comparison toolboxes/FullBNT-1.0.7/bnt/inference/dynamic/@ff_inf_engine/Old/enter_soft_evidence1.m @ 0:e9a9cd732c1e tip

first hg version after svn

+function [marginals, loglik] = enter_soft_evidence(engine, CPDpot, observed, pot_type, filter)
+% ENTER_SOFT_EVIDENCE Add the specified soft evidence to the network (ff)
+% [marginals, loglik] = enter_soft_evidence(engine, CPDpot, observed, pot_type, filter)
+
+assert(pot_type == 'd');
+[ss T] = size(CPDpot);
+fwd = cell(ss,T);
+hnodes = engine.hnodes(:)';
+onodes = engine.onodes(:)';
+bnet = bnet_from_engine(engine);
+ns = bnet.node_sizes;
+onodes2 = [onodes onodes+ss];
+ns(onodes2) = 1;
+
+logscale = zeros(1,T);
+H = length(hnodes);
+local_logscale = zeros(1,ss);
+
+obschild = zeros(1,ss);
+for i=hnodes
+  ocs = myintersect(children(bnet.dag, i), onodes);
+  assert(length(ocs)==1);
+  obschild(i) = ocs(1);
+end  
+  
+t = 1;
+for i=hnodes
+  fwd{i,t} = CPDpot{i,t};
+  c = obschild(i);
+  temp = pot_to_marginal(CPDpot{c,t}); 
+  ev = dpot(i, ns(i), temp.T);
+  fwd{i,t} = multiply_by_pot(fwd{i,t}, ev);
+  [fwd{i,t}, local_logscale(i)] = normalize_pot(fwd{i,t});
+end
+logscale(t) = sum(local_logscale);
+
+for t=2:T
+  for i=hnodes
+    ps = parents(bnet.dag, i+ss);
+    assert(all(ps<=ss)); % in previous slice
+    prior = CPDpot{i,t};
+    for p=ps(:)'
+      prior = multiply_by_pot(prior, fwd{p,t-1});
+    end
+    fwd{i,t} = marginalize_pot(prior, i+ss);
+    fwd{i,t} = set_domain_pot(fwd{i,t}, i);
+    c = obschild(i);
+    temp = pot_to_marginal(CPDpot{c,t});
+    ev = dpot(i, ns(i), temp.T);
+    fwd{i,t} = multiply_by_pot(fwd{i,t}, ev);
+    [fwd{i,t}, local_logscale(i)] = normalize_pot(fwd{i,t});
+  end
+  logscale(t) = sum(local_logscale);
+end
+
+loglik = sum(logscale);
+
+
+if filter
+  marginals = fwd;
+  return;
+end
+
+back = cell(ss,T);
+t = T;
+for i=hnodes
+  back{i,t} = dpot(i, ns(i));
+  back{i,t} = set_domain_pot(back{i,t}, i+ss);
+end
+for t=T-1:-1:1
+  for i=hnodes
+    pot = CPDpot{i,t+1};
+    pot = multiply_by_pot(pot, back{i,t+1});
+    c = obschild(i);
+    temp = pot_to_marginal(CPDpot{c,t+1});
+    ev = dpot(i, ns(i), temp.T);
+    pot = multiply_by_pot(pot, ev);
+    back{i,t} = marginalize_pot(pot, i);
+    back{i,t} = normalize_pot(back{i,t});
+    back{i,t} = set_domain_pot(back{i,t}, i+ss);
+  end
+end
+
+
+
+% COMBINE
+for t=1:T
+  for i=hnodes
+    back{i,t} = set_domain_pot(back{i,t}, i);
+    fwd{i,t} = multiply_by_pot(fwd{i,t}, back{i,t});
+    marginals{i,t} = normalize_pot(fwd{i,t});
+    %fwdback{i,t} = normalize_pot(multiply_pots(fwd{i,t}, back{i,t}));
+  end
+end