weka.classifiers.rules
Class OneR

java.lang.Object
  weka.classifiers.Classifier
      weka.classifiers.rules.OneR

All Implemented Interfaces:

java.lang.Cloneable, OptionHandler, java.io.Serializable

public class OneR

extends Classifier

implements OptionHandler

Class for building and using a 1R classifier. For more information, see

R.C. Holte (1993). Very simple classification rules perform well on most commonly used datasets. Machine Learning, Vol. 11, pp. 63-91.

Valid options are:

-B num
Specify the minimum number of objects in a bucket (default: 6).

Version:

$Revision: 1.16 $

Author:

Ian H. Witten (ihw@cs.waikato.ac.nz)

See Also:

Serialized Form

Nested Class Summary

private class

OneR.OneRRule Class for storing store a 1R rule.

Field Summary

private int	m_minBucketSize The minimum bucket size
private OneR.OneRRule	m_rule A 1-R rule

Fields inherited from class weka.classifiers.Classifier

m_Debug

Constructor Summary

OneR()

Method Summary

void	buildClassifier(Instances instances) Generates the classifier.
double	classifyInstance(Instance inst) Classifies a given instance.
int	getMinBucketSize() Get the value of minBucketSize.
java.lang.String[]	getOptions() Gets the current settings of the OneR classifier.
java.lang.String	globalInfo() Returns a string describing classifier
java.util.Enumeration	listOptions() Returns an enumeration describing the available options..
static void	main(java.lang.String[] argv) Main method for testing this class
java.lang.String	minBucketSizeTipText() Returns the tip text for this property
OneR.OneRRule	newNominalRule(Attribute attr, Instances data, int[] missingValueCounts) Create a rule branching on this nominal attribute.
OneR.OneRRule	newNumericRule(Attribute attr, Instances data, int[] missingValueCounts) Create a rule branching on this numeric attribute
OneR.OneRRule	newRule(Attribute attr, Instances data) Create a rule branching on this attribute.
void	setMinBucketSize(int v) Set the value of minBucketSize.
void	setOptions(java.lang.String[] options) Parses a given list of options.
java.lang.String	toString() Returns a description of the classifier

Methods inherited from class weka.classifiers.Classifier

debugTipText, distributionForInstance, forName, getDebug, makeCopies, setDebug

Methods inherited from class java.lang.Object

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

Field Detail

m_rule

private OneR.OneRRule m_rule

A 1-R rule

m_minBucketSize

private int m_minBucketSize

The minimum bucket size

Constructor Detail

OneR

public OneR()

Method Detail

globalInfo

public java.lang.String globalInfo()

Returns a string describing classifier

Returns:

a description suitable for displaying in the explorer/experimenter gui

classifyInstance

public double classifyInstance(Instance inst)

Classifies a given instance.

Overrides:

classifyInstance in class Classifier

Parameters:

inst - the instance to be classified

Returns:

the predicted most likely class for the instance or Instance.missingValue() if no prediction is made

buildClassifier

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

Generates the classifier.

Specified by:

buildClassifier in class Classifier

Parameters:

instances - the instances to be used for building the classifier

Throws:

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

newRule

public OneR.OneRRule newRule(Attribute attr,
                             Instances data)
                      throws java.lang.Exception

Create a rule branching on this attribute.

Parameters:

attr - the attribute to branch on

data - the data to be used for creating the rule

Throws:

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

newNominalRule

public OneR.OneRRule newNominalRule(Attribute attr,
                                    Instances data,
                                    int[] missingValueCounts)
                             throws java.lang.Exception

Create a rule branching on this nominal attribute.

Parameters:

attr - the attribute to branch on

data - the data to be used for creating the rule

missingValueCounts - to be filled in

Throws:

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

newNumericRule

public OneR.OneRRule newNumericRule(Attribute attr,
                                    Instances data,
                                    int[] missingValueCounts)
                             throws java.lang.Exception

Create a rule branching on this numeric attribute

Parameters:

attr - the attribute to branch on

data - the data to be used for creating the rule

missingValueCounts - to be filled in

Throws:

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

listOptions

public java.util.Enumeration listOptions()

Returns an enumeration describing the available options..

Specified by:

listOptions in interface OptionHandler

Overrides:

listOptions in class Classifier

Returns:

an enumeration of all the available options.

setOptions

public void setOptions(java.lang.String[] options)
                throws java.lang.Exception

Parses a given list of options. Valid options are:

-B num
Specify the minimum number of objects in a bucket (default: 6).

Specified by:

setOptions in interface OptionHandler

Overrides:

setOptions in class Classifier

Parameters:

options - the list of options as an array of strings

Throws:

java.lang.Exception - if an option is not supported

getOptions

public java.lang.String[] getOptions()

Gets the current settings of the OneR classifier.

Specified by:

getOptions in interface OptionHandler

Overrides:

getOptions in class Classifier

Returns:

an array of strings suitable for passing to setOptions

toString

public java.lang.String toString()

Returns a description of the classifier

minBucketSizeTipText

public java.lang.String minBucketSizeTipText()

Returns the tip text for this property

Returns:

tip text for this property suitable for displaying in the explorer/experimenter gui

getMinBucketSize

public int getMinBucketSize()

Get the value of minBucketSize.

Returns:

Value of minBucketSize.

setMinBucketSize

public void setMinBucketSize(int v)

Set the value of minBucketSize.

Parameters:

v - Value to assign to minBucketSize.

main

public static void main(java.lang.String[] argv)

Main method for testing this class