Mercurial > hg > camir-aes2014
diff toolboxes/FullBNT-1.0.7/bnt/inference/dynamic/@hmm_inf_engine/private/mk_hmm_obs_lik_vec.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/dynamic/@hmm_inf_engine/private/mk_hmm_obs_lik_vec.m Tue Feb 10 15:05:51 2015 +0000 @@ -0,0 +1,52 @@ +function obslik = mk_hmm_obs_lik_vec(engine, evidence) + +% P(o1,o2| h) = P(o1|h) * P(o2|h) where h = Q1,Q2,... + +bnet = bnet_from_engine(engine); +ss = length(bnet.intra); +onodes = bnet.observed; +hnodes = mysetdiff(1:ss, onodes); +ns = bnet.node_sizes(:); +ns(onodes) = 1; + +Q = length(engine.startprob); +obslik = ones(Q, 1); + +for i=1:length(onodes) + o = onodes(i); + %data = cell2num(evidence(o,1)); + data = evidence{o,1}; + if myismember(o, bnet.dnodes) + obslik_i = eval_pdf_cond_multinomial(data, engine.obsprob{i}.CPT); + else + if bnet.auto_regressive(o) + error('can''t handle AR nodes') + end + %% calling mk_ghmm_obs_lik, which calls gaussian_prob, is slow, so we inline it + %% and use the pre-computed inverse matrix + %obslik_i = mk_ghmm_obs_lik(data, engine.obsprob{i}.mu, engine.obsprob{i}.Sigma); + x = data(:); + m = engine.obsprob{i}.mu; + Qi = size(m, 2); + obslik_i = size(Qi, 1); + invC = engine.obsprob{i}.inv_Sigma; + denom = engine.obsprob{i}.denom; + for j=1:Qi + numer = exp(-0.5 * (x-m(:,j))' * invC(:,:,j) * (x-m(:,j))); + obslik_i(j) = numer / denom(j); + end + end + % convert P(o|ps) into P(o|h) by multiplying onto a (h,o) potential of all 1s + ps = bnet.parents{o}; + dom = [ps o]; + obspot_i = dpot(dom, ns(dom), obslik_i); + dom = [hnodes o]; + obspot = dpot(dom, ns(dom)); + obspot = multiply_by_pot(obspot, obspot_i); + % compute p(oi|h) * p(oj|h) + S = struct(obspot); + obslik = obslik .* S.T(:); +end + + +