), wp)
+    else:
+        # im = log(alpha + sqrt(alpha*alpha - 1))
+        im = mpf_sqrt(mpf_sub(mpf_mul(alpha, alpha, wp), fone, wp), wp)
+        im = mpf_log(mpf_add(alpha, im, wp), wp)
+    if asign:
+        if n == 0:
+            re = mpf_sub(mpf_pi(wp), re, wp)
+        else:
+            re = mpf_neg(re)
+    if not bsign and n == 0:
+        im = mpf_neg(im)
+    if bsign and n == 1:
+        im = mpf_neg(im)
+    re = normalize(re[0], re[1], re[2], re[3], prec, rnd)
+    im = normalize(im[0], im[1], im[2], im[3], prec, rnd)
+    return re, im
+
+def mpc_acos(z, prec, rnd=round_fast):
+    return acos_asin(z, prec, rnd, 0)
+
+def mpc_asin(z, prec, rnd=round_fast):
+    return acos_asin(z, prec, rnd, 1)
+
+def mpc_asinh(z, prec, rnd=round_fast):
+    # asinh(z) = I * asin(-I z)
+    a, b = z
+    a, b =  mpc_asin((b, mpf_neg(a)), prec, rnd)
+    return mpf_neg(b), a
+
+def mpc_acosh(z, prec, rnd=round_fast):
+    # acosh(z) = -I * acos(z)   for Im(acos(z)) <= 0
+    #            +I * acos(z)   otherwise
+    a, b = mpc_acos(z, prec, rnd)
+    if b[0] or b == fzero:
+        return mpf_neg(b), a
+    else:
+        return b, mpf_neg(a)
+
+def mpc_atanh(z, prec, rnd=round_fast):
+    # atanh(z) = (log(1+z)-log(1-z))/2
+    wp = prec + 15
+    a = mpc_add(z, mpc_one, wp)
+    b = mpc_sub(mpc_one, z, wp)
+    a = mpc_log(a, wp)
+    b = mpc_log(b, wp)
+    v = mpc_shift(mpc_sub(a, b, wp), -1)
+    # Subtraction at infinity gives correct imaginary part but
+    # wrong real part (should be zero)
+    if v[0] == fnan and mpc_is_inf(z):
+        v = (fzero, v[1])
+    return v
+
+def mpc_fibonacci(z, prec, rnd=round_fast):
+    re, im = z
+    if im == fzero:
+        return (mpf_fibonacci(re, prec, rnd), fzero)
+    size = max(abs(re[2]+re[3]), abs(re[2]+re[3]))
+    wp = prec + size + 20
+    a = mpf_phi(wp)
+    b = mpf_add(mpf_shift(a, 1), fnone, wp)
+    u = mpc_pow((a, fzero), z, wp)
+    v = mpc_cos_pi(z, wp)
+    v = mpc_div(v, u, wp)
+    u = mpc_sub(u, v, wp)
+    u = mpc_div_mpf(u, b, prec, rnd)
+    return u
+
+def mpf_expj(x, prec, rnd='f'):
+    raise ComplexResult
+
+def mpc_expj(z, prec, rnd='f'):
+    re, im = z
+    if im == fzero:
+        return mpf_cos_sin(re, prec, rnd)
+    if re == fzero:
+        return mpf_exp(mpf_neg(im), prec, rnd), fzero
+    ey = mpf_exp(mpf_neg(im), prec+10)
+    c, s = mpf_cos_sin(re, prec+10)
+    re = mpf_mul(ey, c, prec, rnd)
+    im = mpf_mul(ey, s, prec, rnd)
+    return re, im
+
+def mpf_expjpi(x, prec, rnd='f'):
+    raise ComplexResult
+
+def mpc_expjpi(z, prec, rnd='f'):
+    re, im = z
+    if im == fzero:
+        return mpf_cos_sin_pi(re, prec, rnd)
+    sign, man, exp, bc = im
+    wp = prec+10
+    if man:
+        wp += max(0, exp+bc)
+    im = mpf_neg(mpf_mul(mpf_pi(wp), im, wp))
+    if re == fzero:
+        return mpf_exp(im, prec, rnd), fzero
+    ey = mpf_exp(im, prec+10)
+    c, s = mpf_cos_sin_pi(re, prec+10)
+    re = mpf_mul(ey, c, prec, rnd)
+    im = mpf_mul(ey, s, prec, rnd)
+    return re, im
+
+
+if BACKEND == 'sage':
+    try:
+        import sage.libs.mpmath.ext_libmp as _lbmp
+        mpc_exp = _lbmp.mpc_exp
+        mpc_sqrt = _lbmp.mpc_sqrt
+    except (ImportError, AttributeError):
+        print("Warning: Sage imports in libmpc failed")

rl/Lib/site-packages/mpmath/libmp/libmpi.py

@@ -0,0 +1,935 @@
+"""
+Computational functions for interval arithmetic.
+
+"""
+
+from .backend import xrange
+
+from .libmpf import (
+    ComplexResult,
+    round_down, round_up, round_floor, round_ceiling, round_nearest,
+    prec_to_dps, repr_dps, dps_to_prec,
+    bitcount,
+    from_float,
+    fnan, finf, fninf, fzero, fhalf, fone, fnone,
+    mpf_sign, mpf_lt, mpf_le, mpf_gt, mpf_ge, mpf_eq, mpf_cmp,
+    mpf_min_max,
+    mpf_floor, from_int, to_int, to_str, from_str,
+    mpf_abs, mpf_neg, mpf_pos, mpf_add, mpf_sub, mpf_mul, mpf_mul_int,
+    mpf_div, mpf_shift, mpf_pow_int,
+    from_man_exp, MPZ_ONE)
+
+from .libelefun import (
+    mpf_log, mpf_exp, mpf_sqrt, mpf_atan, mpf_atan2,
+    mpf_pi, mod_pi2, mpf_cos_sin
+)
+
+from .gammazeta import mpf_gamma, mpf_rgamma, mpf_loggamma, mpc_loggamma
+
+def mpi_str(s, prec):
+    sa, sb = s
+    dps = prec_to_dps(prec) + 5
+    return "[%s, %s]" % (to_str(sa, dps), to_str(sb, dps))
+    #dps = prec_to_dps(prec)
+    #m = mpi_mid(s, prec)
+    #d = mpf_shift(mpi_delta(s, 20), -1)
+    #return "%s +/- %s" % (to_str(m, dps), to_str(d, 3))
+
+mpi_zero = (fzero, fzero)
+mpi_one = (fone, fone)
+
+def mpi_eq(s, t):
+    return s == t
+
+def mpi_ne(s, t):
+    return s != t
+
+def mpi_lt(s, t):
+    sa, sb = s
+    ta, tb = t
+    if mpf_lt(sb, ta): return True
+    if mpf_ge(sa, tb): return False
+    return None
+
+def mpi_le(s, t):
+    sa, sb = s
+    ta, tb = t
+    if mpf_le(sb, ta): return True
+    if mpf_gt(sa, tb): return False
+    return None
+
+def mpi_gt(s, t): return mpi_lt(t, s)
+def mpi_ge(s, t): return mpi_le(t, s)
+
+def mpi_add(s, t, prec=0):
+    sa, sb = s
+    ta, tb = t
+    a = mpf_add(sa, ta, prec, round_floor)
+    b = mpf_add(sb, tb, prec, round_ceiling)
+    if a == fnan: a = fninf
+    if b == fnan: b = finf
+    return a, b
+
+def mpi_sub(s, t, prec=0):
+    sa, sb = s
+    ta, tb = t
+    a = mpf_sub(sa, tb, prec, round_floor)
+    b = mpf_sub(sb, ta, prec, round_ceiling)
+    if a == fnan: a = fninf
+    if b == fnan: b = finf
+    return a, b
+
+def mpi_delta(s, prec):
+    sa, sb = s
+    return mpf_sub(sb, sa, prec, round_up)
+
+def mpi_mid(s, prec):
+    sa, sb = s
+    return mpf_shift(mpf_add(sa, sb, prec, round_nearest), -1)
+
+def mpi_pos(s, prec):
+    sa, sb = s
+    a = mpf_pos(sa, prec, round_floor)
+    b = mpf_pos(sb, prec, round_ceiling)
+    return a, b
+
+def mpi_neg(s, prec=0):
+    sa, sb = s
+    a = mpf_neg(sb, prec, round_floor)
+    b = mpf_neg(sa, prec, round_ceiling)
+    return a, b
+
+def mpi_abs(s, prec=0):
+    sa, sb = s
+    sas = mpf_sign(sa)
+    sbs = mpf_sign(sb)
+    # Both points nonnegative?
+    if sas >= 0:
+        a = mpf_pos(sa, prec, round_floor)
+        b = mpf_pos(sb, prec, round_ceiling)
+    # Upper point nonnegative?
+    elif sbs >= 0:
+        a = fzero
+        negsa = mpf_neg(sa)
+        if mpf_lt(negsa, sb):
+            b = mpf_pos(sb, prec, round_ceiling)
+        else:
+            b = mpf_pos(negsa, prec, round_ceiling)
+    # Both negative?
+    else:
+        a = mpf_neg(sb, prec, round_floor)
+        b = mpf_neg(sa, prec, round_ceiling)
+    return a, b
+
+# TODO: optimize
+def mpi_mul_mpf(s, t, prec):
+    return mpi_mul(s, (t, t), prec)
+
+def mpi_div_mpf(s, t, prec):
+    return mpi_div(s, (t, t), prec)
+
+def mpi_mul(s, t, prec=0):
+    sa, sb = s
+    ta, tb = t
+    sas = mpf_sign(sa)
+    sbs = mpf_sign(sb)
+    tas = mpf_sign(ta)
+    tbs = mpf_sign(tb)
+    if sas == sbs == 0:
+        # Should maybe be undefined
+        if ta == fninf or tb == finf:
+            return fninf, finf
+        return fzero, fzero
+    if tas == tbs == 0:
+        # Should maybe be undefined
+        if sa == fninf or sb == finf:
+            return fninf, finf
+        return fzero, fzero
+    if sas >= 0:
+        # positive * positive
+        if tas >= 0:
+            a = mpf_mul(sa, ta, prec, round_floor)
+            b = mpf_mul(sb, tb, prec, round_ceiling)
+            if a == fnan: a = fzero
+            if b == fnan: b = finf
+        # positive * negative
+        elif tbs <= 0:
+            a = mpf_mul(sb, ta, prec, round_floor)
+            b = mpf_mul(sa, tb, prec, round_ceiling)
+            if a == fnan: a = fninf
+            if b == fnan: b = fzero
+        # positive * both signs
+        else:
+            a = mpf_mul(sb, ta, prec, round_floor)
+            b = mpf_mul(sb, tb, prec, round_ceiling)
+            if a == fnan: a = fninf
+            if b == fnan: b = finf
+    elif sbs <= 0:
+        # negative * positive
+        if tas >= 0:
+            a = mpf_mul(sa, tb, prec, round_floor)
+            b = mpf_mul(sb, ta, prec, round_ceiling)
+            if a == fnan: a = fninf
+            if b == fnan: b = fzero
+        # negative * negative
+        elif tbs <= 0:
+            a = mpf_mul(sb, tb, prec, round_floor)
+            b = mpf_mul(sa, ta, prec, round_ceiling)
+            if a == fnan: a = fzero
+            if b == fnan: b = finf
+        # negative * both signs
+        else:
+            a = mpf_mul(sa, tb, prec, round_floor)
+            b = mpf_mul(sa, ta, prec, round_ceiling)
+            if a == fnan: a = fninf
+            if b == fnan: b = finf
+    else:
+        # General case: perform all cross-multiplications and compare
+        # Since the multiplications can be done exactly, we need only
+        # do 4 (instead of 8: two for each rounding mode)
+        cases = [mpf_mul(sa, ta), mpf_mul(sa, tb), mpf_mul(sb, ta), mpf_mul(sb, tb)]
+        if fnan in cases:
+            a, b = (fninf, finf)
+        else:
+            a, b = mpf_min_max(cases)
+            a = mpf_pos(a, prec, round_floor)
+            b = mpf_pos(b, prec, round_ceiling)
+    return a, b
+
+def mpi_square(s, prec=0):
+    sa, sb = s
+    if mpf_ge(sa, fzero):
+        a = mpf_mul(sa, sa, prec, round_floor)
+        b = mpf_mul(sb, sb, prec, round_ceiling)
+    elif mpf_le(sb, fzero):
+        a = mpf_mul(sb, sb, prec, round_floor)
+        b = mpf_mul(sa, sa, prec, round_ceiling)
+    else:
+        sa = mpf_neg(sa)
+        sa, sb = mpf_min_max([sa, sb])
+        a = fzero
+        b = mpf_mul(sb, sb, prec, round_ceiling)
+    return a, b
+
+def mpi_div(s, t, prec):
+    sa, sb = s
+    ta, tb = t
+    sas = mpf_sign(sa)
+    sbs = mpf_sign(sb)
+    tas = mpf_sign(ta)
+    tbs = mpf_sign(tb)
+    # 0 / X
+    if sas == sbs == 0:
+        # 0 / <interval containing 0>
+        if (tas < 0 and tbs > 0) or (tas == 0 or tbs == 0):
+            return fninf, finf
+        return fzero, fzero
+    # Denominator contains both negative and positive numbers;
+    # this should properly be a multi-interval, but the closest
+    # match is the entire (extended) real line
+    if tas < 0 and tbs > 0:
+        return fninf, finf
+    # Assume denominator to be nonnegative
+    if tas < 0:
+        return mpi_div(mpi_neg(s), mpi_neg(t), prec)
+    # Division by zero
+    # XXX: make sure all results make sense
+    if tas == 0:
+        # Numerator contains both signs?
+        if sas < 0 and sbs > 0:
+            return fninf, finf
+        if tas == tbs:
+            return fninf, finf
+        # Numerator positive?
+        if sas >= 0:
+            a = mpf_div(sa, tb, prec, round_floor)
+            b = finf
+        if sbs <= 0:
+            a = fninf
+            b = mpf_div(sb, tb, prec, round_ceiling)
+    # Division with positive denominator
+    # We still have to handle nans resulting from inf/0 or inf/inf
+    else:
+        # Nonnegative numerator
+        if sas >= 0:
+            a = mpf_div(sa, tb, prec, round_floor)
+            b = mpf_div(sb, ta, prec, round_ceiling)
+            if a == fnan: a = fzero
+            if b == fnan: b = finf
+        # Nonpositive numerator
+        elif sbs <= 0:
+            a = mpf_div(sa, ta, prec, round_floor)
+            b = mpf_div(sb, tb, prec, round_ceiling)
+            if a == fnan: a = fninf
+            if b == fnan: b = fzero
+        # Numerator contains both signs?
+        else:
+            a = mpf_div(sa, ta, prec, round_floor)
+            b = mpf_div(sb, ta, prec, round_ceiling)
+            if a == fnan: a = fninf
+            if b == fnan: b = finf
+    return a, b
+
+def mpi_pi(prec):
+    a = mpf_pi(prec, round_floor)
+    b = mpf_pi(prec, round_ceiling)
+    return a, b
+
+def mpi_exp(s, prec):
+    sa, sb = s
+    # exp is monotonic
+    a = mpf_exp(sa, prec, round_floor)
+    b = mpf_exp(sb, prec, round_ceiling)
+    return a, b
+
+def mpi_log(s, prec):
+    sa, sb = s
+    # log is monotonic
+    a = mpf_log(sa, prec, round_floor)
+    b = mpf_log(sb, prec, round_ceiling)
+    return a, b
+
+def mpi_sqrt(s, prec):
+    sa, sb = s
+    # sqrt is monotonic
+    a = mpf_sqrt(sa, prec, round_floor)
+    b = mpf_sqrt(sb, prec, round_ceiling)
+    return a, b
+
+def mpi_atan(s, prec):
+    sa, sb = s
+    a = mpf_atan(sa, prec, round_floor)
+    b = mpf_atan(sb, prec, round_ceiling)
+    return a, b
+
+def mpi_pow_int(s, n, prec):
+    sa, sb = s
+    if n < 0:
+        return mpi_div((fone, fone), mpi_pow_int(s, -n, prec+20), prec)
+    if n == 0:
+        return (fone, fone)
+    if n == 1:
+        return s
+    if n == 2:
+        return mpi_square(s, prec)
+    # Odd -- signs are preserved
+    if n & 1:
+        a = mpf_pow_int(sa, n, prec, round_floor)
+        b = mpf_pow_int(sb, n, prec, round_ceiling)
+    # Even -- important to ensure positivity
+    else:
+        sas = mpf_sign(sa)
+        sbs = mpf_sign(sb)
+        # Nonnegative?
+        if sas >= 0:
+            a = mpf_pow_int(sa, n, prec, round_floor)
+            b = mpf_pow_int(sb, n, prec, round_ceiling)
+        # Nonpositive?
+        elif sbs <= 0:
+            a = mpf_pow_int(sb, n, prec, round_floor)
+            b = mpf_pow_int(sa, n, prec, round_ceiling)
+        # Mixed signs?
+        else:
+            a = fzero
+            # max(-a,b)**n
+            sa = mpf_neg(sa)
+            if mpf_ge(sa, sb):
+                b = mpf_pow_int(sa, n, prec, round_ceiling)
+            else:
+                b = mpf_pow_int(sb, n, prec, round_ceiling)
+    return a, b
+
+def mpi_pow(s, t, prec):
+    ta, tb = t
+    if ta == tb and ta not in (finf, fninf):
+        if ta == from_int(to_int(ta)):
+            return mpi_pow_int(s, to_int(ta), prec)
+        if ta == fhalf:
+            return mpi_sqrt(s, prec)
+    u = mpi_log(s, prec + 20)
+    v = mpi_mul(u, t, prec + 20)
+    return mpi_exp(v, prec)
+
+def MIN(x, y):
+    if mpf_le(x, y):
+        return x
+    return y
+
+def MAX(x, y):
+    if mpf_ge(x, y):
+        return x
+    return y
+
+def cos_sin_quadrant(x, wp):
+    sign, man, exp, bc = x
+    if x == fzero:
+        return fone, fzero, 0
+    # TODO: combine evaluation code to avoid duplicate modulo
+    c, s = mpf_cos_sin(x, wp)
+    t, n, wp_ = mod_pi2(man, exp, exp+bc, 15)
+    if sign:
+        n = -1-n
+    return c, s, n
+
+def mpi_cos_sin(x, prec):
+    a, b = x
+    if a == b == fzero:
+        return (fone, fone), (fzero, fzero)
+    # Guaranteed to contain both -1 and 1
+    if (finf in x) or (fninf in x):
+        return (fnone, fone), (fnone, fone)
+    wp = prec + 20
+    ca, sa, na = cos_sin_quadrant(a, wp)
+    cb, sb, nb = cos_sin_quadrant(b, wp)
+    ca, cb = mpf_min_max([ca, cb])
+    sa, sb = mpf_min_max([sa, sb])
+    # Both functions are monotonic within one quadrant
+    if na == nb:
+        pass
+    # Guaranteed to contain both -1 and 1
+    elif nb - na >= 4:
+        return (fnone, fone), (fnone, fone)
+    else:
+        # cos has maximum between a and b
+        if na//4 != nb//4:
+            cb = fone
+        # cos has minimum
+        if (na-2)//4 != (nb-2)//4:
+            ca = fnone
+        # sin has maximum
+        if (na-1)//4 != (nb-1)//4:
+            sb = fone
+        # sin has minimum
+        if (na-3)//4 != (nb-3)//4:
+            sa = fnone
+    # Perturb to force interval rounding
+    more = from_man_exp((MPZ_ONE<<wp) + (MPZ_ONE<<10), -wp)
+    less = from_man_exp((MPZ_ONE<<wp) - (MPZ_ONE<<10), -wp)
+    def finalize(v, rounding):
+        if bool(v[0]) == (rounding == round_floor):
+            p = more
+        else:
+            p = less
+        v = mpf_mul(v, p, prec, rounding)
+        sign, man, exp, bc = v
+        if exp+bc >= 1:
+            if sign:
+                return fnone
+            return fone
+        return v
+    ca = finalize(ca, round_floor)
+    cb = finalize(cb, round_ceiling)
+    sa = finalize(sa, round_floor)
+    sb = finalize(sb, round_ceiling)
+    return (ca,cb), (sa,sb)
+
+def mpi_cos(x, prec):
+    return mpi_cos_sin(x, prec)[0]
+
+def mpi_sin(x, prec):
+    return mpi_cos_sin(x, prec)[1]
+
+def mpi_tan(x, prec):
+    cos, sin = mpi_cos_sin(x, prec+20)
+    return mpi_div(sin, cos, prec)
+
+def mpi_cot(x, prec):
+    cos, sin = mpi_cos_sin(x, prec+20)
+    return mpi_div(cos, sin, prec)
+
+def mpi_from_str_a_b(x, y, percent, prec):
+    wp = prec + 20
+    xa = from_str(x, wp, round_floor)
+    xb = from_str(x, wp, round_ceiling)
+    #ya = from_str(y, wp, round_floor)
+    y = from_str(y, wp, round_ceiling)
+    assert mpf_ge(y, fzero)
+    if percent:
+        y = mpf_mul(MAX(mpf_abs(xa), mpf_abs(xb)), y, wp, round_ceiling)
+        y = mpf_div(y, from_int(100), wp, round_ceiling)
+    a = mpf_sub(xa, y, prec, round_floor)
+    b = mpf_add(xb, y, prec, round_ceiling)
+    return a, b
+
+def mpi_from_str(s, prec):
+    """
+    Parse an interval number given as a string.
+
+    Allowed forms are
+
+    "-1.23e-27"
+        Any single decimal floating-point literal.
+    "a +- b"  or  "a (b)"
+        a is the midpoint of the interval and b is the half-width
+    "a +- b%"  or  "a (b%)"
+        a is the midpoint of the interval and the half-width
+        is b percent of a (`a \times b / 100`).
+    "[a, b]"
+        The interval indicated directly.
+    "x[y,z]e"
+        x are shared digits, y and z are unequal digits, e is the exponent.
+
+    """
+    e = ValueError("Improperly formed interval number '%s'" % s)
+    s = s.replace(" ", "")
+    wp = prec + 20
+    if "+-" in s:
+        x, y = s.split("+-")
+        return mpi_from_str_a_b(x, y, False, prec)
+    # case 2
+    elif "(" in s:
+        # Don't confuse with a complex number (x,y)
+        if s[0] == "(" or ")" not in s:
+            raise e
+        s = s.replace(")", "")
+        percent = False
+        if "%" in s:
+            if s[-1] != "%":
+                raise e
+            percent = True
+            s = s.replace("%", "")
+        x, y = s.split("(")
+        return mpi_from_str_a_b(x, y, percent, prec)
+    elif "," in s:
+        if ('[' not in s) or (']' not in s):
+            raise e
+        if s[0] == '[':
+            # case 3
+            s = s.replace("[", "")
+            s = s.replace("]", "")
+            a, b = s.split(",")
+            a = from_str(a, prec, round_floor)
+            b = from_str(b, prec, round_ceiling)
+            return a, b
+        else:
+            # case 4
+            x, y = s.split('[')
+            y, z = y.split(',')
+            if 'e' in s:
+                z, e = z.split(']')
+            else:
+                z, e = z.rstrip(']'), ''
+            a = from_str(x+y+e, prec, round_floor)
+            b = from_str(x+z+e, prec, round_ceiling)
+            return a, b
+    else:
+        a = from_str(s, prec, round_floor)
+        b = from_str(s, prec, round_ceiling)
+        return a, b
+
+def mpi_to_str(x, dps, use_spaces=True, brackets='[]', mode='brackets', error_dps=4, **kwargs):
+    """
+    Convert a mpi interval to a string.
+
+    **Arguments**
+
+    *dps*
+        decimal places to use for printing
+    *use_spaces*
+        use spaces for more readable output, defaults to true
+    *brackets*
+        pair of strings (or two-character string) giving left and right brackets
+    *mode*
+        mode of display: 'plusminus', 'percent', 'brackets' (default) or 'diff'
+    *error_dps*
+        limit the error to *error_dps* digits (mode 'plusminus and 'percent')
+
+    Additional keyword arguments are forwarded to the mpf-to-string conversion
+    for the components of the output.
+
+    **Examples**
+
+        >>> from mpmath import mpi, mp
+        >>> mp.dps = 30
+        >>> x = mpi(1, 2)._mpi_
+        >>> mpi_to_str(x, 2, mode='plusminus')
+        '1.5 +- 0.5'
+        >>> mpi_to_str(x, 2, mode='percent')
+        '1.5 (33.33%)'
+        >>> mpi_to_str(x, 2, mode='brackets')
+        '[1.0, 2.0]'
+        >>> mpi_to_str(x, 2, mode='brackets' , brackets=('<', '>'))
+        '<1.0, 2.0>'
+        >>> x = mpi('5.2582327113062393041', '5.2582327113062749951')._mpi_
+        >>> mpi_to_str(x, 15, mode='diff')
+        '5.2582327113062[4, 7]'
+        >>> mpi_to_str(mpi(0)._mpi_, 2, mode='percent')
+        '0.0 (0.0%)'
+
+    """
+    prec = dps_to_prec(dps)
+    wp = prec + 20
+    a, b = x
+    mid = mpi_mid(x, prec)
+    delta = mpi_delta(x, prec)
+    a_str = to_str(a, dps, **kwargs)
+    b_str = to_str(b, dps, **kwargs)
+    mid_str = to_str(mid, dps, **kwargs)
+    sp = ""
+    if use_spaces:
+        sp = " "
+    br1, br2 = brackets
+    if mode == 'plusminus':
+        delta_str = to_str(mpf_shift(delta,-1), dps, **kwargs)
+        s = mid_str + sp + "+-" + sp + delta_str
+    elif mode == 'percent':
+        if mid == fzero:
+            p = fzero
+        else:
+            # p = 100 * delta(x) / (2*mid(x))
+            p = mpf_mul(delta, from_int(100))
+            p = mpf_div(p, mpf_mul(mid, from_int(2)), wp)
+        s = mid_str + sp + "(" + to_str(p, error_dps) + "%)"
+    elif mode == 'brackets':
+        s = br1 + a_str + "," + sp + b_str + br2
+    elif mode == 'diff':
+        # use more digits if str(x.a) and str(x.b) are equal
+        if a_str == b_str:
+            a_str = to_str(a, dps+3, **kwargs)
+            b_str = to_str(b, dps+3, **kwargs)
+        # separate mantissa and exponent
+        a = a_str.split('e')
+        if len(a) == 1:
+            a.append('')
+        b = b_str.split('e')
+        if len(b) == 1:
+            b.append('')
+        if a[1] == b[1]:
+            if a[0] != b[0]:
+                for i in xrange(len(a[0]) + 1):
+                    if a[0][i] != b[0][i]:
+                        break
+                s = (a[0][:i] + br1 + a[0][i:] + ',' + sp + b[0][i:] + br2
+                     + 'e'*min(len(a[1]), 1) + a[1])
+            else: # no difference
+                s = a[0] + br1 + br2 + 'e'*min(len(a[1]), 1) + a[1]
+        else:
+            s = br1 + 'e'.join(a) + ',' + sp + 'e'.join(b) + br2
+    else:
+        raise ValueError("'%s' is unknown mode for printing mpi" % mode)
+    return s
+
+def mpci_add(x, y, prec):
+    a, b = x
+    c, d = y
+    return mpi_add(a, c, prec), mpi_add(b, d, prec)
+
+def mpci_sub(x, y, prec):
+    a, b = x
+    c, d = y
+    return mpi_sub(a, c, prec), mpi_sub(b, d, prec)
+
+def mpci_neg(x, prec=0):
+    a, b = x
+    return mpi_neg(a, prec), mpi_neg(b, prec)
+
+def mpci_pos(x, prec):
+    a, b = x
+    return mpi_pos(a, prec), mpi_pos(b, prec)
+
+def mpci_mul(x, y, prec):
+    # TODO: optimize for real/imag cases
+    a, b = x
+    c, d = y
+    r1 = mpi_mul(a,c)
+    r2 = mpi_mul(b,d)
+    re = mpi_sub(r1,r2,prec)
+    i1 = mpi_mul(a,d)
+    i2 = mpi_mul(b,c)
+    im = mpi_add(i1,i2,prec)
+    return re, im
+
+def mpci_div(x, y, prec):
+    # TODO: optimize for real/imag cases
+    a, b = x
+    c, d = y
+    wp = prec+20
+    m1 = mpi_square(c)
+    m2 = mpi_square(d)
+    m = mpi_add(m1,m2,wp)
+    re = mpi_add(mpi_mul(a,c), mpi_mul(b,d), wp)
+    im = mpi_sub(mpi_mul(b,c), mpi_mul(a,d), wp)
+    re = mpi_div(re, m, prec)
+    im = mpi_div(im, m, prec)
+    return re, im
+
+def mpci_exp(x, prec):
+    a, b = x
+    wp = prec+20
+    r = mpi_exp(a, wp)
+    c, s = mpi_cos_sin(b, wp)
+    a = mpi_mul(r, c, prec)
+    b = mpi_mul(r, s, prec)
+    return a, b
+
+def mpi_shift(x, n):
+    a, b = x
+    return mpf_shift(a,n), mpf_shift(b,n)
+
+def mpi_cosh_sinh(x, prec):
+    # TODO: accuracy for small x
+    wp = prec+20
+    e1 = mpi_exp(x, wp)
+    e2 = mpi_div(mpi_one, e1, wp)
+    c = mpi_add(e1, e2, prec)
+    s = mpi_sub(e1, e2, prec)
+    c = mpi_shift(c, -1)
+    s = mpi_shift(s, -1)
+    return c, s
+
+def mpci_cos(x, prec):
+    a, b = x
+    wp = prec+10
+    c, s = mpi_cos_sin(a, wp)
+    ch, sh = mpi_cosh_sinh(b, wp)
+    re = mpi_mul(c, ch, prec)
+    im = mpi_mul(s, sh, prec)
+    return re, mpi_neg(im)
+
+def mpci_sin(x, prec):
+    a, b = x
+    wp = prec+10
+    c, s = mpi_cos_sin(a, wp)
+    ch, sh = mpi_cosh_sinh(b, wp)
+    re = mpi_mul(s, ch, prec)
+    im = mpi_mul(c, sh, prec)
+    return re, im
+
+def mpci_abs(x, prec):
+    a, b = x
+    if a == mpi_zero:
+        return mpi_abs(b)
+    if b == mpi_zero:
+        return mpi_abs(a)
+    # Important: nonnegative
+    a = mpi_square(a)
+    b = mpi_square(b)
+    t = mpi_add(a, b, prec+20)
+    return mpi_sqrt(t, prec)
+
+def mpi_atan2(y, x, prec):
+    ya, yb = y
+    xa, xb = x
+    # Constrained to the real line
+    if ya == yb == fzero:
+        if mpf_ge(xa, fzero):
+            return mpi_zero
+        return mpi_pi(prec)
+    # Right half-plane
+    if mpf_ge(xa, fzero):
+        if mpf_ge(ya, fzero):
+            a = mpf_atan2(ya, xb, prec, round_floor)
+        else:
+            a = mpf_atan2(ya, xa, prec, round_floor)
+        if mpf_ge(yb, fzero):
+            b = mpf_atan2(yb, xa, prec, round_ceiling)
+        else:
+            b = mpf_atan2(yb, xb, prec, round_ceiling)
+    # Upper half-plane
+    elif mpf_ge(ya, fzero):
+        b = mpf_atan2(ya, xa, prec, round_ceiling)
+        if mpf_le(xb, fzero):
+            a = mpf_atan2(yb, xb, prec, round_floor)
+        else:
+            a = mpf_atan2(ya, xb, prec, round_floor)
+    # Lower half-plane
+    elif mpf_le(yb, fzero):
+        a = mpf_atan2(yb, xa, prec, round_floor)
+        if mpf_le(xb, fzero):
+            b = mpf_atan2(ya, xb, prec, round_ceiling)
+        else:
+            b = mpf_atan2(yb, xb, prec, round_ceiling)
+    # Covering the origin
+    else:
+        b = mpf_pi(prec, round_ceiling)
+        a = mpf_neg(b)
+    return a, b
+
+def mpci_arg(z, prec):
+    x, y = z
+    return mpi_atan2(y, x, prec)
+
+def mpci_log(z, prec):
+    x, y = z
+    re = mpi_log(mpci_abs(z, prec+20), prec)
+    im = mpci_arg(z, prec)
+    return re, im
+
+def mpci_pow(x, y, prec):
+    # TODO: recognize/speed up real cases, integer y
+    yre, yim = y
+    if yim == mpi_zero:
+        ya, yb = yre
+        if ya == yb:
+            sign, man, exp, bc = yb
+            if man and exp >= 0:
+                return mpci_pow_int(x, (-1)**sign * int(man<<exp), prec)
+            # x^0
+            if yb == fzero:
+                return mpci_pow_int(x, 0, prec)
+    wp = prec+20
+    return mpci_exp(mpci_mul(y, mpci_log(x, wp), wp), prec)
+
+def mpci_square(x, prec):
+    a, b = x
+    # (a+bi)^2 = (a^2-b^2) + 2abi
+    re = mpi_sub(mpi_square(a), mpi_square(b), prec)
+    im = mpi_mul(a, b, prec)
+    im = mpi_shift(im, 1)
+    return re, im
+
+def mpci_pow_int(x, n, prec):
+    if n < 0:
+        return mpci_div((mpi_one,mpi_zero), mpci_pow_int(x, -n, prec+20), prec)
+    if n == 0:
+        return mpi_one, mpi_zero
+    if n == 1:
+        return mpci_pos(x, prec)
+    if n == 2:
+        return mpci_square(x, prec)
+    wp = prec + 20
+    result = (mpi_one, mpi_zero)
+    while n:
+        if n & 1:
+            result = mpci_mul(result, x, wp)
+            n -= 1
+        x = mpci_square(x, wp)
+        n >>= 1
+    return mpci_pos(result, prec)
+
+gamma_min_a = from_float(1.46163214496)
+gamma_min_b = from_float(1.46163214497)
+gamma_min = (gamma_min_a, gamma_min_b)
+gamma_mono_imag_a = from_float(-1.1)
+gamma_mono_imag_b = from_float(1.1)
+
+def mpi_overlap(x, y):
+    a, b = x
+    c, d = y
+    if mpf_lt(d, a): return False
+    if mpf_gt(c, b): return False
+    return True
+
+# type = 0 -- gamma
+# type = 1 -- factorial
+# type = 2 -- 1/gamma
+# type = 3 -- log-gamma
+
+def mpi_gamma(z, prec, type=0):
+    a, b = z
+    wp = prec+20
+
+    if type == 1:
+        return mpi_gamma(mpi_add(z, mpi_one, wp), prec, 0)
+
+    # increasing
+    if mpf_gt(a, gamma_min_b):
+        if type == 0:
+            c = mpf_gamma(a, prec, round_floor)
+            d = mpf_gamma(b, prec, round_ceiling)
+        elif type == 2:
+            c = mpf_rgamma(b, prec, round_floor)
+            d = mpf_rgamma(a, prec, round_ceiling)
+        elif type == 3:
+            c = mpf_loggamma(a, prec, round_floor)
+            d = mpf_loggamma(b, prec, round_ceiling)
+    # decreasing
+    elif mpf_gt(a, fzero) and mpf_lt(b, gamma_min_a):
+        if type == 0:
+            c = mpf_gamma(b, prec, round_floor)
+            d = mpf_gamma(a, prec, round_ceiling)
+        elif type == 2:
+            c = mpf_rgamma(a, prec, round_floor)
+            d = mpf_rgamma(b, prec, round_ceiling)
+        elif type == 3:
+            c = mpf_loggamma(b, prec, round_floor)
+            d = mpf_loggamma(a, prec, round_ceiling)
+    else:
+        # TODO: reflection formula
+        znew = mpi_add(z, mpi_one, wp)
+        if type == 0: return mpi_div(mpi_gamma(znew, prec+2, 0), z, prec)
+        if type == 2: return mpi_mul(mpi_gamma(znew, prec+2, 2), z, prec)
+        if type == 3: return mpi_sub(mpi_gamma(znew, prec+2, 3), mpi_log(z, prec+2), prec)
+    return c, d
+
+def mpci_gamma(z, prec, type=0):
+    (a1,a2), (b1,b2) = z
+
+    # Real case
+    if b1 == b2 == fzero and (type != 3 or mpf_gt(a1,fzero)):
+        return mpi_gamma(z, prec, type), mpi_zero
+
+    # Estimate precision
+    wp = prec+20
+    if type != 3:
+        amag = a2[2]+a2[3]
+        bmag = b2[2]+b2[3]
+        if a2 != fzero:
+            mag = max(amag, bmag)
+        else:
+            mag = bmag
+        an = abs(to_int(a2))
+        bn = abs(to_int(b2))
+        absn = max(an, bn)
+        gamma_size = max(0,absn*mag)
+        wp += bitcount(gamma_size)
+
+    # Assume type != 1
+    if type == 1:
+        (a1,a2) = mpi_add((a1,a2), mpi_one, wp); z = (a1,a2), (b1,b2)
+        type = 0
+
+    # Avoid non-monotonic region near the negative real axis
+    if mpf_lt(a1, gamma_min_b):
+        if mpi_overlap((b1,b2), (gamma_mono_imag_a, gamma_mono_imag_b)):
+            # TODO: reflection formula
+            #if mpf_lt(a2, mpf_shift(fone,-1)):
+            #    znew = mpci_sub((mpi_one,mpi_zero),z,wp)
+            #    ...
+            # Recurrence:
+            # gamma(z) = gamma(z+1)/z
+            znew = mpi_add((a1,a2), mpi_one, wp), (b1,b2)
+            if type == 0: return mpci_div(mpci_gamma(znew, prec+2, 0), z, prec)
+            if type == 2: return mpci_mul(mpci_gamma(znew, prec+2, 2), z, prec)
+            if type == 3: return mpci_sub(mpci_gamma(znew, prec+2, 3), mpci_log(z,prec+2), prec)
+
+    # Use monotonicity (except for a small region close to the
+    # origin and near poles)
+    # upper half-plane
+    if mpf_ge(b1, fzero):
+        minre = mpc_loggamma((a1,b2), wp, round_floor)
+        maxre = mpc_loggamma((a2,b1), wp, round_ceiling)
+        minim = mpc_loggamma((a1,b1), wp, round_floor)
+        maxim = mpc_loggamma((a2,b2), wp, round_ceiling)
+    # lower half-plane
+    elif mpf_le(b2, fzero):
+        minre = mpc_loggamma((a1,b1), wp, round_floor)
+        maxre = mpc_loggamma((a2,b2), wp, round_ceiling)
+        minim = mpc_loggamma((a2,b1), wp, round_floor)
+        maxim = mpc_loggamma((a1,b2), wp, round_ceiling)
+    # crosses real axis
+    else:
+        maxre = mpc_loggamma((a2,fzero), wp, round_ceiling)
+        # stretches more into the lower half-plane
+        if mpf_gt(mpf_neg(b1), b2):
+            minre = mpc_loggamma((a1,b1), wp, round_ceiling)
+        else:
+            minre = mpc_loggamma((a1,b2), wp, round_ceiling)
+        minim = mpc_loggamma((a2,b1), wp, round_floor)
+        maxim = mpc_loggamma((a2,b2), wp, round_floor)
+
+    w = (minre[0], maxre[0]), (minim[1], maxim[1])
+    if type == 3:
+        return mpi_pos(w[0], prec), mpi_pos(w[1], prec)
+    if type == 2:
+        w = mpci_neg(w)
+    return mpci_exp(w, prec)
+
+def mpi_loggamma(z, prec): return mpi_gamma(z, prec, type=3)
+def mpci_loggamma(z, prec): return mpci_gamma(z, prec, type=3)
+
+def mpi_rgamma(z, prec): return mpi_gamma(z, prec, type=2)
+def mpci_rgamma(z, prec): return mpci_gamma(z, prec, type=2)
+
+def mpi_factorial(z, prec): return mpi_gamma(z, prec, type=1)
+def mpci_factorial(z, prec): return mpci_gamma(z, prec, type=1)

rl/Lib/site-packages/mpmath/math2.py

@@ -0,0 +1,672 @@
+"""
+This module complements the math and cmath builtin modules by providing
+fast machine precision versions of some additional functions (gamma, ...)
+and wrapping math/cmath functions so that they can be called with either
+real or complex arguments.
+"""
+
+import operator
+import math
+import cmath
+
+# Irrational (?) constants
+pi = 3.1415926535897932385
+e = 2.7182818284590452354
+sqrt2 = 1.4142135623730950488
+sqrt5 = 2.2360679774997896964
+phi = 1.6180339887498948482
+ln2 = 0.69314718055994530942
+ln10 = 2.302585092994045684
+euler = 0.57721566490153286061
+catalan = 0.91596559417721901505
+khinchin = 2.6854520010653064453
+apery = 1.2020569031595942854
+
+logpi = 1.1447298858494001741
+
+def _mathfun_real(f_real, f_complex):
+    def f(x, **kwargs):
+        if type(x) is float:
+            return f_real(x)
+        if type(x) is complex:
+            return f_complex(x)
+        try:
+            x = float(x)
+            return f_real(x)
+        except (TypeError, ValueError):
+            x = complex(x)
+            return f_complex(x)
+    f.__name__ = f_real.__name__
+    return f
+
+def _mathfun(f_real, f_complex):
+    def f(x, **kwargs):
+        if type(x) is complex:
+            return f_complex(x)
+        try:
+            return f_real(float(x))
+        except (TypeError, ValueError):
+            return f_complex(complex(x))
+    f.__name__ = f_real.__name__
+    return f
+
+def _mathfun_n(f_real, f_complex):
+    def f(*args, **kwargs):
+        try:
+            return f_real(*(float(x) for x in args))
+        except (TypeError, ValueError):
+            return f_complex(*(complex(x) for x in args))
+    f.__name__ = f_real.__name__
+    return f
+
+# Workaround for non-raising log and sqrt in Python 2.5 and 2.4
+# on Unix system
+try:
+    math.log(-2.0)
+    def math_log(x):
+        if x <= 0.0:
+            raise ValueError("math domain error")
+        return math.log(x)
+    def math_sqrt(x):
+        if x < 0.0:
+            raise ValueError("math domain error")
+        return math.sqrt(x)
+except (ValueError, TypeError):
+    math_log = math.log
+    math_sqrt = math.sqrt
+
+pow = _mathfun_n(operator.pow, lambda x, y: complex(x)**y)
+log = _mathfun_n(math_log, cmath.log)
+sqrt = _mathfun(math_sqrt, cmath.sqrt)
+exp = _mathfun_real(math.exp, cmath.exp)
+
+cos = _mathfun_real(math.cos, cmath.cos)
+sin = _mathfun_real(math.sin, cmath.sin)
+tan = _mathfun_real(math.tan, cmath.tan)
+
+acos = _mathfun(math.acos, cmath.acos)
+asin = _mathfun(math.asin, cmath.asin)
+atan = _mathfun_real(math.atan, cmath.atan)
+
+cosh = _mathfun_real(math.cosh, cmath.cosh)
+sinh = _mathfun_real(math.sinh, cmath.sinh)
+tanh = _mathfun_real(math.tanh, cmath.tanh)
+
+floor = _mathfun_real(math.floor,
+    lambda z: complex(math.floor(z.real), math.floor(z.imag)))
+ceil = _mathfun_real(math.ceil,
+    lambda z: complex(math.ceil(z.real), math.ceil(z.imag)))
+
+
+cos_sin = _mathfun_real(lambda x: (math.cos(x), math.sin(x)),
+                        lambda z: (cmath.cos(z), cmath.sin(z)))
+
+cbrt = _mathfun(lambda x: x**(1./3), lambda z: z**(1./3))
+
+def nthroot(x, n):
+    r = 1./n
+    try:
+        return float(x) ** r
+    except (ValueError, TypeError):
+        return complex(x) ** r
+
+def _sinpi_real(x):
+    if x < 0:
+        return -_sinpi_real(-x)
+    n, r = divmod(x, 0.5)
+    r *= pi
+    n %= 4
+    if n == 0: return math.sin(r)
+    if n == 1: return math.cos(r)
+    if n == 2: return -math.sin(r)
+    if n == 3: return -math.cos(r)
+
+def _cospi_real(x):
+    if x < 0:
+        x = -x
+    n, r = divmod(x, 0.5)
+    r *= pi
+    n %= 4
+    if n == 0: return math.cos(r)
+    if n == 1: return -math.sin(r)
+    if n == 2: return -math.cos(r)
+    if n == 3: return math.sin(r)
+
+def _sinpi_complex(z):
+    if z.real < 0:
+        return -_sinpi_complex(-z)
+    n, r = divmod(z.real, 0.5)
+    z = pi*complex(r, z.imag)
+    n %= 4
+    if n == 0: return cmath.sin(z)
+    if n == 1: return cmath.cos(z)
+    if n == 2: return -cmath.sin(z)
+    if n == 3: return -cmath.cos(z)
+
+def _cospi_complex(z):
+    if z.real < 0:
+        z = -z
+    n, r = divmod(z.real, 0.5)
+    z = pi*complex(r, z.imag)
+    n %= 4
+    if n == 0: return cmath.cos(z)
+    if n == 1: return -cmath.sin(z)
+    if n == 2: return -cmath.cos(z)
+    if n == 3: return cmath.sin(z)
+
+cospi = _mathfun_real(_cospi_real, _cospi_complex)
+sinpi = _mathfun_real(_sinpi_real, _sinpi_complex)
+
+def tanpi(x):
+    try:
+        return sinpi(x) / cospi(x)
+    except OverflowError:
+        if complex(x).imag > 10:
+            return 1j
+        if complex(x).imag < 10:
+            return -1j
+        raise
+
+def cotpi(x):
+    try:
+        return cospi(x) / sinpi(x)
+    except OverflowError:
+        if complex(x).imag > 10:
+            return -1j
+        if complex(x).imag < 10:
+            return 1j
+        raise
+
+INF = 1e300*1e300
+NINF = -INF
+NAN = INF-INF
+EPS = 2.2204460492503131e-16
+
+_exact_gamma = (INF, 1.0, 1.0, 2.0, 6.0, 24.0, 120.0, 720.0, 5040.0, 40320.0,
+  362880.0, 3628800.0, 39916800.0, 479001600.0, 6227020800.0, 87178291200.0,
+  1307674368000.0, 20922789888000.0, 355687428096000.0, 6402373705728000.0,
+  121645100408832000.0, 2432902008176640000.0)
+
+_max_exact_gamma = len(_exact_gamma)-1
+
+# Lanczos coefficients used by the GNU Scientific Library
+_lanczos_g = 7
+_lanczos_p = (0.99999999999980993, 676.5203681218851, -1259.1392167224028,
+     771.32342877765313, -176.61502916214059, 12.507343278686905,
+     -0.13857109526572012, 9.9843695780195716e-6, 1.5056327351493116e-7)
+
+def _gamma_real(x):
+    _intx = int(x)
+    if _intx == x:
+        if _intx <= 0:
+            #return (-1)**_intx * INF
+            raise ZeroDivisionError("gamma function pole")
+        if _intx <= _max_exact_gamma:
+            return _exact_gamma[_intx]
+    if x < 0.5:
+        # TODO: sinpi
+        return pi / (_sinpi_real(x)*_gamma_real(1-x))
+    else:
+        x -= 1.0
+        r = _lanczos_p[0]
+        for i in range(1, _lanczos_g+2):
+            r += _lanczos_p[i]/(x+i)
+        t = x + _lanczos_g + 0.5
+        return 2.506628274631000502417 * t**(x+0.5) * math.exp(-t) * r
+
+def _gamma_complex(x):
+    if not x.imag:
+        return complex(_gamma_real(x.real))
+    if x.real < 0.5:
+        # TODO: sinpi
+        return pi / (_sinpi_complex(x)*_gamma_complex(1-x))
+    else:
+        x -= 1.0
+        r = _lanczos_p[0]
+        for i in range(1, _lanczos_g+2):
+            r += _lanczos_p[i]/(x+i)
+        t = x + _lanczos_g + 0.5
+        return 2.506628274631000502417 * t**(x+0.5) * cmath.exp(-t) * r
+
+gamma = _mathfun_real(_gamma_real, _gamma_complex)
+
+def rgamma(x):
+    try:
+        return 1./gamma(x)
+    except ZeroDivisionError:
+        return x*0.0
+
+def factorial(x):
+    return gamma(x+1.0)
+
+def arg(x):
+    if type(x) is float:
+        return math.atan2(0.0,x)
+    return math.atan2(x.imag,x.real)
+
+# XXX: broken for negatives
+def loggamma(x):
+    if type(x) not in (float, complex):
+        try:
+            x = float(x)
+        except (ValueError, TypeError):
+            x = complex(x)
+    try:
+        xreal = x.real
+        ximag = x.imag
+    except AttributeError:   # py2.5
+        xreal = x
+        ximag = 0.0
+    # Reflection formula
+    # http://functions.wolfram.com/GammaBetaErf/LogGamma/16/01/01/0003/
+    if xreal < 0.0:
+        if abs(x) < 0.5:
+            v = log(gamma(x))
+            if ximag == 0:
+                v = v.conjugate()
+            return v
+        z = 1-x
+        try:
+            re = z.real
+            im = z.imag
+        except AttributeError:   # py2.5
+            re = z
+            im = 0.0
+        refloor = floor(re)
+        if im == 0.0:
+            imsign = 0
+        elif im < 0.0:
+            imsign = -1
+        else:
+            imsign = 1
+        return (-pi*1j)*abs(refloor)*(1-abs(imsign)) + logpi - \
+            log(sinpi(z-refloor)) - loggamma(z) + 1j*pi*refloor*imsign
+    if x == 1.0 or x == 2.0:
+        return x*0
+    p = 0.
+    while abs(x) < 11:
+        p -= log(x)
+        x += 1.0
+    s = 0.918938533204672742 + (x-0.5)*log(x) - x
+    r = 1./x
+    r2 = r*r
+    s += 0.083333333333333333333*r; r *= r2
+    s += -0.0027777777777777777778*r; r *= r2
+    s += 0.00079365079365079365079*r; r *= r2
+    s += -0.0005952380952380952381*r; r *= r2
+    s += 0.00084175084175084175084*r; r *= r2
+    s += -0.0019175269175269175269*r; r *= r2
+    s += 0.0064102564102564102564*r; r *= r2
+    s += -0.02955065359477124183*r
+    return s + p
+
+_psi_coeff = [
+0.083333333333333333333,
+-0.0083333333333333333333,
+0.003968253968253968254,
+-0.0041666666666666666667,
+0.0075757575757575757576,
+-0.021092796092796092796,
+0.083333333333333333333,
+-0.44325980392156862745,
+3.0539543302701197438,
+-26.456212121212121212]
+
+def _digamma_real(x):
+    _intx = int(x)
+    if _intx == x:
+        if _intx <= 0:
+            raise ZeroDivisionError("polygamma pole")
+    if x < 0.5:
+        x = 1.0-x
+        s = pi*cotpi(x)
+    else:
+        s = 0.0
+    while x < 10.0:
+        s -= 1.0/x
+        x += 1.0
+    x2 = x**-2
+    t = x2
+    for c in _psi_coeff:
+        s -= c*t
+        if t < 1e-20:
+            break
+        t *= x2
+    return s + math_log(x) - 0.5/x
+
+def _digamma_complex(x):
+    if not x.imag:
+        return complex(_digamma_real(x.real))
+    if x.real < 0.5:
+        x = 1.0-x
+        s = pi*cotpi(x)
+    else:
+        s = 0.0
+    while abs(x) < 10.0:
+        s -= 1.0/x
+        x += 1.0
+    x2 = x**-2
+    t = x2
+    for c in _psi_coeff:
+        s -= c*t
+        if abs(t) < 1e-20:
+            break
+        t *= x2
+    return s + cmath.log(x) - 0.5/x
+
+digamma = _mathfun_real(_digamma_real, _digamma_complex)
+
+# TODO: could implement complex erf and erfc here. Need
+# to find an accurate method (avoiding cancellation)
+# for approx. 1 < abs(x) < 9.
+
+_erfc_coeff_P = [
+    1.0000000161203922312,
+    2.1275306946297962644,
+    2.2280433377390253297,
+    1.4695509105618423961,
+    0.66275911699770787537,
+    0.20924776504163751585,
+    0.045459713768411264339,
+    0.0063065951710717791934,
+    0.00044560259661560421715][::-1]
+
+_erfc_coeff_Q = [
+    1.0000000000000000000,
+    3.2559100272784894318,
+    4.9019435608903239131,
+    4.4971472894498014205,
+    2.7845640601891186528,
+    1.2146026030046904138,
+    0.37647108453729465912,
+    0.080970149639040548613,
+    0.011178148899483545902,
+    0.00078981003831980423513][::-1]
+
+def _polyval(coeffs, x):
+    p = coeffs[0]
+    for c in coeffs[1:]:
+        p = c + x*p
+    return p
+
+def _erf_taylor(x):
+    # Taylor series assuming 0 <= x <= 1
+    x2 = x*x
+    s = t = x
+    n = 1
+    while abs(t) > 1e-17:
+        t *= x2/n
+        s -= t/(n+n+1)
+        n += 1
+        t *= x2/n
+        s += t/(n+n+1)
+        n += 1
+    return 1.1283791670955125739*s
+
+def _erfc_mid(x):
+    # Rational approximation assuming 0 <= x <= 9
+    return exp(-x*x)*_polyval(_erfc_coeff_P,x)/_polyval(_erfc_coeff_Q,x)
+
+def _erfc_asymp(x):
+    # Asymptotic expansion assuming x >= 9
+    x2 = x*x
+    v = exp(-x2)/x*0.56418958354775628695
+    r = t = 0.5 / x2
+    s = 1.0
+    for n in range(1,22,4):
+        s -= t
+        t *= r * (n+2)
+        s += t
+        t *= r * (n+4)
+        if abs(t) < 1e-17:
+            break
+    return s * v
+
+def erf(x):
+    """
+    erf of a real number.
+    """
+    x = float(x)
+    if x != x:
+        return x
+    if x < 0.0:
+        return -erf(-x)
+    if x >= 1.0:
+        if x >= 6.0:
+            return 1.0
+        return 1.0 - _erfc_mid(x)
+    return _erf_taylor(x)
+
+def erfc(x):
+    """
+    erfc of a real number.
+    """
+    x = float(x)
+    if x != x:
+        return x
+    if x < 0.0:
+        if x < -6.0:
+            return 2.0
+        return 2.0-erfc(-x)
+    if x > 9.0:
+        return _erfc_asymp(x)
+    if x >= 1.0:
+        return _erfc_mid(x)
+    return 1.0 - _erf_taylor(x)
+
+gauss42 = [\
+(0.99839961899006235, 0.0041059986046490839),
+(-0.99839961899006235, 0.0041059986046490839),
+(0.9915772883408609, 0.009536220301748501),
+(-0.9915772883408609,0.009536220301748501),
+(0.97934250806374812, 0.014922443697357493),
+(-0.97934250806374812, 0.014922443697357493),
+(0.96175936533820439,0.020227869569052644),
+(-0.96175936533820439, 0.020227869569052644),
+(0.93892355735498811, 0.025422959526113047),
+(-0.93892355735498811,0.025422959526113047),
+(0.91095972490412735, 0.030479240699603467),
+(-0.91095972490412735, 0.030479240699603467),
+(0.87802056981217269,0.03536907109759211),
+(-0.87802056981217269, 0.03536907109759211),
+(0.8402859832618168, 0.040065735180692258),
+(-0.8402859832618168,0.040065735180692258),
+(0.7979620532554873, 0.044543577771965874),
+(-0.7979620532554873, 0.044543577771965874),
+(0.75127993568948048,0.048778140792803244),
+(-0.75127993568948048, 0.048778140792803244),
+(0.70049459055617114, 0.052746295699174064),
+(-0.70049459055617114,0.052746295699174064),
+(0.64588338886924779, 0.056426369358018376),
+(-0.64588338886924779, 0.056426369358018376),
+(0.58774459748510932, 0.059798262227586649),
+(-0.58774459748510932, 0.059798262227586649),
+(0.5263957499311922, 0.062843558045002565),
+(-0.5263957499311922, 0.062843558045002565),
+(0.46217191207042191, 0.065545624364908975),
+(-0.46217191207042191, 0.065545624364908975),
+(0.39542385204297503, 0.067889703376521934),
+(-0.39542385204297503, 0.067889703376521934),
+(0.32651612446541151, 0.069862992492594159),
+(-0.32651612446541151, 0.069862992492594159),
+(0.25582507934287907, 0.071454714265170971),
+(-0.25582507934287907, 0.071454714265170971),
+(0.18373680656485453, 0.072656175243804091),
+(-0.18373680656485453, 0.072656175243804091),
+(0.11064502720851986, 0.073460813453467527),
+(-0.11064502720851986, 0.073460813453467527),
+(0.036948943165351772, 0.073864234232172879),
+(-0.036948943165351772, 0.073864234232172879)]
+
+EI_ASYMP_CONVERGENCE_RADIUS = 40.0
+
+def ei_asymp(z, _e1=False):
+    r = 1./z
+    s = t = 1.0
+    k = 1
+    while 1:
+        t *= k*r
+        s += t
+        if abs(t) < 1e-16:
+            break
+        k += 1
+    v = s*exp(z)/z
+    if _e1:
+        if type(z) is complex:
+            zreal = z.real
+            zimag = z.imag
+        else:
+            zreal = z
+            zimag = 0.0
+        if zimag == 0.0 and zreal > 0.0:
+            v += pi*1j
+    else:
+        if type(z) is complex:
+            if z.imag > 0:
+                v += pi*1j
+            if z.imag < 0:
+                v -= pi*1j
+    return v
+
+def ei_taylor(z, _e1=False):
+    s = t = z
+    k = 2
+    while 1:
+        t = t*z/k
+        term = t/k
+        if abs(term) < 1e-17:
+            break
+        s += term
+        k += 1
+    s += euler
+    if _e1:
+        s += log(-z)
+    else:
+        if type(z) is float or z.imag == 0.0:
+            s += math_log(abs(z))
+        else:
+            s += cmath.log(z)
+    return s
+
+def ei(z, _e1=False):
+    typez = type(z)
+    if typez not in (float, complex):
+        try:
+            z = float(z)
+            typez = float
+        except (TypeError, ValueError):
+            z = complex(z)
+            typez = complex
+    if not z:
+        return -INF
+    absz = abs(z)
+    if absz > EI_ASYMP_CONVERGENCE_RADIUS:
+        return ei_asymp(z, _e1)
+    elif absz <= 2.0 or (typez is float and z > 0.0):
+        return ei_taylor(z, _e1)
+    # Integrate, starting from whichever is smaller of a Taylor
+    # series value or an asymptotic series value
+    if typez is complex and z.real > 0.0:
+        zref = z / absz
+        ref = ei_taylor(zref, _e1)
+    else:
+        zref = EI_ASYMP_CONVERGENCE_RADIUS * z / absz
+        ref = ei_asymp(zref, _e1)
+    C = (zref-z)*0.5
+    D = (zref+z)*0.5
+    s = 0.0
+    if type(z) is complex:
+        _exp = cmath.exp
+    else:
+        _exp = math.exp
+    for x,w in gauss42:
+        t = C*x+D
+        s += w*_exp(t)/t
+    ref -= C*s
+    return ref
+
+def e1(z):
+    # hack to get consistent signs if the imaginary part if 0
+    # and signed
+    typez = type(z)
+    if type(z) not in (float, complex):
+        try:
+            z = float(z)
+            typez = float
+        except (TypeError, ValueError):
+            z = complex(z)
+            typez = complex
+    if typez is complex and not z.imag:
+        z = complex(z.real, 0.0)
+    # end hack
+    return -ei(-z, _e1=True)
+
+_zeta_int = [\
+-0.5,
+0.0,
+1.6449340668482264365,1.2020569031595942854,1.0823232337111381915,
+1.0369277551433699263,1.0173430619844491397,1.0083492773819228268,
+1.0040773561979443394,1.0020083928260822144,1.0009945751278180853,
+1.0004941886041194646,1.0002460865533080483,1.0001227133475784891,
+1.0000612481350587048,1.0000305882363070205,1.0000152822594086519,
+1.0000076371976378998,1.0000038172932649998,1.0000019082127165539,
+1.0000009539620338728,1.0000004769329867878,1.0000002384505027277,
+1.0000001192199259653,1.0000000596081890513,1.0000000298035035147,
+1.0000000149015548284]
+
+_zeta_P = [-3.50000000087575873, -0.701274355654678147,
+-0.0672313458590012612, -0.00398731457954257841,
+-0.000160948723019303141, -4.67633010038383371e-6,
+-1.02078104417700585e-7, -1.68030037095896287e-9,
+-1.85231868742346722e-11][::-1]
+
+_zeta_Q = [1.00000000000000000, -0.936552848762465319,
+-0.0588835413263763741, -0.00441498861482948666,
+-0.000143416758067432622, -5.10691659585090782e-6,
+-9.58813053268913799e-8, -1.72963791443181972e-9,
+-1.83527919681474132e-11][::-1]
+
+_zeta_1 = [3.03768838606128127e-10, -1.21924525236601262e-8,
+2.01201845887608893e-7, -1.53917240683468381e-6,
+-5.09890411005967954e-7, 0.000122464707271619326,
+-0.000905721539353130232, -0.00239315326074843037,
+0.084239750013159168, 0.418938517907442414, 0.500000001921884009]
+
+_zeta_0 = [-3.46092485016748794e-10, -6.42610089468292485e-9,
+1.76409071536679773e-7, -1.47141263991560698e-6, -6.38880222546167613e-7,
+0.000122641099800668209, -0.000905894913516772796, -0.00239303348507992713,
+0.0842396947501199816, 0.418938533204660256, 0.500000000000000052]
+
+def zeta(s):
+    """
+    Riemann zeta function, real argument
+    """
+    if not isinstance(s, (float, int)):
+        try:
+            s = float(s)
+        except (ValueError, TypeError):
+            try:
+                s = complex(s)
+                if not s.imag:
+                    return complex(zeta(s.real))
+            except (ValueError, TypeError):
+                pass
+            raise NotImplementedError
+    if s == 1:
+        raise ValueError("zeta(1) pole")
+    if s >= 27:
+        return 1.0 + 2.0**(-s) + 3.0**(-s)
+    n = int(s)
+    if n == s:
+        if n >= 0:
+            return _zeta_int[n]
+        if not (n % 2):
+            return 0.0
+    if s <= 0.0:
+        return 2.**s*pi**(s-1)*_sinpi_real(0.5*s)*_gamma_real(1-s)*zeta(1-s)
+    if s <= 2.0:
+        if s <= 1.0:
+            return _polyval(_zeta_0,s)/(s-1)
+        return _polyval(_zeta_1,s)/(s-1)
+    z = _polyval(_zeta_P,s) / _polyval(_zeta_Q,s)
+    return 1.0 + 2.0**(-s) + 3.0**(-s) + 4.0**(-s)*z

rl/Lib/site-packages/mpmath/matrices/__init__.py

@@ -0,0 +1,2 @@
+from . import eigen           # to set methods
+from . import eigen_symmetric # to set methods

rl/Lib/site-packages/mpmath/matrices/calculus.py

@@ -0,0 +1,531 @@
+from ..libmp.backend import xrange
+
+# TODO: should use diagonalization-based algorithms
+
+class MatrixCalculusMethods(object):
+
+    def _exp_pade(ctx, a):
+        """
+        Exponential of a matrix using Pade approximants.
+
+        See G. H. Golub, C. F. van Loan 'Matrix Computations',
+        third Ed., page 572
+
+        TODO:
+         - find a good estimate for q
+         - reduce the number of matrix multiplications to improve
+           performance
+        """
+        def eps_pade(p):
+            return ctx.mpf(2)**(3-2*p) * \
+                ctx.factorial(p)**2/(ctx.factorial(2*p)**2 * (2*p + 1))
+        q = 4
+        extraq = 8
+        while 1:
+            if eps_pade(q) < ctx.eps:
+                break
+            q += 1
+        q += extraq
+        j = int(max(1, ctx.mag(ctx.mnorm(a,'inf'))))
+        extra = q
+        prec = ctx.prec
+        ctx.dps += extra + 3
+        try:
+            a = a/2**j
+            na = a.rows
+            den = ctx.eye(na)
+            num = ctx.eye(na)
+            x = ctx.eye(na)
+            c = ctx.mpf(1)
+            for k in range(1, q+1):
+                c *= ctx.mpf(q - k + 1)/((2*q - k + 1) * k)
+                x = a*x
+                cx = c*x
+                num += cx
+                den += (-1)**k * cx
+            f = ctx.lu_solve_mat(den, num)
+            for k in range(j):
+                f = f*f
+        finally:
+            ctx.prec = prec
+        return f*1
+
+    def expm(ctx, A, method='taylor'):
+        r"""
+        Computes the matrix exponential of a square matrix `A`, which is defined
+        by the power series
+
+        .. math ::
+
+            \exp(A) = I + A + \frac{A^2}{2!} + \frac{A^3}{3!} + \ldots
+
+        With method='taylor', the matrix exponential is computed
+        using the Taylor series. With method='pade', Pade approximants
+        are used instead.
+
+        **Examples**
+
+        Basic examples::
+
+            >>> from mpmath import *
+            >>> mp.dps = 15; mp.pretty = True
+            >>> expm(zeros(3))
+            [1.0  0.0  0.0]
+            [0.0  1.0  0.0]
+            [0.0  0.0  1.0]
+            >>> expm(eye(3))
+            [2.71828182845905               0.0               0.0]
+            [             0.0  2.71828182845905               0.0]
+            [             0.0               0.0  2.71828182845905]
+            >>> expm([[1,1,0],[1,0,1],[0,1,0]])
+            [ 3.86814500615414  2.26812870852145  0.841130841230196]
+            [ 2.26812870852145  2.44114713886289   1.42699786729125]
+            [0.841130841230196  1.42699786729125    1.6000162976327]
+            >>> expm([[1,1,0],[1,0,1],[0,1,0]], method='pade')
+            [ 3.86814500615414  2.26812870852145  0.841130841230196]
+            [ 2.26812870852145  2.44114713886289   1.42699786729125]
+            [0.841130841230196  1.42699786729125    1.6000162976327]
+            >>> expm([[1+j, 0], [1+j,1]])
+            [(1.46869393991589 + 2.28735528717884j)                        0.0]
+            [  (1.03776739863568 + 3.536943175722j)  (2.71828182845905 + 0.0j)]
+
+        Matrices with large entries are allowed::
+
+            >>> expm(matrix([[1,2],[2,3]])**25)
+            [5.65024064048415e+2050488462815550  9.14228140091932e+2050488462815550]
+            [9.14228140091932e+2050488462815550  1.47925220414035e+2050488462815551]
+
+        The identity `\exp(A+B) = \exp(A) \exp(B)` does not hold for
+        noncommuting matrices::
+
+            >>> A = hilbert(3)
+            >>> B = A + eye(3)
+            >>> chop(mnorm(A*B - B*A))
+            0.0
+            >>> chop(mnorm(expm(A+B) - expm(A)*expm(B)))
+            0.0
+            >>> B = A + ones(3)
+            >>> mnorm(A*B - B*A)
+            1.8
+            >>> mnorm(expm(A+B) - expm(A)*expm(B))
+            42.0927851137247
+
+        """
+        if method == 'pade':
+            prec = ctx.prec
+            try:
+                A = ctx.matrix(A)
+                ctx.prec += 2*A.rows
+                res = ctx._exp_pade(A)
+            finally:
+                ctx.prec = prec
+            return res
+        A = ctx.matrix(A)
+        prec = ctx.prec
+        j = int(max(1, ctx.mag(ctx.mnorm(A,'inf'))))
+        j += int(0.5*prec**0.5)
+        try:
+            ctx.prec += 10 + 2*j
+            tol = +ctx.eps
+            A = A/2**j
+            T = A
+            Y = A**0 + A
+            k = 2
+            while 1:
+                T *= A * (1/ctx.mpf(k))
+                if ctx.mnorm(T, 'inf') < tol:
+                    break
+                Y += T
+                k += 1
+            for k in xrange(j):
+                Y = Y*Y
+        finally:
+            ctx.prec = prec
+        Y *= 1
+        return Y
+
+    def cosm(ctx, A):
+        r"""
+        Gives the cosine of a square matrix `A`, defined in analogy
+        with the matrix exponential.
+
+        Examples::
+
+            >>> from mpmath import *
+            >>> mp.dps = 15; mp.pretty = True
+            >>> X = eye(3)
+            >>> cosm(X)
+            [0.54030230586814               0.0               0.0]
+            [             0.0  0.54030230586814               0.0]
+            [             0.0               0.0  0.54030230586814]
+            >>> X = hilbert(3)
+            >>> cosm(X)
+            [ 0.424403834569555  -0.316643413047167  -0.221474945949293]
+            [-0.316643413047167   0.820646708837824  -0.127183694770039]
+            [-0.221474945949293  -0.127183694770039   0.909236687217541]
+            >>> X = matrix([[1+j,-2],[0,-j]])
+            >>> cosm(X)
+            [(0.833730025131149 - 0.988897705762865j)  (1.07485840848393 - 0.17192140544213j)]
+            [                                     0.0               (1.54308063481524 + 0.0j)]
+        """
+        B = 0.5 * (ctx.expm(A*ctx.j) + ctx.expm(A*(-ctx.j)))
+        if not sum(A.apply(ctx.im).apply(abs)):
+            B = B.apply(ctx.re)
+        return B
+
+    def sinm(ctx, A):
+        r"""
+        Gives the sine of a square matrix `A`, defined in analogy
+        with the matrix exponential.
+
+        Examples::
+
+            >>> from mpmath import *
+            >>> mp.dps = 15; mp.pretty = True
+            >>> X = eye(3)
+            >>> sinm(X)
+            [0.841470984807897                0.0                0.0]
+            [              0.0  0.841470984807897                0.0]
+            [              0.0                0.0  0.841470984807897]
+            >>> X = hilbert(3)
+            >>> sinm(X)
+            [0.711608512150994  0.339783913247439  0.220742837314741]
+            [0.339783913247439  0.244113865695532  0.187231271174372]
+            [0.220742837314741  0.187231271174372  0.155816730769635]
+            >>> X = matrix([[1+j,-2],[0,-j]])
+            >>> sinm(X)
+            [(1.29845758141598 + 0.634963914784736j)  (-1.96751511930922 + 0.314700021761367j)]
+            [                                    0.0                  (0.0 - 1.1752011936438j)]
+        """
+        B = (-0.5j) * (ctx.expm(A*ctx.j) - ctx.expm(A*(-ctx.j)))
+        if not sum(A.apply(ctx.im).apply(abs)):
+            B = B.apply(ctx.re)
+        return B
+
+    def _sqrtm_rot(ctx, A, _may_rotate):
+        # If the iteration fails to converge, cheat by performing
+        # a rotation by a complex number
+        u = ctx.j**0.3
+        return ctx.sqrtm(u*A, _may_rotate) / ctx.sqrt(u)
+
+    def sqrtm(ctx, A, _may_rotate=2):
+        r"""
+        Computes a square root of the square matrix `A`, i.e. returns
+        a matrix `B = A^{1/2}` such that `B^2 = A`. The square root
+        of a matrix, if it exists, is not unique.
+
+        **Examples**
+
+        Square roots of some simple matrices::
+
+            >>> from mpmath import *
+            >>> mp.dps = 15; mp.pretty = True
+            >>> sqrtm([[1,0], [0,1]])
+            [1.0  0.0]
+            [0.0  1.0]
+            >>> sqrtm([[0,0], [0,0]])
+            [0.0  0.0]
+            [0.0  0.0]
+            >>> sqrtm([[2,0],[0,1]])
+            [1.4142135623731  0.0]
+            [            0.0  1.0]
+            >>> sqrtm([[1,1],[1,0]])
+            [ (0.920442065259926 - 0.21728689675164j)  (0.568864481005783 + 0.351577584254143j)]
+            [(0.568864481005783 + 0.351577584254143j)  (0.351577584254143 - 0.568864481005783j)]
+            >>> sqrtm([[1,0],[0,1]])
+            [1.0  0.0]
+            [0.0  1.0]
+            >>> sqrtm([[-1,0],[0,1]])
+            [(0.0 - 1.0j)           0.0]
+            [         0.0  (1.0 + 0.0j)]
+            >>> sqrtm([[j,0],[0,j]])
+            [(0.707106781186547 + 0.707106781186547j)                                       0.0]
+            [                                     0.0  (0.707106781186547 + 0.707106781186547j)]
+
+        A square root of a rotation matrix, giving the corresponding
+        half-angle rotation matrix::
+
+            >>> t1 = 0.75
+            >>> t2 = t1 * 0.5
+            >>> A1 = matrix([[cos(t1), -sin(t1)], [sin(t1), cos(t1)]])
+            >>> A2 = matrix([[cos(t2), -sin(t2)], [sin(t2), cos(t2)]])
+            >>> sqrtm(A1)
+            [0.930507621912314  -0.366272529086048]
+            [0.366272529086048   0.930507621912314]
+            >>> A2
+            [0.930507621912314  -0.366272529086048]
+            [0.366272529086048   0.930507621912314]
+
+        The identity `(A^2)^{1/2} = A` does not necessarily hold::
+
+            >>> A = matrix([[4,1,4],[7,8,9],[10,2,11]])
+            >>> sqrtm(A**2)
+            [ 4.0  1.0   4.0]
+            [ 7.0  8.0   9.0]
+            [10.0  2.0  11.0]
+            >>> sqrtm(A)**2
+            [ 4.0  1.0   4.0]
+            [ 7.0  8.0   9.0]
+            [10.0  2.0  11.0]
+            >>> A = matrix([[-4,1,4],[7,-8,9],[10,2,11]])
+            >>> sqrtm(A**2)
+            [  7.43715112194995  -0.324127569985474   1.8481718827526]
+            [-0.251549715716942    9.32699765900402  2.48221180985147]
+            [  4.11609388833616   0.775751877098258   13.017955697342]
+            >>> chop(sqrtm(A)**2)
+            [-4.0   1.0   4.0]
+            [ 7.0  -8.0   9.0]
+            [10.0   2.0  11.0]
+
+        For some matrices, a square root does not exist::
+
+            >>> sqrtm([[0,1], [0,0]])
+            Traceback (most recent call last):
+              ...
+            ZeroDivisionError: matrix is numerically singular
+
+        Two examples from the documentation for Matlab's ``sqrtm``::
+
+            >>> mp.dps = 15; mp.pretty = True
+            >>> sqrtm([[7,10],[15,22]])
+            [1.56669890360128  1.74077655955698]
+            [2.61116483933547  4.17786374293675]
+            >>>
+            >>> X = matrix(\
+            ...   [[5,-4,1,0,0],
+            ...   [-4,6,-4,1,0],
+            ...   [1,-4,6,-4,1],
+            ...   [0,1,-4,6,-4],
+            ...   [0,0,1,-4,5]])
+            >>> Y = matrix(\
+            ...   [[2,-1,-0,-0,-0],
+            ...   [-1,2,-1,0,-0],
+            ...   [0,-1,2,-1,0],
+            ...   [-0,0,-1,2,-1],
+            ...   [-0,-0,-0,-1,2]])
+            >>> mnorm(sqrtm(X) - Y)
+            4.53155328326114e-19
+
+        """
+        A = ctx.matrix(A)
+        # Trivial
+        if A*0 == A:
+            return A
+        prec = ctx.prec
+        if _may_rotate:
+            d = ctx.det(A)
+            if abs(ctx.im(d)) < 16*ctx.eps and ctx.re(d) < 0:
+                return ctx._sqrtm_rot(A, _may_rotate-1)
+        try:
+            ctx.prec += 10
+            tol = ctx.eps * 128
+            Y = A
+            Z = I = A**0
+            k = 0
+            # Denman-Beavers iteration
+            while 1:
+                Yprev = Y
+                try:
+                    Y, Z = 0.5*(Y+ctx.inverse(Z)), 0.5*(Z+ctx.inverse(Y))
+                except ZeroDivisionError:
+                    if _may_rotate:
+                        Y = ctx._sqrtm_rot(A, _may_rotate-1)
+                        break
+                    else:
+                        raise
+                mag1 = ctx.mnorm(Y-Yprev, 'inf')
+                mag2 = ctx.mnorm(Y, 'inf')
+                if mag1 <= mag2*tol:
+                    break
+                if _may_rotate and k > 6 and not mag1 < mag2 * 0.001:
+                    return ctx._sqrtm_rot(A, _may_rotate-1)
+                k += 1
+                if k > ctx.prec:
+                    raise ctx.NoConvergence
+        finally:
+            ctx.prec = prec
+        Y *= 1
+        return Y
+
+    def logm(ctx, A):
+        r"""
+        Computes a logarithm of the square matrix `A`, i.e. returns
+        a matrix `B = \log(A)` such that `\exp(B) = A`. The logarithm
+        of a matrix, if it exists, is not unique.
+
+        **Examples**
+
+        Logarithms of some simple matrices::
+
+            >>> from mpmath import *
+            >>> mp.dps = 15; mp.pretty = True
+            >>> X = eye(3)
+            >>> logm(X)
+            [0.0  0.0  0.0]
+            [0.0  0.0  0.0]
+            [0.0  0.0  0.0]
+            >>> logm(2*X)
+            [0.693147180559945                0.0                0.0]
+            [              0.0  0.693147180559945                0.0]
+            [              0.0                0.0  0.693147180559945]
+            >>> logm(expm(X))
+            [1.0  0.0  0.0]
+            [0.0  1.0  0.0]
+            [0.0  0.0  1.0]
+
+        A logarithm of a complex matrix::
+
+            >>> X = matrix([[2+j, 1, 3], [1-j, 1-2*j, 1], [-4, -5, j]])
+            >>> B = logm(X)
+            >>> nprint(B)
+            [ (0.808757 + 0.107759j)    (2.20752 + 0.202762j)   (1.07376 - 0.773874j)]
+            [ (0.905709 - 0.107795j)  (0.0287395 - 0.824993j)  (0.111619 + 0.514272j)]
+            [(-0.930151 + 0.399512j)   (-2.06266 - 0.674397j)  (0.791552 + 0.519839j)]
+            >>> chop(expm(B))
+            [(2.0 + 1.0j)           1.0           3.0]
+            [(1.0 - 1.0j)  (1.0 - 2.0j)           1.0]
+            [        -4.0          -5.0  (0.0 + 1.0j)]
+
+        A matrix `X` close to the identity matrix, for which
+        `\log(\exp(X)) = \exp(\log(X)) = X` holds::
+
+            >>> X = eye(3) + hilbert(3)/4
+            >>> X
+            [              1.25             0.125  0.0833333333333333]
+            [             0.125  1.08333333333333              0.0625]
+            [0.0833333333333333            0.0625                1.05]
+            >>> logm(expm(X))
+            [              1.25             0.125  0.0833333333333333]
+            [             0.125  1.08333333333333              0.0625]
+            [0.0833333333333333            0.0625                1.05]
+            >>> expm(logm(X))
+            [              1.25             0.125  0.0833333333333333]
+            [             0.125  1.08333333333333              0.0625]
+            [0.0833333333333333            0.0625                1.05]
+
+        A logarithm of a rotation matrix, giving back the angle of
+        the rotation::
+
+            >>> t = 3.7
+            >>> A = matrix([[cos(t),sin(t)],[-sin(t),cos(t)]])
+            >>> chop(logm(A))
+            [             0.0  -2.58318530717959]
+            [2.58318530717959                0.0]
+            >>> (2*pi-t)
+            2.58318530717959
+
+        For some matrices, a logarithm does not exist::
+
+            >>> logm([[1,0], [0,0]])
+            Traceback (most recent call last):
+              ...
+            ZeroDivisionError: matrix is numerically singular
+
+        Logarithm of a matrix with large entries::
+
+            >>> logm(hilbert(3) * 10**20).apply(re)
+            [ 45.5597513593433  1.27721006042799  0.317662687717978]
+            [ 1.27721006042799  42.5222778973542   2.24003708791604]
+            [0.317662687717978  2.24003708791604    42.395212822267]
+
+        """
+        A = ctx.matrix(A)
+        prec = ctx.prec
+        try:
+            ctx.prec += 10
+            tol = ctx.eps * 128
+            I = A**0
+            B = A
+            n = 0
+            while 1:
+                B = ctx.sqrtm(B)
+                n += 1
+                if ctx.mnorm(B-I, 'inf') < 0.125:
+                    break
+            T = X = B-I
+            L = X*0
+            k = 1
+            while 1:
+                if k & 1:
+                    L += T / k
+                else:
+                    L -= T / k
+                T *= X
+                if ctx.mnorm(T, 'inf') < tol:
+                    break
+                k += 1
+                if k > ctx.prec:
+                    raise ctx.NoConvergence
+        finally:
+            ctx.prec = prec
+        L *= 2**n
+        return L
+
+    def powm(ctx, A, r):
+        r"""
+        Computes `A^r = \exp(A \log r)` for a matrix `A` and complex
+        number `r`.
+
+        **Examples**
+
+        Powers and inverse powers of a matrix::
+
+            >>> from mpmath import *
+            >>> mp.dps = 15; mp.pretty = True
+            >>> A = matrix([[4,1,4],[7,8,9],[10,2,11]])
+            >>> powm(A, 2)
+            [ 63.0  20.0   69.0]
+            [174.0  89.0  199.0]
+            [164.0  48.0  179.0]
+            >>> chop(powm(powm(A, 4), 1/4.))
+            [ 4.0  1.0   4.0]
+            [ 7.0  8.0   9.0]
+            [10.0  2.0  11.0]
+            >>> powm(extraprec(20)(powm)(A, -4), -1/4.)
+            [ 4.0  1.0   4.0]
+            [ 7.0  8.0   9.0]
+            [10.0  2.0  11.0]
+            >>> chop(powm(powm(A, 1+0.5j), 1/(1+0.5j)))
+            [ 4.0  1.0   4.0]
+            [ 7.0  8.0   9.0]
+            [10.0  2.0  11.0]
+            >>> powm(extraprec(5)(powm)(A, -1.5), -1/(1.5))
+            [ 4.0  1.0   4.0]
+            [ 7.0  8.0   9.0]
+            [10.0  2.0  11.0]
+
+        A Fibonacci-generating matrix::
+
+            >>> powm([[1,1],[1,0]], 10)
+            [89.0  55.0]
+            [55.0  34.0]
+            >>> fib(10)
+            55.0
+            >>> powm([[1,1],[1,0]], 6.5)
+            [(16.5166626964253 - 0.0121089837381789j)  (10.2078589271083 + 0.0195927472575932j)]
+            [(10.2078589271083 + 0.0195927472575932j)  (6.30880376931698 - 0.0317017309957721j)]
+            >>> (phi**6.5 - (1-phi)**6.5)/sqrt(5)
+            (10.2078589271083 - 0.0195927472575932j)
+            >>> powm([[1,1],[1,0]], 6.2)
+            [ (14.3076953002666 - 0.008222855781077j)  (8.81733464837593 + 0.0133048601383712j)]
+            [(8.81733464837593 + 0.0133048601383712j)  (5.49036065189071 - 0.0215277159194482j)]
+            >>> (phi**6.2 - (1-phi)**6.2)/sqrt(5)
+            (8.81733464837593 - 0.0133048601383712j)
+
+        """
+        A = ctx.matrix(A)
+        r = ctx.convert(r)
+        prec = ctx.prec
+        try:
+            ctx.prec += 10
+            if ctx.isint(r):
+                v = A ** int(r)
+            elif ctx.isint(r*2):
+                y = int(r*2)
+                v = ctx.sqrtm(A) ** y
+            else:
+                v = ctx.expm(r*ctx.logm(A))
+        finally:
+            ctx.prec = prec
+        v *= 1
+        return v

rl/Lib/site-packages/mpmath/matrices/eigen.py

@@ -0,0 +1,877 @@
+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+##################################################################################################
+#     module for the eigenvalue problem
+#       Copyright 2013 Timo Hartmann (thartmann15 at gmail.com)
+#
+# todo:
+#  - implement balancing
+#  - agressive early deflation
+#
+##################################################################################################
+
+"""
+The eigenvalue problem
+----------------------
+
+This file contains routines for the eigenvalue problem.
+
+high level routines:
+
+  hessenberg : reduction of a real or complex square matrix to upper Hessenberg form
+  schur : reduction of a real or complex square matrix to upper Schur form
+  eig : eigenvalues and eigenvectors of a real or complex square matrix
+
+low level routines:
+
+  hessenberg_reduce_0 : reduction of a real or complex square matrix to upper Hessenberg form
+  hessenberg_reduce_1 : auxiliary routine to hessenberg_reduce_0
+  qr_step : a single implicitly shifted QR step for an upper Hessenberg matrix
+  hessenberg_qr : Schur decomposition of an upper Hessenberg matrix
+  eig_tr_r : right eigenvectors of an upper triangular matrix
+  eig_tr_l : left  eigenvectors of an upper triangular matrix
+"""
+
+from ..libmp.backend import xrange
+
+class Eigen(object):
+    pass
+
+def defun(f):
+    setattr(Eigen, f.__name__, f)
+    return f
+
+def hessenberg_reduce_0(ctx, A, T):
+    """
+    This routine computes the (upper) Hessenberg decomposition of a square matrix A.
+    Given A, an unitary matrix Q is calculated such that
+
+               Q' A Q = H              and             Q' Q = Q Q' = 1
+
+    where H is an upper Hessenberg matrix, meaning that it only contains zeros
+    below the first subdiagonal. Here ' denotes the hermitian transpose (i.e.
+    transposition and conjugation).
+
+    parameters:
+      A         (input/output) On input, A contains the square matrix A of
+                dimension (n,n). On output, A contains a compressed representation
+                of Q and H.
+      T         (output) An array of length n containing the first elements of
+                the Householder reflectors.
+    """
+
+    # internally we work with householder reflections from the right.
+    # let u be a row vector (i.e. u[i]=A[i,:i]). then
+    # Q is build up by reflectors of the type (1-v'v) where v is a suitable
+    # modification of u. these reflectors are applyed to A from the right.
+    # because we work with reflectors from the right we have to start with
+    # the bottom row of A and work then upwards (this corresponds to
+    # some kind of RQ decomposition).
+    # the first part of the vectors v (i.e. A[i,:(i-1)]) are stored as row vectors
+    # in the lower left part of A (excluding the diagonal and subdiagonal).
+    # the last entry of v is stored in T.
+    # the upper right part of A (including diagonal and subdiagonal) becomes H.
+
+
+    n = A.rows
+    if n <= 2: return
+
+    for i in xrange(n-1, 1, -1):
+
+        # scale the vector
+
+        scale = 0
+        for k in xrange(0, i):
+            scale += abs(ctx.re(A[i,k])) + abs(ctx.im(A[i,k]))
+
+        scale_inv = 0
+        if scale != 0:
+            scale_inv = 1 / scale
+
+        if scale == 0 or ctx.isinf(scale_inv):
+            # sadly there are floating point numbers not equal to zero whose reciprocal is infinity
+            T[i] = 0
+            A[i,i-1] = 0
+            continue
+
+        # calculate parameters for housholder transformation
+
+        H = 0
+        for k in xrange(0, i):
+            A[i,k] *= scale_inv
+            rr = ctx.re(A[i,k])
+            ii = ctx.im(A[i,k])
+            H += rr * rr + ii * ii
+
+        F = A[i,i-1]
+        f = abs(F)
+        G = ctx.sqrt(H)
+        A[i,i-1] = - G * scale
+
+        if f == 0:
+            T[i] = G
+        else:
+            ff = F / f
+            T[i] = F + G * ff
+            A[i,i-1] *= ff
+
+        H += G * f
+        H = 1 / ctx.sqrt(H)
+
+        T[i] *= H
+        for k in xrange(0, i - 1):
+            A[i,k] *= H
+
+        for j in xrange(0, i):
+            # apply housholder transformation (from right)
+
+            G = ctx.conj(T[i]) * A[j,i-1]
+            for k in xrange(0, i-1):
+                G += ctx.conj(A[i,k]) * A[j,k]
+
+            A[j,i-1] -= G * T[i]
+            for k in xrange(0, i-1):
+                A[j,k] -= G * A[i,k]
+
+        for j in xrange(0, n):
+            # apply housholder transformation (from left)
+
+            G = T[i] * A[i-1,j]
+            for k in xrange(0, i-1):
+                G += A[i,k] * A[k,j]
+
+            A[i-1,j] -= G * ctx.conj(T[i])
+            for k in xrange(0, i-1):
+                A[k,j] -= G * ctx.conj(A[i,k])
+
+
+
+def hessenberg_reduce_1(ctx, A, T):
+    """
+    This routine forms the unitary matrix Q described in hessenberg_reduce_0.
+
+    parameters:
+      A    (input/output) On input, A is the same matrix as delivered by
+           hessenberg_reduce_0. On output, A is set to Q.
+
+      T    (input) On input, T is the same array as delivered by hessenberg_reduce_0.
+    """
+
+    n = A.rows
+
+    if n == 1:
+        A[0,0] = 1
+        return
+
+    A[0,0] = A[1,1] = 1
+    A[0,1] = A[1,0] = 0
+
+    for i in xrange(2, n):
+        if T[i] != 0:
+
+            for j in xrange(0, i):
+                G = T[i] * A[i-1,j]
+                for k in xrange(0, i-1):
+                    G += A[i,k] * A[k,j]
+
+                A[i-1,j] -= G * ctx.conj(T[i])
+                for k in xrange(0, i-1):
+                    A[k,j] -= G * ctx.conj(A[i,k])
+
+        A[i,i] = 1
+        for j in xrange(0, i):
+            A[j,i] = A[i,j] = 0
+
+
+
+@defun
+def hessenberg(ctx, A, overwrite_a = False):
+    """
+    This routine computes the Hessenberg decomposition of a square matrix A.
+    Given A, an unitary matrix Q is determined such that
+
+          Q' A Q = H                and               Q' Q = Q Q' = 1
+
+    where H is an upper right Hessenberg matrix. Here ' denotes the hermitian
+    transpose (i.e. transposition and conjugation).
+
+    input:
+      A            : a real or complex square matrix
+      overwrite_a  : if true, allows modification of A which may improve
+                     performance. if false, A is not modified.
+
+    output:
+      Q : an unitary matrix
+      H : an upper right Hessenberg matrix
+
+    example:
+      >>> from mpmath import mp
+      >>> A = mp.matrix([[3, -1, 2], [2, 5, -5], [-2, -3, 7]])
+      >>> Q, H = mp.hessenberg(A)
+      >>> mp.nprint(H, 3) # doctest:+SKIP
+      [  3.15  2.23  4.44]
+      [-0.769  4.85  3.05]
+      [   0.0  3.61   7.0]
+      >>> print(mp.chop(A - Q * H * Q.transpose_conj()))
+      [0.0  0.0  0.0]
+      [0.0  0.0  0.0]
+      [0.0  0.0  0.0]
+
+    return value:   (Q, H)
+    """
+
+    n = A.rows
+
+    if n == 1:
+        return (ctx.matrix([[1]]), A)
+
+    if not overwrite_a:
+        A = A.copy()
+
+    T = ctx.matrix(n, 1)
+
+    hessenberg_reduce_0(ctx, A, T)
+    Q = A.copy()
+    hessenberg_reduce_1(ctx, Q, T)
+
+    for x in xrange(n):
+        for y in xrange(x+2, n):
+            A[y,x] = 0
+
+    return Q, A
+
+
+###########################################################################
+
+
+def qr_step(ctx, n0, n1, A, Q, shift):
+    """
+    This subroutine executes a single implicitly shifted QR step applied to an
+    upper Hessenberg matrix A. Given A and shift as input, first an QR
+    decomposition is calculated:
+
+      Q R = A - shift * 1 .
+
+    The output is then following matrix:
+
+      R Q + shift * 1
+
+    parameters:
+      n0, n1    (input) Two integers which specify the submatrix A[n0:n1,n0:n1]
+                on which this subroutine operators. The subdiagonal elements
+                to the left and below this submatrix must be deflated (i.e. zero).
+                following restriction is imposed: n1>=n0+2
+      A         (input/output) On input, A is an upper Hessenberg matrix.
+                On output, A is replaced by "R Q + shift * 1"
+      Q         (input/output) The parameter Q is multiplied by the unitary matrix
+                Q arising from the QR decomposition. Q can also be false, in which
+                case the unitary matrix Q is not computated.
+      shift     (input) a complex number specifying the shift. idealy close to an
+                eigenvalue of the bottemmost part of the submatrix A[n0:n1,n0:n1].
+
+    references:
+      Stoer, Bulirsch - Introduction to Numerical Analysis.
+      Kresser : Numerical Methods for General and Structured Eigenvalue Problems
+    """
+
+    # implicitly shifted and bulge chasing is explained at p.398/399 in "Stoer, Bulirsch - Introduction to Numerical Analysis"
+    # for bulge chasing see also "Watkins - The Matrix Eigenvalue Problem" sec.4.5,p.173
+
+    # the Givens rotation we used is determined as follows: let c,s be two complex
+    # numbers. then we have following relation:
+    #
+    #     v = sqrt(|c|^2 + |s|^2)
+    #
+    #     1/v [ c~  s~]  [c] = [v]
+    #         [-s   c ]  [s]   [0]
+    #
+    # the matrix on the left is our Givens rotation.
+
+    n = A.rows
+
+    # first step
+
+    # calculate givens rotation
+    c = A[n0  ,n0] - shift
+    s = A[n0+1,n0]
+
+    v = ctx.hypot(ctx.hypot(ctx.re(c), ctx.im(c)), ctx.hypot(ctx.re(s), ctx.im(s)))
+
+    if v == 0:
+        v = 1
+        c = 1
+        s = 0
+    else:
+        c /= v
+        s /= v
+
+    cc = ctx.conj(c)
+    cs = ctx.conj(s)
+
+    for k in xrange(n0, n):
+        # apply givens rotation from the left
+        x = A[n0  ,k]
+        y = A[n0+1,k]
+        A[n0  ,k] = cc * x + cs * y
+        A[n0+1,k] = c * y - s * x
+
+    for k in xrange(min(n1, n0+3)):
+        # apply givens rotation from the right
+        x = A[k,n0  ]
+        y = A[k,n0+1]
+        A[k,n0  ] = c * x + s * y
+        A[k,n0+1] = cc * y - cs * x
+
+    if not isinstance(Q, bool):
+        for k in xrange(n):
+            # eigenvectors
+            x = Q[k,n0  ]
+            y = Q[k,n0+1]
+            Q[k,n0  ] = c * x + s * y
+            Q[k,n0+1] = cc * y - cs * x
+
+    # chase the bulge
+
+    for j in xrange(n0, n1 - 2):
+        # calculate givens rotation
+
+        c = A[j+1,j]
+        s = A[j+2,j]
+
+        v = ctx.hypot(ctx.hypot(ctx.re(c), ctx.im(c)), ctx.hypot(ctx.re(s), ctx.im(s)))
+
+        if v == 0:
+            A[j+1,j] = 0
+            v = 1
+            c = 1
+            s = 0
+        else:
+            A[j+1,j] = v
+            c /= v
+            s /= v
+
+        A[j+2,j] = 0
+
+        cc = ctx.conj(c)
+        cs = ctx.conj(s)
+
+        for k in xrange(j+1, n):
+            # apply givens rotation from the left
+            x = A[j+1,k]
+            y = A[j+2,k]
+            A[j+1,k] = cc * x + cs * y
+            A[j+2,k] = c * y - s * x
+
+        for k in xrange(0, min(n1, j+4)):
+            # apply givens rotation from the right
+            x = A[k,j+1]
+            y = A[k,j+2]
+            A[k,j+1] = c * x + s * y
+            A[k,j+2] = cc * y - cs * x
+
+        if not isinstance(Q, bool):
+            for k in xrange(0, n):
+                # eigenvectors
+                x = Q[k,j+1]
+                y = Q[k,j+2]
+                Q[k,j+1] = c * x + s * y
+                Q[k,j+2] = cc * y - cs * x
+
+
+
+def hessenberg_qr(ctx, A, Q):
+    """
+    This routine computes the Schur decomposition of an upper Hessenberg matrix A.
+    Given A, an unitary matrix Q is determined such that
+
+          Q' A Q = R                   and                  Q' Q = Q Q' = 1
+
+    where R is an upper right triangular matrix. Here ' denotes the hermitian
+    transpose (i.e. transposition and conjugation).
+
+    parameters:
+      A         (input/output) On input, A contains an upper Hessenberg matrix.
+                On output, A is replace by the upper right triangluar matrix R.
+
+      Q         (input/output) The parameter Q is multiplied by the unitary
+                matrix Q arising from the Schur decomposition. Q can also be
+                false, in which case the unitary matrix Q is not computated.
+    """
+
+    n = A.rows
+
+    norm = 0
+    for x in xrange(n):
+        for y in xrange(min(x+2, n)):
+            norm += ctx.re(A[y,x]) ** 2 + ctx.im(A[y,x]) ** 2
+    norm = ctx.sqrt(norm) / n
+
+    if norm == 0:
+        return
+
+    n0 = 0
+    n1 = n
+
+    eps = ctx.eps / (100 * n)
+    maxits = ctx.dps * 4
+
+    its = totalits = 0
+
+    while 1:
+        # kressner p.32 algo 3
+        # the active submatrix is A[n0:n1,n0:n1]
+
+        k = n0
+
+        while k + 1 < n1:
+            s = abs(ctx.re(A[k,k])) + abs(ctx.im(A[k,k])) + abs(ctx.re(A[k+1,k+1])) + abs(ctx.im(A[k+1,k+1]))
+            if s < eps * norm:
+                s = norm
+            if abs(A[k+1,k]) < eps * s:
+                break
+            k += 1
+
+        if k + 1 < n1:
+            # deflation found at position (k+1, k)
+
+            A[k+1,k] = 0
+            n0 = k + 1
+
+            its = 0
+
+            if n0 + 1 >= n1:
+                # block of size at most two has converged
+                n0 = 0
+                n1 = k + 1
+                if n1 < 2:
+                    # QR algorithm has converged
+                    return
+        else:
+            if (its % 30) == 10:
+                # exceptional shift
+                shift = A[n1-1,n1-2]
+            elif (its % 30) == 20:
+                # exceptional shift
+                shift = abs(A[n1-1,n1-2])
+            elif (its % 30) == 29:
+                # exceptional shift
+                shift = norm
+            else:
+                #    A = [ a b ]       det(x-A)=x*x-x*tr(A)+det(A)
+                #        [ c d ]
+                #
+                # eigenvalues bad:   (tr(A)+sqrt((tr(A))**2-4*det(A)))/2
+                #     bad because of cancellation if |c| is small and |a-d| is small, too.
+                #
+                # eigenvalues good:     (a+d+sqrt((a-d)**2+4*b*c))/2
+
+                t =  A[n1-2,n1-2] + A[n1-1,n1-1]
+                s = (A[n1-1,n1-1] - A[n1-2,n1-2]) ** 2 + 4 * A[n1-1,n1-2] * A[n1-2,n1-1]
+                if ctx.re(s) > 0:
+                    s = ctx.sqrt(s)
+                else:
+                    s = ctx.sqrt(-s) * 1j
+                a = (t + s) / 2
+                b = (t - s) / 2
+                if abs(A[n1-1,n1-1] - a) > abs(A[n1-1,n1-1] - b):
+                    shift = b
+                else:
+                    shift = a
+
+            its += 1
+            totalits += 1
+
+            qr_step(ctx, n0, n1, A, Q, shift)
+
+            if its > maxits:
+                raise RuntimeError("qr: failed to converge after %d steps" % its)
+
+
+@defun
+def schur(ctx, A, overwrite_a = False):
+    """
+    This routine computes the Schur decomposition of a square matrix A.
+    Given A, an unitary matrix Q is determined such that
+
+          Q' A Q = R                and               Q' Q = Q Q' = 1
+
+    where R is an upper right triangular matrix. Here ' denotes the
+    hermitian transpose (i.e. transposition and conjugation).
+
+    input:
+      A            : a real or complex square matrix
+      overwrite_a  : if true, allows modification of A which may improve
+                     performance. if false, A is not modified.
+
+    output:
+      Q : an unitary matrix
+      R : an upper right triangular matrix
+
+    return value:   (Q, R)
+
+    example:
+      >>> from mpmath import mp
+      >>> A = mp.matrix([[3, -1, 2], [2, 5, -5], [-2, -3, 7]])
+      >>> Q, R = mp.schur(A)
+      >>> mp.nprint(R, 3) # doctest:+SKIP
+      [2.0  0.417  -2.53]
+      [0.0    4.0  -4.74]
+      [0.0    0.0    9.0]
+      >>> print(mp.chop(A - Q * R * Q.transpose_conj()))
+      [0.0  0.0  0.0]
+      [0.0  0.0  0.0]
+      [0.0  0.0  0.0]
+
+    warning: The Schur decomposition is not unique.
+    """
+
+    n = A.rows
+
+    if n == 1:
+        return (ctx.matrix([[1]]), A)
+
+    if not overwrite_a:
+        A = A.copy()
+
+    T = ctx.matrix(n, 1)
+
+    hessenberg_reduce_0(ctx, A, T)
+    Q = A.copy()
+    hessenberg_reduce_1(ctx, Q, T)
+
+    for x in xrange(n):
+        for y in xrange(x + 2, n):
+            A[y,x] = 0
+
+    hessenberg_qr(ctx, A, Q)
+
+    return Q, A
+
+
+def eig_tr_r(ctx, A):
+    """
+    This routine calculates the right eigenvectors of an upper right triangular matrix.
+
+    input:
+      A      an upper right triangular matrix
+
+    output:
+      ER     a matrix whose columns form the right eigenvectors of A
+
+    return value: ER
+    """
+
+    # this subroutine is inspired by the lapack routines ctrevc.f,clatrs.f
+
+    n = A.rows
+
+    ER = ctx.eye(n)
+
+    eps = ctx.eps
+
+    unfl = ctx.ldexp(ctx.one, -ctx.prec * 30)
+    # since mpmath effectively has no limits on the exponent, we simply scale doubles up
+    # original double has prec*20
+
+    smlnum = unfl * (n / eps)
+    simin = 1 / ctx.sqrt(eps)
+
+    rmax = 1
+
+    for i in xrange(1, n):
+        s = A[i,i]
+
+        smin = max(eps * abs(s), smlnum)
+
+        for j in xrange(i - 1, -1, -1):
+
+            r = 0
+            for k in xrange(j + 1, i + 1):
+                r += A[j,k] * ER[k,i]
+
+            t = A[j,j] - s
+            if abs(t) < smin:
+                t = smin
+
+            r = -r / t
+            ER[j,i] = r
+
+            rmax = max(rmax, abs(r))
+            if rmax > simin:
+                for k in xrange(j, i+1):
+                    ER[k,i] /= rmax
+                rmax = 1
+
+        if rmax != 1:
+            for k in xrange(0, i + 1):
+                ER[k,i] /= rmax
+
+    return ER
+
+def eig_tr_l(ctx, A):
+    """
+    This routine calculates the left eigenvectors of an upper right triangular matrix.
+
+    input:
+      A      an upper right triangular matrix
+
+    output:
+      EL     a matrix whose rows form the left eigenvectors of A
+
+    return value:  EL
+    """
+
+    n = A.rows
+
+    EL = ctx.eye(n)
+
+    eps = ctx.eps
+
+    unfl = ctx.ldexp(ctx.one, -ctx.prec * 30)
+    # since mpmath effectively has no limits on the exponent, we simply scale doubles up
+    # original double has prec*20
+
+    smlnum = unfl * (n / eps)
+    simin = 1 / ctx.sqrt(eps)
+
+    rmax = 1
+
+    for i in xrange(0, n - 1):
+        s = A[i,i]
+
+        smin = max(eps * abs(s), smlnum)
+
+        for j in xrange(i + 1, n):
+
+            r = 0
+            for k in xrange(i, j):
+                r += EL[i,k] * A[k,j]
+
+            t = A[j,j] - s
+            if abs(t) < smin:
+                t = smin
+
+            r = -r / t
+            EL[i,j] = r
+
+            rmax = max(rmax, abs(r))
+            if rmax > simin:
+                for k in xrange(i, j + 1):
+                    EL[i,k] /= rmax
+                rmax = 1
+
+        if rmax != 1:
+            for k in xrange(i, n):
+                EL[i,k] /= rmax
+
+    return EL
+
+@defun
+def eig(ctx, A, left = False, right = True, overwrite_a = False):
+    """
+    This routine computes the eigenvalues and optionally the left and right
+    eigenvectors of a square matrix A. Given A, a vector E and matrices ER
+    and EL are calculated such that
+
+                        A ER[:,i] =         E[i] ER[:,i]
+                EL[i,:] A         = EL[i,:] E[i]
+
+    E contains the eigenvalues of A. The columns of ER contain the right eigenvectors
+    of A whereas the rows of EL contain the left eigenvectors.
+
+
+    input:
+      A           : a real or complex square matrix of shape (n, n)
+      left        : if true, the left eigenvectors are calculated.
+      right       : if true, the right eigenvectors are calculated.
+      overwrite_a : if true, allows modification of A which may improve
+                    performance. if false, A is not modified.
+
+    output:
+      E    : a list of length n containing the eigenvalues of A.
+      ER   : a matrix whose columns contain the right eigenvectors of A.
+      EL   : a matrix whose rows contain the left eigenvectors of A.
+
+    return values:
+       E            if left and right are both false.
+      (E, ER)       if right is true and left is false.
+      (E, EL)       if left is true and right is false.
+      (E, EL, ER)   if left and right are true.
+
+
+    examples:
+      >>> from mpmath import mp
+      >>> A = mp.matrix([[3, -1, 2], [2, 5, -5], [-2, -3, 7]])
+      >>> E, ER = mp.eig(A)
+      >>> print(mp.chop(A * ER[:,0] - E[0] * ER[:,0]))
+      [0.0]
+      [0.0]
+      [0.0]
+
+      >>> E, EL, ER = mp.eig(A,left = True, right = True)
+      >>> E, EL, ER = mp.eig_sort(E, EL, ER)
+      >>> mp.nprint(E)
+      [2.0, 4.0, 9.0]
+      >>> print(mp.chop(A * ER[:,0] - E[0] * ER[:,0]))
+      [0.0]
+      [0.0]
+      [0.0]
+      >>> print(mp.chop( EL[0,:] * A - EL[0,:] * E[0]))
+      [0.0  0.0  0.0]
+
+    warning:
+     - If there are multiple eigenvalues, the eigenvectors do not necessarily
+       span the whole vectorspace, i.e. ER and EL may have not full rank.
+       Furthermore in that case the eigenvectors are numerical ill-conditioned.
+     - In the general case the eigenvalues have no natural order.
+
+    see also:
+      - eigh (or eigsy, eighe) for the symmetric eigenvalue problem.
+      - eig_sort for sorting of eigenvalues and eigenvectors
+    """
+
+    n = A.rows
+
+    if n == 1:
+        if left and (not right):
+            return ([A[0]], ctx.matrix([[1]]))
+
+        if right and (not left):
+            return ([A[0]], ctx.matrix([[1]]))
+
+        return ([A[0]], ctx.matrix([[1]]), ctx.matrix([[1]]))
+
+    if not overwrite_a:
+        A = A.copy()
+
+    T = ctx.zeros(n, 1)
+
+    hessenberg_reduce_0(ctx, A, T)
+
+    if left or right:
+        Q = A.copy()
+        hessenberg_reduce_1(ctx, Q, T)
+    else:
+        Q = False
+
+    for x in xrange(n):
+        for y in xrange(x + 2, n):
+            A[y,x] = 0
+
+    hessenberg_qr(ctx, A, Q)
+
+    E = [0 for i in xrange(n)]
+    for i in xrange(n):
+        E[i] = A[i,i]
+
+    if not (left or right):
+        return E
+
+    if left:
+        EL = eig_tr_l(ctx, A)
+        EL = EL * Q.transpose_conj()
+
+    if right:
+        ER = eig_tr_r(ctx, A)
+        ER = Q * ER
+
+    if left and (not right):
+        return (E, EL)
+
+    if right and (not left):
+        return (E, ER)
+
+    return (E, EL, ER)
+
+@defun
+def eig_sort(ctx, E, EL = False, ER = False, f = "real"):
+    """
+    This routine sorts the eigenvalues and eigenvectors delivered by ``eig``.
+
+    parameters:
+      E  : the eigenvalues as delivered by eig
+      EL : the left  eigenvectors as delivered by eig, or false
+      ER : the right eigenvectors as delivered by eig, or false
+      f  : either a string ("real" sort by increasing real part, "imag" sort by
+           increasing imag part, "abs" sort by absolute value) or a function
+           mapping complexs to the reals, i.e. ``f = lambda x: -mp.re(x) ``
+           would sort the eigenvalues by decreasing real part.
+
+    return values:
+       E            if EL and ER are both false.
+      (E, ER)       if ER is not false and left is false.
+      (E, EL)       if EL is not false and right is false.
+      (E, EL, ER)   if EL and ER are not false.
+
+    example:
+      >>> from mpmath import mp
+      >>> A = mp.matrix([[3, -1, 2], [2, 5, -5], [-2, -3, 7]])
+      >>> E, EL, ER = mp.eig(A,left = True, right = True)
+      >>> E, EL, ER = mp.eig_sort(E, EL, ER)
+      >>> mp.nprint(E)
+      [2.0, 4.0, 9.0]
+      >>> E, EL, ER = mp.eig_sort(E, EL, ER,f = lambda x: -mp.re(x))
+      >>> mp.nprint(E)
+      [9.0, 4.0, 2.0]
+      >>> print(mp.chop(A * ER[:,0] - E[0] * ER[:,0]))
+      [0.0]
+      [0.0]
+      [0.0]
+      >>> print(mp.chop( EL[0,:] * A - EL[0,:] * E[0]))
+      [0.0  0.0  0.0]
+    """
+
+    if isinstance(f, str):
+        if f == "real":
+            f = ctx.re
+        elif f == "imag":
+            f = ctx.im
+        elif f == "abs":
+            f = abs
+        else:
+            raise RuntimeError("unknown function %s" % f)
+
+    n = len(E)
+
+    # Sort eigenvalues (bubble-sort)
+
+    for i in xrange(n):
+        imax = i
+        s = f(E[i])         # s is the current maximal element
+
+        for j in xrange(i + 1, n):
+            c = f(E[j])
+            if c < s:
+                s = c
+                imax = j
+
+        if imax != i:
+            # swap eigenvalues
+
+            z = E[i]
+            E[i] = E[imax]
+            E[imax] = z
+
+            if not isinstance(EL, bool):
+                for j in xrange(n):
+                    z = EL[i,j]
+                    EL[i,j] = EL[imax,j]
+                    EL[imax,j] = z
+
+            if not isinstance(ER, bool):
+                for j in xrange(n):
+                    z = ER[j,i]
+                    ER[j,i] = ER[j,imax]
+                    ER[j,imax] = z
+
+    if isinstance(EL, bool) and isinstance(ER, bool):
+        return E
+
+    if isinstance(EL, bool) and not(isinstance(ER, bool)):
+        return (E, ER)
+
+    if isinstance(ER, bool) and not(isinstance(EL, bool)):
+        return (E, EL)
+
+    return (E, EL, ER)

rl/Lib/site-packages/mpmath/matrices/linalg.py

@@ -0,0 +1,790 @@
+"""
+Linear algebra
+--------------
+
+Linear equations
+................
+
+Basic linear algebra is implemented; you can for example solve the linear
+equation system::
+
+      x + 2*y = -10
+    3*x + 4*y =  10
+
+using ``lu_solve``::
+
+    >>> from mpmath import *
+    >>> mp.pretty = False
+    >>> A = matrix([[1, 2], [3, 4]])
+    >>> b = matrix([-10, 10])
+    >>> x = lu_solve(A, b)
+    >>> x
+    matrix(
+    [['30.0'],
+     ['-20.0']])
+
+If you don't trust the result, use ``residual`` to calculate the residual ||A*x-b||::
+
+    >>> residual(A, x, b)
+    matrix(
+    [['3.46944695195361e-18'],
+     ['3.46944695195361e-18']])
+    >>> str(eps)
+    '2.22044604925031e-16'
+
+As you can see, the solution is quite accurate. The error is caused by the
+inaccuracy of the internal floating point arithmetic. Though, it's even smaller
+than the current machine epsilon, which basically means you can trust the
+result.
+
+If you need more speed, use NumPy, or ``fp.lu_solve`` for a floating-point computation.
+
+    >>> fp.lu_solve(A, b)   # doctest: +ELLIPSIS
+    matrix(...)
+
+``lu_solve`` accepts overdetermined systems. It is usually not possible to solve
+such systems, so the residual is minimized instead. Internally this is done
+using Cholesky decomposition to compute a least squares approximation. This means
+that that ``lu_solve`` will square the errors. If you can't afford this, use
+``qr_solve`` instead. It is twice as slow but more accurate, and it calculates
+the residual automatically.
+
+
+Matrix factorization
+....................
+
+The function ``lu`` computes an explicit LU factorization of a matrix::
+
+    >>> P, L, U = lu(matrix([[0,2,3],[4,5,6],[7,8,9]]))
+    >>> print(P)
+    [0.0  0.0  1.0]
+    [1.0  0.0  0.0]
+    [0.0  1.0  0.0]
+    >>> print(L)
+    [              1.0                0.0  0.0]
+    [              0.0                1.0  0.0]
+    [0.571428571428571  0.214285714285714  1.0]
+    >>> print(U)
+    [7.0  8.0                9.0]
+    [0.0  2.0                3.0]
+    [0.0  0.0  0.214285714285714]
+    >>> print(P.T*L*U)
+    [0.0  2.0  3.0]
+    [4.0  5.0  6.0]
+    [7.0  8.0  9.0]
+
+Interval matrices
+-----------------
+
+Matrices may contain interval elements. This allows one to perform
+basic linear algebra operations such as matrix multiplication
+and equation solving with rigorous error bounds::
+
+    >>> a = iv.matrix([['0.1','0.3','1.0'],
+    ...             ['7.1','5.5','4.8'],
+    ...             ['3.2','4.4','5.6']])
+    >>>
+    >>> b = iv.matrix(['4','0.6','0.5'])
+    >>> c = iv.lu_solve(a, b)
+    >>> print(c)
+    [   [5.2582327113062568605927528666, 5.25823271130625686059275702219]]
+    [[-13.1550493962678375411635581388, -13.1550493962678375411635540152]]
+    [  [7.42069154774972557628979076189, 7.42069154774972557628979190734]]
+    >>> print(a*c)
+    [  [3.99999999999999999999999844904, 4.00000000000000000000000155096]]
+    [[0.599999999999999999999968898009, 0.600000000000000000000031763736]]
+    [[0.499999999999999999999979320485, 0.500000000000000000000020679515]]
+"""
+
+# TODO:
+# *implement high-level qr()
+# *test unitvector
+# *iterative solving
+
+from copy import copy
+
+from ..libmp.backend import xrange
+
+class LinearAlgebraMethods(object):
+
+    def LU_decomp(ctx, A, overwrite=False, use_cache=True):
+        """
+        LU-factorization of a n*n matrix using the Gauss algorithm.
+        Returns L and U in one matrix and the pivot indices.
+
+        Use overwrite to specify whether A will be overwritten with L and U.
+        """
+        if not A.rows == A.cols:
+            raise ValueError('need n*n matrix')
+        # get from cache if possible
+        if use_cache and isinstance(A, ctx.matrix) and A._LU:
+            return A._LU
+        if not overwrite:
+            orig = A
+            A = A.copy()
+        tol = ctx.absmin(ctx.mnorm(A,1) * ctx.eps) # each pivot element has to be bigger
+        n = A.rows
+        p = [None]*(n - 1)
+        for j in xrange(n - 1):
+            # pivoting, choose max(abs(reciprocal row sum)*abs(pivot element))
+            biggest = 0
+            for k in xrange(j, n):
+                s = ctx.fsum([ctx.absmin(A[k,l]) for l in xrange(j, n)])
+                if ctx.absmin(s) <= tol:
+                    raise ZeroDivisionError('matrix is numerically singular')
+                current = 1/s * ctx.absmin(A[k,j])
+                if current > biggest: # TODO: what if equal?
+                    biggest = current
+                    p[j] = k
+            # swap rows according to p
+            ctx.swap_row(A, j, p[j])
+            if ctx.absmin(A[j,j]) <= tol:
+                raise ZeroDivisionError('matrix is numerically singular')
+            # calculate elimination factors and add rows
+            for i in xrange(j + 1, n):
+                A[i,j] /= A[j,j]
+                for k in xrange(j + 1, n):
+                    A[i,k] -= A[i,j]*A[j,k]
+        if ctx.absmin(A[n - 1,n - 1]) <= tol:
+            raise ZeroDivisionError('matrix is numerically singular')
+        # cache decomposition
+        if not overwrite and isinstance(orig, ctx.matrix):
+            orig._LU = (A, p)
+        return A, p
+
+    def L_solve(ctx, L, b, p=None):
+        """
+        Solve the lower part of a LU factorized matrix for y.
+        """
+        if L.rows != L.cols:
+            raise RuntimeError("need n*n matrix")
+        n = L.rows
+        if len(b) != n:
+            raise ValueError("Value should be equal to n")
+        b = copy(b)
+        if p: # swap b according to p
+            for k in xrange(0, len(p)):
+                ctx.swap_row(b, k, p[k])
+        # solve
+        for i in xrange(1, n):
+            for j in xrange(i):
+                b[i] -= L[i,j] * b[j]
+        return b
+
+    def U_solve(ctx, U, y):
+        """
+        Solve the upper part of a LU factorized matrix for x.
+        """
+        if U.rows != U.cols:
+            raise RuntimeError("need n*n matrix")
+        n = U.rows
+        if len(y) != n:
+            raise ValueError("Value should be equal to n")
+        x = copy(y)
+        for i in xrange(n - 1, -1, -1):
+            for j in xrange(i + 1, n):
+                x[i] -= U[i,j] * x[j]
+            x[i] /= U[i,i]
+        return x
+
+    def lu_solve(ctx, A, b, **kwargs):
+        """
+        Ax = b => x
+
+        Solve a determined or overdetermined linear equations system.
+        Fast LU decomposition is used, which is less accurate than QR decomposition
+        (especially for overdetermined systems), but it's twice as efficient.
+        Use qr_solve if you want more precision or have to solve a very ill-
+        conditioned system.
+
+        If you specify real=True, it does not check for overdeterminded complex
+        systems.
+        """
+        prec = ctx.prec
+        try:
+            ctx.prec += 10
+            # do not overwrite A nor b
+            A, b = ctx.matrix(A, **kwargs).copy(), ctx.matrix(b, **kwargs).copy()
+            if A.rows < A.cols:
+                raise ValueError('cannot solve underdetermined system')
+            if A.rows > A.cols:
+                # use least-squares method if overdetermined
+                # (this increases errors)
+                AH = A.H
+                A = AH * A
+                b = AH * b
+                if (kwargs.get('real', False) or
+                    not sum(type(i) is ctx.mpc for i in A)):
+                    # TODO: necessary to check also b?
+                    x = ctx.cholesky_solve(A, b)
+                else:
+                    x = ctx.lu_solve(A, b)
+            else:
+                # LU factorization
+                A, p = ctx.LU_decomp(A)
+                b = ctx.L_solve(A, b, p)
+                x = ctx.U_solve(A, b)
+        finally:
+            ctx.prec = prec
+        return x
+
+    def improve_solution(ctx, A, x, b, maxsteps=1):
+        """
+        Improve a solution to a linear equation system iteratively.
+
+        This re-uses the LU decomposition and is thus cheap.
+        Usually 3 up to 4 iterations are giving the maximal improvement.
+        """
+        if A.rows != A.cols:
+            raise RuntimeError("need n*n matrix") # TODO: really?
+        for _ in xrange(maxsteps):
+            r = ctx.residual(A, x, b)
+            if ctx.norm(r, 2) < 10*ctx.eps:
+                break
+            # this uses cached LU decomposition and is thus cheap
+            dx = ctx.lu_solve(A, -r)
+            x += dx
+        return x
+
+    def lu(ctx, A):
+        """
+        A -> P, L, U
+
+        LU factorisation of a square matrix A. L is the lower, U the upper part.
+        P is the permutation matrix indicating the row swaps.
+
+        P*A = L*U
+
+        If you need efficiency, use the low-level method LU_decomp instead, it's
+        much more memory efficient.
+        """
+        # get factorization
+        A, p = ctx.LU_decomp(A)
+        n = A.rows
+        L = ctx.matrix(n)
+        U = ctx.matrix(n)
+        for i in xrange(n):
+            for j in xrange(n):
+                if i > j:
+                    L[i,j] = A[i,j]
+                elif i == j:
+                    L[i,j] = 1
+                    U[i,j] = A[i,j]
+                else:
+                    U[i,j] = A[i,j]
+        # calculate permutation matrix
+        P = ctx.eye(n)
+        for k in xrange(len(p)):
+            ctx.swap_row(P, k, p[k])
+        return P, L, U
+
+    def unitvector(ctx, n, i):
+        """
+        Return the i-th n-dimensional unit vector.
+        """
+        assert 0 < i <= n, 'this unit vector does not exist'
+        return [ctx.zero]*(i-1) + [ctx.one] + [ctx.zero]*(n-i)
+
+    def inverse(ctx, A, **kwargs):
+        """
+        Calculate the inverse of a matrix.
+
+        If you want to solve an equation system Ax = b, it's recommended to use
+        solve(A, b) instead, it's about 3 times more efficient.
+        """
+        prec = ctx.prec
+        try:
+            ctx.prec += 10
+            # do not overwrite A
+            A = ctx.matrix(A, **kwargs).copy()
+            n = A.rows
+            # get LU factorisation
+            A, p = ctx.LU_decomp(A)
+            cols = []
+            # calculate unit vectors and solve corresponding system to get columns
+            for i in xrange(1, n + 1):
+                e = ctx.unitvector(n, i)
+                y = ctx.L_solve(A, e, p)
+                cols.append(ctx.U_solve(A, y))
+            # convert columns to matrix
+            inv = []
+            for i in xrange(n):
+                row = []
+                for j in xrange(n):
+                    row.append(cols[j][i])
+                inv.append(row)
+            result = ctx.matrix(inv, **kwargs)
+        finally:
+            ctx.prec = prec
+        return result
+
+    def householder(ctx, A):
+        """
+        (A|b) -> H, p, x, res
+
+        (A|b) is the coefficient matrix with left hand side of an optionally
+        overdetermined linear equation system.
+        H and p contain all information about the transformation matrices.
+        x is the solution, res the residual.
+        """
+        if not isinstance(A, ctx.matrix):
+            raise TypeError("A should be a type of ctx.matrix")
+        m = A.rows
+        n = A.cols
+        if m < n - 1:
+            raise RuntimeError("Columns should not be less than rows")
+        # calculate Householder matrix
+        p = []
+        for j in xrange(0, n - 1):
+            s = ctx.fsum(abs(A[i,j])**2 for i in xrange(j, m))
+            if not abs(s) > ctx.eps:
+                raise ValueError('matrix is numerically singular')
+            p.append(-ctx.sign(ctx.re(A[j,j])) * ctx.sqrt(s))
+            kappa = ctx.one / (s - p[j] * A[j,j])
+            A[j,j] -= p[j]
+            for k in xrange(j+1, n):
+                y = ctx.fsum(ctx.conj(A[i,j]) * A[i,k] for i in xrange(j, m)) * kappa
+                for i in xrange(j, m):
+                    A[i,k] -= A[i,j] * y
+        # solve Rx = c1
+        x = [A[i,n - 1] for i in xrange(n - 1)]
+        for i in xrange(n - 2, -1, -1):
+            x[i] -= ctx.fsum(A[i,j] * x[j] for j in xrange(i + 1, n - 1))
+            x[i] /= p[i]
+        # calculate residual
+        if not m == n - 1:
+            r = [A[m-1-i, n-1] for i in xrange(m - n + 1)]
+        else:
+            # determined system, residual should be 0
+            r = [0]*m # maybe a bad idea, changing r[i] will change all elements
+        return A, p, x, r
+
+    #def qr(ctx, A):
+    #    """
+    #    A -> Q, R
+    #
+    #    QR factorisation of a square matrix A using Householder decomposition.
+    #    Q is orthogonal, this leads to very few numerical errors.
+    #
+    #    A = Q*R
+    #    """
+    #    H, p, x, res = householder(A)
+    # TODO: implement this
+
+    def residual(ctx, A, x, b, **kwargs):
+        """
+        Calculate the residual of a solution to a linear equation system.
+
+        r = A*x - b for A*x = b
+        """
+        oldprec = ctx.prec
+        try:
+            ctx.prec *= 2
+            A, x, b = ctx.matrix(A, **kwargs), ctx.matrix(x, **kwargs), ctx.matrix(b, **kwargs)
+            return A*x - b
+        finally:
+            ctx.prec = oldprec
+
+    def qr_solve(ctx, A, b, norm=None, **kwargs):
+        """
+        Ax = b => x, ||Ax - b||
+
+        Solve a determined or overdetermined linear equations system and
+        calculate the norm of the residual (error).
+        QR decomposition using Householder factorization is applied, which gives very
+        accurate results even for ill-conditioned matrices. qr_solve is twice as
+        efficient.
+        """
+        if norm is None:
+            norm = ctx.norm
+        prec = ctx.prec
+        try:
+            ctx.prec += 10
+            # do not overwrite A nor b
+            A, b = ctx.matrix(A, **kwargs).copy(), ctx.matrix(b, **kwargs).copy()
+            if A.rows < A.cols:
+                raise ValueError('cannot solve underdetermined system')
+            H, p, x, r = ctx.householder(ctx.extend(A, b))
+            res = ctx.norm(r)
+            # calculate residual "manually" for determined systems
+            if res == 0:
+                res = ctx.norm(ctx.residual(A, x, b))
+            return ctx.matrix(x, **kwargs), res
+        finally:
+            ctx.prec = prec
+
+    def cholesky(ctx, A, tol=None):
+        r"""
+        Cholesky decomposition of a symmetric positive-definite matrix `A`.
+        Returns a lower triangular matrix `L` such that `A = L \times L^T`.
+        More generally, for a complex Hermitian positive-definite matrix,
+        a Cholesky decomposition satisfying `A = L \times L^H` is returned.
+
+        The Cholesky decomposition can be used to solve linear equation
+        systems twice as efficiently as LU decomposition, or to
+        test whether `A` is positive-definite.
+
+        The optional parameter ``tol`` determines the tolerance for
+        verifying positive-definiteness.
+
+        **Examples**
+
+        Cholesky decomposition of a positive-definite symmetric matrix::
+
+            >>> from mpmath import *
+            >>> mp.dps = 25; mp.pretty = True
+            >>> A = eye(3) + hilbert(3)
+            >>> nprint(A)
+            [     2.0      0.5  0.333333]
+            [     0.5  1.33333      0.25]
+            [0.333333     0.25       1.2]
+            >>> L = cholesky(A)
+            >>> nprint(L)
+            [ 1.41421      0.0      0.0]
+            [0.353553  1.09924      0.0]
+            [0.235702  0.15162  1.05899]
+            >>> chop(A - L*L.T)
+            [0.0  0.0  0.0]
+            [0.0  0.0  0.0]
+            [0.0  0.0  0.0]
+
+        Cholesky decomposition of a Hermitian matrix::
+
+            >>> A = eye(3) + matrix([[0,0.25j,-0.5j],[-0.25j,0,0],[0.5j,0,0]])
+            >>> L = cholesky(A)
+            >>> nprint(L)
+            [          1.0                0.0                0.0]
+            [(0.0 - 0.25j)  (0.968246 + 0.0j)                0.0]
+            [ (0.0 + 0.5j)  (0.129099 + 0.0j)  (0.856349 + 0.0j)]
+            >>> chop(A - L*L.H)
+            [0.0  0.0  0.0]
+            [0.0  0.0  0.0]
+            [0.0  0.0  0.0]
+
+        Attempted Cholesky decomposition of a matrix that is not positive
+        definite::
+
+            >>> A = -eye(3) + hilbert(3)
+            >>> L = cholesky(A)
+            Traceback (most recent call last):
+              ...
+            ValueError: matrix is not positive-definite
+
+        **References**
+
+        1. [Wikipedia]_ http://en.wikipedia.org/wiki/Cholesky_decomposition
+
+        """
+        if not isinstance(A, ctx.matrix):
+            raise RuntimeError("A should be a type of ctx.matrix")
+        if not A.rows == A.cols:
+            raise ValueError('need n*n matrix')
+        if tol is None:
+            tol = +ctx.eps
+        n = A.rows
+        L = ctx.matrix(n)
+        for j in xrange(n):
+            c = ctx.re(A[j,j])
+            if abs(c-A[j,j]) > tol:
+                raise ValueError('matrix is not Hermitian')
+            s = c - ctx.fsum((L[j,k] for k in xrange(j)),
+                absolute=True, squared=True)
+            if s < tol:
+                raise ValueError('matrix is not positive-definite')
+            L[j,j] = ctx.sqrt(s)
+            for i in xrange(j, n):
+                it1 = (L[i,k] for k in xrange(j))
+                it2 = (L[j,k] for k in xrange(j))
+                t = ctx.fdot(it1, it2, conjugate=True)
+                L[i,j] = (A[i,j] - t) / L[j,j]
+        return L
+
+    def cholesky_solve(ctx, A, b, **kwargs):
+        """
+        Ax = b => x
+
+        Solve a symmetric positive-definite linear equation system.
+        This is twice as efficient as lu_solve.
+
+        Typical use cases:
+        * A.T*A
+        * Hessian matrix
+        * differential equations
+        """
+        prec = ctx.prec
+        try:
+            ctx.prec += 10
+            # do not overwrite A nor b
+            A, b = ctx.matrix(A, **kwargs).copy(), ctx.matrix(b, **kwargs).copy()
+            if A.rows !=  A.cols:
+                raise ValueError('can only solve determined system')
+            # Cholesky factorization
+            L = ctx.cholesky(A)
+            # solve
+            n = L.rows
+            if len(b) != n:
+                raise ValueError("Value should be equal to n")
+            for i in xrange(n):
+                b[i] -= ctx.fsum(L[i,j] * b[j] for j in xrange(i))
+                b[i] /= L[i,i]
+            x = ctx.U_solve(L.T, b)
+            return x
+        finally:
+            ctx.prec = prec
+
+    def det(ctx, A):
+        """
+        Calculate the determinant of a matrix.
+        """
+        prec = ctx.prec
+        try:
+            # do not overwrite A
+            A = ctx.matrix(A).copy()
+            # use LU factorization to calculate determinant
+            try:
+                R, p = ctx.LU_decomp(A)
+            except ZeroDivisionError:
+                return 0
+            z = 1
+            for i, e in enumerate(p):
+                if i != e:
+                    z *= -1
+            for i in xrange(A.rows):
+                z *= R[i,i]
+            return z
+        finally:
+            ctx.prec = prec
+
+    def cond(ctx, A, norm=None):
+        """
+        Calculate the condition number of a matrix using a specified matrix norm.
+
+        The condition number estimates the sensitivity of a matrix to errors.
+        Example: small input errors for ill-conditioned coefficient matrices
+        alter the solution of the system dramatically.
+
+        For ill-conditioned matrices it's recommended to use qr_solve() instead
+        of lu_solve(). This does not help with input errors however, it just avoids
+        to add additional errors.
+
+        Definition:    cond(A) = ||A|| * ||A**-1||
+        """
+        if norm is None:
+            norm = lambda x: ctx.mnorm(x,1)
+        return norm(A) * norm(ctx.inverse(A))
+
+    def lu_solve_mat(ctx, a, b):
+        """Solve a * x = b  where a and b are matrices."""
+        r = ctx.matrix(a.rows, b.cols)
+        for i in range(b.cols):
+            c = ctx.lu_solve(a, b.column(i))
+            for j in range(len(c)):
+                r[j, i] = c[j]
+        return r
+
+    def qr(ctx, A, mode = 'full', edps = 10):
+        """
+        Compute a QR factorization $A = QR$ where
+        A is an m x n matrix of real or complex numbers where m >= n
+
+        mode has following meanings:
+        (1) mode = 'raw' returns two matrixes (A, tau) in the
+            internal format used by LAPACK
+        (2) mode = 'skinny' returns the leading n columns of Q
+            and n rows of R
+        (3) Any other value returns the leading m columns of Q
+            and m rows of R
+
+        edps is the increase in mp precision used for calculations
+
+        **Examples**
+
+            >>> from mpmath import *
+            >>> mp.dps = 15
+            >>> mp.pretty = True
+            >>> A = matrix([[1, 2], [3, 4], [1, 1]])
+            >>> Q, R = qr(A)
+            >>> Q
+            [-0.301511344577764   0.861640436855329   0.408248290463863]
+            [-0.904534033733291  -0.123091490979333  -0.408248290463863]
+            [-0.301511344577764  -0.492365963917331   0.816496580927726]
+            >>> R
+            [-3.3166247903554  -4.52267016866645]
+            [             0.0  0.738548945875996]
+            [             0.0                0.0]
+            >>> Q * R
+            [1.0  2.0]
+            [3.0  4.0]
+            [1.0  1.0]
+            >>> chop(Q.T * Q)
+            [1.0  0.0  0.0]
+            [0.0  1.0  0.0]
+            [0.0  0.0  1.0]
+            >>> B = matrix([[1+0j, 2-3j], [3+j, 4+5j]])
+            >>> Q, R = qr(B)
+            >>> nprint(Q)
+            [     (-0.301511 + 0.0j)   (0.0695795 - 0.95092j)]
+            [(-0.904534 - 0.301511j)  (-0.115966 + 0.278318j)]
+            >>> nprint(R)
+            [(-3.31662 + 0.0j)  (-5.72872 - 2.41209j)]
+            [              0.0       (3.91965 + 0.0j)]
+            >>> Q * R
+            [(1.0 + 0.0j)  (2.0 - 3.0j)]
+            [(3.0 + 1.0j)  (4.0 + 5.0j)]
+            >>> chop(Q.T * Q.conjugate())
+            [1.0  0.0]
+            [0.0  1.0]
+
+        """
+
+        # check values before continuing
+        assert isinstance(A, ctx.matrix)
+        m = A.rows
+        n = A.cols
+        assert n >= 0
+        assert m >= n
+        assert edps >= 0
+
+        # check for complex data type
+        cmplx = any(type(x) is ctx.mpc for x in A)
+
+        # temporarily increase the precision and initialize
+        with ctx.extradps(edps):
+            tau = ctx.matrix(n,1)
+            A = A.copy()
+
+            # ---------------
+            # FACTOR MATRIX A
+            # ---------------
+            if cmplx:
+                one = ctx.mpc('1.0', '0.0')
+                zero = ctx.mpc('0.0', '0.0')
+                rzero = ctx.mpf('0.0')
+
+                # main loop to factor A (complex)
+                for j in xrange(0, n):
+                    alpha = A[j,j]
+                    alphr = ctx.re(alpha)
+                    alphi = ctx.im(alpha)
+
+                    if (m-j) >= 2:
+                        xnorm = ctx.fsum( A[i,j]*ctx.conj(A[i,j]) for i in xrange(j+1, m) )
+                        xnorm = ctx.re( ctx.sqrt(xnorm) )
+                    else:
+                        xnorm = rzero
+
+                    if (xnorm == rzero) and (alphi == rzero):
+                        tau[j] = zero
+                        continue
+
+                    if alphr < rzero:
+                        beta = ctx.sqrt(alphr**2 + alphi**2 + xnorm**2)
+                    else:
+                        beta = -ctx.sqrt(alphr**2 + alphi**2 + xnorm**2)
+
+                    tau[j] = ctx.mpc( (beta - alphr) / beta, -alphi / beta )
+                    t = -ctx.conj(tau[j])
+                    za = one / (alpha - beta)
+
+                    for i in xrange(j+1, m):
+                        A[i,j] *= za
+
+                    A[j,j] = one
+                    for k in xrange(j+1, n):
+                        y = ctx.fsum(A[i,j] * ctx.conj(A[i,k]) for i in xrange(j, m))
+                        temp = t * ctx.conj(y)
+                        for i in xrange(j, m):
+                            A[i,k] += A[i,j] * temp
+
+                    A[j,j] = ctx.mpc(beta, '0.0')
+            else:
+                one = ctx.mpf('1.0')
+                zero = ctx.mpf('0.0')
+
+                # main loop to factor A (real)
+                for j in xrange(0, n):
+                    alpha = A[j,j]
+
+                    if (m-j) > 2:
+                        xnorm = ctx.fsum( (A[i,j])**2 for i in xrange(j+1, m) )
+                        xnorm = ctx.sqrt(xnorm)
+                    elif (m-j) == 2:
+                        xnorm = abs( A[m-1,j] )
+                    else:
+                        xnorm = zero
+
+                    if xnorm == zero:
+                        tau[j] = zero
+                        continue
+
+                    if alpha < zero:
+                        beta = ctx.sqrt(alpha**2 + xnorm**2)
+                    else:
+                        beta = -ctx.sqrt(alpha**2 + xnorm**2)
+
+                    tau[j] = (beta - alpha) / beta
+                    t = -tau[j]
+                    da = one / (alpha - beta)
+
+                    for i in xrange(j+1, m):
+                        A[i,j] *= da
+
+                    A[j,j] = one
+                    for k in xrange(j+1, n):
+                        y = ctx.fsum( A[i,j] * A[i,k] for i in xrange(j, m) )
+                        temp = t * y
+                        for i in xrange(j,m):
+                            A[i,k] += A[i,j] * temp
+
+                    A[j,j] = beta
+
+            # return factorization in same internal format as LAPACK
+            if (mode == 'raw') or (mode == 'RAW'):
+                return A, tau
+
+            # ----------------------------------
+            # FORM Q USING BACKWARD ACCUMULATION
+            # ----------------------------------
+
+            # form R before the values are overwritten
+            R = A.copy()
+            for j in xrange(0, n):
+                for i in xrange(j+1, m):
+                    R[i,j] = zero
+
+            # set the value of p (number of columns of Q to return)
+            p = m
+            if (mode == 'skinny') or (mode == 'SKINNY'):
+                p = n
+
+            # add columns to A if needed and initialize
+            A.cols += (p-n)
+            for j in xrange(0, p):
+                A[j,j] = one
+                for i in xrange(0, j):
+                    A[i,j] = zero
+
+            # main loop to form Q
+            for j in xrange(n-1, -1, -1):
+                t = -tau[j]
+                A[j,j] += t
+
+                for k in xrange(j+1, p):
+                    if cmplx:
+                        y = ctx.fsum(A[i,j] * ctx.conj(A[i,k]) for i in xrange(j+1, m))
+                        temp = t * ctx.conj(y)
+                    else:
+                        y = ctx.fsum(A[i,j] * A[i,k] for i in xrange(j+1, m))
+                        temp = t * y
+                    A[j,k] = temp
+                    for i in xrange(j+1, m):
+                        A[i,k] += A[i,j] * temp
+
+                for i in xrange(j+1, m):
+                    A[i, j] *= t
+
+            return A, R[0:p,0:n]
+
+        # ------------------
+        # END OF FUNCTION QR
+        # ------------------

rl/Lib/site-packages/mpmath/rational.py

@@ -0,0 +1,240 @@
+import operator
+import sys
+from .libmp import int_types, mpf_hash, bitcount, from_man_exp, HASH_MODULUS
+
+new = object.__new__
+
+def create_reduced(p, q, _cache={}):
+    key = p, q
+    if key in _cache:
+        return _cache[key]
+    x, y = p, q
+    while y:
+        x, y = y, x % y
+    if x != 1:
+        p //= x
+        q //= x
+    v = new(mpq)
+    v._mpq_ = p, q
+    # Speedup integers, half-integers and other small fractions
+    if q <= 4 and abs(key[0]) < 100:
+        _cache[key] = v
+    return v
+
+class mpq(object):
+    """
+    Exact rational type, currently only intended for internal use.
+    """
+
+    __slots__ = ["_mpq_"]
+
+    def __new__(cls, p, q=1):
+        if type(p) is tuple:
+            p, q = p
+        elif hasattr(p, '_mpq_'):
+            p, q = p._mpq_
+        return create_reduced(p, q)
+
+    def __repr__(s):
+        return "mpq(%s,%s)" % s._mpq_
+
+    def __str__(s):
+        return "(%s/%s)" % s._mpq_
+
+    def __int__(s):
+        a, b = s._mpq_
+        return a // b
+
+    def __nonzero__(s):
+        return bool(s._mpq_[0])
+
+    __bool__ = __nonzero__
+
+    def __hash__(s):
+        a, b = s._mpq_
+        if sys.version_info >= (3, 2):
+            inverse = pow(b, HASH_MODULUS-2, HASH_MODULUS)
+            if not inverse:
+                h = sys.hash_info.inf
+            else:
+                h = (abs(a) * inverse) % HASH_MODULUS
+            if a < 0: h = -h
+            if h == -1: h = -2
+            return h
+        else:
+            if b == 1:
+                return hash(a)
+            # Power of two: mpf compatible hash
+            if not (b & (b-1)):
+                return mpf_hash(from_man_exp(a, 1-bitcount(b)))
+            return hash((a,b))
+
+    def __eq__(s, t):
+        ttype = type(t)
+        if ttype is mpq:
+            return s._mpq_ == t._mpq_
+        if ttype in int_types:
+            a, b = s._mpq_
+            if b != 1:
+                return False
+            return a == t
+        return NotImplemented
+
+    def __ne__(s, t):
+        ttype = type(t)
+        if ttype is mpq:
+            return s._mpq_ != t._mpq_
+        if ttype in int_types:
+            a, b = s._mpq_
+            if b != 1:
+                return True
+            return a != t
+        return NotImplemented
+
+    def _cmp(s, t, op):
+        ttype = type(t)
+        if ttype in int_types:
+            a, b = s._mpq_
+            return op(a, t*b)
+        if ttype is mpq:
+            a, b = s._mpq_
+            c, d = t._mpq_
+            return op(a*d, b*c)
+        return NotImplementedError
+
+    def __lt__(s, t): return s._cmp(t, operator.lt)
+    def __le__(s, t): return s._cmp(t, operator.le)
+    def __gt__(s, t): return s._cmp(t, operator.gt)
+    def __ge__(s, t): return s._cmp(t, operator.ge)
+
+    def __abs__(s):
+        a, b = s._mpq_
+        if a >= 0:
+            return s
+        v = new(mpq)
+        v._mpq_ = -a, b
+        return v
+
+    def __neg__(s):
+        a, b = s._mpq_
+        v = new(mpq)
+        v._mpq_ = -a, b
+        return v
+
+    def __pos__(s):
+        return s
+
+    def __add__(s, t):
+        ttype = type(t)
+        if ttype is mpq:
+            a, b = s._mpq_
+            c, d = t._mpq_
+            return create_reduced(a*d+b*c, b*d)
+        if ttype in int_types:
+            a, b = s._mpq_
+            v = new(mpq)
+            v._mpq_ = a+b*t, b
+            return v
+        return NotImplemented
+
+    __radd__ = __add__
+
+    def __sub__(s, t):
+        ttype = type(t)
+        if ttype is mpq:
+            a, b = s._mpq_
+            c, d = t._mpq_
+            return create_reduced(a*d-b*c, b*d)
+        if ttype in int_types:
+            a, b = s._mpq_
+            v = new(mpq)
+            v._mpq_ = a-b*t, b
+            return v
+        return NotImplemented
+
+    def __rsub__(s, t):
+        ttype = type(t)
+        if ttype is mpq:
+            a, b = s._mpq_
+            c, d = t._mpq_
+            return create_reduced(b*c-a*d, b*d)
+        if ttype in int_types:
+            a, b = s._mpq_
+            v = new(mpq)
+            v._mpq_ = b*t-a, b
+            return v
+        return NotImplemented
+
+    def __mul__(s, t):
+        ttype = type(t)
+        if ttype is mpq:
+            a, b = s._mpq_
+            c, d = t._mpq_
+            return create_reduced(a*c, b*d)
+        if ttype in int_types:
+            a, b = s._mpq_
+            return create_reduced(a*t, b)
+        return NotImplemented
+
+    __rmul__ = __mul__
+
+    def __div__(s, t):
+        ttype = type(t)
+        if ttype is mpq:
+            a, b = s._mpq_
+            c, d = t._mpq_
+            return create_reduced(a*d, b*c)
+        if ttype in int_types:
+            a, b = s._mpq_
+            return create_reduced(a, b*t)
+        return NotImplemented
+
+    def __rdiv__(s, t):
+        ttype = type(t)
+        if ttype is mpq:
+            a, b = s._mpq_
+            c, d = t._mpq_
+            return create_reduced(b*c, a*d)
+        if ttype in int_types:
+            a, b = s._mpq_
+            return create_reduced(b*t, a)
+        return NotImplemented
+
+    def __pow__(s, t):
+        ttype = type(t)
+        if ttype in int_types:
+            a, b = s._mpq_
+            if t:
+                if t < 0:
+                    a, b, t = b, a, -t
+                v = new(mpq)
+                v._mpq_ = a**t, b**t
+                return v
+            raise ZeroDivisionError
+        return NotImplemented
+
+
+mpq_1 = mpq((1,1))
+mpq_0 = mpq((0,1))
+mpq_1_2 = mpq((1,2))
+mpq_3_2 = mpq((3,2))
+mpq_1_4 = mpq((1,4))
+mpq_1_16 = mpq((1,16))
+mpq_3_16 = mpq((3,16))
+mpq_5_2 = mpq((5,2))
+mpq_3_4 = mpq((3,4))
+mpq_7_4 = mpq((7,4))
+mpq_5_4 = mpq((5,4))
+
+
+# Register with "numbers" ABC
+#     We do not subclass, hence we do not use the @abstractmethod checks. While
+#     this is less invasive it may turn out that we do not actually support
+#     parts of the expected interfaces.  See
+#     http://docs.python.org/2/library/numbers.html for list of abstract
+#     methods.
+try:
+    import numbers
+    numbers.Rational.register(mpq)
+except ImportError:
+    pass