moa.classifiers.core.attributeclassobservers

Class NominalAttributeClassObserver

java.lang.Object

moa.AbstractMOAObject

moa.options.AbstractOptionHandler

moa.classifiers.core.attributeclassobservers.NominalAttributeClassObserver

All Implemented Interfaces:

Serializable, AttributeClassObserver, DiscreteAttributeClassObserver, MOAObject, OptionHandler

public class NominalAttributeClassObserver
extends AbstractOptionHandler
implements DiscreteAttributeClassObserver

Class for observing the class data distribution for a nominal attribute. This observer monitors the class distribution of a given attribute. Used in naive Bayes and decision trees to monitor data statistics on leaves.

Version:

$Revision: 7 $

Author:

Richard Kirkby (rkirkby@cs.waikato.ac.nz)

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
AutoExpandVector<DoubleVector>	attValDistPerClass
protected double	missingWeightObserved
protected double	totalWeightObserved

Fields inherited from class moa.options.AbstractOptionHandler

classOptionNamesToPreparedObjects, options

Constructor Summary

Constructors

Constructor and Description
NominalAttributeClassObserver()

Method Summary

Methods

Modifier and Type	Method and Description
AttributeSplitSuggestion	getBestEvaluatedSplitSuggestion(SplitCriterion criterion, double[] preSplitDist, int attIndex, boolean binaryOnly) Gets the best split suggestion given a criterion and a class distribution
double[][]	getClassDistsResultingFromBinarySplit(int valIndex)
double[][]	getClassDistsResultingFromMultiwaySplit(int maxAttValsObserved)
void	getDescription(StringBuilder sb, int indent) Returns a string representation of this object.
int	getMaxAttValsObserved()
void	observeAttributeClass(double attVal, int classVal, double weight) Updates statistics of this observer given an attribute value, a class and the weight of the instance observed
void	observeAttributeTarget(double attVal, double target)
protected void	prepareForUseImpl(TaskMonitor monitor, ObjectRepository repository) This method describes the implementation of how to prepare this object for use.
double	probabilityOfAttributeValueGivenClass(double attVal, int classVal) Gets the probability for an attribute value given a class
double	totalWeightOfClassObservations()
double	weightOfObservedMissingValues()

Methods inherited from class moa.options.AbstractOptionHandler

copy, discoverOptionsViaReflection, getCLICreationString, getOptions, getPreparedClassOption, getPreparedClassOption, getPurposeString, prepareClassOptions, prepareForUse, prepareForUse

Methods inherited from class moa.AbstractMOAObject

copy, measureByteSize, measureByteSize, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface moa.options.OptionHandler

copy, getCLICreationString, getOptions, getPurposeString, prepareForUse, prepareForUse

Methods inherited from interface moa.MOAObject

measureByteSize

Field Detail

totalWeightObserved

protected double totalWeightObserved

missingWeightObserved

protected double missingWeightObserved

attValDistPerClass

public AutoExpandVector<DoubleVector> attValDistPerClass

Constructor Detail

NominalAttributeClassObserver

public NominalAttributeClassObserver()

Method Detail

observeAttributeClass

public void observeAttributeClass(double attVal,
                         int classVal,
                         double weight)

Description copied from interface: AttributeClassObserver

Updates statistics of this observer given an attribute value, a class and the weight of the instance observed

Specified by:

observeAttributeClass in interface AttributeClassObserver

Parameters:

attVal - the value of the attribute

classVal - the class

weight - the weight of the instance

probabilityOfAttributeValueGivenClass

public double probabilityOfAttributeValueGivenClass(double attVal,
                                           int classVal)

Description copied from interface: AttributeClassObserver

Gets the probability for an attribute value given a class

Specified by:

probabilityOfAttributeValueGivenClass in interface AttributeClassObserver

Parameters:

attVal - the attribute value

classVal - the class

Returns:

probability for an attribute value given a class

totalWeightOfClassObservations

public double totalWeightOfClassObservations()

weightOfObservedMissingValues

public double weightOfObservedMissingValues()

getBestEvaluatedSplitSuggestion

public AttributeSplitSuggestion getBestEvaluatedSplitSuggestion(SplitCriterion criterion,
                                                       double[] preSplitDist,
                                                       int attIndex,
                                                       boolean binaryOnly)

Description copied from interface: AttributeClassObserver

Gets the best split suggestion given a criterion and a class distribution

Specified by:

getBestEvaluatedSplitSuggestion in interface AttributeClassObserver

Parameters:

criterion - the split criterion to use

preSplitDist - the class distribution before the split

attIndex - the attribute index

binaryOnly - true to use binary splits

Returns:

suggestion of best attribute split

getMaxAttValsObserved

public int getMaxAttValsObserved()

getClassDistsResultingFromMultiwaySplit

public double[][] getClassDistsResultingFromMultiwaySplit(int maxAttValsObserved)

getClassDistsResultingFromBinarySplit

public double[][] getClassDistsResultingFromBinarySplit(int valIndex)

getDescription

public void getDescription(StringBuilder sb,
                  int indent)

Description copied from interface: MOAObject

Returns a string representation of this object. Used in AbstractMOAObject.toString to give a string representation of the object.

Specified by:

getDescription in interface MOAObject

Parameters:

sb - the stringbuilder to add the description

indent - the number of characters to indent

prepareForUseImpl

protected void prepareForUseImpl(TaskMonitor monitor,
                     ObjectRepository repository)

Description copied from class: AbstractOptionHandler

This method describes the implementation of how to prepare this object for use. All classes that extends this class have to implement prepareForUseImpl and not prepareForUse since prepareForUse calls prepareForUseImpl.

Specified by:

prepareForUseImpl in class AbstractOptionHandler

Parameters:

monitor - the TaskMonitor to use

repository - the ObjectRepository to use

observeAttributeTarget

public void observeAttributeTarget(double attVal,
                          double target)

Specified by:

observeAttributeTarget in interface AttributeClassObserver