edu.uci.ics.jung.algorithms.importance
Class RandomWalkSTBetweenness<V,E>

java.lang.Object
  edu.uci.ics.jung.algorithms.util.IterativeProcess
      edu.uci.ics.jung.algorithms.importance.AbstractRanker<V,E>
          edu.uci.ics.jung.algorithms.importance.RandomWalkSTBetweenness<V,E>

All Implemented Interfaces:

IterativeContext

Direct Known Subclasses:

RandomWalkBetweenness

public class RandomWalkSTBetweenness<V,E>
extends AbstractRanker<V,E>

/** Computes s-t betweenness centrality for each vertex in the graph. The betweenness values in this case are based on random walks, measuring the expected number of times a node is traversed by a random walk from s to t. The result is that each vertex has a UserData element of type MutableDouble whose key is 'centrality.RandomWalkBetweennessCentrality' A simple example of usage is:
RandomWalkSTBetweenness ranker = new RandomWalkBetweenness(someGraph,someSource,someTarget);
ranker.evaluate();
ranker.printRankings();

Running time is: O(n^3).

Author:

Scott White

See Also:

"Mark Newman: A measure of betweenness centrality based on random walks, 2002."

Field Summary

static String

CENTRALITY

Fields inherited from class edu.uci.ics.jung.algorithms.importance.AbstractRanker

edgeRankScores, vertexRankScores

Constructor Summary

RandomWalkSTBetweenness(UndirectedGraph<V,E> g, V s, V t)
Constructor which initializes the algorithm

Method Summary

protected void	computeBetweenness()
double	computeSTBetweenness(V ithVertex, V source, V target)
protected org.apache.commons.collections15.BidiMap<V,Integer>	getIndexer()
String	getRankScoreKey() the user datum key used to store the rank scores
protected cern.colt.matrix.DoubleMatrix2D	getVoltageMatrix()
protected void	setUp()
void	step() Evaluate the result of the current iteration.

Methods inherited from class edu.uci.ics.jung.algorithms.importance.AbstractRanker

assignDefaultEdgeTransitionWeights, finalizeIterations, getEdgeRankScore, getEdgeRankScore, getEdgeRankScores, getEdgeRankScores, getEdgeWeight, getEdgeWeights, getGraph, getRankings, getRankScores, getVertexCount, getVertexRankScore, getVertexRankScore, getVertexRankScores, getVertexRankScores, getVertices, initialize, isRankingEdges, isRankingNodes, normalizeEdgeTransitionWeights, normalizeRankings, onFinalize, printRankings, removeEdgeRankScore, removeEdgeRankScore, removeVertexRankScore, removeVertexRankScore, reset, setEdgeRankScore, setEdgeRankScore, setEdgeWeight, setEdgeWeights, setNormalizeRankings, setRemoveRankScoresOnFinalize, setVertexRankScore, setVertexRankScore

Methods inherited from class edu.uci.ics.jung.algorithms.util.IterativeProcess

done, evaluate, getDesiredPrecision, getIterations, getMaximumIterations, getPrecision, hasConverged, initializeIterations, relativePrecision, setDesiredPrecision, setMaximumIterations, setPrecision

Methods inherited from class java.lang.Object

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

Field Detail

CENTRALITY

public static final String CENTRALITY

See Also:

Constant Field Values

Constructor Detail

RandomWalkSTBetweenness

public RandomWalkSTBetweenness(UndirectedGraph<V,E> g,
                               V s,
                               V t)

Constructor which initializes the algorithm

Parameters:

g - the graph whose nodes are to be analyzed

s - the source vertex

t - the target vertex

Method Detail

getIndexer

protected org.apache.commons.collections15.BidiMap<V,Integer> getIndexer()

getVoltageMatrix

protected cern.colt.matrix.DoubleMatrix2D getVoltageMatrix()

setUp

protected void setUp()

computeBetweenness

protected void computeBetweenness()

computeSTBetweenness

public double computeSTBetweenness(V ithVertex,
                                   V source,
                                   V target)

getRankScoreKey

public String getRankScoreKey()

the user datum key used to store the rank scores

Specified by:

getRankScoreKey in class AbstractRanker<V,E>

Returns:

the key

step

public void step()

Description copied from class: IterativeProcess

Evaluate the result of the current iteration.

Specified by:

step in interface IterativeContext

Specified by:

step in class IterativeProcess