weka.classifiers.trees.j48
Class PruneableClassifierTree

java.lang.Object
  weka.classifiers.trees.j48.ClassifierTree
      weka.classifiers.trees.j48.PruneableClassifierTree

All Implemented Interfaces:

Drawable, java.io.Serializable

public class PruneableClassifierTree

extends ClassifierTree

Class for handling a tree structure that can be pruned using a pruning set.

Version:

$Revision: 1.8 $

Author:

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

See Also:

Serialized Form

Field Summary

private boolean	m_cleanup Cleanup after the tree has been built.
private int	m_seed The random number seed.
private int	numSets How many subsets of equal size?
private boolean	pruneTheTree True if the tree is to be pruned.

Fields inherited from class weka.classifiers.trees.j48.ClassifierTree

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

Fields inherited from interface weka.core.Drawable

BayesNet, NOT_DRAWABLE, TREE

Constructor Summary

PruneableClassifierTree(ModelSelection toSelectLocModel, boolean pruneTree, int num, boolean cleanup, int seed)
Constructor for pruneable tree structure.

Method Summary

void	buildClassifier(Instances data) Method for building a pruneable classifier tree.
private double	errorsForLeaf() Computes estimated errors for leaf.
private double	errorsForTree() Computes estimated errors for tree.
protected ClassifierTree	getNewTree(Instances train, Instances test) Returns a newly created tree.
private ClassifierSplitModel	localModel() Method just exists to make program easier to read.
void	prune() Prunes a tree.
private PruneableClassifierTree	son(int index) Method just exists to make program easier to read.

Methods inherited from class weka.classifiers.trees.j48.ClassifierTree

assignIDs, buildTree, buildTree, classifyInstance, cleanup, distributionForInstance, getNewTree, graph, graphType, nextID, numLeaves, numNodes, prefix, resetID, toSource, toString

Methods inherited from class java.lang.Object

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

Field Detail

pruneTheTree

private boolean pruneTheTree

True if the tree is to be pruned.

numSets

private int numSets

How many subsets of equal size? One used for pruning, the rest for training.

m_cleanup

private boolean m_cleanup

Cleanup after the tree has been built.

m_seed

private int m_seed

The random number seed.

Constructor Detail

PruneableClassifierTree

public PruneableClassifierTree(ModelSelection toSelectLocModel,
                               boolean pruneTree,
                               int num,
                               boolean cleanup,
                               int seed)
                        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

pruneTree - true if the tree is to be pruned

num - number of subsets of equal size

Throws:

java.lang.Exception - if something goes wrong

Method Detail

buildClassifier

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

Method for building a pruneable classifier tree.

Overrides:

buildClassifier in class ClassifierTree

Throws:

java.lang.Exception - if tree can't be built successfully

prune

public void prune()
           throws java.lang.Exception

Prunes a tree.

Throws:

java.lang.Exception - if tree can't be pruned successfully

getNewTree

protected ClassifierTree getNewTree(Instances train,
                                    Instances test)
                             throws java.lang.Exception

Returns a newly created tree.

Overrides:

getNewTree in class ClassifierTree

Parameters:

test - the pruning data.

Throws:

java.lang.Exception - if something goes wrong

errorsForTree

private double errorsForTree()
                      throws java.lang.Exception

Computes estimated errors for tree.

Throws:

java.lang.Exception - if error estimate can't be computed

errorsForLeaf

private double errorsForLeaf()
                      throws java.lang.Exception

Computes estimated errors for leaf.

Throws:

java.lang.Exception - if error estimate can't be computed

localModel

private ClassifierSplitModel localModel()

Method just exists to make program easier to read.

son

private PruneableClassifierTree son(int index)

Method just exists to make program easier to read.