annotate toolboxes/FullBNT-1.0.7/bnt/examples/static/StructLearn/mcmc1.m @ 0:e9a9cd732c1e tip

first hg version after svn
author wolffd
date Tue, 10 Feb 2015 15:05:51 +0000
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wolffd@0 1 % We compare MCMC structure learning with exhaustive enumeration of all dags.
wolffd@0 2
wolffd@0 3 N = 3;
wolffd@0 4 %N = 4;
wolffd@0 5 dag = mk_rnd_dag(N);
wolffd@0 6 ns = 2*ones(1,N);
wolffd@0 7 bnet = mk_bnet(dag, ns);
wolffd@0 8 for i=1:N
wolffd@0 9 bnet.CPD{i} = tabular_CPD(bnet, i);
wolffd@0 10 end
wolffd@0 11
wolffd@0 12 ncases = 100;
wolffd@0 13 data = zeros(N, ncases);
wolffd@0 14 for m=1:ncases
wolffd@0 15 data(:,m) = cell2num(sample_bnet(bnet));
wolffd@0 16 end
wolffd@0 17
wolffd@0 18 dags = mk_all_dags(N);
wolffd@0 19 score = score_dags(data, ns, dags);
wolffd@0 20 post = normalise(exp(score));
wolffd@0 21
wolffd@0 22 [sampled_graphs, accept_ratio] = learn_struct_mcmc(data, ns, 'nsamples', 100, 'burnin', 10);
wolffd@0 23 mcmc_post = mcmc_sample_to_hist(sampled_graphs, dags);
wolffd@0 24
wolffd@0 25 if 0
wolffd@0 26 subplot(2,1,1)
wolffd@0 27 bar(post)
wolffd@0 28 subplot(2,1,2)
wolffd@0 29 bar(mcmc_post)
wolffd@0 30 print(gcf, '-djpeg', '/home/cs/murphyk/public_html/Bayes/Figures/mcmc_post.jpg')
wolffd@0 31
wolffd@0 32 clf
wolffd@0 33 plot(accept_ratio)
wolffd@0 34 print(gcf, '-djpeg', '/home/cs/murphyk/public_html/Bayes/Figures/mcmc_accept.jpg')
wolffd@0 35 end