comparison toolboxes/FullBNT-1.0.7/bnt/inference/dynamic/@ff_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 (ff)
+% [engine, loglik] = enter_evidence(engine, evidence, ...)
+%
+% evidence{i,t} = [] if if X(i,t) is hidden, and otherwise contains its observed value (scalar or
+% column vector)
+%
+% The following optional arguments can be specified in the form of name/value pairs:
+% [default value in brackets]
+%
+% maximize - if 1, does max-product (not yet supported), else sum-product [0]
+% filter -   if 1, do filtering, else smoothing [0]
+%
+% e.g., engine = enter_evidence(engine, ev, 'maximize', 1)
+
+maximize = 0;
+filter = 0;
+
+% parse optional params
+args = varargin;
+nargs = length(args);
+if nargs > 0
+  for i=1:2:nargs
+    switch args{i},
+     case 'maximize', maximize = args{i+1}; 
+     case 'filter', filter = args{i+1}; 
+     otherwise,  
+      error(['invalid argument name ' args{i}]);       
+    end
+  end
+end
+
+assert(~maximize);
+
+
+[ss T] = size(evidence);
+observed = ~isemptycell(evidence);
+bnet = bnet_from_engine(engine);
+%pot_type = determine_pot_type(find(observed(:,1)), bnet.cnodes_slice, bnet.intra);
+pot_type = determine_pot_type(bnet, observed);
+% we assume we can use the same pot_type in all slices
+
+CPDpot = convert_dbn_CPDs_to_pots(bnet, evidence, pot_type);
+
+% Now convert CPDs on observed nodes to be potentials just on their parents
+assert(pot_type == 'd');
+onodes = bnet.observed(:);
+ns = bnet.node_sizes_slice;
+ns(onodes) = 1;
+for t=1:T
+  for i=onodes
+    p = parents(bnet.dag, i);
+    %CPDpot{i,t} = set_domain_pot(CPDpot{i,t}, p); % leaves size too long
+    temp = pot_to_marginal(CPDpot{i,t});
+    CPDpot{i,t} = dpot(p, ns(p), temp.T); % assumes pot_type = d
+  end
+end
+
+[engine.marginals, engine.fwd, engine.back, loglik] = enter_soft_evidence(engine, CPDpot, observed, pot_type, filter);
+
+engine.CPDpot = CPDpot;
+engine.filter = filter;