enter_evidence.m

来自「Bayes网络工具箱」· M 代码 · 共 30 行

function [engine, loglik] = enter_evidence(engine, evidence)
% ENTER_EVIDENCE Add the specified evidence to the network (fast_jtree)
% [engine, loglik] = enter_evidence(engine, evidence)
% 
% evidence{i} = [] if if X(i) is hidden, and otherwise contains its observed value (scalar or column vector)
% All and only the nodes that were declared observed when the engine was created must contain evidence.
% All the hidden nodes must be discrete.

bnet = bnet_from_engine(engine);
onodes = find(~isemptycell(evidence));
assert(isequal(onodes, engine.onodes));
cnodes = bnet.cnodes;
pot_type = determine_pot_type(onodes, cnodes, bnet.dag);
assert(pot_type == 'd');
ns = bnet.node_sizes;

% Evaluate CPDs with evidence, and convert to potentials
N = length(bnet.dag);
CPDpot = cell(1,N);
for n=1:N
  fam = family(bnet.dag, n);
  e = bnet.equiv_class(n);
  CPDpot{n} = CPD_to_table(bnet.CPD{e}, fam, ns, cnodes, evidence);
end

jengine = struct(engine.jtree_inf_engine); % violate object privacy
[clpot, loglik] = enter_soft_evidence(engine, jengine.clq_ass_to_node, CPDpot, engine.CPD_ndx);

engine.cltables = clpot;