45 lines
1.0 KiB
Python
45 lines
1.0 KiB
Python
from __future__ import division, print_function, absolute_import
|
|
|
|
import numpy as np
|
|
|
|
try:
|
|
import mpmath
|
|
import matplotlib.pyplot as plt
|
|
except ImportError:
|
|
pass
|
|
|
|
|
|
def mpmath_wrightomega(x):
|
|
return mpmath.lambertw(mpmath.exp(x), mpmath.mpf('-0.5'))
|
|
|
|
|
|
def wrightomega_series_error(x):
|
|
series = x
|
|
desired = mpmath_wrightomega(x)
|
|
return abs(series - desired) / desired
|
|
|
|
|
|
def wrightomega_exp_error(x):
|
|
exponential_approx = mpmath.exp(x)
|
|
desired = mpmath_wrightomega(x)
|
|
return abs(exponential_approx - desired) / desired
|
|
|
|
|
|
def main():
|
|
desired_error = 2 * np.finfo(float).eps
|
|
print('Series Error')
|
|
for x in [1e5, 1e10, 1e15, 1e20]:
|
|
with mpmath.workdps(100):
|
|
error = wrightomega_series_error(x)
|
|
print(x, error, error < desired_error)
|
|
|
|
print('Exp error')
|
|
for x in [-10, -25, -50, -100, -200, -400, -700, -740]:
|
|
with mpmath.workdps(100):
|
|
error = wrightomega_exp_error(x)
|
|
print(x, error, error < desired_error)
|
|
|
|
|
|
if __name__ == '__main__':
|
|
main()
|