comparison toolboxes/FullBNT-1.0.7/bnt/inference/static/@global_joint_inf_engine/enter_evidence.m @ 0:e9a9cd732c1e tip

first hg version after svn

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