Section (3) gamma
Name
gamma, gammaf, gammal — (logarithm of the) gamma function
Synopsis
#include <math.h>
double
gamma( 
double x) ; 
float
gammaf( 
float x) ; 
long double
gammal( 
long double x) ; 
Note  


Note  

Link with 
DESCRIPTION
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).
*BSD version
The libm in 4.4BSD and some versions of FreeBSD had a
gamma
() function that
computes the Gamma function, as one would expect.
glibc version
Glibc has a gamma
()
function that is equivalent to lgamma(3) and computes
the natural logarithm of the Gamma function.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).
Interface  Attribute  Value 
gamma (), gammaf (), gammal () 
Thread safety  MTUnsafe race:signgam 
CONFORMING TO
Because of historical variations in behavior across systems, this function is not specified in any recent standard. It was documented in SVID 2.
NOTES
History
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.
COLOPHON
This page is part of release 4.16 of the Linux manpages
project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://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 