/**
* Returns null if the belief network <tt>bn</tt> has no directed cycles. Otherwise returns an
* <tt>Enumeration</tt> of variables, which begins at a variable contained in a directed cycle,
* leads through the cycle (parent by parent), and ends at that same variable.
*/
public static Enumeration has_directed_cycle(AbstractBeliefNetwork bn) throws RemoteException {
// If is_ancestor returns true, then this stack contains a path from some variable all the
// way back to that same variable. If is_ancestor returns false, then this stack remains empty.
Stack path_stack = new Stack();
AbstractVariable[] u = bn.get_variables();
for (int i = 0; i < u.length; i++) {
if (is_ancestor(u[i], u[i], path_stack)) {
path_stack.push(u[i]);
return path_stack.elements();
}
}
return null;
}
public static Hashtable compile_all_paths(AbstractBeliefNetwork bn) throws RemoteException {
Hashtable path_sets = new Hashtable();
// SHOULD SYNCHRONIZE ON bn TO PREVENT EDITING WHILE compile_all_paths IS RUNNING !!!
AbstractVariable[] variables = bn.get_variables();
for (int i = 0; i < variables.length; i++) {
// Skip through the other variables, up to and including the current variable;
// we only need half the connectivity matrix, since it is symmetric.
for (int j = i + 1; j < variables.length; j++) {
compile_paths(variables[i], variables[j], path_sets);
}
}
return path_sets;
}
public static void main(String[] args) {
boolean all_x = false, do_bind = false;
String bn_name = "", context_name = "";
int i;
for (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 'c':
context_name = args[++i];
break;
case 'r':
do_bind = true;
break;
}
}
AbstractBeliefNetworkContext bnc = null;
AbstractBeliefNetwork bn = null;
AbstractVariable x = null, e_var = null;
try {
if ("".equals(context_name)) {
BeliefNetworkContext local_bnc = new BeliefNetworkContext(null);
bnc = local_bnc;
} else {
String url = "rmi://" + context_name;
System.err.println("Informativeness: url: " + url);
long t0 = System.currentTimeMillis();
bnc = (AbstractBeliefNetworkContext) Naming.lookup(url);
long tf = System.currentTimeMillis();
System.err.println(
"Informativeness: Naming.lookup complete (for belief net context), elapsed time: "
+ ((tf - t0) / 1000.0)
+ " [s]");
}
bn = (AbstractBeliefNetwork) bnc.load_network(bn_name);
if (do_bind) {
System.err.println("Informativeness: bind belief net.");
bnc.bind(bn);
}
String e_name, x_name;
double e_value;
for (i = 0; i < args.length; i++) {
if (args[i].charAt(0) != '-') continue;
switch (args[i].charAt(1)) {
case 'x':
if ("-xall".equals(args[i])) {
AbstractVariable[] u = bn.get_variables();
for (int j = 0; j < u.length; j++) {
Distribution xposterior = bn.get_posterior(u[j]);
System.out.println("Informativeness: posterior for " + u[j].get_name() + ":");
System.out.print(" " + xposterior.format_string(" "));
}
} else {
x_name = args[++i];
long t0 = System.currentTimeMillis();
x = (AbstractVariable) bn.name_lookup(x_name);
long tf = System.currentTimeMillis();
System.err.println(
"Informativeness: Naming.lookup complete (for variable ref), elapsed time: "
+ ((tf - t0) / 1000.0)
+ " [s]");
if (x == null) throw new Exception("name_lookup failed: x: " + x_name);
Distribution xposterior = bn.get_posterior(x);
System.out.println("Informativeness: posterior for " + x.get_name() + ":");
System.out.print(" " + xposterior.format_string(" "));
}
break;
case 'e':
if (args[i].length() > 2 && args[i].charAt(2) == '-') {
e_name = args[++i];
System.err.println("Informativeness.main: evidence: clear " + e_name);
e_var = (AbstractVariable) bn.name_lookup(e_name);
bn.clear_posterior(e_var);
} else {
e_name = args[++i];
e_value = Double.parseDouble(args[++i]);
System.err.println(
"Informativeness.main: evidence: set " + e_name + " to " + e_value);
long t0 = System.currentTimeMillis();
e_var = (AbstractVariable) bn.name_lookup(e_name);
long tf = System.currentTimeMillis();
System.err.println(
"Informativeness: Naming.lookup complete (for variable ref), elapsed time: "
+ ((tf - t0) / 1000.0)
+ " [s]");
bn.assign_evidence(e_var, e_value);
}
break;
default:
continue;
}
}
} catch (Exception e) {
e.printStackTrace();
}
System.exit(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);
}
}