org.javanetworkanalyzer.alg
Class DijkstraForCentrality<E extends EdgeSPT>

java.lang.Object
  org.javanetworkanalyzer.alg.GraphSearchAlgorithm<V,E>
      org.javanetworkanalyzer.alg.Dijkstra<VWCent,E>
          org.javanetworkanalyzer.alg.DijkstraForCentrality<E>

All Implemented Interfaces:

CentralityAlg<VWCent,E,WeightedPathLengthData>, TraversalAlg<VWCent,E>

public class DijkstraForCentrality<E extends EdgeSPT>
extends Dijkstra<VWCent,E>
implements CentralityAlg<VWCent,E,WeightedPathLengthData>

An implementation of Dijkstra's algorithm which can be used to calculate betweenness and closeness in a GraphAnalyzer.

Author:

Adam Gouge

Field Summary

Fields inherited from class org.javanetworkanalyzer.alg.Dijkstra

TOLERANCE

Fields inherited from class org.javanetworkanalyzer.alg.GraphSearchAlgorithm

currentStartNode, graph

Constructor Summary

DijkstraForCentrality(org.jgrapht.Graph<VWCent,E> graph, Stack<VWCent> stack)
Constructs a new DijkstraForCentrality object.

Method Summary

WeightedPathLengthData	getPaths() Returns the path length data.
protected void	init(VWCent startNode) Performs any initializations to be done at the start of the TraversalAlg.calculate(V) method.
protected void	multipleShortestPathUpdate(VWCent u, VWCent v, E e) Updates to be performed if the path to v through u is a new multiple shortest path.
protected boolean	preRelaxStep(VWCent startNode, VWCent u) Before relaxing the outgoing edges of u, we push it to the stack and record its shortest path length.
protected void	shortestPathSoFarUpdate(VWCent startNode, VWCent u, VWCent v, Double uvWeight, E e, PriorityQueue<VWCent> queue) Updates to be performed if the path to v through u is the shortest path to v found so far.

Methods inherited from class org.javanetworkanalyzer.alg.Dijkstra

calculate, calculate, manyToMany, manyToOne, oneToMany, oneToOne, reconstructTraversalGraph, relax

Methods inherited from class org.javanetworkanalyzer.alg.GraphSearchAlgorithm

outdegree, outgoingEdgesOf, outgoingEdgesOf, reconstructTraversalGraph, successorListOf

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.javanetworkanalyzer.alg.TraversalAlg

calculate, reconstructTraversalGraph

Constructor Detail

DijkstraForCentrality

public DijkstraForCentrality(org.jgrapht.Graph<VWCent,E> graph,
                             Stack<VWCent> stack)

Constructs a new DijkstraForCentrality object.

Parameters:

graph - The graph.

stack - The stack which will return nodes ordered by non-increasing distance from startNode.

Method Detail

init

protected void init(VWCent startNode)

Description copied from class: GraphSearchAlgorithm

Performs any initializations to be done at the start of the TraversalAlg.calculate(V) method.

Overrides:

init in class Dijkstra<VWCent,E extends EdgeSPT>

Parameters:

startNode - Start node

preRelaxStep

protected boolean preRelaxStep(VWCent startNode,
                               VWCent u)

Before relaxing the outgoing edges of u, we push it to the stack and record its shortest path length.

Overrides:

preRelaxStep in class Dijkstra<VWCent,E extends EdgeSPT>

Parameters:

u - Vertex u.

Returns:

true if we should stop the Dijkstra search.

shortestPathSoFarUpdate

protected void shortestPathSoFarUpdate(VWCent startNode,
                                       VWCent u,
                                       VWCent v,
                                       Double uvWeight,
                                       E e,
                                       PriorityQueue<VWCent> queue)

Description copied from class: Dijkstra

Updates to be performed if the path to v through u is the shortest path to v found so far.

Overrides:

shortestPathSoFarUpdate in class Dijkstra<VWCent,E extends EdgeSPT>

u - Vertex u

v - Vertex v

uvWeight - w(u,v)

e - Edge e

queue - Queue

multipleShortestPathUpdate

protected void multipleShortestPathUpdate(VWCent u,
                                          VWCent v,
                                          E e)

Description copied from class: Dijkstra

Updates to be performed if the path to v through u is a new multiple shortest path. There is no need to set the distance on v since this is a multiple shortest path.

Overrides:

multipleShortestPathUpdate in class Dijkstra<VWCent,E extends EdgeSPT>

Parameters:

u - Vertex u

v - Vertex v

e - Edge e

getPaths

public WeightedPathLengthData getPaths()

Description copied from interface: CentralityAlg

Returns the path length data.

Specified by:

getPaths in interface CentralityAlg<VWCent,E extends EdgeSPT,WeightedPathLengthData>

Returns:

The path length data