Ejemplo n.º 1
0
  public void testUndirected() {
    UndirectedGraph<String, DefaultEdge> g =
        new SimpleGraph<String, DefaultEdge>(DefaultEdge.class);
    g.addVertex(V1);
    g.addVertex(V2);
    g.addEdge(V1, V2);
    g.addVertex(V3);
    g.addEdge(V3, V1);

    StringWriter w = new StringWriter();
    exporter.export(w, g);
    assertEquals(UNDIRECTED, w.toString());
  }
Ejemplo n.º 2
0
  public void testAdjacencyUndirected() {
    UndirectedGraph<String, DefaultEdge> g =
        new Pseudograph<String, DefaultEdge>(DefaultEdge.class);
    g.addVertex(V1);
    g.addVertex(V2);
    g.addEdge(V1, V2);
    g.addVertex(V3);
    g.addEdge(V3, V1);
    g.addEdge(V1, V1);

    StringWriter w = new StringWriter();
    exporter.exportAdjacencyMatrix(w, g);
    assertEquals(UNDIRECTED_ADJACENCY, w.toString());
  }
Ejemplo n.º 3
0
  public void testLaplacian() {
    UndirectedGraph<String, DefaultEdge> g =
        new SimpleGraph<String, DefaultEdge>(DefaultEdge.class);
    g.addVertex(V1);
    g.addVertex(V2);
    g.addEdge(V1, V2);
    g.addVertex(V3);
    g.addEdge(V3, V1);

    StringWriter w = new StringWriter();
    exporter.exportLaplacianMatrix(w, g);
    assertEquals(LAPLACIAN, w.toString());

    w = new StringWriter();
    exporter.exportNormalizedLaplacianMatrix(w, g);
    assertEquals(NORMALIZED_LAPLACIAN, w.toString());
  }
Ejemplo n.º 4
0
  public void testUndirectedEdgeList() {
    UndirectedGraph<Integer, DefaultEdge> g = new SimpleGraph<>(DefaultEdge.class);
    g.addVertex(1);
    g.addVertex(2);
    g.addVertex(3);
    g.addVertex(4);
    g.addVertex(5);
    g.addEdge(1, 2);
    g.addEdge(1, 3);
    g.addEdge(3, 1);
    g.addEdge(3, 4);
    g.addEdge(4, 5);
    g.addEdge(5, 1);

    CSVExporter<Integer, DefaultEdge> exporter =
        new CSVExporter<>(nameProvider, CSVFormat.EDGE_LIST, ';');
    StringWriter w = new StringWriter();
    exporter.exportGraph(g, w);
    assertEquals(UNDIRECTED_EDGE_LIST, w.toString());
  }
  /**
   * Create a copy of a graph for internal use.
   *
   * @param graph the graph to copy.
   * @return A copy of the graph projected to a SimpleGraph.
   */
  private static <V, E> UndirectedGraph<V, E> copyAsSimpleGraph(UndirectedGraph<V, E> graph) {
    UndirectedGraph<V, E> copy = new SimpleGraph<>(graph.getEdgeFactory());

    if (graph instanceof SimpleGraph) {
      Graphs.addGraph(copy, graph);
    } else {
      // project graph to SimpleGraph
      Graphs.addAllVertices(copy, graph.vertexSet());
      for (E e : graph.edgeSet()) {
        V v1 = graph.getEdgeSource(e);
        V v2 = graph.getEdgeTarget(e);
        if ((v1 != v2) && !copy.containsEdge(e)) {
          copy.addEdge(v1, v2);
        }
      }
    }
    return copy;
  }
  /**
   * Compute the minimal triangulation of the graph. Implementation of Algorithm MCS-M+ as described
   * in Berry et al. (2010), DOI:10.3390/a3020197 <a href="http://www.mdpi.com/1999-4893/3/2/197">
   * http://www.mdpi.com/1999-4893/3/2/197</a>
   */
  private void computeMinimalTriangulation() {
    // initialize chordGraph with same vertices as graph
    chordalGraph = new SimpleGraph<>(graph.getEdgeFactory());
    for (V v : graph.vertexSet()) {
      chordalGraph.addVertex(v);
    }

    // initialize g' as subgraph of graph (same vertices and edges)
    final UndirectedGraph<V, E> gprime = copyAsSimpleGraph(graph);
    int s = -1;
    generators = new ArrayList<>();
    meo = new LinkedList<>();

    final Map<V, Integer> vertexLabels = new HashMap<>();
    for (V v : gprime.vertexSet()) {
      vertexLabels.put(v, 0);
    }
    for (int i = 1, n = graph.vertexSet().size(); i <= n; i++) {
      V v = getMaxLabelVertex(vertexLabels);
      LinkedList<V> Y = new LinkedList<>(Graphs.neighborListOf(gprime, v));

      if (vertexLabels.get(v) <= s) {
        generators.add(v);
      }

      s = vertexLabels.get(v);

      // Mark x reached and all other vertices of gprime unreached
      HashSet<V> reached = new HashSet<>();
      reached.add(v);

      // mark neighborhood of x reached and add to reach(label(y))
      HashMap<Integer, HashSet<V>> reach = new HashMap<>();

      // mark y reached and add y to reach
      for (V y : Y) {
        reached.add(y);
        addToReach(vertexLabels.get(y), y, reach);
      }

      for (int j = 0; j < graph.vertexSet().size(); j++) {
        if (!reach.containsKey(j)) {
          continue;
        }
        while (reach.get(j).size() > 0) {
          // remove a vertex y from reach(j)
          V y = reach.get(j).iterator().next();
          reach.get(j).remove(y);

          for (V z : Graphs.neighborListOf(gprime, y)) {
            if (!reached.contains(z)) {
              reached.add(z);
              if (vertexLabels.get(z) > j) {
                Y.add(z);
                E fillEdge = graph.getEdgeFactory().createEdge(v, z);
                fillEdges.add(fillEdge);
                addToReach(vertexLabels.get(z), z, reach);
              } else {
                addToReach(j, z, reach);
              }
            }
          }
        }
      }

      for (V y : Y) {
        chordalGraph.addEdge(v, y);
        vertexLabels.put(y, vertexLabels.get(y) + 1);
      }

      meo.addLast(v);
      gprime.removeVertex(v);
      vertexLabels.remove(v);
    }
  }