Beispiel #1
0
  @Test
  public void canGetMultiplePathsInTriangleGraph() throws Exception {
    Node nodeA = graph.makeNode("A");
    Node nodeB = graph.makeNode("B");
    Node nodeC = graph.makeNode("C");
    Set<Relationship> expectedFirsts = new HashSet<Relationship>();
    expectedFirsts.add(graph.makeEdge("A", "B", "length", 1d));
    expectedFirsts.add(graph.makeEdge("A", "B", "length", 1d));
    Relationship expectedSecond = graph.makeEdge("B", "C", "length", 2d);
    graph.makeEdge("A", "C", "length", 5d);

    Dijkstra algo =
        new Dijkstra(
            PathExpanders.allTypesAndDirections(), CommonEvaluators.doubleCostEvaluator("length"));

    Iterator<WeightedPath> paths = algo.findAllPaths(nodeA, nodeC).iterator();
    for (int i = 0; i < 2; i++) {
      assertTrue("expected more paths", paths.hasNext());
      Path path = paths.next();
      assertPath(path, nodeA, nodeB, nodeC);

      Iterator<Relationship> relationships = path.relationships().iterator();
      assertTrue("found shorter path than expected", relationships.hasNext());
      assertTrue(
          "path contained unexpected relationship", expectedFirsts.remove(relationships.next()));
      assertTrue("found shorter path than expected", relationships.hasNext());
      assertEquals(expectedSecond, relationships.next());
      assertFalse("found longer path than expected", relationships.hasNext());
    }
    assertFalse("expected at most two paths", paths.hasNext());
  }
Beispiel #2
0
  @Test
  public void canGetPathsInTriangleGraph() throws Exception {
    Node nodeA = graph.makeNode("A");
    Node nodeB = graph.makeNode("B");
    Node nodeC = graph.makeNode("C");
    graph.makeEdge("A", "B", "length", 2d);
    graph.makeEdge("B", "C", "length", 3d);
    graph.makeEdge("A", "C", "length", 10d);

    Dijkstra algo =
        new Dijkstra(
            PathExpanders.allTypesAndDirections(), CommonEvaluators.doubleCostEvaluator("length"));

    Iterator<WeightedPath> paths = algo.findAllPaths(nodeA, nodeC).iterator();
    assertTrue("expected at least one path", paths.hasNext());
    assertPath(paths.next(), nodeA, nodeB, nodeC);
    assertFalse("expected at most one path", paths.hasNext());

    assertPath(algo.findSinglePath(nodeA, nodeC), nodeA, nodeB, nodeC);
  }
Beispiel #3
0
  @Test
  public void canGetMultiplePathsInASmallRoadNetwork() throws Exception {
    Node nodeA = graph.makeNode("A");
    Node nodeB = graph.makeNode("B");
    Node nodeC = graph.makeNode("C");
    Node nodeD = graph.makeNode("D");
    Node nodeE = graph.makeNode("E");
    Node nodeF = graph.makeNode("F");
    graph.makeEdge("A", "B", "length", 2d);
    graph.makeEdge("A", "C", "length", 2.5d);
    graph.makeEdge("C", "D", "length", 7.3d);
    graph.makeEdge("B", "D", "length", 2.5d);
    graph.makeEdge("D", "E", "length", 3d);
    graph.makeEdge("C", "E", "length", 5d);
    graph.makeEdge("E", "F", "length", 5d);
    graph.makeEdge("C", "F", "length", 12d);
    graph.makeEdge("A", "F", "length", 25d);

    Dijkstra algo =
        new Dijkstra(
            PathExpanders.allTypesAndDirections(), CommonEvaluators.doubleCostEvaluator("length"));

    // Try the search in both directions.
    for (Node[] nodes : new Node[][] {{nodeA, nodeF}, {nodeF, nodeA}}) {
      int found = 0;
      Iterator<WeightedPath> paths = algo.findAllPaths(nodes[0], nodes[1]).iterator();
      for (int i = 0; i < 2; i++) {
        assertTrue("expected more paths", paths.hasNext());
        Path path = paths.next();
        if (path.length() != found && path.length() == 3) {
          assertContains(path.nodes(), nodeA, nodeC, nodeE, nodeF);
        } else if (path.length() != found && path.length() == 4) {
          assertContains(path.nodes(), nodeA, nodeB, nodeD, nodeE, nodeF);
        } else {
          fail("unexpected path length: " + path.length());
        }
        found = path.length();
      }
      assertFalse("expected at most two paths", paths.hasNext());
    }
  }
 private static Iterator<Node> findPath(Node s, Node e) {
   Iterator<Node> it;
   try (Transaction tx = graphDb.beginTx()) {
     PathFinder<Path> finder =
         GraphAlgoFactory.shortestPath(
             PathExpanders.forTypeAndDirection(RelTypes.STD, Direction.OUTGOING), 15);
     Iterable<Path> paths = finder.findAllPaths(s, e);
     Path path = paths.iterator().next();
     it = path.nodes().iterator();
     if (it.hasNext()) {
       System.out.println(it.next().getProperty("name"));
     }
     if (it.hasNext()) {
       System.out.println(it.next().getProperty("name"));
     }
     if (it.hasNext()) {
       System.out.println(it.next().getProperty("name"));
     }
     tx.success();
   }
   return it;
 }
Beispiel #5
0
 protected PathFinder<Path> instantiatePathFinder(int maxDepth) {
   return allPaths(PathExpanders.allTypesAndDirections(), maxDepth);
 }