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; where erf(x) = 2/sqrt(pi)∗integral from 0 to x of exp(−t∗t) dt.  erf(x) := (2/√π)∫0s10xexp(−t2)dt.

erfc(x) returns 1.0 − erf(x). 

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

math(3M)

NEWS-OSRelease 4.2.1R