diff toolboxes/FullBNT-1.0.7/bnt/inference/dynamic/@bk_inf_engine/dbn_update_bel.m @ 0:e9a9cd732c1e tip

first hg version after svn
author wolffd
date Tue, 10 Feb 2015 15:05:51 +0000
parents
children
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolboxes/FullBNT-1.0.7/bnt/inference/dynamic/@bk_inf_engine/dbn_update_bel.m	Tue Feb 10 15:05:51 2015 +0000
@@ -0,0 +1,37 @@
+function [engine, loglik] = dbn_update_bel(engine, evidence)
+% DBN_UPDATE_BEL Update the belief state (bk)
+% [engine, loglik] = dbn_update_bel(engine, evidence)
+%
+% evidence{i,1} contains the evidence on node i in slice t-1
+% evidence{i,2} contains the evidence on node i in slice t
+
+oldbel = engine.bel;
+
+ss = size(evidence, 1);
+bnet = bnet_from_engine(engine);
+CPDpot = cell(1, ss);
+for n=1:ss
+  fam = family(bnet.dag, n, 2);
+  e = bnet.equiv_class(n, 2);
+  CPDpot{n} = convert_to_pot(bnet.CPD{e}, engine.pot_type, fam(:), evidence);
+end
+
+observed = ~isemptycell(evidence);
+onodes2 = find(observed(:));
+clqs = [engine.clq_ass_to_cluster(:,1); engine.clq_ass_to_node(:,2)];
+pots = [oldbel(:); CPDpot(:)];
+
+[clpot, loglik] = enter_soft_evidence(engine.sub_engine, clqs, pots, onodes2(:), engine.pot_type);
+
+C = length(engine.clusters);
+newbel = cell(1,C);
+for c=1:C
+  k = engine.clq_ass_to_cluster(c,2);
+  cl = engine.clusters{c};
+  newbel{c} = marginalize_pot(clpot{k}, cl+ss); % extract slice 2 posterior
+  newbel{c} = set_domain_pot(newbel{c}, cl); % shift back to slice 1 for re-use as prior
+end
+
+engine.bel = newbel;
+engine.bel_clpot = clpot;
+engine.slice1 = 0;