wolffd@0: function engine = distribute_evidence(engine, root)
wolffd@0: 
wolffd@0: if isempty(engine.preorder{root})
wolffd@0:   % this is the first time we have distributed from this root
wolffd@0:   % memoize the order
wolffd@0:   [jtree, preorder, postorder] = mk_rooted_tree(engine.jtree, root);
wolffd@0:   preorder_children = cell(1,length(preorder));
wolffd@0:   for n=preorder
wolffd@0:     preorder_children{n} = children(jtree, n);
wolffd@0:   end
wolffd@0:   engine.preorder{root} = preorder;
wolffd@0:   engine.preorder_children{root} = preorder_children;
wolffd@0: else
wolffd@0:   preorder = engine.preorder{root};
wolffd@0:   preorder_children = engine.preorder_children{root};
wolffd@0: end
wolffd@0: 
wolffd@0: 
wolffd@0: % distribute from root (node to children)
wolffd@0: for n=preorder(:)'
wolffd@0:   for c=preorder_children{n}(:)'
wolffd@0:     engine.clpot{c} = divide_by_pot(engine.clpot{c}, engine.seppot{n,c}); 
wolffd@0:     engine.seppot{n,c} = marginalize_pot(engine.clpot{n}, engine.separator{n,c}, engine.maximize);
wolffd@0:     engine.clpot{c} = multiply_by_pot(engine.clpot{c}, engine.seppot{n,c});
wolffd@0:   end
wolffd@0: end