nl.cwts.networkanalysis

Class LouvainAlgorithm

java.lang.Object

nl.cwts.networkanalysis.CPMClusteringAlgorithm

nl.cwts.networkanalysis.IncrementalCPMClusteringAlgorithm

nl.cwts.networkanalysis.IterativeCPMClusteringAlgorithm

nl.cwts.networkanalysis.LouvainAlgorithm

All Implemented Interfaces:

java.lang.Cloneable, ClusteringAlgorithm, IncrementalClusteringAlgorithm, QualityClusteringAlgorithm

public class LouvainAlgorithm
extends IterativeCPMClusteringAlgorithm

Louvain algorithm.

The Louvain algorithm consists of two phases:

1. local moving of nodes between clusters,
2. aggregation of the network based on the clusters.

These phases are repeated until no further improvements can be made. By default, local moving of nodes is performed using the StandardLocalMovingAlgorithm.

Field Summary

Fields

Modifier and Type	Field and Description
protected IncrementalCPMClusteringAlgorithm	localMovingAlgorithm Local moving algorithm.

Fields inherited from class nl.cwts.networkanalysis.IterativeCPMClusteringAlgorithm

DEFAULT_N_ITERATIONS, nIterations

Fields inherited from class nl.cwts.networkanalysis.CPMClusteringAlgorithm

DEFAULT_RESOLUTION, resolution

Constructor Summary

Constructors

Constructor and Description
LouvainAlgorithm() Constructs a Louvain algorithm.
LouvainAlgorithm(double resolution, int nIterations, IncrementalCPMClusteringAlgorithm localMovingAlgorithm) Constructs a Louvain algorithm for a specified resolution parameter, number of iterations, and local moving algorithm.
LouvainAlgorithm(double resolution, int nIterations, java.util.Random random) Constructs a Louvain algorithm for a specified resolution parameter and number of iterations.
LouvainAlgorithm(java.util.Random random) Constructs a Louvain algorithm.

Method Summary

Modifier and Type	Method and Description
LouvainAlgorithm	clone() Clones the algorithm.
IncrementalCPMClusteringAlgorithm	getLocalMovingAlgorithm() Returns the local moving algorithm.
protected boolean	improveClusteringOneIteration(Network network, Clustering clustering) Improves a clustering by performing one iteration of the Louvain algorithm.
void	setLocalMovingAlgorithm(IncrementalCPMClusteringAlgorithm localMovingAlgorithm) Sets the local moving algorithm.
void	setResolution(double resolution) Sets the resolution parameter.

Methods inherited from class nl.cwts.networkanalysis.IterativeCPMClusteringAlgorithm

getNIterations, improveClustering, setNIterations

Methods inherited from class nl.cwts.networkanalysis.IncrementalCPMClusteringAlgorithm

findClustering

Methods inherited from class nl.cwts.networkanalysis.CPMClusteringAlgorithm

calcQuality, getResolution, removeCluster, removeSmallClustersBasedOnNNodes, removeSmallClustersBasedOnWeight

Methods inherited from class java.lang.Object

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

Field Detail

localMovingAlgorithm

protected IncrementalCPMClusteringAlgorithm localMovingAlgorithm

Local moving algorithm.

Constructor Detail

LouvainAlgorithm

public LouvainAlgorithm()

Constructs a Louvain algorithm.

LouvainAlgorithm

public LouvainAlgorithm(java.util.Random random)

Constructs a Louvain algorithm.

Parameters:

random - Random number generator

LouvainAlgorithm

public LouvainAlgorithm(double resolution,
                        int nIterations,
                        java.util.Random random)

Constructs a Louvain algorithm for a specified resolution parameter and number of iterations.

Parameters:

resolution - Resolution parameter

nIterations - Number of iterations

random - Random number generator

LouvainAlgorithm

public LouvainAlgorithm(double resolution,
                        int nIterations,
                        IncrementalCPMClusteringAlgorithm localMovingAlgorithm)

Constructs a Louvain algorithm for a specified resolution parameter, number of iterations, and local moving algorithm.

Parameters:

resolution - Resolution parameter

nIterations - Number of iterations

localMovingAlgorithm - Local moving algorithm

Method Detail

clone

public LouvainAlgorithm clone()

Clones the algorithm.

Overrides:

clone in class CPMClusteringAlgorithm

Returns:

Cloned algorithm

getLocalMovingAlgorithm

public IncrementalCPMClusteringAlgorithm getLocalMovingAlgorithm()

Returns the local moving algorithm.

Returns:

Local moving algorithm

setResolution

public void setResolution(double resolution)

Sets the resolution parameter. Also sets the resolution parameter for the local moving algorithm.

Overrides:

setResolution in class CPMClusteringAlgorithm

Parameters:

resolution - Resolution parameter

setLocalMovingAlgorithm

public void setLocalMovingAlgorithm(IncrementalCPMClusteringAlgorithm localMovingAlgorithm)

Sets the local moving algorithm.

Parameters:

localMovingAlgorithm - Local moving algorithm

improveClusteringOneIteration

protected boolean improveClusteringOneIteration(Network network,
                                                Clustering clustering)

Improves a clustering by performing one iteration of the Louvain algorithm.

The Louvain algorithm consists of two phases:

1. local moving of nodes between clusters,
2. aggregation of the network based on the clusters.

These phases are repeated until no further improvements can be made.

Specified by:

improveClusteringOneIteration in class IterativeCPMClusteringAlgorithm

Parameters:

network - Network

clustering - Clustering

Returns:

Boolean indicating whether the clustering has been improved