enter_evidence.m

来自「Bayes网络工具箱」· M 代码 · 共 31 行

function [engine, loglik] = enter_evidence(engine, evidence, filter)
% ENTER_EVIDENCE Add the specified evidence to the network (frontier)
% [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


[ss T] = size(evidence);
bnet = bnet_from_engine(engine);
onodes = find(~isemptycell(evidence));
cnodes = unroll_set(bnet.cnodes(:), ss, T);
big_dag = unroll_dbn_topology(bnet.intra1, bnet.intra, bnet.inter, T);
pot_type = determine_pot_type(onodes, cnodes, big_dag);
eclass = [bnet.equiv_class(:,1) repmat(bnet.equiv_class(:,2), 1, T-1)];   
ns = repmat(bnet.node_sizes_slice(:), 1, T);          

% Convert evidence-specific CPDs to potentials
CPD = cell(ss,T);
for t=1:T
  for i=1:ss
    fam = family(bnet.dag, i, t);
    CPD{i,t} = CPD_to_pot(pot_type, bnet.CPD{eclass(i,t)}, fam, ns, cnodes, evidence);   
  end
end

[engine.fwdback, loglik, engine.fwd_frontier, engine.back_frontier] = enter_soft_evidence(engine, CPD, onodes, pot_type, filter);