gammal

       #include <math.h>

       double gamma(double x);
       float gammaf(float x);
       long double gammal(long double x);

       Link with -lm.

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       gamma():
           _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE
       gammaf(), gammal():
           _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600

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 com-
       putes the natural logarithm of the Gamma function.

RETURN VALUE
       See lgamma(3).

ERRORS
       See lgamma(3).

ATTRIBUTES
       For  an  explanation  of  the  terms  used   in   this   section,   see
       attributes(7).

       +----------------------------+---------------+------------------------+
       |Interface                   | Attribute     | Value                  |
       +----------------------------+---------------+------------------------+
       |gamma(), gammaf(), gammal() | Thread safety | MT-Unsafe race:signgam |
       +----------------------------+---------------+------------------------+
CONFORMING TO
       Because of historical variations in behavior across systems, this func-
       tion is not specified in any standard.

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

       description of the project, information about reporting bugs,  and  the
       latest     version     of     this    page,    can    be    found    at
       http://www.kernel.org/doc/man-pages/.

GNU                               2015-03-02                          GAMMA(3)
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