DOKK / manpages / debian 10 / manpages-pt-dev / lgamma.3.pt
LGAMMA(3) Linux Programmer's Manual LGAMMA(3)

lgamma - log gamma function

#include <math.h>

double lgamma(double x);

The lgamma() function returns the log of the absolute value of the Gamma function. The sign of the Gamma function is returned in the external integer signgam.

For negative integer values of x, lgamma() returns HUGE_VAL and errno is set to ERANGE.

Invalid argument - negative integer value of x.

SVID 3, BSD 4.3

infnan(3)

June 25, 1993 BSD