wolffd@0: function engine = collect_evidence(engine, root)
wolffd@0: 
wolffd@0: if isempty(engine.postorder{root})
wolffd@0:   % this is the first time we have collected to this root
wolffd@0:   % memoize the order
wolffd@0:   [jtree, preorder, postorder] = mk_rooted_tree(engine.jtree, root);
wolffd@0:   postorder_parents = cell(1,length(postorder));
wolffd@0:   for n=postorder(1:end-1)
wolffd@0:     postorder_parents{n} = parents(jtree, n);
wolffd@0:   end
wolffd@0:   engine.postorder{root} = postorder;
wolffd@0:   engine.postorder_parents{root} = postorder_parents;
wolffd@0: else
wolffd@0:   postorder = engine.postorder{root};
wolffd@0:   postorder_parents = engine.postorder_parents{root};
wolffd@0: end
wolffd@0: 
wolffd@0: C = length(engine.clpot);
wolffd@0: seppot = cell(C, C);
wolffd@0: % separators are implicitely initialized to 1s
wolffd@0: 
wolffd@0: % collect to root (node to parents)
wolffd@0: for n=postorder(1:end-1)
wolffd@0:   for p=postorder_parents{n}
wolffd@0:     %clpot{p} = divide_by_pot(clpot{n}, seppot{p,n}); % dividing by 1 is redundant
wolffd@0:     engine.seppot{p,n} = marginalize_pot(engine.clpot{n}, engine.separator{p,n}, engine.maximize);
wolffd@0:     engine.clpot{p} = multiply_by_pot(engine.clpot{p}, engine.seppot{p,n});
wolffd@0:   end
wolffd@0: end