Пример #1
0
  public static boolean are_d_connected(AbstractVariable x1, AbstractVariable x2, Vector evidence)
      throws RemoteException {
    // Find all paths between x1 and x2, then see if there is some path which is
    // d-connecting given the evidence. If so, return true, otherwise false.

    Hashtable path_sets = new Hashtable(); // HEY !!! THIS OUGHT TO BE CACHED SOMEWHERE !!!
    PathAnalysis.compile_paths(x1, x2, path_sets);

    Vector path_set = (Vector) path_sets.get(new VariablePair(x1, x2));
    if (path_set == null)
      // No connections whatsoever.
      return false;

    Enumeration path_set_enum = path_set.elements();
    while (path_set_enum.hasMoreElements()) {
      AbstractVariable[] path = (AbstractVariable[]) path_set_enum.nextElement();
      if (is_d_connecting(path, evidence)) {
        System.err.print("PathAnalysis.are_d_connected: path ");
        int i;
        for (i = 0; i < path.length; i++) System.err.print(path[i].get_name() + " ");
        System.err.print("is d-connected given evidence ");
        for (i = 0; i < evidence.size(); i++)
          System.err.print(((AbstractVariable) evidence.elementAt(i)).get_name() + " ");
        System.err.println("");
        return true;
      }
    }

    return false;
  }
Пример #2
0
  public static void main(String[] args) {
    boolean do_compile_all = false;
    String bn_name = "", x1_name = "", x2_name = "";
    Vector evidence_names = new Vector();

    for (int i = 0; i < args.length; i++) {
      if (args[i].charAt(0) != '-') continue;

      switch (args[i].charAt(1)) {
        case 'b':
          bn_name = args[++i];
          break;
        case 'a':
          do_compile_all = true;
          break;
        case 'x':
          if (args[i].charAt(2) == '1') x1_name = args[++i];
          else if (args[i].charAt(2) == '2') x2_name = args[++i];
          else System.err.println("PathAnalysis.main: " + args[i] + " -- huh???");
          break;
        case 'e':
          evidence_names.addElement(args[++i]);
          break;
        default:
          System.err.println("PathAnalysis.main: " + args[i] + " -- huh???");
      }
    }

    try {
      BeliefNetworkContext bnc = new BeliefNetworkContext(null);
      bnc.add_path("/bechtel/users10/krarti/dodier/belief-nets/assorted");
      AbstractBeliefNetwork bn = bnc.load_network(bn_name);
      Hashtable path_sets;
      Enumeration p;

      if ((p = PathAnalysis.has_directed_cycle(bn)) == null)
        System.err.println("PathAnalysis: no directed cycles found in " + bn_name);
      else {
        System.err.println("PathAnalysis.main: " + bn_name + " has a directed cycle; quit.");
        System.err.print(" cycle is: ");
        while (p.hasMoreElements()) {
          System.err.print(((AbstractVariable) p.nextElement()).get_name());
          if (p.hasMoreElements()) System.err.print(" -> ");
          else System.err.println("");
        }

        System.exit(1);
      }

      Vector evidence = new Vector();
      if (evidence_names.size() > 0) {
        for (int i = 0; i < evidence_names.size(); i++)
          evidence.addElement(bn.name_lookup((String) (evidence_names.elementAt(i))));
      }

      if (do_compile_all) {
        path_sets = PathAnalysis.compile_all_paths(bn);
      } else {
        AbstractVariable x1 = (AbstractVariable) bn.name_lookup(x1_name);
        AbstractVariable x2 = (AbstractVariable) bn.name_lookup(x2_name);
        path_sets = new Hashtable();
        PathAnalysis.compile_paths(x1, x2, path_sets);

        if (PathAnalysis.are_d_connected(x1, x2, evidence))
          System.err.print(
              x1.get_name() + " and " + x2.get_name() + " are d-connected given evidence ");
        else
          System.err.print(
              x1.get_name() + " and " + x2.get_name() + " are NOT d-connected given evidence ");

        for (int i = 0; i < evidence.size(); i++)
          System.err.print(((AbstractVariable) evidence.elementAt(i)).get_name() + " ");
        System.err.println("");
      }

      System.err.println("PathAnalysis.main: results of path finding:");

      AbstractVariable[] u = bn.get_variables();
      for (int i = 0; i < u.length; i++) {
        System.err.println(" --- paths from: " + u[i].get_name() + " ---");

        for (int j = i + 1; j < u.length; j++) {
          VariablePair vp = new VariablePair(u[i], u[j]);
          Vector path_set = (Vector) path_sets.get(vp);
          if (path_set == null) continue;

          Enumeration path_set_enum = path_set.elements();
          while (path_set_enum.hasMoreElements()) {
            AbstractVariable[] path = (AbstractVariable[]) path_set_enum.nextElement();
            System.err.print(" path: ");
            for (int k = 0; k < path.length; k++) System.err.print(path[k].get_name() + " ");
            System.err.println("");
          }
        }
      }

      System.exit(0);
    } catch (Exception e) {
      System.err.println("PathAnalysis.main:");
      e.printStackTrace();
      System.exit(1);
    }
  }