marginal compiles and runs for frontal node in clique

cpp/BayesTree-inl.h

@@ -6,7 +6,7 @@
 
 #include <boost/foreach.hpp>
 #include "BayesTree.h"
-#include "FactorGraph.h"
+#include "FactorGraph-inl.h"
 
 namespace gtsam {
 
@@ -120,6 +120,7 @@ namespace gtsam {
 
 	/* ************************************************************************* */
 	template<class Conditional>
+	template<class Factor>
 	boost::shared_ptr<Conditional> BayesTree<Conditional>::marginal(const string& key) const {
 
 		// find the clique to which key belongs
@@ -128,16 +129,39 @@ namespace gtsam {
 						"BayesTree::marginal('"+key+"'): key not found"));
 
 		// find all cliques on the path to the root and turn into factor graph
-		// FactorGraph
 		node_ptr node = it->second;
-		int i=0;
+		Ordering ordering;
+		FactorGraph<Factor> graph;
 		while (node!=NULL) {
-			//node->print("node");
+
+			// extend ordering
+			Ordering cliqueOrdering = node->ordering();
+			ordering.splice (ordering.end(), cliqueOrdering);
+
+			// extend factor graph
+			boost::shared_ptr<BayesNet<Conditional> > bayesNet = node;
+			FactorGraph<Factor> cliqueGraph(*bayesNet);
+			typename FactorGraph<Factor>::const_iterator factor=cliqueGraph.begin();
+			for(; factor!=cliqueGraph.end(); factor++)
+				graph.push_back(*factor);
+
+			// move up the tree
 			node = node->parent_;
 		}
 
-		boost::shared_ptr<Conditional> result(new Conditional);
-		return result;
+		//graph.print();
+		ordering.reverse();
+		//ordering.print();
+
+		// eliminate to get marginal
+		boost::shared_ptr<BayesNet<Conditional> > bayesNet;
+		typename boost::shared_ptr<BayesNet<Conditional> > chordalBayesNet =
+				graph.eliminate(bayesNet,ordering);
+
+		//chordalBayesNet->print("chordalBayesNet");
+
+		boost::shared_ptr<Conditional> marginal = chordalBayesNet->back();
+		return marginal;
 	}
 
 	/* ************************************************************************* */

cpp/BayesTree.h

@@ -94,6 +94,7 @@ namespace gtsam {
 		boost::shared_ptr<BayesNet<Conditional> > root() const {return root_;}
 
 		/** return marginal on any variable */
+		template<class Factor>
 		boost::shared_ptr<Conditional> marginal(const std::string& key) const;
 
 	}; // BayesTree

cpp/testBayesTree.cpp

@@ -127,9 +127,14 @@ TEST( BayesTree, balanced_smoother_marginals )
 	//CHECK(assert_equal(expected_root,actual_root));
 
 	// Check marginal on x1
-	ConditionalGaussian expected;
-	ConditionalGaussian::shared_ptr actual = bayesTree.marginal("x1");
-	CHECK(assert_equal(expected,*actual));
+  double data1[] = { 1.0, 0.0,
+                     0.0, 1.0};
+  Matrix R1 = Matrix_(2,2, data1);
+  Vector d1(2); d1(0) = -0.615385; d1(1) = 0;
+  Vector tau1(2); tau1(0) = 1.61803; tau1(1) = 1.61803;
+	ConditionalGaussian expected("x1",d1, R1, tau1);
+	ConditionalGaussian::shared_ptr actual = bayesTree.marginal<LinearFactor>("x1");
+	CHECK(assert_equal(expected,*actual,1e-4));
 
 	// JunctionTree is an undirected tree of cliques
 	// JunctionTree<ConditionalGaussian> marginals = bayesTree.marginals();