com.numericalmethod.suanshu.analysis.differentiation.univariate

Class DBeta

java.lang.Object

com.numericalmethod.suanshu.analysis.function.rn2r1.BivariateRealFunction

com.numericalmethod.suanshu.analysis.differentiation.univariate.DBeta

All Implemented Interfaces:

Function<Vector,java.lang.Double>, RealScalarFunction, java.io.Serializable

public class DBeta
extends BivariateRealFunction

This is the first order derivative function of the Beta function w.r.t x, \({\partial \over \partial x} \mathrm{B}(x, y)\). \[ {\partial \over \partial x} \mathrm{B}(x, y) = \mathrm{B}(x, y) (\psi(x) - \psi(x + y)) \] where \(x > 0, y > 0\), \(\psi\) is the Digamma function.

See Also:

Wikipedia: Derivatives, Beta, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface com.numericalmethod.suanshu.analysis.function.Function

Function.EvaluationException

Constructor Summary

Constructors

Constructor and Description
DBeta()

Method Summary

Modifier and Type	Method and Description
double	evaluate(double x, double y) Evaluate \({\partial \over \partial x} \mathrm{B}(x, y)\).

Methods inherited from class com.numericalmethod.suanshu.analysis.function.rn2r1.BivariateRealFunction

dimensionOfDomain, dimensionOfRange, evaluate

Methods inherited from class java.lang.Object

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

Constructor Detail

DBeta

public DBeta()

Method Detail

evaluate

public double evaluate(double x,
                       double y)

Evaluate \({\partial \over \partial x} \mathrm{B}(x, y)\).

Specified by:

evaluate in class BivariateRealFunction

Parameters:

x - x > 0

y - y > 0

Returns:

\({\partial \over \partial x} \mathrm{B}(x, y)\)