scipy.special.ndtri_exp#
- scipy.special.ndtri_exp(y, out=None) = <ufunc 'ndtri_exp'>#
- Inverse of - log_ndtrvs x. Allows for greater precision than- ndtricomposed with- numpy.expfor very small values of y and for y close to 0.- Parameters:
- yarray_like of float
- Function argument 
- outndarray, optional
- Optional output array for the function results 
 
- Returns:
- scalar or ndarray
- Inverse of the log CDF of the standard normal distribution, evaluated at y. 
 
 - See also - Examples - >>> import numpy as np >>> import scipy.special as sc - ndtri_expagrees with the naive implementation when the latter does not suffer from underflow.- >>> sc.ndtri_exp(-1) -0.33747496376420244 >>> sc.ndtri(np.exp(-1)) -0.33747496376420244 - For extreme values of y, the naive approach fails - >>> sc.ndtri(np.exp(-800)) -inf >>> sc.ndtri(np.exp(-1e-20)) inf - whereas - ndtri_expis still able to compute the result to high precision.- >>> sc.ndtri_exp(-800) -39.88469483825668 >>> sc.ndtri_exp(-1e-20) 9.262340089798409