scipy.special.erfinv

scipy.special.erfinv(y)

Inverse of the error function erf.

Computes the inverse of the error function.

In complex domain, there is no unique complex number w satisfying erf(w)=z. This indicates a true inverse function would have multi-value. When the domain restricts to the real, -1 < x < 1, there is a unique real number satisfying erf(erfinv(x)) = x.

Parameters

yndarray

Argument at which to evaluate. Domain: [-1, 1]

Returns

erfinvndarray

The inverse of erf of y, element-wise

Examples

1. evaluating a float number

>>> from scipy import special
>>> special.erfinv(0.5)
0.4769362762044698

2. evaluating a ndarray

>>> from scipy import special
>>> y = np.linspace(-1.0, 1.0, num=10)
>>> special.erfinv(y)
array([       -inf, -0.86312307, -0.5407314 , -0.30457019, -0.0987901 ,
        0.0987901 ,  0.30457019,  0.5407314 ,  0.86312307,         inf])