wolffd@0: function CPD = learn_params(CPD, fam, data, ns, cnodes) wolffd@0: %function CPD = learn_params(CPD, fam, data, ns, cnodes) wolffd@0: % LEARN_PARAMS Compute the maximum likelihood estimate of the params of a gaussian CPD given complete data wolffd@0: % CPD = learn_params(CPD, fam, data, ns, cnodes) wolffd@0: % wolffd@0: % data(i,m) is the value of node i in case m (can be cell array). wolffd@0: % We assume this node has a maximize_params method. wolffd@0: wolffd@0: ncases = size(data, 2); wolffd@0: CPD = reset_ess(CPD); wolffd@0: % make a fully observed joint distribution over the family wolffd@0: fmarginal.domain = fam; wolffd@0: fmarginal.T = 1; wolffd@0: fmarginal.mu = []; wolffd@0: fmarginal.Sigma = []; wolffd@0: if ~iscell(data) wolffd@0: cases = num2cell(data); wolffd@0: else wolffd@0: cases = data; wolffd@0: end wolffd@0: hidden_bitv = zeros(1, max(fam)); wolffd@0: for m=1:ncases wolffd@0: % specify (as a bit vector) which elements in the family domain are hidden wolffd@0: hidden_bitv = zeros(1, max(fmarginal.domain)); wolffd@0: ev = cases(:,m); wolffd@0: hidden_bitv(find(isempty(ev)))=1; wolffd@0: CPD = update_ess(CPD, fmarginal, ev, ns, cnodes, hidden_bitv); wolffd@0: end wolffd@0: CPD = maximize_params(CPD); wolffd@0: wolffd@0: