weka.classifiers.j48
Class C45PruneableDecList

java.lang.Object
  |
  +--weka.classifiers.j48.ClassifierDecList
        |
        +--weka.classifiers.j48.C45PruneableDecList

All Implemented Interfaces:

java.io.Serializable

public class C45PruneableDecList

extends ClassifierDecList

Class for handling a partial tree structure pruned using C4.5's pruning heuristic.

Author:

Eibe Frank (eibe@cs.waikato.ac.nz)

See Also:

Serialized Form

Fields inherited from class weka.classifiers.j48.ClassifierDecList

indeX, m_isEmpty, m_isLeaf, m_localModel, m_sons, m_test, m_toSelectModel, m_train

Constructor Summary

C45PruneableDecList(ModelSelection toSelectLocModel, double cf, int minNum)
Constructor for pruneable tree structure.

Method Summary

void	buildRule(Instances data) Method for building a pruned partial tree.
int	chooseIndex() Method for choosing a subset to expand.
int	chooseLastIndex() Choose last index (ie.
double	getEstimatedErrorsForLeaf() Computes estimated errors for leaf.
protected ClassifierDecList	getNewDecList(Instances data, boolean leaf) Returns a newly created tree.
protected void	pruneEnd() Prunes the end of the rule.

Methods inherited from class weka.classifiers.j48.ClassifierDecList

buildDecList, buildDecList, classifyInstance, cleanup, distributionForInstance, getNewDecList, toString, weight

Methods inherited from class java.lang.Object

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

Constructor Detail

C45PruneableDecList

public C45PruneableDecList(ModelSelection toSelectLocModel,
                           double cf,
                           int minNum)
                    throws java.lang.Exception

Constructor for pruneable tree structure. Stores reference to associated training data at each node.

Parameters:

toSelectLocModel - selection method for local splitting model

cf - the confidence factor for pruning

minNum - the minimum number of objects in a leaf

Throws:

java.lang.Exception - if something goes wrong

Method Detail

buildRule

public void buildRule(Instances data)
               throws java.lang.Exception

Method for building a pruned partial tree.

Throws:

java.lang.Exception - if something goes wrong

chooseIndex

public final int chooseIndex()

Method for choosing a subset to expand.

Overrides:

chooseIndex in class ClassifierDecList

chooseLastIndex

public final int chooseLastIndex()

Choose last index (ie. choose rule).

Overrides:

chooseLastIndex in class ClassifierDecList

getNewDecList

protected ClassifierDecList getNewDecList(Instances data,
                                          boolean leaf)
                                   throws java.lang.Exception

Returns a newly created tree.

Overrides:

getNewDecList in class ClassifierDecList

Throws:

java.lang.Exception - if something goes wrong

pruneEnd

protected void pruneEnd()

Prunes the end of the rule.

Overrides:

pruneEnd in class ClassifierDecList

getEstimatedErrorsForLeaf

public double getEstimatedErrorsForLeaf()

Computes estimated errors for leaf.