gamma(3m) gamma(3m)
Name
gamma, lgamma, signgam - log gamma function
Syntax
#include <math.h>
double gamma(x)
double x;
double lgamma(x)
double x;
extern int
Description _ _
The fu_ction returns ln || (|x|)|. The sign of | (|x|) is returned in the external integer The following C program might be used to calcu-
late | :
y = gamma(x);
if (y > 88.0)
error();
y = exp(y);
if(signgam)
y = -y;
The function is another name for the function.
Return Values
The and functions return NaN when x is NaN or when it is an integer value less than or equal to zero. On overflow and functions return
HUGE_VAL.
Environment
When your program is compiled using the System V environment for nonpositive integer values, HUGE is returned, and errno is set to EDOM. A
message indicating DOMAIN error is printed on the standard error output.
If the correct value would overflow, returns HUGE and sets errno to ERANGE.
These error-handling procedures may be changed with the function
See Also
matherr(3m)
RISC gamma(3m)
