wolffd@0: function [engine, loglik] = enter_evidence(engine, evidence, varargin)
wolffd@0: % ENTER_EVIDENCE Add the specified evidence to the network (global_joint)
wolffd@0: % [engine, loglik] = enter_evidence(engine, evidence, ...)
wolffd@0: %
wolffd@0: % evidence{i} = [] if if X(i) is hidden, and otherwise contains its observed value.
wolffd@0: %
wolffd@0: % Warning: Computing the log likelihood requires marginalizing all the nodes and can be slow.
wolffd@0: %
wolffd@0: % The list below gives optional arguments [default value in brackets].      
wolffd@0: %
wolffd@0: % exclude - list of nodes whose potential will not be included in the joint [ [] ]
wolffd@0: %
wolffd@0: % e.g., engine = enter_evidence(engine, ev, 'exclude', 3)
wolffd@0: 
wolffd@0: exclude = [];
wolffd@0: maximize = 0;
wolffd@0: 
wolffd@0: if nargin >= 3
wolffd@0:   args = varargin;
wolffd@0:   nargs = length(args);
wolffd@0:   for i=1:2:nargs
wolffd@0:     switch args{i},
wolffd@0:      case 'exclude', exclude = args{i+1};
wolffd@0:      case 'maximize', maximize = 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: bnet = bnet_from_engine(engine);
wolffd@0: N = length(bnet.node_sizes);
wolffd@0: %[engine.jpot, loglik] = compute_joint_pot(bnet, mysetdiff(1:N, exclude), evidence, 1:N);
wolffd@0: [engine.jpot] = compute_joint_pot(bnet, mysetdiff(1:N, exclude), evidence, 1:N);
wolffd@0: % jpot should not be normalized, otherwise it gives wrong resutls for limids like asia_dt1
wolffd@0: if nargout == 2
wolffd@0:   [m] = marginal_nodes(engine, []);
wolffd@0:   [T, lik] = normalize(m.T);
wolffd@0:   loglik = log(lik);
wolffd@0: end     
wolffd@0: %[engine.jpot loglik] = normalize_pot(engine.jpot);