Mercurial > hg > camir-aes2014
annotate toolboxes/FullBNT-1.0.7/bnt/general/Old/calc_mpe_given_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 |
parents | |
children |
rev | line source |
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wolffd@0 | 1 function [mpe, prob] = calc_mpe_given_inf_engine(engine, evidence) |
wolffd@0 | 2 % CALC_MPE_GIVEN_ENGINE Computes the most probable explanation of the evidence |
wolffd@0 | 3 % [mpe, prob] = calc_mpe_given_inf_engine(engine, evidence) |
wolffd@0 | 4 % |
wolffd@0 | 5 % INPUT |
wolffd@0 | 6 % engine must support max-propagation |
wolffd@0 | 7 % evidence{i} is the obsevred value of node i, or [] if hidden |
wolffd@0 | 8 % |
wolffd@0 | 9 % OUTPUT |
wolffd@0 | 10 % mpe(i) is the most likely value of node i |
wolffd@0 | 11 % prob is the likelihood of the globally best assignment |
wolffd@0 | 12 % |
wolffd@0 | 13 % This currently only works when all nodes are discrete |
wolffd@0 | 14 |
wolffd@0 | 15 [engine, ll] = enter_evidence(engine, evidence); |
wolffd@0 | 16 |
wolffd@0 | 17 observed = ~isemptycell(evidence); |
wolffd@0 | 18 N = length(evidence); |
wolffd@0 | 19 mpe = zeros(1,N); |
wolffd@0 | 20 for i=1:N |
wolffd@0 | 21 m = marginal_nodes(engine, i); |
wolffd@0 | 22 % discrete observed nodes are all set to 1 inside the inference engine, so we must undo this |
wolffd@0 | 23 if observed(i) |
wolffd@0 | 24 mpe(i) = evidence{i}; |
wolffd@0 | 25 else |
wolffd@0 | 26 mpe(i) = argmax(m.T); |
wolffd@0 | 27 end |
wolffd@0 | 28 end |
wolffd@0 | 29 |
wolffd@0 | 30 bnet = bnet_from_engine(engine); |
wolffd@0 | 31 ll = log_lik_complete(bnet, num2cell(mpe(:))); |
wolffd@0 | 32 prob = exp(ll); |