Package moa.classifiers.meta

Class OnlineAccuracyUpdatedEnsemble

java.lang.Object

moa.AbstractMOAObject

moa.options.AbstractOptionHandler

moa.classifiers.AbstractClassifier

moa.classifiers.meta.OnlineAccuracyUpdatedEnsemble

All Implemented Interfaces:

Configurable, java.io.Serializable, CapabilitiesHandler, Classifier, MultiClassClassifier, AWTRenderable, Learner<Example<Instance>>, MOAObject, OptionHandler

public class OnlineAccuracyUpdatedEnsemble
extends AbstractClassifier
implements MultiClassClassifier

The online version of the Accuracy Updated Ensemble as proposed by Brzezinski and Stefanowski in "Combining block-based and online methods in learning ensembles from concept drifting data streams", Information Sciences, 2014.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	OnlineAccuracyUpdatedEnsemble.ClassifierWithMemory

Field Summary

Fields

Modifier and Type	Field	Description
protected OnlineAccuracyUpdatedEnsemble.ClassifierWithMemory	candidate	Candidate classifier.
protected long[]	classDistributions	Class distributions.
protected int[]	currentWindow	Current window of instance class values.
protected OnlineAccuracyUpdatedEnsemble.ClassifierWithMemory[]	ensemble	Ensemble classifiers.
ClassOption	learnerOption	Type of classifier to use as a component classifier.
FlagOption	linearOption	Determines whether additional information should be sent to the output.
IntOption	maxByteSizeOption	Determines the maximum size of model (evaluated after every chunk).
IntOption	memberCountOption	Number of component classifiers.
protected double	mse_r	The mean square residual in a given moment, based on a window of latest examples.
protected int	processedInstances	Number of processed examples.
FlagOption	verboseOption	Determines whether additional information should be sent to the output.
protected double[][]	weights	The weights of stored classifiers.
protected int	windowSize	Window size.
FloatOption	windowSizeOption	Chunk size.

Fields inherited from class moa.classifiers.AbstractClassifier

classifierRandom, modelContext, randomSeed, randomSeedOption, trainingWeightSeenByModel

Fields inherited from class moa.options.AbstractOptionHandler

config

Constructor Summary

Constructors

Constructor	Description
OnlineAccuracyUpdatedEnsemble()

Method Summary

Modifier and Type	Method	Description
protected void	addToStored(OnlineAccuracyUpdatedEnsemble.ClassifierWithMemory newClassifier, double newClassifiersWeight)	Adds a classifier to the storage.
protected void	computeMseR()	Computes the MSEr threshold.
protected double	computeWeight(int i, Instance example)	Computes the weight of a learner before training a given example.
protected void	createNewClassifier(Instance inst)	Processes a chunk.
protected void	enforceMemoryLimit()	Checks if the memory limit is exceeded and if so prunes the classifiers in the ensemble.
void	getModelDescription(java.lang.StringBuilder out, int indent)	Returns a string representation of the model.
protected Measurement[]	getModelMeasurementsImpl()	Adds ensemble weights to the measurements.
Classifier[]	getSubClassifiers()	Gets the classifiers of this ensemble.
double[]	getVotesForInstance(Instance inst)	Predicts a class for an example.
boolean	isRandomizable()	Determines whether the classifier is randomizable.
void	prepareForUseImpl(TaskMonitor monitor, ObjectRepository repository)	This method describes the implementation of how to prepare this object for use.
void	resetLearningImpl()	Resets this classifier.
void	trainOnInstanceImpl(Instance inst)	Trains this classifier incrementally using the given instance. The reason for ...Impl methods: ease programmer burden by not requiring them to remember calls to super in overridden methods.

Methods inherited from class moa.classifiers.AbstractClassifier

contextIsCompatible, copy, correctlyClassifies, defineImmutableCapabilities, getAttributeNameString, getAWTRenderer, getClassLabelString, getClassNameString, getDescription, getModel, getModelContext, getModelMeasurements, getNominalValueString, getPredictionForInstance, getPredictionForInstance, getPurposeString, getSublearners, getVotesForInstance, modelAttIndexToInstanceAttIndex, modelAttIndexToInstanceAttIndex, resetLearning, setModelContext, setRandomSeed, trainingHasStarted, trainingWeightSeenByModel, trainOnInstance, trainOnInstance

Methods inherited from class moa.AbstractMOAObject

copy, measureByteSize, measureByteSize, toString

Methods inherited from class moa.options.AbstractOptionHandler

getCLICreationString, getOptions, getPreparedClassOption, prepareClassOptions, prepareForUse, prepareForUse

Methods inherited from interface moa.capabilities.CapabilitiesHandler

getCapabilities

Methods inherited from interface moa.MOAObject

measureByteSize

Methods inherited from class java.lang.Object

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

Methods inherited from interface moa.options.OptionHandler

getCLICreationString, getOptions, prepareForUse, prepareForUse

Field Detail

learnerOption

public ClassOption learnerOption

Type of classifier to use as a component classifier.

memberCountOption

public IntOption memberCountOption

Number of component classifiers.

windowSizeOption

public FloatOption windowSizeOption

Chunk size.

maxByteSizeOption

public IntOption maxByteSizeOption

Determines the maximum size of model (evaluated after every chunk).

verboseOption

public FlagOption verboseOption

Determines whether additional information should be sent to the output.

linearOption

public FlagOption linearOption

Determines whether additional information should be sent to the output.

weights

protected double[][] weights

The weights of stored classifiers. weights[x][0] = weight weights[x][1] = classifier number in learners

classDistributions

protected long[] classDistributions

Class distributions.

ensemble

protected OnlineAccuracyUpdatedEnsemble.ClassifierWithMemory[] ensemble

Ensemble classifiers.

processedInstances

protected int processedInstances

Number of processed examples.

candidate

protected OnlineAccuracyUpdatedEnsemble.ClassifierWithMemory candidate

Candidate classifier.

currentWindow

protected int[] currentWindow

Current window of instance class values.

mse_r

protected double mse_r

The mean square residual in a given moment, based on a window of latest examples.

windowSize

protected int windowSize

Window size.

Constructor Detail

OnlineAccuracyUpdatedEnsemble

public OnlineAccuracyUpdatedEnsemble()

Method Detail

prepareForUseImpl

public 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.

Overrides:

prepareForUseImpl in class AbstractClassifier

Parameters:

monitor - the TaskMonitor to use

repository - the ObjectRepository to use

resetLearningImpl

public void resetLearningImpl()

Description copied from class: AbstractClassifier

Resets this classifier. It must be similar to starting a new classifier from scratch.

The reason for ...Impl methods: ease programmer burden by not requiring them to remember calls to super in overridden methods. Note that this will produce compiler errors if not overridden.

Specified by:

resetLearningImpl in class AbstractClassifier

trainOnInstanceImpl

public void trainOnInstanceImpl(Instance inst)

Description copied from class: AbstractClassifier

Trains this classifier incrementally using the given instance.

The reason for ...Impl methods: ease programmer burden by not requiring them to remember calls to super in overridden methods. Note that this will produce compiler errors if not overridden.

Specified by:

trainOnInstanceImpl in class AbstractClassifier

Parameters:

inst - the instance to be used for training

isRandomizable

public boolean isRandomizable()

Determines whether the classifier is randomizable.

Specified by:

isRandomizable in interface Learner<Example<Instance>>

Returns:

true if the learner needs a random seed.

getVotesForInstance

public double[] getVotesForInstance(Instance inst)

Predicts a class for an example.

Specified by:

getVotesForInstance in interface Classifier

Specified by:

getVotesForInstance in class AbstractClassifier

Parameters:

inst - the instance to be classified

Returns:

an array containing the estimated membership probabilities of the test instance in each class

getModelDescription

public void getModelDescription(java.lang.StringBuilder out,
                                int indent)

Description copied from class: AbstractClassifier

Returns a string representation of the model.

Specified by:

getModelDescription in class AbstractClassifier

Parameters:

out - the stringbuilder to add the description

indent - the number of characters to indent

getSubClassifiers

public Classifier[] getSubClassifiers()

Description copied from interface: Classifier

Gets the classifiers of this ensemble. Returns null if this learner is a single learner.

Specified by:

getSubClassifiers in interface Classifier

Overrides:

getSubClassifiers in class AbstractClassifier

Returns:

an array of the learners of the ensemble

createNewClassifier

protected void createNewClassifier(Instance inst)

Processes a chunk.

Parameters:

inst - New example

enforceMemoryLimit

protected void enforceMemoryLimit()

Checks if the memory limit is exceeded and if so prunes the classifiers in the ensemble.

computeMseR

protected void computeMseR()

Computes the MSEr threshold.

computeWeight

protected double computeWeight(int i,
                               Instance example)

Computes the weight of a learner before training a given example.

Parameters:

i - the identifier (in terms of array learners) of the classifier for which the weight is supposed to be computed

example - the newest example

Returns:

the computed weight.

getModelMeasurementsImpl

protected Measurement[] getModelMeasurementsImpl()

Adds ensemble weights to the measurements.

Specified by:

getModelMeasurementsImpl in class AbstractClassifier

Returns:

an array of measurements to be used in evaluation tasks

addToStored

protected void addToStored(OnlineAccuracyUpdatedEnsemble.ClassifierWithMemory newClassifier,
                           double newClassifiersWeight)

Adds a classifier to the storage.

Parameters:

newClassifier - The classifier to add.

newClassifiersWeight - The new classifiers weight.