Daniel@0: % example to illustrate why nodes must be numbered topologically. Daniel@0: % Due to Shinya OHTANI Daniel@0: % 9 June 2004 Daniel@0: Daniel@0: %%%%%%%%% WRONG RESULTS because 2 -> 1 Daniel@0: % should have P(parent|no evidence) = prior = [03. 0.7] Daniel@0: Daniel@0: node = struct('ChildNode', 1, ... Daniel@0: 'ParentNode', 2); Daniel@0: Daniel@0: adjacency = zeros(2); Daniel@0: adjacency([node.ParentNode], node.ChildNode) = 1; Daniel@0: Daniel@0: value = {{'TRUE'; 'FALSE'}, ... Daniel@0: {'TRUE'; 'FALSE'}}; Daniel@0: Daniel@0: bnet = mk_bnet(adjacency, [2 2]); Daniel@0: bnet.CPD{node.ChildNode} = tabular_CPD(bnet, node.ChildNode, [0.2 0.4 0.8 0.6]); Daniel@0: bnet.CPD{node.ParentNode} = tabular_CPD(bnet, node.ParentNode, [0.3 0.7]); Daniel@0: Daniel@0: evidence = cell(1,2); Daniel@0: % evidence{node.ChildNode} = 1; Daniel@0: % evidence{node.ParentNode} = 1; Daniel@0: Daniel@0: engine = jtree_inf_engine(bnet); Daniel@0: [engine, loglik] = enter_evidence(engine, evidence); Daniel@0: Daniel@0: Daniel@0: marg = marginal_nodes(engine, node.ChildNode); Daniel@0: disp(sprintf(' ChildNode : %8.6f %8.6f',marg.T(1),marg.T(2)) ); Daniel@0: marg = marginal_nodes(engine, node.ParentNode); Daniel@0: disp(sprintf(' ParentNode : %8.6f %8.6f',marg.T(1),marg.T(2)) ); Daniel@0: Daniel@0: % Daniel@0: % ChildNode : 0.534483 0.465517 Daniel@0: % ParentNode : 0.155172 0.844828 Daniel@0: % loglik = 0.15 Daniel@0: Daniel@0: Daniel@0: Daniel@0: %%%%%%%%% RIGHT RESULTS because 1 -> 2 Daniel@0: Daniel@0: node = struct('ChildNode', 2, ... Daniel@0: 'ParentNode', 1); Daniel@0: Daniel@0: Daniel@0: adjacency = zeros(2); Daniel@0: adjacency([node.ParentNode], node.ChildNode) = 1; Daniel@0: Daniel@0: value = {{'TRUE'; 'FALSE'}, ... Daniel@0: {'TRUE'; 'FALSE'}}; Daniel@0: Daniel@0: bnet = mk_bnet(adjacency, [2 2]); Daniel@0: bnet.CPD{node.ChildNode} = tabular_CPD(bnet, node.ChildNode, [0.2 0.4 0.8 0.6]); Daniel@0: bnet.CPD{node.ParentNode} = tabular_CPD(bnet, node.ParentNode, [0.3 0.7]); Daniel@0: Daniel@0: evidence = cell(1,2); Daniel@0: % evidence{node.ChildNode} = 1; Daniel@0: % evidence{node.ParentNode} = 1; Daniel@0: Daniel@0: engine = jtree_inf_engine(bnet); Daniel@0: [engine, loglik] = enter_evidence(engine, evidence); Daniel@0: Daniel@0: Daniel@0: marg = marginal_nodes(engine, node.ChildNode); Daniel@0: disp(sprintf(' ChildNode : %8.6f %8.6f',marg.T(1),marg.T(2)) ); Daniel@0: marg = marginal_nodes(engine, node.ParentNode); Daniel@0: disp(sprintf(' ParentNode : %8.6f %8.6f',marg.T(1),marg.T(2)) );