NAME

erf, erfc − error functions

SYNOPSIS

#include <math.h>

double erf(x)
double x;

double erfc(x)
double x;

DESCRIPTION

Erf(x) returns the error function of x. 

Erfc(x) returns 1.0−erf(x). 

Erf(x) is defined by 2 over √πx∫0e−t2dt. 

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

SEE ALSO

intro(3M)

PRPQs 5799-WZQ/5799-PFF: IBM/4.3  —  30 Sep 1985