
gamma, gammaf, gammal — (logarithm of the) gamma function
#include <math.h>
double
gamma( 
double x) ; 
float
gammaf( 
float x) ; 
long double
gammal( 
long double x) ; 
Note  


Note  

Link with 
These functions are deprecated: instead, use either the tgamma(3) or the lgamma(3) functions, as appropriate.
For the definition of the Gamma function, see tgamma(3).
The libm in 4.4BSD and some versions of FreeBSD had a
gamma
() function that
computes the Gamma function, as one would expect.
Glibc has a gamma
()
function that is equivalent to lgamma(3) and computes
the natural logarithm of the Gamma function.
Because of historical variations in behavior across systems, this function is not specified in any standard.
4.2BSD had a gamma
() that
computed ln(Gamma(x
)), leaving the sign of
Gamma(x
) in the
external integer signgam
. In
4.3BSD the name was changed to lgamma(3), and the man
page promises
"At some time in the future the name gamma will be rehabilitated and used for the Gamma function"
This did indeed happen in 4.4BSD, where gamma
() computes the Gamma function (with
no effect on signgam
).
However, this came too late, and we now have tgamma(3), the "true
gamma" function.
This page is part of release 3.52 of the Linux manpages
project. A
description of the project, and information about reporting
bugs, can be found at
http://www.kernel.org/doc/man−pages/.
Copyright 2002 Walter Harms (walter.harmsinformatik.unioldenburg.de) %%%LICENSE_START(GPL_NOVERSION_ONELINE) Distributed under GPL %%%LICENSE_END Modified 20031118, aeb: historical remarks 