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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