1 files changed, 27 insertions, 0 deletions
diff --git a/sourcecodes/bnt-master/BNT/inference/online/@jtree_2TBN_inf_engine/back.m b/sourcecodes/bnt-master/BNT/inference/online/@jtree_2TBN_inf_engine/back.m
new file mode 100644
index 00000000..7f686d55
--- /dev/null
+++ b/sourcecodes/bnt-master/BNT/inference/online/@jtree_2TBN_inf_engine/back.m
@@ -0,0 +1,27 @@
+function b = back(engine, bfuture, f, t)
+
+if f.t ~= t
+  error('mixed up time stamps')
+end
+if t==1
+  b = back1(engine, bfuture, f, t);
+  return;
+end
+
+bnet = bnet_from_engine(engine);
+ss = bnet.nnodes_per_slice;
+
+int = engine.interface;
+D = engine.in_clq;
+C = engine.out_clq;
+phiD = marginalize_pot(bfuture.clpot{D}, int, engine.maximize);
+phiD = set_domain_pot(phiD, int+ss); % shift to slice 2
+phiC = marginalize_pot(f.clpot{C}, int+ss, engine.maximize);
+ratio = divide_by_pot(phiD, phiC);
+f.clpot{C} = multiply_by_pot(f.clpot{C}, ratio);
+
+[b.clpot, seppot] = distribute_evidence(engine.jtree_engine, f.clpot, f.seppot);
+for c=1:length(b.clpot)
+  [b.clpot{c}, ll(c)] = normalize_pot(b.clpot{c});
+end
+b.t = t;