edu.cmu.minorthird.classify.transform
Class InfoGainTransformLearner

java.lang.Object
  edu.cmu.minorthird.classify.transform.InfoGainTransformLearner

All Implemented Interfaces:

InstanceTransformLearner

public class InfoGainTransformLearner
extends java.lang.Object
implements InstanceTransformLearner

A simple feature filter based on Ingormation Gain. The frequency model is resposible for deciding 'what to count'. If set to "document" this filter counts the number of documents which contain a Feature; if set to "word" this filter counts the number of times a Feature appears in the whole dataset.

Constructor Summary

InfoGainTransformLearner()
Constructors

InfoGainTransformLearner(java.lang.String model)

Method Summary

InstanceTransform	batchTrain(Dataset dataset) Examine data, build an instance transformer
double	Entropy(double P1, double P2) compute the entropy of a binary attribute
double	getLength(Example e) Get the total number of words in an Example
static void	main(java.lang.String[] args)
void	setSchema(ExampleSchema schema) Accept an ExampleSchema - constraints on what the Examples will be.

Methods inherited from class java.lang.Object

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

Constructor Detail

InfoGainTransformLearner

public InfoGainTransformLearner()

Constructors

InfoGainTransformLearner

public InfoGainTransformLearner(java.lang.String model)

Method Detail

setSchema

public void setSchema(ExampleSchema schema)

Accept an ExampleSchema - constraints on what the Examples will be.

Specified by:

setSchema in interface InstanceTransformLearner

batchTrain

public InstanceTransform batchTrain(Dataset dataset)

Examine data, build an instance transformer

Specified by:

batchTrain in interface InstanceTransformLearner

Entropy

public double Entropy(double P1,
                      double P2)

compute the entropy of a binary attribute

getLength

public double getLength(Example e)

Get the total number of words in an Example

main

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