org.apache.commons.math.special
Class Beta

java.lang.Object
  extended by org.apache.commons.math.special.Beta

public class Beta
extends Object

This is a utility class that provides computation methods related to the Beta family of functions.

Version:
$Revision: 780933 $ $Date: 2009-06-02 00:39:12 -0400 (Tue, 02 Jun 2009) $

Field Summary
private static double DEFAULT_EPSILON
          Maximum allowed numerical error.
 
Constructor Summary
private Beta()
          Default constructor.
 
Method Summary
static double logBeta(double a, double b)
          Returns the natural logarithm of the beta function B(a, b).
static double logBeta(double a, double b, double epsilon, int maxIterations)
          Returns the natural logarithm of the beta function B(a, b).
static double regularizedBeta(double x, double a, double b)
          Returns the regularized beta function I(x, a, b).
static double regularizedBeta(double x, double a, double b, double epsilon)
          Returns the regularized beta function I(x, a, b).
static double regularizedBeta(double x, double a, double b, double epsilon, int maxIterations)
          Returns the regularized beta function I(x, a, b).
static double regularizedBeta(double x, double a, double b, int maxIterations)
          Returns the regularized beta function I(x, a, b).
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

DEFAULT_EPSILON

private static final double DEFAULT_EPSILON
Maximum allowed numerical error.

See Also:
Constant Field Values
Constructor Detail

Beta

private Beta()
Default constructor. Prohibit instantiation.

Method Detail

regularizedBeta

public static double regularizedBeta(double x,
                                     double a,
                                     double b)
                              throws MathException
Returns the regularized beta function I(x, a, b).

Parameters:
x - the value.
a - the a parameter.
b - the b parameter.
Returns:
the regularized beta function I(x, a, b)
Throws:
MathException - if the algorithm fails to converge.

regularizedBeta

public static double regularizedBeta(double x,
                                     double a,
                                     double b,
                                     double epsilon)
                              throws MathException
Returns the regularized beta function I(x, a, b).

Parameters:
x - the value.
a - the a parameter.
b - the b parameter.
epsilon - When the absolute value of the nth item in the series is less than epsilon the approximation ceases to calculate further elements in the series.
Returns:
the regularized beta function I(x, a, b)
Throws:
MathException - if the algorithm fails to converge.

regularizedBeta

public static double regularizedBeta(double x,
                                     double a,
                                     double b,
                                     int maxIterations)
                              throws MathException
Returns the regularized beta function I(x, a, b).

Parameters:
x - the value.
a - the a parameter.
b - the b parameter.
maxIterations - Maximum number of "iterations" to complete.
Returns:
the regularized beta function I(x, a, b)
Throws:
MathException - if the algorithm fails to converge.

regularizedBeta

public static double regularizedBeta(double x,
                                     double a,
                                     double b,
                                     double epsilon,
                                     int maxIterations)
                              throws MathException
Returns the regularized beta function I(x, a, b). The implementation of this method is based on:

Parameters:
x - the value.
a - the a parameter.
b - the b parameter.
epsilon - When the absolute value of the nth item in the series is less than epsilon the approximation ceases to calculate further elements in the series.
maxIterations - Maximum number of "iterations" to complete.
Returns:
the regularized beta function I(x, a, b)
Throws:
MathException - if the algorithm fails to converge.

logBeta

public static double logBeta(double a,
                             double b)
Returns the natural logarithm of the beta function B(a, b).

Parameters:
a - the a parameter.
b - the b parameter.
Returns:
log(B(a, b))

logBeta

public static double logBeta(double a,
                             double b,
                             double epsilon,
                             int maxIterations)
Returns the natural logarithm of the beta function B(a, b). The implementation of this method is based on:

Parameters:
a - the a parameter.
b - the b parameter.
epsilon - When the absolute value of the nth item in the series is less than epsilon the approximation ceases to calculate further elements in the series.
maxIterations - Maximum number of "iterations" to complete.
Returns:
log(B(a, b))


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