erff(3) [netbsd man page]

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

NAME

     erf, erff, erfc, erfcf -- error function operators

LIBRARY

     Math Library (libm, -lm)

SYNOPSIS

     #include <math.h>

     double
     erf(double x);

     float
     erff(float x);

     double
     erfc(double x);

     float
     erfcf(float x);

DESCRIPTION

     These functions calculate the error function of x.

     The erf() 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.

SEE ALSO

     math(3)

HISTORY

     The erf() and erfc() functions appeared in 4.3BSD.

BSD
								  April 20, 1991							       BSD

erfc(3M)						  Mathematical Library Functions						  erfc(3M)

NAME

       erfc, erfcf, erfcl - complementary error function

SYNOPSIS

       cc [ flag... ] file... -lm [ library... ]
       #include <math.h>

       double erfc(double x);

       float erfcf(float x);

       long double erfcl(long double x);

DESCRIPTION

       These function compute the complementary error function 1.0 - erf(x).

RETURN VALUES

       Upon successful completion, these functions return the value of the complementary error function.

       If x is NaN, a NaN is returned.

       If x is +-0, +1 is returned.

       If x is -Inf, +2 is returned.

       If x is +Inf, 0 is returned.

ERRORS

       No errors are defined.

USAGE

       The  erfc() function is provided because of the extreme loss of relative accuracy if erf(x) is called for large x and the result subtracted
       from 1.0.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       erf(3M), isnan(3M), math.h(3HEAD), attributes(5), standards(5)

SunOS 5.10							    1 Sep 2002								  erfc(3M)