|
wolffd@0
|
1 function [marginal, loglik] = marginal_nodes(engine, query, add_ev)
|
|
wolffd@0
|
2 % MARGINAL_NODES Compute the marginal on the specified query nodes (var_elim)
|
|
wolffd@0
|
3 % [marginal, loglik] = marginal_nodes(engine, query)
|
|
wolffd@0
|
4
|
|
wolffd@0
|
5 if nargin < 3, add_ev = 0; end
|
|
wolffd@0
|
6
|
|
wolffd@0
|
7 assert(length(query)>=1);
|
|
wolffd@0
|
8
|
|
wolffd@0
|
9 evidence = engine.evidence;
|
|
wolffd@0
|
10
|
|
wolffd@0
|
11 bnet = bnet_from_engine(engine);
|
|
wolffd@0
|
12 ns = bnet.node_sizes;
|
|
wolffd@0
|
13 n = length(bnet.dag);
|
|
wolffd@0
|
14
|
|
wolffd@0
|
15 onodes = find(~isemptycell(evidence));
|
|
wolffd@0
|
16 hnodes = find(isemptycell(evidence));
|
|
wolffd@0
|
17 pot_type = determine_pot_type(bnet, onodes);
|
|
wolffd@0
|
18
|
|
wolffd@0
|
19 % Fold the evidence into the CPTs - this could be done in 'enter_evidence'
|
|
wolffd@0
|
20 CPT = cell(1,n);
|
|
wolffd@0
|
21 for i=1:n
|
|
wolffd@0
|
22 fam = family(bnet.dag, i);
|
|
wolffd@0
|
23 CPT{i} = convert_to_pot(bnet.CPD{bnet.equiv_class(i)}, pot_type, fam(:), evidence);
|
|
wolffd@0
|
24 end
|
|
wolffd@0
|
25
|
|
wolffd@0
|
26
|
|
wolffd@0
|
27
|
|
wolffd@0
|
28 sum_over = mysetdiff(1:n, query);
|
|
wolffd@0
|
29 order = [query sum_over]; % no attempt to optimize this
|
|
wolffd@0
|
30
|
|
wolffd@0
|
31 % Initialize the buckets with the product of the CPTs assigned to them
|
|
wolffd@0
|
32 B = cell(1,n+1);
|
|
wolffd@0
|
33 for b=1:n+1
|
|
wolffd@0
|
34 B{b} = mk_initial_pot(pot_type, [], [], [], []);
|
|
wolffd@0
|
35 end
|
|
wolffd@0
|
36 for i=1:n
|
|
wolffd@0
|
37 b = bucket_num(domain_pot(CPT{i}), order);
|
|
wolffd@0
|
38 B{b} = multiply_pots(B{b}, CPT{i});
|
|
wolffd@0
|
39 end
|
|
wolffd@0
|
40
|
|
wolffd@0
|
41 % Do the marginalization
|
|
wolffd@0
|
42 sum_over = sum_over(length(sum_over):-1:1); % reverse
|
|
wolffd@0
|
43 for i=sum_over(:)'
|
|
wolffd@0
|
44 % summing over variable i which occurs in bucket j
|
|
wolffd@0
|
45 j = bucket_num(i, order);
|
|
wolffd@0
|
46 rest = mysetdiff(domain_pot(B{j}), i);
|
|
wolffd@0
|
47 % minka
|
|
wolffd@0
|
48 if ~isempty(rest)
|
|
wolffd@0
|
49 temp = marginalize_pot(B{j}, rest);
|
|
wolffd@0
|
50 b = bucket_num(domain_pot(temp), order);
|
|
wolffd@0
|
51 %fprintf('summing over bucket %d (var %d), putting result into bucket %d\n', j, i, b);
|
|
wolffd@0
|
52 B{b} = multiply_pots(B{b}, temp);
|
|
wolffd@0
|
53 end
|
|
wolffd@0
|
54 end
|
|
wolffd@0
|
55
|
|
wolffd@0
|
56 % Combine all the remaining buckets into one
|
|
wolffd@0
|
57 result = B{1};
|
|
wolffd@0
|
58 for i=2:length(query)
|
|
wolffd@0
|
59 if ~isempty(domain_pot(B{i}))
|
|
wolffd@0
|
60 result = multiply_pots(result, B{i});
|
|
wolffd@0
|
61 end
|
|
wolffd@0
|
62 end
|
|
wolffd@0
|
63 [result, loglik] = normalize_pot(result);
|
|
wolffd@0
|
64
|
|
wolffd@0
|
65
|
|
wolffd@0
|
66 marginal = pot_to_marginal(result);
|
|
wolffd@0
|
67 % minka: from jtree_inf_engine
|
|
wolffd@0
|
68 if add_ev
|
|
wolffd@0
|
69 bnet = bnet_from_engine(engine);
|
|
wolffd@0
|
70 %marginal = add_ev_to_dmarginal(marginal, engine.evidence, bnet.node_sizes);
|
|
wolffd@0
|
71 marginal = add_evidence_to_gmarginal(marginal, engine.evidence, bnet.node_sizes, bnet.cnodes);
|
|
wolffd@0
|
72 end
|
|
wolffd@0
|
73
|
|
wolffd@0
|
74 %%%%%%%%%
|
|
wolffd@0
|
75
|
|
wolffd@0
|
76 function b = bucket_num(domain, order)
|
|
wolffd@0
|
77
|
|
wolffd@0
|
78 b = max(find_equiv_posns(domain, order));
|
|
wolffd@0
|
79
|
