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

first hg version after svn

+function marginal = marginal_nodes(engine, query, add_ev)
+% MARGINAL_NODES Compute the marginal on the specified query nodes (loopy)
+% marginal = marginal_nodes(engine, query, add_ev)
+%
+% 'query' must be a single node.
+% add_ev is an optional argument; if 1, observed nodes will be set to their original size,
+% otherwise they will be treated like points.
+   
+if nargin < 3, add_ev = 0; end
+
+if length(query) > 1
+  error('can only compute marginal on single nodes or families')
+end
+bnet = bnet_from_engine(engine);
+ns = bnet.node_sizes(:);
+
+switch engine.msg_type
+ case 'd',
+  T = engine.marginal{query};
+  if ~add_ev
+    marginal.T = shrink_obs_dims_in_table(T, query, engine.evidence);
+  else
+    marginal.T = T;
+  end
+  marginal.domain = query;
+ 
+ case 'g',
+  if engine.disconnected_nodes_bitv(query)
+    marginal.T = 1;
+    marginal.domain = query;
+    if add_ev
+      marginal = add_ev_to_dmarginal(marginal, engine.evidence, ns)
+    end
+    return;
+  end
+
+  marginal = engine.marginal{query};
+  marginal.domain = query;
+  if ~add_ev
+    marginal = shrink_obs_dims_in_gaussian(marginal, query, engine.evidence, ns);
+  end
+end
+