Package es.uam.eps.ir.relison.sna.metrics.vertex

Class KatzCentrality<U>

java.lang.Object

es.uam.eps.ir.relison.sna.metrics.vertex.MatrixBasedVertexMetric<U>

es.uam.eps.ir.relison.sna.metrics.vertex.KatzCentrality<U>

All Implemented Interfaces:

VertexMetric<U>

public class KatzCentrality<U>
extends MatrixBasedVertexMetric<U>

Finds the Katz centrality of the nodes, which estimates the importance of a node considering the paths between the node and the rest of the network. Katz centrality of the nodes.

Reference: Katz, L. A new status index derived from sociometric analysis. Psychometrika 18(1), pp. 33-43 (1953)

Field Summary

Fields

Modifier and Type	Field	Description
private double	alpha	A dumping factor.
private EdgeOrientation	orient	The orientation of the paths.

Constructor Summary

Constructors

Constructor	Description
KatzCentrality(double alpha)	Constructor.
KatzCentrality(EdgeOrientation orient, double alpha)	Constructor.
KatzCentrality(MatrixLibrary library, double alpha)	Constructor.
KatzCentrality(MatrixLibrary library, EdgeOrientation orient, double alpha)	Constructor.

Method Summary

Modifier and Type	Method	Description
protected double[]	getCOLTScores(Graph<U> graph)	Obtains the values of the metric for the different users using the COLT library.
protected double[]	getJBLASScores(Graph<U> graph)	Obtains the values of the metric for the different users using the JBLAS library.
protected double[]	getMTJScores(Graph<U> graph)	Obtains the values of the metric for the different users using the MTJ library.

Methods inherited from class es.uam.eps.ir.relison.sna.metrics.vertex.MatrixBasedVertexMetric

compute, compute, compute, getScores

Methods inherited from class java.lang.Object

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

Methods inherited from interface es.uam.eps.ir.relison.sna.metrics.VertexMetric

averageValue, averageValue

Field Details

orient

private final EdgeOrientation orient

The orientation of the paths.

alpha

private final double alpha

A dumping factor.

Constructor Details

KatzCentrality

public KatzCentrality(MatrixLibrary library, EdgeOrientation orient, double alpha)

Constructor.

Parameters:

library - the matrix library to use.

orient - the orientation to choose for the adjacency matrix.

alpha - the dumping factor for paths at large distances.

KatzCentrality

public KatzCentrality(MatrixLibrary library, double alpha)

Constructor. By default, it considers the paths leading to the user.

Parameters:

library - the matrix library to use.

alpha - the dumping factor for paths at large distances.

KatzCentrality

public KatzCentrality(EdgeOrientation orient, double alpha)

Constructor. It uses the default matrix libraries.

Parameters:

orient - the orientation to choose for the adjacency matrix.

alpha - the dumping factor for paths at large distances.

KatzCentrality

public KatzCentrality(double alpha)

Constructor. It uses the default matrix libraries and considers the paths leading to the users.

Parameters:

alpha - the dumping factor for paths at large distances.

Method Details

getJBLASScores

protected double[] getJBLASScores(Graph<U> graph)

Description copied from class: MatrixBasedVertexMetric

Obtains the values of the metric for the different users using the JBLAS library.

Specified by:

getJBLASScores in class MatrixBasedVertexMetric<U>

Parameters:

graph - the network.

Returns:

an array containing the value of the metric for each user.

getMTJScores

protected double[] getMTJScores(Graph<U> graph)

Description copied from class: MatrixBasedVertexMetric

Obtains the values of the metric for the different users using the MTJ library.

Specified by:

getMTJScores in class MatrixBasedVertexMetric<U>

Parameters:

graph - the network.

Returns:

an array containing the value of the metric for each user.

getCOLTScores

protected double[] getCOLTScores(Graph<U> graph)

Description copied from class: MatrixBasedVertexMetric

Obtains the values of the metric for the different users using the COLT library.

Specified by:

getCOLTScores in class MatrixBasedVertexMetric<U>

Parameters:

graph - the network.

Returns:

an array containing the value of the metric for each user.