nl.cwts.networkanalysis

Class StandardLocalMovingAlgorithm

java.lang.Object

nl.cwts.networkanalysis.CPMClusteringAlgorithm

nl.cwts.networkanalysis.IncrementalCPMClusteringAlgorithm

nl.cwts.networkanalysis.StandardLocalMovingAlgorithm

All Implemented Interfaces:

java.lang.Cloneable, ClusteringAlgorithm, IncrementalClusteringAlgorithm, QualityClusteringAlgorithm

public class StandardLocalMovingAlgorithm
extends IncrementalCPMClusteringAlgorithm

Standard local moving algorithm.

The standard local moving algorithm iterates over the nodes in a network. A node is moved to the cluster that results in the largest increase in the quality function. If the current cluster assignment of the node is already optimal, the node is not moved. The algorithm continues iterating over the nodes in a network until no more nodes can be moved.

A fast variant of the standard local moving algorithm is provided by the FastLocalMovingAlgorithm.

Field Summary

Fields

Modifier and Type	Field and Description
protected java.util.Random	random Random number generator.

Fields inherited from class nl.cwts.networkanalysis.CPMClusteringAlgorithm

DEFAULT_RESOLUTION, resolution

Constructor Summary

Constructors

Constructor and Description
StandardLocalMovingAlgorithm() Constructs a standard local moving algorithm.
StandardLocalMovingAlgorithm(double resolution, java.util.Random random) Constructs a standard local moving algorithm for a specified resolution parameter.
StandardLocalMovingAlgorithm(java.util.Random random) Constructs a standard local moving algorithm.

Method Summary

Modifier and Type	Method and Description
boolean	improveClustering(Network network, Clustering clustering) Improves a clustering of the nodes in a network using the standard local moving algorithm.

Methods inherited from class nl.cwts.networkanalysis.IncrementalCPMClusteringAlgorithm

findClustering

Methods inherited from class nl.cwts.networkanalysis.CPMClusteringAlgorithm

calcQuality, clone, getResolution, removeCluster, removeSmallClustersBasedOnNNodes, removeSmallClustersBasedOnWeight, setResolution

Methods inherited from class java.lang.Object

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

Field Detail

random

protected java.util.Random random

Random number generator.

Constructor Detail

StandardLocalMovingAlgorithm

public StandardLocalMovingAlgorithm()

Constructs a standard local moving algorithm.

StandardLocalMovingAlgorithm

public StandardLocalMovingAlgorithm(java.util.Random random)

Constructs a standard local moving algorithm.

Parameters:

random - Random number generator

StandardLocalMovingAlgorithm

public StandardLocalMovingAlgorithm(double resolution,
                                    java.util.Random random)

Constructs a standard local moving algorithm for a specified resolution parameter.

Parameters:

resolution - Resolution parameter

random - Random number generator

Method Detail

improveClustering

public boolean improveClustering(Network network,
                                 Clustering clustering)

Improves a clustering of the nodes in a network using the standard local moving algorithm.

The standard local moving algorithm iterates over the nodes in a network. A node is moved to the cluster that results in the largest increase in the quality function. If the current cluster assignment of the node is already optimal, the node is not moved. The algorithm continues iterating over the nodes in a network until no more nodes can be moved.

Parameters:

network - Network

clustering - Clustering

Returns:

Boolean indicating whether the clustering has been improved