jtree_dbn_fast_inf_engine.m

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function engine = jtree_dbn_fast_inf_engine(bnet, onodes, compiled)
% JTREE_DBN_FAST_INF_ENGINE Like jtree_dbn, but with optimizations
% function engine = jtree_dbn_fast_inf_engine(bnet, onodes, compiled)
%
% This is just like jtree_dbn, except the onodes argument (which specifies which nodes are observed in
% every slice) is required. All the hidden nodes must always be discrete.
% It is like BK in exact mode, except we exploit the fact that there is only one cluster.
% Internally, this uses fast_jtree_onepass_inf_engine instead of jtree_inf_engine.
% For a description of what we mean by 'fast', see the documentation for fast_jtree_inf_engine.

if nargin < 3, compiled = []; end

ss = length(bnet.intra);

clusters = { 1:ss };
slice1 = (1:ss);
slice2 = (1:ss)+ss;
onodes2 = [onodes(:) onodes(:)+ss];
ns = bnet.node_sizes_slice(:);
ns(onodes) = 1;


% 1 slice network to get started
bnet1 = mk_bnet(bnet.intra1, bnet.node_sizes_slice, bnet.dnodes, bnet.equiv_class(:,1));
for i=1:max(bnet1.equiv_class)
  bnet1.CPD{i} = bnet.CPD{i};
end
engine.sub_engine1 = jtree_onepass_fast_inf_engine(bnet1, slice1, onodes, [], compiled);
[engine.fwd1.clq_ass_to_cluster, engine.fwd1.cluster_ndx, engine.fwd1.marg_cluster_ndx] = ...
    mk_cluster_clq_ndx(engine.sub_engine1, ns, clusters, 1);
[engine.fwd1.clq_ass_to_node, engine.fwd1.CPD_ndx] = mk_CPD_clq_ndx(engine.sub_engine1, ss, 1);

engine.fwd.engine = jtree_onepass_fast_inf_engine(bnet, slice2, onodes2(:), {slice1}, compiled);
[engine.fwd.clq_ass_to_cluster, engine.fwd.cluster_ndx, engine.fwd.marg_cluster_ndx] = ...
    mk_cluster_clq_ndx(engine.fwd.engine, ns, clusters, 2);
[engine.fwd.clq_ass_to_node, engine.fwd.CPD_ndx] = mk_CPD_clq_ndx(engine.fwd.engine, ss, 2);

engine.back.engine = jtree_onepass_fast_inf_engine(bnet, slice1, onodes2(:), {slice2}, compiled);
[engine.back.clq_ass_to_cluster, engine.back.cluster_ndx, engine.back.marg_cluster_ndx] = ...
    mk_cluster_clq_ndx(engine.back.engine, ns, clusters, 2);
[engine.back.clq_ass_to_node, engine.back.CPD_ndx] = mk_CPD_clq_ndx(engine.back.engine, ss, 2);

% we call it sub_engine so it is compatible with the fast_bk methods
engine.sub_engine = jtree_fast_inf_engine(bnet, onodes2(:), { slice1, slice2 }, compiled);
[engine.fb.clq_ass_to_cluster, engine.fb.cluster_ndx, engine.fb.marg_cluster_ndx] = ...
    mk_cluster_clq_ndx(engine.sub_engine, ns, clusters, 2);
[engine.fb.clq_ass_to_node, engine.fb.CPD_ndx] = mk_CPD_clq_ndx(engine.sub_engine, ss, 2);

engine.cltables = [];
engine.filter = [];
engine.T = [];
engine.onodes = onodes;

engine = class(engine, 'jtree_dbn_fast_inf_engine', inf_engine(bnet));