weka.estimators
Class DiscreteEstimator

java.lang.Object
  weka.estimators.DiscreteEstimator

All Implemented Interfaces:

Estimator, java.io.Serializable

public class DiscreteEstimator

extends java.lang.Object

implements Estimator

Simple symbolic probability estimator based on symbol counts.

Version:

$Revision: 1.5 $

Author:

Len Trigg (trigg@cs.waikato.ac.nz)

See Also:

Serialized Form

Field Summary

private double[]	m_Counts Hold the counts
private double	m_SumOfCounts Hold the sum of counts

Constructor Summary

DiscreteEstimator(int numSymbols, boolean laplace)
Constructor

DiscreteEstimator(int nSymbols, double fPrior)
Constructor

Method Summary

void	addValue(double data, double weight) Add a new data value to the current estimator.
int	getNumSymbols() Gets the number of symbols this estimator operates with
double	getProbability(double data) Get a probability estimate for a value
static void	main(java.lang.String[] argv) Main method for testing this class.
java.lang.String	toString() Display a representation of this estimator

Methods inherited from class java.lang.Object

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

Field Detail

m_Counts

private double[] m_Counts

Hold the counts

m_SumOfCounts

private double m_SumOfCounts

Hold the sum of counts

Constructor Detail

DiscreteEstimator

public DiscreteEstimator(int numSymbols,
                         boolean laplace)

Constructor

Parameters:

numSymbols - the number of possible symbols (remember to include 0)

laplace - if true, counts will be initialised to 1

DiscreteEstimator

public DiscreteEstimator(int nSymbols,
                         double fPrior)

Constructor

Parameters:

nSymbols - the number of possible symbols (remember to include 0)

fPrior - value with which counts will be initialised

Method Detail

addValue

public void addValue(double data,
                     double weight)

Add a new data value to the current estimator.

Specified by:

addValue in interface Estimator

Parameters:

data - the new data value

weight - the weight assigned to the data value

getProbability

public double getProbability(double data)

Get a probability estimate for a value

Specified by:

getProbability in interface Estimator

Parameters:

data - the value to estimate the probability of

Returns:

the estimated probability of the supplied value

getNumSymbols

public int getNumSymbols()

Gets the number of symbols this estimator operates with

Returns:

the number of estimator symbols

toString

public java.lang.String toString()

Display a representation of this estimator

main

public static void main(java.lang.String[] argv)

Main method for testing this class.

Parameters:

argv - should contain a sequence of integers which will be treated as symbolic.