de.lmu.ifi.dbs.elki.algorithm.classification

Class PriorProbabilityClassifier

java.lang.Object

de.lmu.ifi.dbs.elki.algorithm.AbstractAlgorithm<R>

de.lmu.ifi.dbs.elki.algorithm.classification.AbstractClassifier<Object,Result>

de.lmu.ifi.dbs.elki.algorithm.classification.PriorProbabilityClassifier

All Implemented Interfaces:

Algorithm, Classifier<Object>

@Title(value="Prior Probability Classifier")
@Description(value="Classifier to predict simply prior probabilities for all classes as defined by their relative abundance in a given database.")
public class PriorProbabilityClassifier
extends AbstractClassifier<Object,Result>

Classifier to classify instances based on the prior probability of classes in the database, without using the actual data values.

Author:

Arthur Zimek

Field Summary

Fields

Modifier and Type	Field and Description
protected double[]	distribution Holds the prior probabilities.
protected ArrayList<ClassLabel>	labels Class labels seen.
private static Logging	LOG The logger for this class.
protected ClassLabel	prediction Index of the most abundant class.

Constructor Summary

Constructors

Constructor and Description
PriorProbabilityClassifier() Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	buildClassifier(Database database, Relation<? extends ClassLabel> labelrep) Learns the prior probability for all classes.
ClassLabel	classify(Object instance) Classify a single instance.
double[]	classProbabilities(Object instance, ArrayList<ClassLabel> labels)
TypeInformation[]	getInputTypeRestriction() Get the input type restriction used for negotiating the data query.
protected Logging	getLogger() Get the (STATIC) logger for this class.
String	model() Produce a String representation of the classification model.

Methods inherited from class de.lmu.ifi.dbs.elki.algorithm.classification.AbstractClassifier

alignLabels, run

Methods inherited from class de.lmu.ifi.dbs.elki.algorithm.AbstractAlgorithm

makeParameterDistanceFunction

Methods inherited from class java.lang.Object

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

Field Detail

LOG

private static final Logging LOG

The logger for this class.

distribution

protected double[] distribution

Holds the prior probabilities.

prediction

protected ClassLabel prediction

Index of the most abundant class.

labels

protected ArrayList<ClassLabel> labels

Class labels seen.

Constructor Detail

PriorProbabilityClassifier

public PriorProbabilityClassifier()

Constructor.

Method Detail

buildClassifier

public void buildClassifier(Database database,
                   Relation<? extends ClassLabel> labelrep)

Learns the prior probability for all classes.

Parameters:

database - the database to build the model on

labelrep - the classes to be learned

classProbabilities

public double[] classProbabilities(Object instance,
                          ArrayList<ClassLabel> labels)

classify

public ClassLabel classify(Object instance)

Description copied from interface: Classifier

Classify a single instance.

Parameters:

instance - an instance to classify

Returns:

predicted class label of the given instance

model

public String model()

Description copied from interface: Classifier

Produce a String representation of the classification model.

Returns:

a String representation of the classification model

getInputTypeRestriction

public TypeInformation[] getInputTypeRestriction()

Description copied from class: AbstractAlgorithm

Get the input type restriction used for negotiating the data query.

Specified by:

getInputTypeRestriction in interface Algorithm

Specified by:

getInputTypeRestriction in class AbstractAlgorithm<Result>

Returns:

Type restriction

getLogger

protected Logging getLogger()

Description copied from class: AbstractAlgorithm

Get the (STATIC) logger for this class.

Specified by:

getLogger in class AbstractAlgorithm<Result>

Returns:

the static logger