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;
}
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);
}
}