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

first hg version after svn

+% We compare MCMC structure learning with exhaustive enumeration of all dags.
+
+N = 3;
+%N = 4;
+dag = mk_rnd_dag(N);
+ns = 2*ones(1,N);
+bnet = mk_bnet(dag, ns);
+for i=1:N
+  bnet.CPD{i} = tabular_CPD(bnet, i);
+end
+
+ncases = 100;
+data = zeros(N, ncases);
+for m=1:ncases
+  data(:,m) = cell2num(sample_bnet(bnet));
+end
+
+dags = mk_all_dags(N);
+score = score_dags(data, ns, dags);
+post  = normalise(exp(score));
+
+[sampled_graphs, accept_ratio] = learn_struct_mcmc(data, ns, 'nsamples', 100, 'burnin', 10);
+mcmc_post = mcmc_sample_to_hist(sampled_graphs, dags);
+
+if 0
+  subplot(2,1,1)
+  bar(post)
+  subplot(2,1,2)
+  bar(mcmc_post)
+  print(gcf, '-djpeg', '/home/cs/murphyk/public_html/Bayes/Figures/mcmc_post.jpg')
+
+  clf
+  plot(accept_ratio)
+  print(gcf, '-djpeg', '/home/cs/murphyk/public_html/Bayes/Figures/mcmc_accept.jpg')
+end