NAME

erf, erfc − error functions

SYNTAX

#include <math.h>

double erf(x)
double x;

double erfc(x)
double x;

DESCRIPTION

The erf function returns the error function of x defined as follows:

erf(x) = 2/sqrt(pi)∗integral from 0 to x of exp(−t∗t) dt. }

The erfc function returns 1.0−erf(x).

The entry for the erfc function is provided because of the extreme loss of relative accuracy if erf(x) is called for large x and the result subtracted from 1. For example if x = 10, 12 places are lost.

SEE ALSO

math(3m)

Subroutines