Mercurial > hg > camir-aes2014
diff toolboxes/FullBNT-1.0.7/bnt/inference/static/@belprop_inf_engine/Old/enter_evidence1.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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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/toolboxes/FullBNT-1.0.7/bnt/inference/static/@belprop_inf_engine/Old/enter_evidence1.m Tue Feb 10 15:05:51 2015 +0000 @@ -0,0 +1,94 @@ +function engine = enter_evidence(engine, evidence) + +doms = engine.fgraph.doms; +ndoms = length(doms); +ns = engine.fgraph.node_sizes; +obs = find(~isemptycell(evidence)); +cobs = myintersect(obs, engine.fgraph.cnodes); +dobs = myintersect(obs, engine.fgraph.dnodes); +ns(cobs) = 0; +ns(dobs) = 1; + +% recompute the weight of each domain now that we know what nodes are observed +for i=1:ndoms + engine.dom_weight(i) = prod(ns(engine.fgraph.doms{i})); +end + +% prime each local kernel with evidence (if any) +local_kernel = cell(1, ndoms); +for i=1:length(engine.fgraph.kernels_of_type) + u = engine.fgraph.kernels_of_type{i}; + local_kernel(u) = kernel_to_dpots(engine.fgraph.kernels{i}, evidence, engine.fgraph.domains_of_type{i}); +end + +% initialise all msgs to 1s +msg = cell(ndoms, ndoms); +for i=1:ndoms + nbrs = engine.fgraph.nbrs{i}; + for j=nbrs(:)' + dom = engine.fgraph.sepset{i,j}; + msg{i,j} = dpot(dom, ns(dom)); + end +end + +prod_of_msg = cell(1, ndoms); +bel = cell(1, ndoms); +old_bel = cell(1, ndoms); + +converged = 0; +iter = 1; +while ~converged & (iter <= engine.max_iter) + + % each node multiplies all its incoming msgs + for i=1:ndoms + prod_of_msg{i} = dpot(doms{i}, ns(doms{i})); + nbrs = engine.fgraph.nbrs{i}; + for j=nbrs(:)' + prod_of_msg{i} = multiply_by_pot(prod_of_msg{i}, msg{j,i}); + end + end + + % each node computes its local belief + old_bel = bel; + for i=1:ndoms + bel{i} = normalize_pot(multiply_pots(prod_of_msg{i}, local_kernel{i})); + end + + % converged? + if iter==1 + converged = 0; + else + converged = 1; + for i=1:ndoms + belT = get_params(bel{i}, 'table'); + old_belT = get_params(old_bel{i}, 'table'); + if ~approxeq(belT, old_belT, engine.tol) + converged = 0; + break; + end + end + end + + if ~converged + old_msg = msg; + % each node sends a msg to each of its neighbors + for i=1:ndoms + nbrs = engine.fgraph.nbrs{i}; + for j=nbrs(:)' + % multiply all incoming msgs except from j + temp = prod_of_msg{i}; + temp = divide_by_pot(temp, old_msg{j,i}); + % send msg from i to j + temp = multiply_by_pot(temp, local_kernel{i}); + msg{i,j} = normalize_pot(marginalize_pot(temp, engine.fgraph.sepset{i,j})); + end + end + end + + iter = iter + 1 +end + +engine.marginal_domains = bel; +%for i=1:ndoms + %engine.marginal_domains{i} = get_params(bel{i}, 'table'); +%end