scipy.special.erfinv#
- scipy.special.erfinv(y, out=None) = <ufunc 'erfinv'>#
- Inverse of the error function. - Computes the inverse of the error function. - In the complex domain, there is no unique complex number w satisfying erf(w)=z. This indicates a true inverse function would be multivalued. 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] 
- outndarray, optional
- Optional output array for the function values 
 
- Returns:
- erfinvscalar or ndarray
- The inverse of erf of y, element-wise 
 
 - See also - Notes - This function wraps the - erf_invroutine from the Boost Math C++ library [1].- References [1]- The Boost Developers. “Boost C++ Libraries”. https://www.boost.org/. - Examples - >>> import numpy as np >>> import matplotlib.pyplot as plt >>> from scipy.special import erfinv, erf - >>> erfinv(0.5) 0.4769362762044699 - >>> y = np.linspace(-1.0, 1.0, num=9) >>> x = erfinv(y) >>> x array([ -inf, -0.81341985, -0.47693628, -0.22531206, 0. , 0.22531206, 0.47693628, 0.81341985, inf]) - Verify that - erf(erfinv(y))is- y.- >>> erf(x) array([-1. , -0.75, -0.5 , -0.25, 0. , 0.25, 0.5 , 0.75, 1. ]) - Plot the function: - >>> y = np.linspace(-1, 1, 200) >>> fig, ax = plt.subplots() >>> ax.plot(y, erfinv(y)) >>> ax.grid(True) >>> ax.set_xlabel('y') >>> ax.set_title('erfinv(y)') >>> plt.show() 