Mercurial > hg > camir-aes2014
diff toolboxes/FullBNT-1.0.7/bnt/inference/dynamic/@pearl_dbn_inf_engine/Old/filter_evidence_obj_oriented.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/@pearl_dbn_inf_engine/Old/filter_evidence_obj_oriented.m Tue Feb 10 15:05:51 2015 +0000 @@ -0,0 +1,158 @@ +function [marginal, msg, loglik] = filter_evidence_old(engine, evidence) +% [marginal, msg, loglik] = filter_evidence(engine, evidence) (pearl_dbn) + +[ss T] = size(evidence); +bnet = bnet_from_engine(engine); +bnet2 = dbn_to_bnet(bnet, T); +ns = bnet2.node_sizes; +hnodes = mysetdiff(1:ss, engine.onodes); +hnodes = hnodes(:)'; + +[engine.parent_index, engine.child_index] = mk_pearl_msg_indices(bnet2); + +msg = init_msgs(bnet2.dag, ns, evidence); +msg = init_ev_msgs(engine, evidence, msg); + +verbose = 1; +if verbose, fprintf('\nold filtering\n'); end + +for t=1:T + % update pi + for i=hnodes + n = i + (t-1)*ss; + ps = parents(bnet2.dag, n); + if t==1 + e = bnet.equiv_class(i,1); + else + e = bnet.equiv_class(i,2); + end + msg{n}.pi = compute_pi(bnet.CPD{e}, n, ps, msg); + %if verbose, fprintf('%d computes pi\n', n); disp(msg{n}.pi); end + msg{n}.pi = normalise(msg{n}.pi(:) .* msg{n}.lambda_from_self(:)); + if verbose, fprintf('%d recomputes pi\n', n); disp(msg{n}.pi); end + end + % send pi msg to children + for i=hnodes + n = i + (t-1)*ss; + cs = children(bnet2.dag, n); + for c=cs(:)' + j = engine.parent_index{c}(n); % n is c's j'th parent + pi_msg = normalise(compute_pi_msg(n, cs, msg, c, ns)); + msg{c}.pi_from_parent{j} = pi_msg; + if verbose, fprintf('%d sends pi to %d\n', n,c); disp(pi_msg); end + end + end +end + + +marginal = cell(ss,T); +lik = zeros(1,ss*T); +for t=1:T + for i=1:ss + n = i + (t-1)*ss; + %[bel, lik(n)] = normalise(msg{n}.pi .* msg{n}.lambda); + [bel, lik(n)] = normalise(msg{n}.pi); + marginal{i,t} = bel; + end +end + +loglik = sum(log(lik)); + + + +%%%%%%% + +function lambda = compute_lambda(n, cs, msg, ns) +% Pearl p183 eq 4.50 +lambda = prod_lambda_msgs(n, cs, msg, ns); + +%%%%%%% + +function pi_msg = compute_pi_msg(n, cs, msg, c, ns) +% Pearl p183 eq 4.53 and 4.51 +pi_msg = msg{n}.pi .* prod_lambda_msgs(n, cs, msg, ns, c); + +%%%%%%%%% + +function lam = prod_lambda_msgs(n, cs, msg, ns, except) + +if nargin < 5, except = -1; end + +%lam = msg{n}.lambda_from_self(:); +lam = ones(ns(n), 1); +for i=1:length(cs) + c = cs(i); + if c ~= except + lam = lam .* msg{n}.lambda_from_child{i}; + end +end + + +%%%%%%%%%%% + +function msg = init_msgs(dag, ns, evidence) +% INIT_MSGS Initialize the lambda/pi message and state vectors (pearl_dbn) +% msg = init_msgs(dag, ns, evidence) +% +% We assume all the hidden nodes are discrete. + +N = length(dag); +msg = cell(1,N); +observed = ~isemptycell(evidence(:)); + +for n=1:N + ps = parents(dag, n); + msg{n}.pi_from_parent = cell(1, length(ps)); + for i=1:length(ps) + p = ps(i); + msg{n}.pi_from_parent{i} = ones(ns(p), 1); + end + + cs = children(dag, n); + msg{n}.lambda_from_child = cell(1, length(cs)); + for i=1:length(cs) + c = cs(i); + msg{n}.lambda_from_child{i} = ones(ns(n), 1); + end + + msg{n}.lambda = ones(ns(n), 1); + msg{n}.pi = ones(ns(n), 1); + + msg{n}.lambda_from_self = ones(ns(n), 1); +end + + +%%%%%%%%% + +function msg = init_ev_msgs(engine, evidence, msg) +% Initialize the lambdas with any evidence + +[ss T] = size(evidence); +bnet = bnet_from_engine(engine); +pot_type = 'd'; +t = 1; +hnodes = mysetdiff(1:ss, engine.onodes); +for i=hnodes(:)' + c = engine.obschild(i); + if c > 0 + fam = family(bnet.dag, c); + e = bnet.equiv_class(c, 1); + CPDpot = CPD_to_pot(pot_type, bnet.CPD{e}, fam, bnet.node_sizes(:), bnet.cnodes(:), evidence(:,1)); + temp = pot_to_marginal(CPDpot); + n = i; + msg{n}.lambda_from_self = temp.T; + end +end +for t=2:T + for i=hnodes(:)' + c = engine.obschild(i); + if c > 0 + fam = family(bnet.dag, c, 2); + e = bnet.equiv_class(c, 2); + CPDpot = CPD_to_pot(pot_type, bnet.CPD{e}, fam, bnet.node_sizes(:), bnet.cnodes(:), evidence(:,t-1:t)); + temp = pot_to_marginal(CPDpot); + n = i + (t-1)*ss; + msg{n}.lambda_from_self = temp.T; + end + end +end