NAME

erf, erfc − error function and complementary error function

SYNOPSIS

#include <math.h>

long float erf (x)
long float x;

long float erfc (x)
long float x;

DESCRIPTION

Erf returns the error function of x, defined as 2 over √πx∫0e−t2dt.

Erfc, 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). 

Version 2.4  —  May 08, 1986