Manpage of ERF
ERF
Section: NEWLIB (3)
Updated: 2005 Feb 23
Index
Return to Main Contents
NAME
1.11 `erf', `erff', `erfc', `erfcf'--error function
SYNOPSIS
#include <math.h>
double erf(double X);
float erff(float X);
double erfc(double X);
float erfcf(float X);
DESCRIPTION
`erf' calculates an approximation to the "error function", which
estimates the probability that an observation will fall within X
standard deviations of the mean (assuming a normal distribution).
`erfc' calculates the complementary probability; that is, `erfc(X)'
is `1 - erf(X)'. `erfc' is computed directly, so that you can use it
to avoid the loss of precision that would result from subtracting large
probabilities (on large X) from 1.
`erff' and `erfcf' differ from `erf' and `erfc' only in the argument
and result types.
RETURNS
For positive arguments, `erf' and all its variants return a
probability--a number between 0 and 1.
PORTABILITY
None of the variants of `erf' are ANSI C.
SEE ALSO
erf
is part of the
libm
library.
The full documentation for
libm
is maintained as a Texinfo manual. If
info
and
libm
are properly installed at your site, the command
-
info libm
will give you access to the complete manual.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURNS
-
- PORTABILITY
-
- SEE ALSO
-
This document was created by
man2html,
using the manual pages.
Time: 21:25:16 GMT, May 16, 2005
www.fiveanddime.net