// Create shortest-path graph for every vertex by depth-first traversal algorithm
  private Multigraph<String, DefaultEdge> DijkstraAlgorithm(
      WeightedMultigraph<String, DefaultWeightedEdge> originalGraph, String thisVertex) {

    // 1. Simplify the multi-graph of the active power flow into a simple graph
    SimpleWeightedGraph<String, DefaultWeightedEdge> originalSimpleGraph =
        new SimpleWeightedGraph<String, DefaultWeightedEdge>(DefaultWeightedEdge.class);
    for (String curVertex : originalGraph.vertexSet()) originalSimpleGraph.addVertex(curVertex);
    for (DefaultWeightedEdge curEdge : originalGraph.edgeSet()) {
      String sourceVertex = originalGraph.getEdgeSource(curEdge);
      String targetVertex = originalGraph.getEdgeTarget(curEdge);
      if (originalSimpleGraph.containsEdge(sourceVertex, targetVertex)) {
        DefaultWeightedEdge modifiedEdge = originalSimpleGraph.getEdge(sourceVertex, targetVertex);
        double newEdgeWeight =
            originalSimpleGraph.getEdgeWeight(modifiedEdge) + originalGraph.getEdgeWeight(curEdge);
        originalSimpleGraph.setEdgeWeight(modifiedEdge, newEdgeWeight);
      } else {
        DefaultWeightedEdge newEdge = new DefaultWeightedEdge();
        originalSimpleGraph.addEdge(sourceVertex, targetVertex, newEdge);
        originalSimpleGraph.setEdgeWeight(newEdge, originalGraph.getEdgeWeight(curEdge));
      }
    }
    // Issue (2010/10/25): Maybe larger amount of active power transfer still means weaker
    // relationship between the two terminal buses of a certain branch,
    // thus originalSimpleGraph other than inverseGraph should be used here.
    // Use the inverse of active power to build a new weighted directed graph (the larger the active
    // power is, the close the two buses will be)
    //		SimpleDirectedWeightedGraph<String, DefaultWeightedEdge> inverseGraph =
    //			new SimpleDirectedWeightedGraph<String, DefaultWeightedEdge>(DefaultWeightedEdge.class);
    //		for (String curVertex : originalSimpleGraph.vertexSet())
    //			inverseGraph.addVertex(curVertex);
    //		for (DefaultWeightedEdge curEdge : originalSimpleGraph.edgeSet()) {
    //			String sourceVertex = originalSimpleGraph.getEdgeSource(curEdge);
    //			String targetVertex = originalSimpleGraph.getEdgeTarget(curEdge);
    //			DefaultWeightedEdge newEdge = new DefaultWeightedEdge();
    //			inverseGraph.addEdge(sourceVertex, targetVertex, newEdge);
    //			inverseGraph.setEdgeWeight(newEdge, 1 / originalSimpleGraph.getEdgeWeight(curEdge));
    //		}
    // 2. Initialize the map of vertices and the corresponding weights (distance from current vertex
    // to the first vertex)
    HashMap<String, Double> mapVertexShortestDistance = new HashMap<String, Double>();
    //		for (String thisOriginalVertex : inverseGraph.vertexSet())
    for (String thisOriginalVertex : originalSimpleGraph.vertexSet())
      mapVertexShortestDistance.put(thisOriginalVertex, 10E10);
    // The weight of the first vertex is zero
    mapVertexShortestDistance.put(thisVertex, 0.0);

    // 3. Depth-first traversing, update the shortest-path values
    Stack<String> bfiVertices =
        new Stack<String>(); // Stack to store passed vertices in a breadth-first traversing
    // The map of a weighted edge and the flag of having been visited
    //		HashMap<DefaultWeightedEdge, Boolean> mapEdgeVisited = new HashMap<DefaultWeightedEdge,
    // Boolean>();
    //		for (DefaultWeightedEdge thisEdge : inverseGraph.edgeSet())
    //			mapEdgeVisited.put(thisEdge, false);
    String currentVertex = thisVertex;
    bfiVertices.push(currentVertex);
    //		System.out.println(bfiVertices.toString());
    while (!bfiVertices.isEmpty()) {
      // Operate the following codes for those edges started with current vertex
      boolean hasNewEdge = false;
      //			for (DefaultWeightedEdge curEdge : inverseGraph.outgoingEdgesOf(currentVertex)) {
      for (DefaultWeightedEdge curEdge : originalSimpleGraph.edgesOf(currentVertex)) {
        //				if (!mapEdgeVisited.get(curEdge)) {	// Used for those edges that have not been treated
        // yet
        // 3.1. Mark current edge as already been visited
        //					mapEdgeVisited.put(curEdge, true);
        //				String nextVertex = inverseGraph.getEdgeTarget(curEdge);
        String nextVertex = originalSimpleGraph.getEdgeTarget(curEdge);
        // 3.2. Update shortest-path values
        double curSD = mapVertexShortestDistance.get(currentVertex);
        //					double edgeWeight = inverseGraph.getEdgeWeight(curEdge);
        double edgeWeight = originalSimpleGraph.getEdgeWeight(curEdge);
        double newSD = curSD + edgeWeight;
        if (mapVertexShortestDistance.get(nextVertex) > newSD) {
          hasNewEdge = true;
          mapVertexShortestDistance.put(nextVertex, newSD);
          // 3.3. Push the target vertex of current edge into the stack
          bfiVertices.push(nextVertex);
          //						System.out.println(bfiVertices.toString());
          break;
          //						System.out.println("New shortest path [" + nextVertex + "]: " + newSD);
        }
        //				}
      }
      if (!hasNewEdge) {
        bfiVertices.pop();
      }
      if (!bfiVertices.isEmpty()) currentVertex = bfiVertices.peek();
    }
    // 4. Create shortest-path digraph of current vertex
    // 4.1. Initialize the shortest-path digraph
    Multigraph<String, DefaultEdge> shortestPathGraph =
        new Multigraph<String, DefaultEdge>(DefaultEdge.class);
    // 4.2. Add all qualified edges
    //		for (DefaultWeightedEdge curEdge : inverseGraph.edgeSet()) {
    for (DefaultWeightedEdge curEdge : originalSimpleGraph.edgeSet()) {
      // 4.2.1. Evaluate if current edge is suitable
      //			String sourceVertex = inverseGraph.getEdgeSource(curEdge);
      //			String targetVertex = inverseGraph.getEdgeTarget(curEdge);
      String sourceVertex = originalSimpleGraph.getEdgeSource(curEdge);
      String targetVertex = originalSimpleGraph.getEdgeTarget(curEdge);
      //			if (Math.abs(inverseGraph.getEdgeWeight(curEdge) -
      if (originalSimpleGraph.getEdgeWeight(curEdge) > 1.0E-5) {
        if (Math.abs(
                originalSimpleGraph.getEdgeWeight(curEdge)
                    - (mapVertexShortestDistance.get(targetVertex)
                        - mapVertexShortestDistance.get(sourceVertex)))
            < 1.0E-5) {
          // 4.2.2. Add suitable edge that found just now
          DefaultEdge newEdge = new DefaultEdge();
          if (!shortestPathGraph.containsVertex(sourceVertex))
            shortestPathGraph.addVertex(sourceVertex);
          if (!shortestPathGraph.containsVertex(targetVertex))
            shortestPathGraph.addVertex(targetVertex);
          shortestPathGraph.addEdge(sourceVertex, targetVertex, newEdge);
        }
      }
    }
    return shortestPathGraph;
  }
  /**
   * Tests graph types: In case of invalid graph types or invalid combination of graph arguments
   * UnsupportedOperationException or InvalidArgumentException is expected
   */
  @Test
  public void testGraphTypes() {

    DirectedGraph<Integer, DefaultEdge> dg1 = new DefaultDirectedGraph<>(DefaultEdge.class);

    dg1.addVertex(1);
    dg1.addVertex(2);

    dg1.addEdge(1, 2);

    SimpleGraph<Integer, DefaultEdge> sg1 = new SimpleGraph<>(DefaultEdge.class);

    sg1.addVertex(1);
    sg1.addVertex(2);

    sg1.addEdge(1, 2);

    Multigraph<Integer, DefaultEdge> mg1 = new Multigraph<>(DefaultEdge.class);

    mg1.addVertex(1);
    mg1.addVertex(2);

    mg1.addEdge(1, 2);

    Pseudograph<Integer, DefaultEdge> pg1 = new Pseudograph<>(DefaultEdge.class);

    pg1.addVertex(1);
    pg1.addVertex(2);

    pg1.addEdge(1, 2);

    /* GT-0 test graph=null */

    try {
      @SuppressWarnings("unused")
      VF2SubgraphIsomorphismInspector<Integer, DefaultEdge> gt0 =
          new VF2SubgraphIsomorphismInspector<>(null, sg1);
      Assert.fail("Expected UnsupportedOperationException");
    } catch (NullPointerException ex) {
    }

    /* GT-1: multigraphs */

    try {
      @SuppressWarnings("unused")
      VF2SubgraphIsomorphismInspector<Integer, DefaultEdge> gt1 =
          new VF2SubgraphIsomorphismInspector<>(mg1, mg1);
      Assert.fail("Expected UnsupportedOperationException");
    } catch (UnsupportedOperationException ex) {
    }

    /* GT-2: pseudographs */

    try {
      @SuppressWarnings("unused")
      VF2SubgraphIsomorphismInspector<Integer, DefaultEdge> gt2 =
          new VF2SubgraphIsomorphismInspector<>(pg1, pg1);
      Assert.fail("Expected UnsupportedOperationException");
    } catch (UnsupportedOperationException ex) {
    }

    /* GT-3: simple graphs */

    VF2SubgraphIsomorphismInspector<Integer, DefaultEdge> gt3 =
        new VF2SubgraphIsomorphismInspector<>(sg1, sg1);
    assertEquals(true, gt3.getMappings().hasNext());

    /* GT-4: directed graphs */

    VF2SubgraphIsomorphismInspector<Integer, DefaultEdge> gt4 =
        new VF2SubgraphIsomorphismInspector<>(dg1, dg1);
    assertEquals("[1=1 2=2]", gt4.getMappings().next().toString());

    /* GT-5: simple graph + multigraph */

    try {
      @SuppressWarnings("unused")
      VF2SubgraphIsomorphismInspector<Integer, DefaultEdge> gt5 =
          new VF2SubgraphIsomorphismInspector<>(sg1, mg1);
      Assert.fail("Expected UnsupportedOperationException");
    } catch (UnsupportedOperationException ex) {
    }

    /* GT-6: simple graph + pseudograph */

    try {
      @SuppressWarnings("unused")
      VF2SubgraphIsomorphismInspector<Integer, DefaultEdge> gt6 =
          new VF2SubgraphIsomorphismInspector<>(sg1, pg1);
      Assert.fail("Expected UnsupportedOperationException");
    } catch (UnsupportedOperationException ex) {
    }

    /* GT-7: directed graph + multigraph */

    try {
      @SuppressWarnings("unused")
      VF2SubgraphIsomorphismInspector<Integer, DefaultEdge> gt7 =
          new VF2SubgraphIsomorphismInspector<>(dg1, mg1);
      Assert.fail("Expected UnsupportedOperationException");
    } catch (UnsupportedOperationException ex) {
    }

    /* GT-8: directed graph + pseudograph */

    try {
      @SuppressWarnings("unused")
      VF2SubgraphIsomorphismInspector<Integer, DefaultEdge> gt8 =
          new VF2SubgraphIsomorphismInspector<>(dg1, pg1);
      Assert.fail("Expected UnsupportedOperationException");
    } catch (UnsupportedOperationException ex) {
    }

    /* GT-9: pseudograph + multigraph */

    try {
      @SuppressWarnings("unused")
      VF2SubgraphIsomorphismInspector<Integer, DefaultEdge> gt9 =
          new VF2SubgraphIsomorphismInspector<>(pg1, mg1);
      Assert.fail("Expected UnsupportedOperationException");
    } catch (UnsupportedOperationException ex) {
    }

    /* GT-10: simple graph + directed graph */

    try {
      @SuppressWarnings("unused")
      VF2SubgraphIsomorphismInspector<Integer, DefaultEdge> gt10 =
          new VF2SubgraphIsomorphismInspector<>(sg1, dg1);
      Assert.fail("Expected IllegalArgumentException");
    } catch (IllegalArgumentException ex) {
    }
  }
Beispiel #3
0
 public void addEdge(ApplicationEdge ed, ApplicationVertex av1, ApplicationVertex av2) {
   graph.addEdge(av1, av2, ed);
 }