diff toolboxes/FullBNT-1.0.7/bnt/inference/static/@jtree_limid_inf_engine/marginal_family.m @ 0:e9a9cd732c1e tip

first hg version after svn

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolboxes/FullBNT-1.0.7/bnt/inference/static/@jtree_limid_inf_engine/marginal_family.m	Tue Feb 10 15:05:51 2015 +0000
@@ -0,0 +1,52 @@
+function [m, pot] = marginal_family(engine, query)
+% MARGINAL_NODES Compute the marginal on the family of the specified node (jtree_limid)
+% [m, pot] = marginal_family(engine, query)
+%
+% query should be a single decision node
+
+bnet = bnet_from_engine(engine);
+d = query;
+assert(myismember(d, bnet.decision_nodes));
+fam = family(bnet.dag, d);
+
+clpot = init_clpot(bnet, engine.cliques, engine.clq_ass_to_node, engine.evidence, engine.exclude);
+
+% collect to root (clique containing d) 
+C = length(engine.cliques);
+seppot = cell(C, C);    % separators are implicitely initialized to 1s
+for n=engine.postorder{d}(1:end-1)
+  for p=parents(engine.rooted_jtree{d}, n)
+    %clpot{p} = divide_by_pot(clpot{n}, seppot{p,n}); % dividing by 1 is redundant
+    seppot{p,n} = marginalize_pot(clpot{n}, engine.separator{p,n});
+    clpot{p} = multiply_by_pot(clpot{p}, seppot{p,n});
+  end
+end
+
+root = engine.clq_ass_to_node(d);
+assert(root == engine.postorder{d}(end));
+pot = marginalize_pot(clpot{root}, fam);
+m = pot_to_marginal(pot);
+
+%%%%%%%%%%%
+
+
+function clpot = init_clpot(bnet, cliques, clq_ass_to_node, evidence, exclude)
+
+% Set the clique potentials to all 1s
+C = length(cliques);
+clpot = cell(1, C);
+ns = bnet.node_sizes;
+for i=1:C
+  clpot{i} = upot(cliques{i}, ns(cliques{i}));
+end
+
+N = length(bnet.dag);
+nodes = mysetdiff(1:N, exclude);
+
+for n=nodes(:)'
+  fam = family(bnet.dag, n);
+  e = bnet.equiv_class(n);
+  c = clq_ass_to_node(n);
+  pot = convert_to_pot(bnet.CPD{e}, 'u', fam(:), evidence);
+  clpot{c} = multiply_by_pot(clpot{c}, pot);
+end