opendarwin man page for erf

ERF(3)							   BSD Library Functions Manual 						    ERF(3)

NAME
     erf, erfc -- error function operators

SYNOPSIS
     #include <math.h>

     double
     erf(double x);

     double
     erfc(double x);

DESCRIPTION
     These functions calculate the error function of x.

     The erf() function calculates the error function of x; where

	   erf(x) = 2/sqrt(pi)*integral from 0 to x of exp(-t*t) dt.

     The erfc() function calculates the complementary error function of x; that is erfc() subtracts the result of the error function erf(x) from
     1.0.  This is useful, since for large x places disappear.

SPECIAL VALUES
     erf(+-0) returns +-0.

     erf(+-infinity) returns +-1.

     erfc(-infinity) returns 2.

     erfc(+infinity) returns +0.

SEE ALSO
     math(3)

STANDARDS
     The erf() and erfc() functions conform to ISO/IEC 9899:1999(E).

4.3 Berkeley Distribution					 January 30, 2003					 4.3 Berkeley Distribution