matthiasm@8: function [engine, loglik] = enter_evidence(engine, evidence, varargin)
matthiasm@8: % this is unchanged from bk_inf_engine.
matthiasm@8: % ENTER_EVIDENCE Add the specified evidence to the network (bk)
matthiasm@8: % [engine, loglik] = enter_evidence(engine, evidence, ...)
matthiasm@8: %
matthiasm@8: % evidence{i,t} = [] if if X(i,t) is hidden, and otherwise contains its observed value (scalar or column vector)
matthiasm@8: %
matthiasm@8: % The following optional arguments can be specified in the form of name/value pairs:
matthiasm@8: % [default value in brackets]
matthiasm@8: %
matthiasm@8: % maximize - if 1, does max-product instead of sum-product [0]
matthiasm@8: % filter -   if 1, do filtering, else smoothing [0]
matthiasm@8: %
matthiasm@8: % e.g., engine = enter_evidence(engine, ev, 'maximize', 1)
matthiasm@8: 
matthiasm@8: maximize = 0;
matthiasm@8: filter = 0;
matthiasm@8: 
matthiasm@8: % parse optional params
matthiasm@8: args = varargin;
matthiasm@8: nargs = length(args);
matthiasm@8: if nargs > 0
matthiasm@8:   for i=1:2:nargs
matthiasm@8:     switch args{i},
matthiasm@8:      case 'maximize', maximize = args{i+1}; 
matthiasm@8:      case 'filter', filter = args{i+1}; 
matthiasm@8:      otherwise,  
matthiasm@8:       error(['invalid argument name ' args{i}]);       
matthiasm@8:     end
matthiasm@8:   end
matthiasm@8: end
matthiasm@8: 
matthiasm@8: [ss T] = size(evidence);
matthiasm@8: engine.filter = filter;
matthiasm@8: engine.maximize = maximize;
matthiasm@8: engine.T = T;
matthiasm@8: 
matthiasm@8: if maximize
matthiasm@8:   error('BK does not yet support max propagation')
matthiasm@8:   % because it calls enter_soft_evidence, not enter_evidence
matthiasm@8: end
matthiasm@8: 
matthiasm@8: observed_bitv = ~isemptycell(evidence);
matthiasm@8: onodes = find(observed_bitv);
matthiasm@8: bnet = bnet_from_engine(engine);
matthiasm@8: pot_type = determine_pot_type(bnet, onodes); 
matthiasm@8: CPDpot = convert_dbn_CPDs_to_pots(bnet, evidence, pot_type);
matthiasm@8: [engine.clpot, loglik] = enter_soft_evidence(engine, CPDpot, observed_bitv, pot_type, filter);