usr/man/man3/gamma.3m

.TH GAMMA 3M
.SH NAME
gamma \- log gamma function
.SH SYNOPSIS
.B #include <math.h>
.PP
.B double gamma(x)
.br
.B double x;
.SH DESCRIPTION
.I Gamma
returns
ln |\(*G(|\fIx\fR|)|.
The sign of
\(*G(|\fIx\fR|)
is returned in the external integer
.IR signgam .
The following C program might be
used to calculate
\(*G:
.PP
        y = gamma(x);
.br
        if (y > 88.)
.br
                error( );
.br
        y = exp(y);
.br
        if(signgam)
.br
                y = \-y;
.SH DIAGNOSTICS
A huge value is returned for negative integer arguments.
.SH BUGS
There should be a positive indication of error.