erf(3M)

NAME

erf, erfc − error functions

SYNOPSIS

#include <math.h>

double erf(double x);

double erfc(double x);

MT-LEVEL

MT-Safe with exceptions

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)∫0s0xexp (−t2)dt.

erfc(x) returns 1.0−erf(x), computed however by other methods that avoid cancellation for large x.

NOTES

These functions are MT-Safe when compiled with the shared library, libm.so, but are unsafe if compiled with the archived library libm.a.