weka.classifiers.j48
Class EntropyBasedSplitCrit

java.lang.Object
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  +--weka.classifiers.j48.SplitCriterion
        |
        +--weka.classifiers.j48.EntropyBasedSplitCrit
All Implemented Interfaces:
java.io.Serializable
Direct Known Subclasses:
EntropySplitCrit, GainRatioSplitCrit, InfoGainSplitCrit

public abstract class EntropyBasedSplitCrit
extends SplitCriterion

"Abstract" class for computing splitting criteria based on the entropy of a class distribution.

Author:
Eibe Frank (eibe@cs.waikato.ac.nz)
See Also:
Serialized Form

Field Summary
protected static double log2
          The log of 2.
 
Constructor Summary
EntropyBasedSplitCrit()
           
 
Method Summary
protected  double logFunc(double num)
          Help method for computing entropy.
 double newEnt(Distribution bags)
          Computes entropy of distribution after splitting.
 double oldEnt(Distribution bags)
          Computes entropy of distribution before splitting.
 double splitEnt(Distribution bags)
          Computes entropy after splitting without considering the class values.
 
Methods inherited from class weka.classifiers.j48.SplitCriterion
splitCritValue, splitCritValue, splitCritValue, splitCritValue
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

log2

protected static double log2
The log of 2.
Constructor Detail

EntropyBasedSplitCrit

public EntropyBasedSplitCrit()
Method Detail

logFunc

protected final double logFunc(double num)
Help method for computing entropy.

oldEnt

public final double oldEnt(Distribution bags)
Computes entropy of distribution before splitting.

newEnt

public final double newEnt(Distribution bags)
Computes entropy of distribution after splitting.

splitEnt

public final double splitEnt(Distribution bags)
Computes entropy after splitting without considering the class values.