Mercurial > hg > camir-aes2014
diff toolboxes/FullBNT-1.0.7/bnt/general/log_marg_lik_complete.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/general/log_marg_lik_complete.m Tue Feb 10 15:05:51 2015 +0000 @@ -0,0 +1,40 @@ +function L = log_marg_lik_complete(bnet, cases, clamped) +% LOG_MARG_LIK_COMPLETE Compute sum_m sum_i log P(x(i,m)| x(pi_i,m)) for a completely observed data set +% L = log_marg_lik_complete(bnet, cases, clamped) +% +% This differs from log_lik_complete because we integrate out the parameters. +% If there is a missing data, you must use an inference engine. +% cases(i,m) is the value assigned to node i in case m. +% (If there are vector-valued nodes, cases should be a cell array.) +% clamped(i,m) = 1 if node i was set by intervention in case m (default: clamped = zeros) +% Clamped nodes contribute a factor of 1.0 to the likelihood. +% +% If there is a single case, clamped is a list of the clamped nodes, not a bit vector. + +if iscell(cases), usecell = 1; else usecell = 0; end + +n = length(bnet.dag); +ncases = size(cases, 2); +if n ~= size(cases, 1) + error('data should be of size nnodes * ncases'); +end + +if ncases == 1 + if nargin < 3, clamped = []; end + clamp_set = clamped; + clamped = zeros(n,1); + clamped(clamp_set) = 1; +else + if nargin < 3, clamped = zeros(n,ncases); end +end + +L = 0; +for i=1:n + ps = parents(bnet.dag, i); + e = bnet.equiv_class(i); + u = find(clamped(i,:)==0); + L = L + log_marg_prob_node(bnet.CPD{e}, cases(i,u), cases(ps,u)); +end + + +