Name

erf, erfc − error function and complementary error function

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 \π20∫xe−t2dt.

The erfc function, which returns 1.0 − erf(x), is provided because of the extreme loss of relative accuracy if erf(x) is called for large x and the result subtracted from 1.0 (e.g. for x = 5, 12 places are lost). 

See Also

exp(3m)
ULTRIX Programmer’s Manual, Unsupported