weka.clusterers
Class DistributionClusterer

java.lang.Object
  |
  +--weka.clusterers.Clusterer
        |
        +--weka.clusterers.DistributionClusterer

All Implemented Interfaces:

java.lang.Cloneable, java.io.Serializable

Direct Known Subclasses:

DistributionMetaClusterer, EM

public abstract class DistributionClusterer

extends Clusterer

Abstract clustering model that produces (for each test instance) an estimate of the membership in each cluster (ie. a probability distribution).

Author:

Mark Hall (mhall@cs.waikato.ac.nz)

See Also:

Serialized Form

Constructor Summary

DistributionClusterer()

Method Summary

int	clusterInstance(Instance instance) Assigns an instance to a Cluster.
abstract double	densityForInstance(Instance instance) Computes the density for a given instance.
abstract double[]	distributionForInstance(Instance instance) Predicts the cluster memberships for a given instance.

Methods inherited from class weka.clusterers.Clusterer

buildClusterer, forName, makeCopies, numberOfClusters

Methods inherited from class java.lang.Object

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

Constructor Detail

DistributionClusterer

public DistributionClusterer()

Method Detail

densityForInstance

public abstract double densityForInstance(Instance instance)
                                   throws java.lang.Exception

Computes the density for a given instance.

Parameters:

instance - the instance to compute the density for

Returns:

the density.

Throws:

java.lang.Exception - if the density could not be computed successfully

distributionForInstance

public abstract double[] distributionForInstance(Instance instance)
                                          throws java.lang.Exception

Predicts the cluster memberships for a given instance.

Parameters:

instance - the instance to be assigned a cluster.

Returns:

an array containing the estimated membership probabilities of the test instance in each cluster (this should sum to at most 1)

Throws:

java.lang.Exception - if distribution could not be computed successfully

clusterInstance

public int clusterInstance(Instance instance)
                    throws java.lang.Exception

Assigns an instance to a Cluster.

Overrides:

clusterInstance in class Clusterer

Parameters:

instance - the instance to be classified

Returns:

the predicted most likely cluster for the instance.

Throws:

java.lang.Exception - if an error occurred during the prediction