com.numericalmethod.suanshu.analysis.function.special.beta

Class BetaRegularized

java.lang.Object

com.numericalmethod.suanshu.analysis.function.rn2r1.univariate.UnivariateRealFunction

com.numericalmethod.suanshu.analysis.function.special.beta.BetaRegularized

All Implemented Interfaces:

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

public class BetaRegularized
extends UnivariateRealFunction

The Regularized Incomplete Beta function is defined as: \[ I_x(p,q) = \frac{B(x;\,p,q)}{B(p,q)} = \frac{1}{B(p,q)} \int_0^x t^{p-1}\,(1-t)^{q-1}\,dt, p > 0, q > 0 \]

The R equivalent function is pbeta.

See Also:

• "Amparo Gil, Javier Segura, and Nico M. Temme. "Sections 6.7," Numerical Methods for Special Functions."
• Wikipedia: Incomplete beta function

, 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
BetaRegularized(double p, double q) Construct an instance of Ix(p,q) with the parameters p and q.

Method Summary

Modifier and Type	Method and Description
double	evaluate(double x) Evaluate Ix(p,q).
double	p() Get p, the shape parameter.
double	q() Get q, the shape parameter.

Methods inherited from class com.numericalmethod.suanshu.analysis.function.rn2r1.univariate.UnivariateRealFunction

dimensionOfDomain, dimensionOfRange, evaluate

Methods inherited from class java.lang.Object

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

Constructor Detail

BetaRegularized

public BetaRegularized(double p,
                       double q)

Construct an instance of I_x(p,q) with the parameters p and q.

Parameters:

p - p > 0

q - q > 0

Method Detail

p

public double p()

Get p, the shape parameter.

Returns:

p

q

public double q()

Get q, the shape parameter.

Returns:

q

evaluate

public double evaluate(double x)

Evaluate I_x(p,q).

Specified by:

evaluate in class UnivariateRealFunction

Parameters:

x - 0 <= x <= 1

Returns:

I_x(p,q)