NAME

gamma − log gamma function

USAGE

#include <math.h>
 
double gamma(x) double x;

DESCRIPTION

Gamma returns ln |Γ(|x|)|. The sign of Γ(|x|) is returned in the external integer signgam. 

EXAMPLE

The following C program might be used to calculate Γ: y = gamma(x); if (y > 88.0) error(); y = exp(y); if(signgam)  y = −y;

DIAGNOSTICS

HUGE is returned for negative integer arguments. 

NOTES

There is no positive indication of error.