comparison toolboxes/FullBNT-1.0.7/bnt/general/mk_fgraph_given_ev.m @ 0:e9a9cd732c1e tip

first hg version after svn

+function fg = mk_fgraph_given_ev(G, node_sizes, factors, ev_CPD, evidence, varargin)
+% MK_FGRAPH_GIVEN_EV Make a factor graph where each node has its own private evidence term
+% fg = mk_fgraph(G, node_sizes, factors, ev_CPD, evidence, ...)
+%
+% G, node_sizes and factors are as in mk_fgraph, but they refer to the hidden nodes.
+% ev_CPD{i} is a CPD for the i'th hidden node; this will be converted into a factor
+% for node i using evidence{i}.
+% We currently assume all hidden nodes are discrete, for simplicity.
+%
+% The list below gives optional arguments [default value in brackets].
+% 
+% equiv_class - equiv_class(i)=j  means factor node i gets its params from factors{j} [1:F]
+% ev_equiv_class - ev_equiv_class(i)=j  means evidence node i gets its params from ev_CPD{j} [1:N]
+
+
+N = length(node_sizes);
+nfactors = length(factors);
+
+% default values for parameters
+eclass = 1:nfactors;
+ev_eclass = 1:N;
+
+if nargin >= 6
+  args = varargin;
+  nargs = length(args);
+  for i=1:2:nargs
+    switch args{i},
+     case 'equiv_class', eclass = args{i+1}; 
+     case 'ev_equiv_class', ev_eclass = args{i+1}; 
+     otherwise,  
+      error(['invalid argument name ' args{i}]);       
+    end
+  end
+end
+
+pot_type = 'd';
+for x=1:N
+  ev = cell(1,2); % cell 1 is the hidden parent, cell 2 is the observed child
+  ev(2) = evidence(x); 
+  dom = 1:2;
+  F = convert_to_pot(ev_CPD{ev_eclass(x)}, pot_type, dom(:), ev);
+  M = pot_to_marginal(F);
+  %factors{end+1} = tabular_CPD('self', 1, 'ps', [], 'sz', node_sizes(x), 'CPT', M.T);
+  factors{end+1} = mk_isolated_tabular_CPD(node_sizes(x), {'CPT', M.T});
+end
+
+E = max(eclass);
+fg = mk_fgraph([G eye(N)], node_sizes, factors, 'equiv_class', [eclass E+1:E+N]);