de.jstacs.utils.random
Class FastDirichletMRGParams

java.lang.Object
  de.jstacs.utils.random.MRGParams
      de.jstacs.utils.random.DiMRGParams
          de.jstacs.utils.random.FastDirichletMRGParams

public class FastDirichletMRGParams
extends DiMRGParams

The container for parameters of a Dirichlet random generator that uses the same hyperparameter at all positions.

Author:

Jens Keilwagen

See Also:

MRGParams, DirichletMRGParams

Constructor Summary

FastDirichletMRGParams(double alpha)
Creates the hyperparameter for a Dirichlet random generator which is used at all positions for the hyperparameter vector of the underlying Dirichlet distribution.

Method Summary

int	getDimension() Returns the dimension of the hyperparameter vector of the underlying Dirichlet distribution and therefore the dimension of the generated random array.
double	getHyperparameter(int i) Returns the value at position i of the hyperparameter vector of the underlying Dirichlet distribution.

Methods inherited from class java.lang.Object

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

Constructor Detail

FastDirichletMRGParams

public FastDirichletMRGParams(double alpha)
                       throws IllegalArgumentException

Creates the hyperparameter for a Dirichlet random generator which is used at all positions for the hyperparameter vector of the underlying Dirichlet distribution.

Parameters:

alpha - the hyperparameter for all positions of the hyperparameter vector

Throws:

IllegalArgumentException - if the value for alpha is chosen incorrectly (negative or 0), the parameter has to be positive

Method Detail

getDimension

public int getDimension()

Description copied from class: DiMRGParams

Returns the dimension of the hyperparameter vector of the underlying Dirichlet distribution and therefore the dimension of the generated random array.

Specified by:

getDimension in class DiMRGParams

Returns:

the dimension of the hyperparameter vector of the underlying Dirichlet distribution and therefore the dimension of the generated random array

getHyperparameter

public double getHyperparameter(int i)

Description copied from class: DiMRGParams

Returns the value at position i of the hyperparameter vector of the underlying Dirichlet distribution.

Specified by:

getHyperparameter in class DiMRGParams

Parameters:

i - the position of the hyperparameter vector

Returns:

the value at position i of the hyperparameter vector of the underlying Dirichlet distribution