annotate toolboxes/FullBNT-1.0.7/bnt/inference/dynamic/@bk_ff_hmm_inf_engine/bk_ff_hmm_inf_engine.m @ 0:e9a9cd732c1e tip

first hg version after svn
author wolffd
date Tue, 10 Feb 2015 15:05:51 +0000
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wolffd@0 1 function engine = bk_ff_hmm_inf_engine(bnet)
wolffd@0 2 % BK_FF_HMM_INF_ENGINE Naive (HMM-based) implementation of fully factored form of Boyen-Koller
wolffd@0 3 % engine = bk_ff_hmm_inf_engine(bnet)
wolffd@0 4 %
wolffd@0 5 % This is implemented on top of the forwards-backwards algo for HMMs,
wolffd@0 6 % so it is *less* efficient than exact inference! However, it is good for educational purposes,
wolffd@0 7 % because it illustrates the BK algorithm very clearly.
wolffd@0 8
wolffd@0 9 [persistent_nodes, transient_nodes] = partition_dbn_nodes(bnet.intra, bnet.inter);
wolffd@0 10 assert(isequal(sort(bnet.observed), transient_nodes));
wolffd@0 11 [engine.prior, engine.transmat] = dbn_to_hmm(bnet);
wolffd@0 12
wolffd@0 13 ss = length(bnet.intra);
wolffd@0 14
wolffd@0 15 engine.bel = [];
wolffd@0 16 engine.bel_marginals = [];
wolffd@0 17 engine.marginals = [];
wolffd@0 18
wolffd@0 19
wolffd@0 20 engine = class(engine, 'bk_ff_hmm_inf_engine', inf_engine(bnet));
wolffd@0 21