예제 #1
0
  private Graph changeLatentNames(Graph full, Clusters measurements, List<String> latentVarList) {
    Graph g2 = null;

    try {
      g2 = (Graph) new MarshalledObject(full).get();
    } catch (IOException e) {
      e.printStackTrace();
    } catch (ClassNotFoundException e) {
      e.printStackTrace();
    }

    for (int i = 0; i < measurements.getNumClusters(); i++) {
      List<String> d = measurements.getCluster(i);
      String latentName = latentVarList.get(i);

      for (Node node : full.getNodes()) {
        if (!(node.getNodeType() == NodeType.LATENT)) {
          continue;
        }

        List<Node> _children = full.getChildren(node);

        _children.removeAll(ReidentifyVariables.getLatents(full));

        List<String> childNames = getNames(_children);

        if (new HashSet<String>(childNames).equals(new HashSet<String>(d))) {
          g2.getNode(node.getName()).setName(latentName);
        }
      }
    }

    return g2;
  }
  /**
   * Transforms a maximally directed pattern (PDAG) represented in graph <code>g</code> into an
   * arbitrary DAG by modifying <code>g</code> itself. Based on the algorithm described in
   * Chickering (2002) "Optimal structure identification with greedy search" Journal of Machine
   * Learning Research. R. Silva, June 2004
   */
  public static void pdagToDag(Graph g) {
    Graph p = new EdgeListGraph(g);
    List<Edge> undirectedEdges = new ArrayList<Edge>();

    for (Edge edge : g.getEdges()) {
      if (edge.getEndpoint1() == Endpoint.TAIL
          && edge.getEndpoint2() == Endpoint.TAIL
          && !undirectedEdges.contains(edge)) {
        undirectedEdges.add(edge);
      }
    }
    g.removeEdges(undirectedEdges);
    List<Node> pNodes = p.getNodes();

    do {
      Node x = null;

      for (Node pNode : pNodes) {
        x = pNode;

        if (p.getChildren(x).size() > 0) {
          continue;
        }

        Set<Node> neighbors = new HashSet<Node>();

        for (Edge edge : p.getEdges()) {
          if (edge.getNode1() == x || edge.getNode2() == x) {
            if (edge.getEndpoint1() == Endpoint.TAIL && edge.getEndpoint2() == Endpoint.TAIL) {
              if (edge.getNode1() == x) {
                neighbors.add(edge.getNode2());
              } else {
                neighbors.add(edge.getNode1());
              }
            }
          }
        }
        if (neighbors.size() > 0) {
          Collection<Node> parents = p.getParents(x);
          Set<Node> all = new HashSet<Node>(neighbors);
          all.addAll(parents);
          if (!GraphUtils.isClique(all, p)) {
            continue;
          }
        }

        for (Node neighbor : neighbors) {
          Node node1 = g.getNode(neighbor.getName());
          Node node2 = g.getNode(x.getName());

          g.addDirectedEdge(node1, node2);
        }
        p.removeNode(x);
        break;
      }
      pNodes.remove(x);
    } while (pNodes.size() > 0);
  }