of the observedd nodes in each slice,
which correspond to y):
<pre>
ev = sample_dbn(bnet, T);
evidence = cell(ss,T);
evidence(onodes,:) = ev(onodes, :); % all cells besides onodes are empty
[engine, ll] = enter_evidence(engine, evidence);
marg = marginal_nodes(engine, i, t);
</pre>


<h2><a name="discrete">Discrete hidden nodes</h2>

If all the hidden nodes are discrete,
we can use the junction tree algorithm to perform inference.
The simplest approach,
<tt>jtree_unrolled_dbn_inf_engine</tt>,
unrolls the DB