Mercurial > hg > camir-aes2014
diff toolboxes/FullBNT-1.0.7/bnt/CPDs/@discrete_CPD/sample_node.m @ 0:e9a9cd732c1e tip
first hg version after svn
author | wolffd |
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date | Tue, 10 Feb 2015 15:05:51 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/toolboxes/FullBNT-1.0.7/bnt/CPDs/@discrete_CPD/sample_node.m Tue Feb 10 15:05:51 2015 +0000 @@ -0,0 +1,34 @@ +function y = sample_node(CPD, pvals) +% SAMPLE_NODE Draw a random sample from P(Xi | x(pi_i), theta_i) (discrete) +% y = sample_node(CPD, parent_evidence) +% +% parent_evidence{i} is the value of the i'th parent + +if 0 +n = length(pvals)+1; +dom = 1:n; +evidence = cell(1,n); +evidence(1:n-1) = pvals; +T = convert_to_table(CPD, dom, evidence); +y = sample_discrete(T); +end + + +CPT = CPD_to_CPT(CPD); +sz = mysize(CPT); +nparents = length(sz)-1; +switch nparents + case 0, T = CPT; + case 1, T = CPT(pvals{1}, :); + case 2, T = CPT(pvals{1}, pvals{2}, :); + case 3, T = CPT(pvals{1}, pvals{2}, pvals{3}, :); + case 4, T = CPT(pvals{1}, pvals{2}, pvals{3}, pvals{4}, :); + otherwise, + pvals = cat(1, pvals{:}); + psz = sz(1:end-1); + ssz = sz(end); + i = subv2ind(psz, pvals(:)'); + T = reshape(CPT, [prod(psz) ssz]); + T = T(i,:); +end +y = sample_discrete(T);