log_gamma
Evaluates the logarithm of the absolute value of the gamma function log ∣Γ(x)∣.
Synopsis
#include <imsl.h>
float imsl_f_log_gamma (float x)
The type double procedure is imsl_d_log_gamma.
Required Arguments
float x (Input)
Point at which the logarithm of the absolute value of the gamma function is to be evaluated.
Return Value
The value of the logarithm of gamma function, log ∣Γ(x)∣.
Description
The logarithm of the absolute value of the gamma function log ∣Γ(x)∣ is computed.
Figure 9.14 — Plot of log ∣Γ(x)∣
Example
In this example, log ∣Γ(3.5)∣ is computed and printed.
#include <stdio.h>
#include <imsl.h>
int main()
{
float x = 3.5;
float ans;
ans = imsl_f_log_gamma(x);
printf("log gamma(%f) = %f\n", x, ans);
}
Output
log gamma(3.500000) = 1.200974
Warning Errors
IMSL_NEAR_NEG_INT_WARN | The result is accurate to less than one-half precision because x is too close to a negative integer. |
Fatal Errors
IMSL_NEGATIVE_INTEGER | The argument for the function cannot be a negative integer. |
IMSL_NEAR_NEG_INT_FATAL | The argument for the function is too close to a negative integer. |
IMSL_LARGE_ABS_ARG_OVERFLOW | |x| must not be so large that the result overflows. |
