## Class LogGamma

• public final class LogGamma
extends Object
Natural logarithm of the absolute value of $$\Gamma(x)$$.

$\operatorname{lgamma}(z) = \ln \lvert \Gamma(x) \rvert$

This code has been adapted from the Boost c++ implementation <boost/math/special_functions/gamma.hpp>.

Boost C++ Log Gamma functions
• ### Method Summary

All Methods
Modifier and Type Method Description
static double value​(double x)
Computes the function $$\ln \lvert \Gamma(x) \rvert$$, the natural logarithm of the absolute value of $$\Gamma(x)$$.
static double value​(double x, int[] sign)
Computes the function $$\ln \lvert \Gamma(x) \rvert$$, the natural logarithm of the absolute value of $$\Gamma(x)$$.
• ### 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 $$\ln \lvert \Gamma(x) \rvert$$, the natural logarithm of the absolute value of $$\Gamma(x)$$.
Parameters:
x - Argument.
Returns:
$$\ln \lvert \Gamma(x) \rvert$$, or NaN if x <= 0 and is an integer.
• #### value

public static double value​(double x,
int[] sign)
Computes the function $$\ln \lvert \Gamma(x) \rvert$$, the natural logarithm of the absolute value of $$\Gamma(x)$$.

The sign output is set to 1 if the sign of gamma(x) is positive or zero; otherwise it is set to -1.

Parameters:
x - Argument.
sign - Sign output. If a non-zero length the first index sign[0] is set on output to the sign of gamma(z).
Returns:
$$\ln \lvert \Gamma(x) \rvert$$, or NaN if x <= 0 and is an integer.
Since:
1.1