enter_evidence.m

来自「Bayes网络工具箱」· M 代码 · 共 29 行

function [engine, loglik] = enter_evidence(engine, evidence, filter)
% ENTER_EVIDENCE Add the specified evidence to the network (bk_ff_hmm)
% [engine, loglik] = enter_evidence(engine, evidence, filter)
%
% evidence{i,t} = [] if if X(i,t) is hidden, and otherwise contains its observed value (scalar or column vector)
% If filter = 1, we do filtering, otherwise smoothing (default).

if nargin < 3, filter = 0; end

bnet = bnet_from_engine(engine);
ss = length(bnet.intra);
onodes = engine.onodes;
hnodes = engine.hnodes;
T = size(evidence, 2);
assert(~any(isemptycell(evidence(onodes,:))));

obslik = mk_hmm_obs_lik_mat(bnet, onodes, evidence);

ns = bnet.node_sizes_slice;
ns(onodes) = 1;

[gamma, loglik, marginals, marginalsT] = bk_ff_fb(engine.prior, engine.transmat, obslik, filter, engine.hnodes, ns);
  
for t=1:T
  for i=hnodes(:)'
    engine.marginals{i,t} = pot_to_marginal(marginalsT{i,t});
  end
end