wolffd@0: function [engine, loglik] = enter_evidence(engine, evidence, varargin)
wolffd@0: % ENTER_EVIDENCE Add the specified evidence to the network (bk_ff_hmm)
wolffd@0: % [engine, loglik] = enter_evidence(engine, evidence, ...)
wolffd@0: %
wolffd@0: % evidence{i,t} = [] if if X(i,t) is hidden, and otherwise contains its observed value (scalar or column vector)
wolffd@0: %
wolffd@0: % The following optional arguments can be specified in the form of name/value pairs:
wolffd@0: % [default value in brackets]
wolffd@0: %
wolffd@0: % maximize - if 1, does max-product (not yet supported), else sum-product [0]
wolffd@0: % filter -   if 1, do filtering, else smoothing [0]
wolffd@0: %
wolffd@0: % e.g., engine = enter_evidence(engine, ev, 'maximize', 1)
wolffd@0: 
wolffd@0: maximize = 0;
wolffd@0: filter = 0;
wolffd@0: 
wolffd@0: % parse optional params
wolffd@0: args = varargin;
wolffd@0: nargs = length(args);
wolffd@0: if nargs > 0
wolffd@0:   for i=1:2:nargs
wolffd@0:     switch args{i},
wolffd@0:      case 'maximize', maximize = args{i+1}; 
wolffd@0:      case 'filter', filter = args{i+1}; 
wolffd@0:      otherwise,  
wolffd@0:       error(['invalid argument name ' args{i}]);       
wolffd@0:     end
wolffd@0:   end
wolffd@0: end
wolffd@0: 
wolffd@0: assert(~maximize);
wolffd@0: 
wolffd@0: bnet = bnet_from_engine(engine);
wolffd@0: ss = length(bnet.intra);
wolffd@0: onodes = bnet.observed;
wolffd@0: hnodes = mysetdiff(1:ss, onodes);
wolffd@0: T = size(evidence, 2);
wolffd@0: assertBNT(~any(isemptycell(evidence(onodes,:))));
wolffd@0: 
wolffd@0: obslik = mk_hmm_obs_lik_mat(bnet, onodes, evidence);
wolffd@0: 
wolffd@0: ns = bnet.node_sizes_slice;
wolffd@0: ns(onodes) = 1;
wolffd@0: 
wolffd@0: [gamma, loglik, marginals, marginalsT] = bk_ff_fb(engine.prior, engine.transmat, obslik, filter, hnodes, ns);
wolffd@0:   
wolffd@0: for t=1:T
wolffd@0:   for i=hnodes(:)'
wolffd@0:     engine.marginals{i,t} = pot_to_marginal(marginalsT{i,t});
wolffd@0:   end
wolffd@0:   for i=onodes(:)'
wolffd@0:     m.domain = i + (t-1)*ss;
wolffd@0:     m.T = 1;
wolffd@0:     engine.marginals{i,t} = m;
wolffd@0:   end
wolffd@0: end
wolffd@0: 
wolffd@0: 
wolffd@0: