Mercurial > hg > camir-aes2014
view toolboxes/FullBNT-1.0.7/bnt/inference/static/@jtree_limid_inf_engine/jtree_limid_inf_engine.m @ 0:e9a9cd732c1e tip
first hg version after svn
author | wolffd |
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date | Tue, 10 Feb 2015 15:05:51 +0000 |
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function engine = jtree_limid_inf_engine(bnet) % JTREE_LIMID_INF_ENGINE Make a junction tree engine for use by solve_limid % engine = jtree_limid_inf_engine(bnet) % % This engine is designed to compute marginals on decision nodes MG = moralize(bnet.dag); % We do not remove the utility nodes, because that complicates the book-keeping. % Leaving them in will not introduce any un-necessary triangulation arcs, because they are always leaves. % Also, since utility nodes have size 1, they do not increase the size of the potentials. ns = bnet.node_sizes; elim_order = best_first_elim_order(MG, ns); [MTG, engine.cliques] = triangulate(MG, elim_order); [engine.jtree, root, B, w] = cliques_to_jtree(engine.cliques, ns); % A node can be a member of many cliques, but is assigned to exactly one, to avoid % double-counting its CPD. We assign node i to clique c if c is the "lightest" clique that % contains i's family, so it can accomodate its CPD. N = length(bnet.dag); engine.clq_ass_to_node = zeros(1, N); for i=1:N clqs_containing_family = find(all(B(:,family(bnet.dag, i)), 2)); % all selected columns must be 1 c = clqs_containing_family(argmin(w(clqs_containing_family))); engine.clq_ass_to_node(i) = c; end % Compute the separators between connected cliques. [is,js] = find(engine.jtree > 0); num_cliques = length(engine.cliques); engine.separator = cell(num_cliques, num_cliques); for k=1:length(is) i = is(k); j = js(k); engine.separator{i,j} = find(B(i,:) & B(j,:)); % intersect(cliques{i}, cliques{j}); end % create |D| different rooted jtree's engine.rooted_jtree = cell(1, N); engine.preorder = cell(1, N); engine.postorder = cell(1, N); for d=bnet.decision_nodes(:)' root = engine.clq_ass_to_node(d); [engine.rooted_jtree{d}, engine.preorder{d}, engine.postorder{d}] = mk_rooted_tree(engine.jtree, root); end engine.exclude = []; engine.evidence = []; engine = class(engine, 'jtree_limid_inf_engine', inf_engine(bnet));