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'); endfor 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  endendmarginal = 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;  endendloglik = sum(log(lik));%%%%%%%function lambda = compute_lambda(n, cs, msg, ns)% Pearl p183 eq 4.50lambda = prod_lambda_msgs(n, cs, msg, ns);%%%%%%%function pi_msg = compute_pi_msg(n, cs, msg, c, ns)% Pearl p183 eq 4.53 and 4.51pi_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};  endend   %%%%%%%%%%%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;  endendfor 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  endend