weka.classifiers.trees

Class DecisionStump

java.lang.Object

weka.classifiers.AbstractClassifier

weka.classifiers.trees.DecisionStump

All Implemented Interfaces:

Serializable, Cloneable, Classifier, Sourcable, CapabilitiesHandler, OptionHandler, RevisionHandler, WeightedInstancesHandler

public class DecisionStump
extends AbstractClassifier
implements WeightedInstancesHandler, Sourcable

Class for building and using a decision stump. Usually used in conjunction with a boosting algorithm. Does regression (based on mean-squared error) or classification (based on entropy). Missing is treated as a separate value.

Typical usage:

java weka.classifiers.meta.LogitBoost -I 100 -W weka.classifiers.trees.DecisionStump -t training_data

Valid options are:

 -D
  If set, classifier is run in debug mode and
  may output additional info to the console

Version:

$Revision: 8034 $

Author:

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

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
DecisionStump()

Method Summary

Methods

Modifier and Type	Method and Description
void	buildClassifier(Instances instances) Generates the classifier.
double[]	distributionForInstance(Instance instance) Calculates the class membership probabilities for the given test instance.
Capabilities	getCapabilities() Returns default capabilities of the classifier.
String	getRevision() Returns the revision string.
String	globalInfo() Returns a string describing classifier
static void	main(String[] argv) Main method for testing this class.
String	toSource(String className) Returns the decision tree as Java source code.
String	toString() Returns a description of the classifier.

Methods inherited from class weka.classifiers.AbstractClassifier

classifyInstance, debugTipText, forName, getDebug, getOptions, listOptions, makeCopies, makeCopy, runClassifier, setDebug, setOptions

Methods inherited from class java.lang.Object

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

Constructor Detail

DecisionStump

public DecisionStump()

Method Detail

globalInfo

public String globalInfo()

Returns a string describing classifier

Returns:

a description suitable for displaying in the explorer/experimenter gui

getCapabilities

public Capabilities getCapabilities()

Returns default capabilities of the classifier.

Specified by:

getCapabilities in interface Classifier

Specified by:

getCapabilities in interface CapabilitiesHandler

Overrides:

getCapabilities in class AbstractClassifier

Returns:

the capabilities of this classifier

See Also:

Capabilities

buildClassifier

public void buildClassifier(Instances instances)
                     throws Exception

Generates the classifier.

Specified by:

buildClassifier in interface Classifier

Parameters:

instances - set of instances serving as training data

Throws:

Exception - if the classifier has not been generated successfully

distributionForInstance

public double[] distributionForInstance(Instance instance)
                                 throws Exception

Calculates the class membership probabilities for the given test instance.

Specified by:

distributionForInstance in interface Classifier

Overrides:

distributionForInstance in class AbstractClassifier

Parameters:

instance - the instance to be classified

Returns:

predicted class probability distribution

Throws:

Exception - if distribution can't be computed

toSource

public String toSource(String className)
                throws Exception

Returns the decision tree as Java source code.

Specified by:

toSource in interface Sourcable

Parameters:

className - the classname of the generated code

Returns:

the tree as Java source code

Throws:

Exception - if something goes wrong

toString

public String toString()

Returns a description of the classifier.

Overrides:

toString in class Object

Returns:

a description of the classifier as a string.

getRevision

public String getRevision()

Returns the revision string.

Specified by:

getRevision in interface RevisionHandler

Overrides:

getRevision in class AbstractClassifier

Returns:

the revision

main

public static void main(String[] argv)

Main method for testing this class.

Parameters:

argv - the options