weka.classifiers.trees.j48

Class C45PruneableClassifierTreeG

java.lang.Object

weka.classifiers.trees.j48.ClassifierTree

weka.classifiers.trees.j48.C45PruneableClassifierTreeG

All Implemented Interfaces:

java.io.Serializable, CapabilitiesHandler, Drawable, RevisionHandler

public class C45PruneableClassifierTreeG
extends ClassifierTree

Class for handling a tree structure that can be pruned using C4.5 procedures and have nodes grafted on.

Version:

$Revision: 5535 $

Author:

Janice Boughton (based on code by Eibe Frank)

See Also:

Serialized Form

Field Summary

Fields inherited from interface weka.core.Drawable

BayesNet, Newick, NOT_DRAWABLE, TREE

Constructor Summary

Constructors

Constructor and Description
C45PruneableClassifierTreeG(ModelSelection toSelectLocModel, boolean pruneTree, float cf, boolean raiseTree, boolean relabel, boolean cleanup) Constructor for pruneable tree structure.
C45PruneableClassifierTreeG(ModelSelection toSelectLocModel, Instances data, ClassifierSplitModel gs, boolean prune, float cf, boolean raise, boolean isLeaf, boolean relabel, boolean cleanup) Constructor for pruneable tree structure.

Method Summary

Modifier and Type	Method and Description
double	biprob(double x, double n, double r) Significance test
void	buildClassifier(Instances data) Method for building a pruneable classifier tree.
void	collapse() Collapses a tree to a node if training error doesn't increase.
void	doGrafting(Instances data) Initializes variables for grafting.
Capabilities	getCapabilities() Returns default capabilities of the classifier tree.
java.lang.String	getRevision() Returns the revision string.
void	prune() Prunes a tree using C4.5's pruning procedure.
void	setDescendents(java.util.ArrayList t, C45PruneableClassifierTreeG originalLeaf) add the grafted nodes at originalLeaf's position in tree.
java.lang.String	toString() Prints tree structure.

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

assignIDs, buildTree, buildTree, classifyInstance, cleanup, distributionForInstance, graph, graphType, numLeaves, numNodes, prefix, toSource

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

C45PruneableClassifierTreeG

public C45PruneableClassifierTreeG(ModelSelection toSelectLocModel,
                                   boolean pruneTree,
                                   float cf,
                                   boolean raiseTree,
                                   boolean relabel,
                                   boolean cleanup)
                            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

cf - the confidence factor for pruning

raiseTree -

cleanup -

Throws:

java.lang.Exception - if something goes wrong

C45PruneableClassifierTreeG

public C45PruneableClassifierTreeG(ModelSelection toSelectLocModel,
                                   Instances data,
                                   ClassifierSplitModel gs,
                                   boolean prune,
                                   float cf,
                                   boolean raise,
                                   boolean isLeaf,
                                   boolean relabel,
                                   boolean cleanup)

Constructor for pruneable tree structure. Used to create new nodes in the tree during grafting.

Parameters:

toSelectLocModel - selection method for local splitting model

data - the dta used to produce split model

gs - the split model

prune - true if the tree is to be pruned

cf - the confidence factor for pruning

raise -

isLeaf - if this node is a leaf or not

relabel - whether relabeling occured

cleanup -

Throws:

java.lang.Exception - if something goes wrong

Method Detail

getCapabilities

public Capabilities getCapabilities()

Returns default capabilities of the classifier tree.

Specified by:

getCapabilities in interface CapabilitiesHandler

Overrides:

getCapabilities in class ClassifierTree

Returns:

the capabilities of this classifier tree

See Also:

Capabilities

buildClassifier

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

Method for building a pruneable classifier tree.

Overrides:

buildClassifier in class ClassifierTree

Parameters:

datathe - data for building the tree

Throws:

java.lang.Exception - if something goes wrong

collapse

public final void collapse()

Collapses a tree to a node if training error doesn't increase.

prune

public void prune()
           throws java.lang.Exception

Prunes a tree using C4.5's pruning procedure.

Throws:

java.lang.Exception - if something goes wrong

doGrafting

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

Initializes variables for grafting. sets up limits array (for numeric attributes) and calls the recursive function traverseTree.

Parameters:

data - the data for the tree

Throws:

java.lang.Exception - if anything goes wrong

setDescendents

public void setDescendents(java.util.ArrayList t,
                           C45PruneableClassifierTreeG originalLeaf)

add the grafted nodes at originalLeaf's position in tree. a recursive function that terminates when t is empty.

Parameters:

t - the list of nodes to graft

originalLeaf - the leaf that the grafts are replacing

biprob

public double biprob(double x,
                     double n,
                     double r)
              throws java.lang.Exception

Significance test

Parameters:

double - x, double n, double r.

Returns:

returns the probability of obtaining x or MORE out of n if r proportion of n are positive. z for normal estimation of binomial probability of obtaining x or more out of n, if r proportion of n are positive

Throws:

java.lang.Exception

toString

public java.lang.String toString()

Prints tree structure.

Overrides:

toString in class ClassifierTree

Returns:

the tree structure

getRevision

public java.lang.String getRevision()

Returns the revision string.

Specified by:

getRevision in interface RevisionHandler

Overrides:

getRevision in class ClassifierTree

Returns:

the revision