cc.mallet.cluster

Class GreedyAgglomerative

java.lang.Object

cc.mallet.cluster.Clusterer

cc.mallet.cluster.KBestClusterer

cc.mallet.cluster.HillClimbingClusterer

cc.mallet.cluster.GreedyAgglomerative

All Implemented Interfaces:

java.io.Serializable

Direct Known Subclasses:

GreedyAgglomerativeByDensity

public class GreedyAgglomerative
extends HillClimbingClusterer

Greedily merges Instances until convergence. New merges are scored using NeighborEvaluator.

Since:

1.0

See Also:

HillClimbingClusterer, Serialized Form

Constructor Summary

Constructors

Constructor and Description
GreedyAgglomerative(Pipe instancePipe, NeighborEvaluator evaluator, double stoppingThreshold)

Method Summary

Modifier and Type	Method and Description
boolean	converged(Clustering clustering)
Clustering	improveClustering(Clustering clustering) For each pair of clusters, calculate the score of the Neighbor that would result from merging the two clusters.
Clustering	initializeClustering(InstanceList instances)
void	reset() Reset convergence to false so a new round of clustering can begin.
java.lang.String	toString()

Methods inherited from class cc.mallet.cluster.HillClimbingClusterer

cluster, cluster, clusterKBest, clusterKBest, getEvaluator

Methods inherited from class cc.mallet.cluster.Clusterer

getPipe

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

GreedyAgglomerative

public GreedyAgglomerative(Pipe instancePipe,
                           NeighborEvaluator evaluator,
                           double stoppingThreshold)

Parameters:

instancePipe - Pipe for each underying Instance.

evaluator - To score potential merges.

stoppingThreshold - Clustering converges when the evaluator score is below this value.

Method Detail

initializeClustering

public Clustering initializeClustering(InstanceList instances)

Specified by:

initializeClustering in class HillClimbingClusterer

Parameters:

instances -

Returns:

A singleton clustering (each Instance in its own cluster).

converged

public boolean converged(Clustering clustering)

Specified by:

converged in class HillClimbingClusterer

Returns:

True if clustering is complete.

reset

public void reset()

Reset convergence to false so a new round of clustering can begin.

Specified by:

reset in class HillClimbingClusterer

improveClustering

public Clustering improveClustering(Clustering clustering)

For each pair of clusters, calculate the score of the Neighbor that would result from merging the two clusters. Choose the merge that obtains the highest score. If no merge improves score, return original Clustering

Specified by:

improveClustering in class HillClimbingClusterer

Parameters:

clustering -

Returns:

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object