Package org.apache.commons.numbers.gamma

Class Trigamma

java.lang.Object

org.apache.commons.numbers.gamma.Trigamma

public final class Trigamma
extends Object

Trigamma function. It is the derivative of the digamma function: \( \psi_1(x) = \frac{d^2}{dx^2} (\ln \Gamma(x)) \).

Method Summary

Modifier and Type	Method	Description
static double	value(double x)	Computes the trigamma function.

Methods inherited from class java.lang.Object

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

Method Details

value

public static double value(double x)

Computes the trigamma function.

Parameters:

x - Argument.

Returns:

trigamma(x) to within 1e-8 relative or absolute error whichever is larger.