org.wdssii.decisiontree
Class GainRatioFitnessFunction

java.lang.Object
  org.wdssii.decisiontree.GainRatioFitnessFunction

All Implemented Interfaces:

FitnessFunction

public class GainRatioFitnessFunction
extends Object
implements FitnessFunction

Picks a threshold to maximize the gain but uses gain-ratio as the fitness of this attribute

Author:

lakshman

Nested Class Summary

private static class

GainRatioFitnessFunction.ValueAndCategory

Nested classes/interfaces inherited from interface org.wdssii.decisiontree.FitnessFunction

FitnessFunction.Split

Field Summary

private static double

LOG2

Constructor Summary

GainRatioFitnessFunction()

Method Summary

private float	computeGain(GainRatioFitnessFunction.ValueAndCategory[] all, int numCategories, int split)
private float	computeGainRatio(GainRatioFitnessFunction.ValueAndCategory[] all, int numCategories, int split)
private float	computeInfo(GainRatioFitnessFunction.ValueAndCategory[] all, int numCategories, int start, int end)
FitnessFunction.Split	computeSplitAndGain(float[][] inputData, int[] targetClass, int numCategories, int[] toConsider, int attribute)
private static float	log2(float p)

Methods inherited from class java.lang.Object

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

Field Detail

LOG2

private static double LOG2

Constructor Detail

GainRatioFitnessFunction

public GainRatioFitnessFunction()

Method Detail

computeSplitAndGain

public FitnessFunction.Split computeSplitAndGain(float[][] inputData,
                                                 int[] targetClass,
                                                 int numCategories,
                                                 int[] toConsider,
                                                 int attribute)

Specified by:

computeSplitAndGain in interface FitnessFunction

computeGain

private float computeGain(GainRatioFitnessFunction.ValueAndCategory[] all,
                          int numCategories,
                          int split)

computeInfo

private float computeInfo(GainRatioFitnessFunction.ValueAndCategory[] all,
                          int numCategories,
                          int start,
                          int end)

log2

private static float log2(float p)

computeGainRatio

private float computeGainRatio(GainRatioFitnessFunction.ValueAndCategory[] all,
                               int numCategories,
                               int split)