Package org.apache.commons.numbers.gamma

Class LogGamma

java.lang.Object

org.apache.commons.numbers.gamma.LogGamma

public final class LogGamma
extends Object

Function $\ln \mathrm{\Gamma }(x)$. Class is immutable.

Method Summary

Modifier and Type	Method	Description
static double	value(double x)	Computes the function $\ln \mathrm{\Gamma }(x)$ for x >= 0.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

value

public static double value(double x)

Computes the function $\ln \mathrm{\Gamma }(x)$ for x >= 0. For x <= 8, the implementation is based on the double precision implementation in the NSWC Library of Mathematics Subroutines, DGAMLN. For x >= 8, the implementation is based on

• Gamma Function, equation (28).
• Lanczos Approximation, equations (1) through (5).
• Paul Godfrey, A note on the computation of the convergent Lanczos complex Gamma approximation

Parameters:

x - Argument.

Returns:

$\ln \mathrm{\Gamma }(x)$, or NaN if x <= 0.