/**
* Returns the weight of the clique that would be added to a graph if a given vertex would be
* removed in the triangulation procedure. The return value is the number of edges in the
* elimination clique of V that are not already present.
*/
private int weightRequired(UndirectedGraph mdl, Variable v) {
int rating = 1;
for (Iterator it1 = neighborsIterator(mdl, v); it1.hasNext(); ) {
Variable neighbor = (Variable) it1.next();
rating *= neighbor.getNumOutcomes();
}
// System.out.println(v+" = "+rating);
return rating;
}
/** Adds edges to graph until it is triangulated. */
private void triangulate(final UndirectedGraph mdl) {
UndirectedGraph mdl2 = dupGraph(mdl);
ArrayList<Variable> vars = new ArrayList<Variable>(mdl.vertexSet());
Alphabet<Variable> varMap = makeVertexMap(vars);
cliques = new ArrayList();
// debug
if (logger.isLoggable(Level.FINER)) {
logger.finer("Triangulating model: " + mdl);
String ret = "";
for (int i = 0; i < vars.size(); i++) {
Variable next = (Variable) vars.get(i);
ret += next.toString() + "\n"; // " (" + mdl.getIndex(next) + ")\n ";
}
logger.finer(ret);
}
while (!vars.isEmpty()) {
Variable v = (Variable) pickVertexToRemove(mdl2, vars);
logger.finer("Triangulating vertex " + v);
VarSet varSet = new BitVarSet(v.getUniverse(), GraphHelper.neighborListOf(mdl2, v));
varSet.add(v);
if (!findSuperClique(cliques, varSet)) {
cliques.add(varSet);
if (logger.isLoggable(Level.FINER)) {
logger.finer(
" Elim clique " + varSet + " size " + varSet.size() + " weight " + varSet.weight());
}
}
// must remove V from graph first, because adding the edges
// will change the rating of other vertices
connectNeighbors(mdl2, v);
vars.remove(v);
mdl2.removeVertex(v);
}
if (logger.isLoggable(Level.FINE)) {
logger.fine("Triangulation done. Cliques are: ");
int totSize = 0, totWeight = 0, maxSize = 0, maxWeight = 0;
for (Iterator it = cliques.iterator(); it.hasNext(); ) {
VarSet c = (VarSet) it.next();
logger.finer(c.toString());
totSize += c.size();
maxSize = Math.max(c.size(), maxSize);
totWeight += c.weight();
maxWeight = Math.max(c.weight(), maxWeight);
}
double sz = cliques.size();
logger.fine(
"Jt created "
+ sz
+ " cliques. Size: avg "
+ (totSize / sz)
+ " max "
+ (maxSize)
+ " Weight: avg "
+ (totWeight / sz)
+ " max "
+ (maxWeight));
}
}