Mercurial > hg > camir-aes2014
diff toolboxes/FullBNT-1.0.7/bnt/inference/static/@jtree_mnet_inf_engine/find_mpe.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/@jtree_mnet_inf_engine/find_mpe.m Tue Feb 10 15:05:51 2015 +0000 @@ -0,0 +1,71 @@ +function mpe = find_mpe(engine, evidence, varargin) +% FIND_MPE Find the most probable explanation of the data (assignment to the hidden nodes) +% function mpe = find_mpe(engine, evidence,...) +% +% evidence{i} = [] if X(i) is hidden, and otherwise contains its observed value (scalar or column vector). +% +% The following optional arguments can be specified in the form of name/value pairs: +% [default value in brackets] +% +% soft - a cell array of soft/virtual evidence; +% soft{i} is a prob. distrib. over i's values, or [] [ cell(1,N) ] +% + +bnet = bnet_from_engine(engine); +ns = bnet.node_sizes(:); +N = length(bnet.dag); + +engine.evidence = evidence; + +% set default params +exclude = []; +soft_evidence = cell(1,N); + +% parse optional params +args = varargin; +nargs = length(args); +for i=1:2:nargs + switch args{i}, + case 'soft', soft_evidence = args{i+1}; + otherwise, + error(['invalid argument name ' args{i}]); + end +end +engine.maximize = 1; + +onodes = find(~isemptycell(evidence)); +hnodes = find(isemptycell(evidence)); +pot_type = determine_pot_type(bnet, onodes); + if strcmp(pot_type, 'cg') + check_for_cd_arcs(onodes, bnet.cnodes, bnet.dag); +end + +hard_nodes = 1:N; +soft_nodes = find(~isemptycell(soft_evidence)); +S = length(soft_nodes); +if S > 0 + assert(pot_type == 'd'); + assert(mysubset(soft_nodes, bnet.dnodes)); +end + +% Evaluate CPDs with evidence, and convert to potentials +pot = cell(1, N+S); +for n=1:N + fam = family(bnet.dag, n); + e = bnet.equiv_class(n); + if isempty(bnet.CPD{e}) + error(['must define CPD ' num2str(e)]) + else + pot{n} = convert_to_pot(bnet.CPD{e}, pot_type, fam(:), evidence); + end +end + +for i=1:S + n = soft_nodes(i); + pot{N+i} = dpot(n, ns(n), soft_evidence{n}); +end +clqs = engine.clq_ass_to_node([hard_nodes soft_nodes]); + +[clpot, seppot] = init_pot(engine, clqs, pot, pot_type, onodes); +[clpot, seppot] = collect_evidence(engine, clpot, seppot); +mpe = find_max_config(engine, clpot, seppot);