scipy.special.erf¶
-
scipy.special.
erf
(z) = <ufunc 'erf'>¶ Returns the error function of complex argument.
It is defined as
2/sqrt(pi)*integral(exp(-t**2), t=0..z)
.Parameters: x : ndarray
Input array.
Returns: res : ndarray
The values of the error function at the given points x.
Notes
The cumulative of the unit normal distribution is given by
Phi(z) = 1/2[1 + erf(z/sqrt(2))]
.References
[R407] http://en.wikipedia.org/wiki/Error_function [R408] Milton Abramowitz and Irene A. Stegun, eds. Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables. New York: Dover, 1972. http://www.math.sfu.ca/~cbm/aands/page_297.htm [R409] Steven G. Johnson, Faddeeva W function implementation. http://ab-initio.mit.edu/Faddeeva Examples
>>> from scipy import special >>> import matplotlib.pyplot as plt >>> x = np.linspace(-3, 3) >>> plt.plot(x, special.erf(x)) >>> plt.xlabel('$x$') >>> plt.ylabel('$erf(x)$') >>> plt.show()