comparison toolboxes/FullBNT-1.0.7/bnt/inference/dynamic/@bk_ff_hmm_inf_engine/enter_evidence.m @ 0:e9a9cd732c1e tip

first hg version after svn
author wolffd
date Tue, 10 Feb 2015 15:05:51 +0000
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-1:000000000000 0:e9a9cd732c1e
1 function [engine, loglik] = enter_evidence(engine, evidence, varargin)
2 % ENTER_EVIDENCE Add the specified evidence to the network (bk_ff_hmm)
3 % [engine, loglik] = enter_evidence(engine, evidence, ...)
4 %
5 % evidence{i,t} = [] if if X(i,t) is hidden, and otherwise contains its observed value (scalar or column vector)
6 %
7 % The following optional arguments can be specified in the form of name/value pairs:
8 % [default value in brackets]
9 %
10 % maximize - if 1, does max-product (not yet supported), else sum-product [0]
11 % filter - if 1, do filtering, else smoothing [0]
12 %
13 % e.g., engine = enter_evidence(engine, ev, 'maximize', 1)
14
15 maximize = 0;
16 filter = 0;
17
18 % parse optional params
19 args = varargin;
20 nargs = length(args);
21 if nargs > 0
22 for i=1:2:nargs
23 switch args{i},
24 case 'maximize', maximize = args{i+1};
25 case 'filter', filter = args{i+1};
26 otherwise,
27 error(['invalid argument name ' args{i}]);
28 end
29 end
30 end
31
32 assert(~maximize);
33
34 bnet = bnet_from_engine(engine);
35 ss = length(bnet.intra);
36 onodes = bnet.observed;
37 hnodes = mysetdiff(1:ss, onodes);
38 T = size(evidence, 2);
39 assertBNT(~any(isemptycell(evidence(onodes,:))));
40
41 obslik = mk_hmm_obs_lik_mat(bnet, onodes, evidence);
42
43 ns = bnet.node_sizes_slice;
44 ns(onodes) = 1;
45
46 [gamma, loglik, marginals, marginalsT] = bk_ff_fb(engine.prior, engine.transmat, obslik, filter, hnodes, ns);
47
48 for t=1:T
49 for i=hnodes(:)'
50 engine.marginals{i,t} = pot_to_marginal(marginalsT{i,t});
51 end
52 for i=onodes(:)'
53 m.domain = i + (t-1)*ss;
54 m.T = 1;
55 engine.marginals{i,t} = m;
56 end
57 end
58
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