annotate _FullBNT/BNT/inference/static/@enumerative_inf_engine/marginal_nodes.m @ 9:4ea6619cb3f5 tip

removed log files
author matthiasm
date Fri, 11 Apr 2014 15:55:11 +0100
parents b5b38998ef3b
children
rev   line source
matthiasm@8 1 function [marginal, loglik] = marginal_nodes(engine, query)
matthiasm@8 2 % MARGINAL_NODES Compute the marginal on the specified query nodes (enumerative_inf)
matthiasm@8 3 % [marginal, loglik] = marginal_nodes(engine, query)
matthiasm@8 4
matthiasm@8 5
matthiasm@8 6 if isempty(query) & nargout < 2
matthiasm@8 7 marginal.T = 1;
matthiasm@8 8 marginal.domain = [];
matthiasm@8 9 return;
matthiasm@8 10 end
matthiasm@8 11
matthiasm@8 12 evidence = engine.evidence;
matthiasm@8 13 bnet = bnet_from_engine(engine);
matthiasm@8 14 assert(isempty(bnet.cnodes));
matthiasm@8 15 n = length(bnet.dag);
matthiasm@8 16 observed = ~isemptycell(evidence);
matthiasm@8 17 vals = cat(1,evidence{observed});
matthiasm@8 18 vals = vals(:)';
matthiasm@8 19 ns = bnet.node_sizes;
matthiasm@8 20
matthiasm@8 21 sz = ns(query);
matthiasm@8 22 T = 0*myones(sz);
matthiasm@8 23 p = 0;
matthiasm@8 24 for i=1:prod(ns)
matthiasm@8 25 inst = ind2subv(ns, i); % i'th instantiation
matthiasm@8 26 if isempty(vals) | inst(observed) == vals % agrees with evidence
matthiasm@8 27 prob = exp(log_lik_complete(bnet, num2cell(inst(:))));
matthiasm@8 28 p = p + prob;
matthiasm@8 29 v = inst(query);
matthiasm@8 30 j = subv2ind(sz, v);
matthiasm@8 31 T(j) = T(j) + prob;
matthiasm@8 32 end
matthiasm@8 33 end
matthiasm@8 34
matthiasm@8 35 [T, lik] = normalise(T);
matthiasm@8 36 lik = p;
matthiasm@8 37 loglik = log(lik);
matthiasm@8 38
matthiasm@8 39 Tsmall = shrink_obs_dims_in_table(T, query, evidence);
matthiasm@8 40 marginal.domain = query;
matthiasm@8 41 marginal.T = Tsmall;