weka.clusterers

Interface DensityBasedClusterer

All Superinterfaces:

Clusterer

All Known Implementing Classes:

AbstractDensityBasedClusterer, EM, MakeDensityBasedClusterer, RandomizableDensityBasedClusterer

public interface DensityBasedClusterer
extends Clusterer

Interface for clusterers that can estimate the density for a given instance. Implementations will typically extend AbstractDensityBasedClusterer.

Version:

$Revision: 1.9 $

Author:

Mark Hall ([email protected]), Eibe Frank ([email protected])

Method Summary

Methods

Modifier and Type	Method and Description
double[]	clusterPriors() Returns the prior probability of each cluster.
double[]	distributionForInstance(Instance instance) Returns the cluster probability distribution for an instance.
double	logDensityForInstance(Instance instance) Computes the density for a given instance.
double[]	logDensityPerClusterForInstance(Instance instance) Computes the log of the conditional density (per cluster) for a given instance.
double[]	logJointDensitiesForInstance(Instance inst) Returns the logs of the joint densities for a given instance.

Methods inherited from interface weka.clusterers.Clusterer

buildClusterer, clusterInstance, getCapabilities, numberOfClusters

Method Detail

clusterPriors

double[] clusterPriors()
                       throws Exception

Returns the prior probability of each cluster.

Returns:

the prior probability for each cluster

Throws:

Exception - if priors could not be returned successfully

logDensityPerClusterForInstance

double[] logDensityPerClusterForInstance(Instance instance)
                                         throws Exception

Computes the log of the conditional density (per cluster) for a given instance.

Parameters:

instance - the instance to compute the density for

Returns:

an array containing the estimated densities

Throws:

Exception - if the density could not be computed successfully

logDensityForInstance

double logDensityForInstance(Instance instance)
                             throws Exception

Computes the density for a given instance.

Parameters:

instance - the instance to compute the density for

Returns:

the density.

Throws:

Exception - if the density could not be computed successfully

logJointDensitiesForInstance

double[] logJointDensitiesForInstance(Instance inst)
                                      throws Exception

Returns the logs of the joint densities for a given instance.

Parameters:

inst - the instance

Returns:

the array of values

Throws:

Exception - if values could not be computed

distributionForInstance

double[] distributionForInstance(Instance instance)
                                 throws Exception

Returns the cluster probability distribution for an instance.

Specified by:

distributionForInstance in interface Clusterer

Parameters:

instance - the instance to be clustered

Returns:

the probability distribution

Throws:

Exception - if computation fails