LSR/env/lib/python3.6/site-packages/scipy/special/_precompute/loggamma.py
2020-06-04 17:24:47 +02:00

46 lines
1.1 KiB
Python

"""Precompute series coefficients for log-Gamma."""
from __future__ import division, print_function, absolute_import
try:
import mpmath
except ImportError:
pass
def stirling_series(N):
with mpmath.workdps(100):
coeffs = [mpmath.bernoulli(2*n)/(2*n*(2*n - 1))
for n in range(1, N + 1)]
return coeffs
def taylor_series_at_1(N):
coeffs = []
with mpmath.workdps(100):
coeffs.append(-mpmath.euler)
for n in range(2, N + 1):
coeffs.append((-1)**n*mpmath.zeta(n)/n)
return coeffs
def main():
print(__doc__)
print()
stirling_coeffs = [mpmath.nstr(x, 20, min_fixed=0, max_fixed=0)
for x in stirling_series(8)[::-1]]
taylor_coeffs = [mpmath.nstr(x, 20, min_fixed=0, max_fixed=0)
for x in taylor_series_at_1(23)[::-1]]
print("Stirling series coefficients")
print("----------------------------")
print("\n".join(stirling_coeffs))
print()
print("Taylor series coefficients")
print("--------------------------")
print("\n".join(taylor_coeffs))
print()
if __name__ == '__main__':
main()