4.3BSD - /usr/man/cat3/erf.0

ERF(3M)                                                                ERF(3M)


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.

       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)


4.3 Berkeley Distribution        May 12, 1986                          ERF(3M)