Package org.apache.commons.numbers.gamma

Class Beta

java.lang.Object

org.apache.commons.numbers.gamma.Beta

public final class Beta
extends Object

Beta function.

$$B(a,b)=\frac{\mathrm{\Gamma }(a)\mathrm{\Gamma }(b)}{\mathrm{\Gamma }(a+b)}=\frac{(a-1)!(b-1)!}{(a+b-1)!}$$

where $\mathrm{\Gamma }(z)$ is the gamma function.

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

Since:

1.1

See Also:

Boost C++ Beta function

Method Summary

Modifier and Type	Method	Description
static double	value(double a, double b)	Computes the value of the beta function B(a, b).

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 a,
                           double b)

Computes the value of the beta function B(a, b).

$$B(a,b)=\frac{\mathrm{\Gamma }(a)\mathrm{\Gamma }(b)}{\mathrm{\Gamma }(a+b)}$$

where $\mathrm{\Gamma }(z)$ is the gamma function.

Parameters:

a - Parameter a.

b - Parameter b.

Returns:

the beta function $B(a,b)$.