annotate toolboxes/FullBNT-1.0.7/bnt/CPDs/@gaussian_CPD/learn_params.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 function CPD = learn_params(CPD, fam, data, ns, cnodes)
wolffd@0 2 %function CPD = learn_params(CPD, fam, data, ns, cnodes)
wolffd@0 3 % LEARN_PARAMS Compute the maximum likelihood estimate of the params of a gaussian CPD given complete data
wolffd@0 4 % CPD = learn_params(CPD, fam, data, ns, cnodes)
wolffd@0 5 %
wolffd@0 6 % data(i,m) is the value of node i in case m (can be cell array).
wolffd@0 7 % We assume this node has a maximize_params method.
wolffd@0 8
wolffd@0 9 ncases = size(data, 2);
wolffd@0 10 CPD = reset_ess(CPD);
wolffd@0 11 % make a fully observed joint distribution over the family
wolffd@0 12 fmarginal.domain = fam;
wolffd@0 13 fmarginal.T = 1;
wolffd@0 14 fmarginal.mu = [];
wolffd@0 15 fmarginal.Sigma = [];
wolffd@0 16 if ~iscell(data)
wolffd@0 17 cases = num2cell(data);
wolffd@0 18 else
wolffd@0 19 cases = data;
wolffd@0 20 end
wolffd@0 21 hidden_bitv = zeros(1, max(fam));
wolffd@0 22 for m=1:ncases
wolffd@0 23 % specify (as a bit vector) which elements in the family domain are hidden
wolffd@0 24 hidden_bitv = zeros(1, max(fmarginal.domain));
wolffd@0 25 ev = cases(:,m);
wolffd@0 26 hidden_bitv(find(isempty(ev)))=1;
wolffd@0 27 CPD = update_ess(CPD, fmarginal, ev, ns, cnodes, hidden_bitv);
wolffd@0 28 end
wolffd@0 29 CPD = maximize_params(CPD);
wolffd@0 30
wolffd@0 31