Daniel@0: function [engine, loglik] = enter_evidence(engine, evidence, varargin)
Daniel@0: % ENTER_EVIDENCE Add the specified evidence to the network (ff)
Daniel@0: % [engine, loglik] = enter_evidence(engine, evidence, ...)
Daniel@0: %
Daniel@0: % evidence{i,t} = [] if if X(i,t) is hidden, and otherwise contains its observed value (scalar or
Daniel@0: % column vector)
Daniel@0: %
Daniel@0: % The following optional arguments can be specified in the form of name/value pairs:
Daniel@0: % [default value in brackets]
Daniel@0: %
Daniel@0: % maximize - if 1, does max-product (not yet supported), else sum-product [0]
Daniel@0: % filter -   if 1, do filtering, else smoothing [0]
Daniel@0: %
Daniel@0: % e.g., engine = enter_evidence(engine, ev, 'maximize', 1)
Daniel@0: 
Daniel@0: maximize = 0;
Daniel@0: filter = 0;
Daniel@0: 
Daniel@0: % parse optional params
Daniel@0: args = varargin;
Daniel@0: nargs = length(args);
Daniel@0: if nargs > 0
Daniel@0:   for i=1:2:nargs
Daniel@0:     switch args{i},
Daniel@0:      case 'maximize', maximize = args{i+1}; 
Daniel@0:      case 'filter', filter = args{i+1}; 
Daniel@0:      otherwise,  
Daniel@0:       error(['invalid argument name ' args{i}]);       
Daniel@0:     end
Daniel@0:   end
Daniel@0: end
Daniel@0: 
Daniel@0: assert(~maximize);
Daniel@0: 
Daniel@0: 
Daniel@0: [ss T] = size(evidence);
Daniel@0: observed = ~isemptycell(evidence);
Daniel@0: bnet = bnet_from_engine(engine);
Daniel@0: %pot_type = determine_pot_type(find(observed(:,1)), bnet.cnodes_slice, bnet.intra);
Daniel@0: pot_type = determine_pot_type(bnet, observed);
Daniel@0: % we assume we can use the same pot_type in all slices
Daniel@0: 
Daniel@0: CPDpot = convert_dbn_CPDs_to_pots(bnet, evidence, pot_type);
Daniel@0: 
Daniel@0: % Now convert CPDs on observed nodes to be potentials just on their parents
Daniel@0: assert(pot_type == 'd');
Daniel@0: onodes = bnet.observed(:);
Daniel@0: ns = bnet.node_sizes_slice;
Daniel@0: ns(onodes) = 1;
Daniel@0: for t=1:T
Daniel@0:   for i=onodes
Daniel@0:     p = parents(bnet.dag, i);
Daniel@0:     %CPDpot{i,t} = set_domain_pot(CPDpot{i,t}, p); % leaves size too long
Daniel@0:     temp = pot_to_marginal(CPDpot{i,t});
Daniel@0:     CPDpot{i,t} = dpot(p, ns(p), temp.T); % assumes pot_type = d
Daniel@0:   end
Daniel@0: end
Daniel@0: 
Daniel@0: [engine.marginals, engine.fwd, engine.back, loglik] = enter_soft_evidence(engine, CPDpot, observed, pot_type, filter);
Daniel@0: 
Daniel@0: engine.CPDpot = CPDpot;
Daniel@0: engine.filter = filter;