erf, erfc, erfcx

Purpose

Error functions.

Synopsis

y = erf(x)
y = erfc(x)
y = erfcx(x)

Description

y = erf(x), the error function, is the integral of the Gaussian distribution function from 0 to x:

y = erfc(x) returns the value of the complementary error function:

y = erfcx(x) returns the value of the scaled complementary error function:

For large x, erfcx(x) is approximately

Algorithm

The MATLAB code is a translation of a FORTRAN program by W. J. Cody, Argonne National Laboratory, NETLIB/SPECFUN, March 19, 1990. The main computation evaluates near-minimax rational approximations from "Rational Chebyshev Approximations for the Error Function" by W. J. Cody, Math. Comp., 1969, pgs. 631-638.

See Also

erfinv

(c) Copyright 1994 by The MathWorks, Inc.