private WeightedMultigraph<Vertex, LabeledWeightedEdge> step1() {
logger.debug("<enter");
WeightedMultigraph<Vertex, LabeledWeightedEdge> g =
new WeightedMultigraph<Vertex, LabeledWeightedEdge>(LabeledWeightedEdge.class);
for (int i = 0; i < steinerNodes.size(); i++) {
g.addVertex(steinerNodes.get(i));
}
BellmanFordShortestPath<Vertex, LabeledWeightedEdge> path;
for (int i = 0; i < steinerNodes.size(); i++) {
path =
new BellmanFordShortestPath<Vertex, LabeledWeightedEdge>(this.graph, steinerNodes.get(i));
for (int j = 0; j < steinerNodes.size(); j++) {
if (i == j) continue;
if (g.containsEdge(steinerNodes.get(i), steinerNodes.get(j))) continue;
String id = "e" + String.valueOf(i) + String.valueOf(j);
LabeledWeightedEdge e = new LabeledWeightedEdge(id, new URI(id, null, null), null);
g.addEdge(steinerNodes.get(i), steinerNodes.get(j), e);
g.setEdgeWeight(e, path.getCost(steinerNodes.get(j)));
}
}
logger.debug("exit>");
return g;
}
public EdgeBetweennessGraph(WeightedMultigraph<String, DefaultWeightedEdge> originalGraph) {
super(DefaultWeightedEdge.class); // Constructor inherented from parent class
// 1. Initialize the edge betweenness digraph
// 1.1. Add vertices
for (String thisVertex : originalGraph.vertexSet()) this.addVertex(thisVertex);
// 1.2. Add edges
for (DefaultWeightedEdge thisEdge : originalGraph.edgeSet()) {
DefaultWeightedEdge newEdge = new DefaultWeightedEdge();
String sendingName = originalGraph.getEdgeSource(thisEdge);
String receivingName = originalGraph.getEdgeTarget(thisEdge);
this.addEdge(sendingName, receivingName, newEdge);
this.setEdgeWeight(newEdge, 0.0);
}
// 1.3. Create corresponding unweighted graph
// 1.3.1. Add vertices
WeightedMultigraph<String, DefaultWeightedEdge> originalUnweightedGraph =
new WeightedMultigraph<String, DefaultWeightedEdge>(DefaultWeightedEdge.class);
for (String thisVertex : originalGraph.vertexSet())
originalUnweightedGraph.addVertex(thisVertex);
// 1.3.2. Add edges
for (DefaultWeightedEdge thisEdge : originalGraph.edgeSet()) {
DefaultWeightedEdge newEdge = new DefaultWeightedEdge();
String sendingName = originalGraph.getEdgeSource(thisEdge);
String receivingName = originalGraph.getEdgeTarget(thisEdge);
originalUnweightedGraph.addEdge(sendingName, receivingName, newEdge);
originalUnweightedGraph.setEdgeWeight(newEdge, 1.0);
}
for (String thisVertex : this.vertexSet()) {
// 2. Create shortest-path graph for every vertex by Dijkstra algorithm
Multigraph<String, DefaultEdge> shortestPathDigraph =
DijkstraAlgorithm(originalUnweightedGraph, thisVertex);
// 3. Calculate the contribution of current vertex's shortest-path graph to final edge
// betweenness (Newman algorithm)
SimpleWeightedGraph<String, DefaultWeightedEdge> edgeBetweennessDigraph =
NewmanAlgorithm(shortestPathDigraph, thisVertex);
// 4. Update final edge betweenness digraph with current vertex's shortest-path graph
if (edgeBetweennessDigraph != null)
for (DefaultWeightedEdge thisEdge : edgeBetweennessDigraph.edgeSet()) {
String sourceVertex = edgeBetweennessDigraph.getEdgeSource(thisEdge);
String targetVertex = edgeBetweennessDigraph.getEdgeTarget(thisEdge);
double betweennessWeight = edgeBetweennessDigraph.getEdgeWeight(thisEdge);
DefaultWeightedEdge edgeInWholeGraph = this.getEdge(sourceVertex, targetVertex);
double newWeight = this.getEdgeWeight(edgeInWholeGraph) + betweennessWeight;
this.setEdgeWeight(edgeInWholeGraph, newWeight);
}
}
// 5. Revise the edge betweenness digraph with the original active power digraph
for (DefaultWeightedEdge thisEdge : this.edgeSet()) {
String sourceVertex = this.getEdgeSource(thisEdge);
String targetVertex = this.getEdgeTarget(thisEdge);
double betweennessWeight = this.getEdgeWeight(thisEdge);
DefaultWeightedEdge edgeInWholeGraph = originalGraph.getEdge(sourceVertex, targetVertex);
double newWeight = betweennessWeight / originalGraph.getEdgeWeight(edgeInWholeGraph);
this.setEdgeWeight(thisEdge, newWeight);
// System.out.println("Final edge betweenness between " + sourceVertex + " and " +
// targetVertex + ": " + newWeight);
}
}
