scipy.special.erfcinv — SciPy v1.15.2 Manual (original) (raw)

scipy.special.erfcinv(y, out=None) = <ufunc 'erfcinv'>#

Inverse of the complementary error function.

Computes the inverse of the complementary error function.

In the complex domain, there is no unique complex number w satisfying erfc(w)=z. This indicates a true inverse function would be multivalued. When the domain restricts to the real, 0 < x < 2, there is a unique real number satisfying erfc(erfcinv(x)) = erfcinv(erfc(x)).

It is related to inverse of the error function by erfcinv(1-x) = erfinv(x)

Parameters:

yndarray

Argument at which to evaluate. Domain: [0, 2]

outndarray, optional

Optional output array for the function values

Returns:

erfcinvscalar or ndarray

The inverse of erfc of y, element-wise

See also

erf

Error function of a complex argument

erfc

Complementary error function, 1 - erf(x)

erfinv

Inverse of the error function

Examples

import numpy as np import matplotlib.pyplot as plt from scipy.special import erfcinv

erfcinv(0.5) 0.4769362762044699

y = np.linspace(0.0, 2.0, num=11) erfcinv(y) array([ inf, 0.9061938 , 0.59511608, 0.37080716, 0.17914345, -0. , -0.17914345, -0.37080716, -0.59511608, -0.9061938 , -inf])

Plot the function:

y = np.linspace(0, 2, 200) fig, ax = plt.subplots() ax.plot(y, erfcinv(y)) ax.grid(True) ax.set_xlabel('y') ax.set_title('erfcinv(y)') plt.show()