weka.classifiers.rules

Class ZeroR

java.lang.Object

weka.classifiers.Classifier

weka.classifiers.rules.ZeroR

All Implemented Interfaces:

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

public class ZeroR
extends Classifier
implements WeightedInstancesHandler, Sourcable

Class for building and using a 0-R classifier. Predicts the mean (for a numeric class) or the mode (for a nominal class).

Valid options are:

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

Version:

$Revision: 5529 $

Author:

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

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ZeroR()

Method Summary

Modifier and Type	Method and Description
void	buildClassifier(Instances instances) Generates the classifier.
double	classifyInstance(Instance instance) Classifies a given instance.
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 a string that describes the classifier as source.
String	toString() Returns a description of the classifier.

Methods inherited from class weka.classifiers.Classifier

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

Methods inherited from class java.lang.Object

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

Constructor Detail

ZeroR

public ZeroR()

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 CapabilitiesHandler

Overrides:

getCapabilities in class Classifier

Returns:

the capabilities of this classifier

See Also:

Capabilities

buildClassifier

public void buildClassifier(Instances instances)
                     throws Exception

Generates the classifier.

Specified by:

buildClassifier in class Classifier

Parameters:

instances - set of instances serving as training data

Throws:

Exception - if the classifier has not been generated successfully

classifyInstance

public double classifyInstance(Instance instance)

Classifies a given instance.

Overrides:

classifyInstance in class Classifier

Parameters:

instance - the instance to be classified

Returns:

index of the predicted class

distributionForInstance

public double[] distributionForInstance(Instance instance)
                                 throws Exception

Calculates the class membership probabilities for the given test instance.

Overrides:

distributionForInstance in class Classifier

Parameters:

instance - the instance to be classified

Returns:

predicted class probability distribution

Throws:

Exception - if class is numeric

toSource

public String toSource(String className)
                throws Exception

Returns a string that describes the classifier as source. The classifier will be contained in a class with the given name (there may be auxiliary classes), and will contain a method with the signature:

 public static double classify(Object[] i);
 

where the array i contains elements that are either Double, String, with missing values represented as null. The generated code is public domain and comes with no warranty.

Specified by:

toSource in interface Sourcable

Parameters:

className - the name that should be given to the source class.

Returns:

the object source described by a string

Throws:

Exception - if the souce can't be computed

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 Classifier

Returns:

the revision

main

public static void main(String[] argv)

Main method for testing this class.

Parameters:

argv - the options