Mercurial > hg > camir-aes2014
view toolboxes/FullBNT-1.0.7/bnt/CPDs/@tabular_CPD/log_nextcase_prob_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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function L = log_nextcase_prob_node(CPD, self_ev, pev, test_self_ev, test_pev) % LOG_NEXTCASE_PROB_NODE compute the joint distribution of a node (tabular) of a new case given % completely observed data. % % The input arguments are mainly similar with log_marg_prob_node(CPD, self_ev, pev, usecell), % but add test_self_ev, test_pev, and without usecell % test_self_ev(m) is the evidence on this node in a test case. % test_pev(i) is the evidence on the i'th parent in the test case (if there are any parents). % % Written by qian.diao@intel.com ncases = length(self_ev); sz = CPD.sizes; nparents = length(sz)-1; assert(ncases == size(pev, 2)); if nargin < 6 %usecell = 0; if iscell(self_ev) usecell = 1; else usecell = 0; end end if ncases==0 L = 0; return; elseif ncases==1 % speedup the sequential learning case; here need correction!!! CPT = CPD.CPT; % We assume the CPTs are already set to the mean of the posterior (due to bayes_update_params) if usecell x = cat(1, pev{:})'; y = self_ev{1}; else %x = pev(:)'; x = pev; y = self_ev; end switch nparents case 0, p = CPT(y); case 1, p = CPT(x(1), y); case 2, p = CPT(x(1), x(2), y); case 3, p = CPT(x(1), x(2), x(3), y); otherwise, ind = subv2ind(sz, [x y]); p = CPT(ind); end L = log(p); else % We ignore the CPTs here and assume the prior has not been changed % We arrange the data as in the following example. % Let there be 2 parents and 3 cases. Let p(i,m) be parent i in case m, % and y(m) be the child in case m. Then we create the data matrix % % p(1,1) p(1,2) p(1,3) % p(2,1) p(2,2) p(2,3) % y(1) y(2) y(3) if usecell data = [cell2num(pev); cell2num(self_ev)]; else data = [pev; self_ev]; end counts = compute_counts(data, sz); % compute the (N_ijk'+ N_ijk)/(N_ij' + N_ij) under the condition of 1_m+1,ijk = 1 L = predict_family(counts, CPD.prior, test_self_ev, test_pev); end