dbn_update_bel.m

Bayes网络工具箱

function [engine, newbel, loglik] = dbn_update(engine, oldbel, evidence)
% DBN_UPDATE Do one step of Bayesian updating in the dynamic model
% [engine, newbel, loglik] = dbn_update(engine, oldbel, evidence)
%
% oldbel is Pr(X(t-1)|Y(1:t-1)), newbel is Pr(X(t)|Y(1:t))
% evidence{i} contains the evidence on node i in slice t

ss = length(evidence);
bnet = bnet_from_engine(engine);
CPDpot = cell(1, ss);
for n=1:ss
  fam = family(bnet.dag, n, 2);
  e = bnet.equiv_class(n, 2);
  CPDpot{n} = CPD_to_table(bnet.CPD{e}, fam, bnet.node_sizes, bnet.cnodes, evidence);
end

clqs = [engine.fwd.clq_ass_to_cluster(:,1); engine.fwd.clq_ass_to_node(:,2)];
ndx = [engine.fwd.cluster_ndx(:,1); engine.fwd.CPD_ndx(:,2)];
pots = [oldbel; CPDpot];
[newbel, loglik] = enter_soft_evidence(engine.fwd.engine, clqs, pots, ndx);