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NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | STANDARDS | HISTORY | SEE ALSO | COLOPHON |
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gamma(3) Library Functions Manual gamma(3)
gamma, gammaf, gammal - (logarithm of the) gamma function
Math library (libm, -lm)
#include <math.h>
[[deprecated]] double gamma(double x);
[[deprecated]] float gammaf(float x);
[[deprecated]] long double gammal(long double x);
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
gamma():
_XOPEN_SOURCE
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
gammaf(), gammal():
_XOPEN_SOURCE >= 600 || (_XOPEN_SOURCE && _ISOC99_SOURCE)
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
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.
See lgamma(3).
See lgamma(3).
For an explanation of the terms used in this section, see
attributes(7).
┌──────────────────────┬───────────────┬────────────────────────┐
│ Interface │ Attribute │ Value │
├──────────────────────┼───────────────┼────────────────────────┤
│ gamma(), gammaf(), │ Thread safety │ MT-Unsafe race:signgam │
│ gammal() │ │ │
└──────────────────────┴───────────────┴────────────────────────┘
None.
SVID 2.
Because of historical variations in behavior across systems, this
function is not specified in any recent 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.
lgamma(3), signgam(3), tgamma(3)
This page is part of the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
the project can be found at
⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
for this manual page, see
⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
This page was obtained from the tarball man-pages-6.9.1.tar.gz
fetched from
⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
2024-06-26. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
[email protected]
Linux man-pages 6.9.1 2024-05-02 gamma(3)
Pages that refer to this page: tgamma(3)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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