function engine = jtree_dbn_inf_engine(bnet, varargin)% JTREE_DBN_INF_ENGINE Junction tree inference algorithm for DBNs.ss = length(bnet.intra);onodes = [];if nargin >= 2  args = varargin;  nargs = length(args);  for i=1:2:nargs    switch args{i},     case 'observed', onodes = args{i+1};    end  endend[int, engine.persist, engine.transient] = compute_interface_nodes(bnet.intra, bnet.inter);%engine.interface = engine.persist; % WRONG!engine.interface = int;engine.nonint = mysetdiff(1:ss, int);if 0  % Create a 2 slice jtree  % We force there to be cliques containing the in and out interfaces for slices t and t+1.  obs_nodes = [onodes(:) onodes(:)+ss];  engine.jtree_engine = jtree_inf_engine(bnet, 'observed', obs_nodes(:), ...					 'clusters', {int, int+ss}, 'root', int+ss);else  % Create a "1.5 slice" jtree, containing slice 1 and the interface nodes of slice 2  nodes15 = [1:ss int+ss];  N = length(nodes15);  dag15 = bnet.dag(nodes15, nodes15);  ns15 = bnet.node_sizes(nodes15);  eclass15 = bnet.equiv_class(nodes15);  discrete_bitv = zeros(1,2*ss);  discrete_bitv(bnet.dnodes) = 1;  discrete15 = find(discrete_bitv(nodes15));  bnet15 = mk_bnet(dag15, ns15, 'equiv_class', eclass15, 'discrete', discrete15);  bnet15.CPD = bnet.CPD; % CPDs for non-interface nodes in slice 2 will not be used  obs_bitv = zeros(1, 2*ss);  obs_bitv([onodes onodes+ss]) = 1;  obs_nodes15 = find(obs_bitv(nodes15));  int_bitv = zeros(1,ss);  int_bitv(int) = 1;  engine.jtree_engine = jtree_inf_engine(bnet15, 'observed', obs_nodes15(:), ...				     'clusters', {int, int+ss}, 'root', int+ss);endengine.in_clq = clq_containing_nodes(engine.jtree_engine, int);engine.out_clq = clq_containing_nodes(engine.jtree_engine, int+ss);engine.clq_ass_to_node = zeros(ss, 2);for i=1:ss  engine.clq_ass_to_node(i, 1) = clq_containing_nodes(engine.jtree_engine, i);  engine.clq_ass_to_node(i, 2) = clq_containing_nodes(engine.jtree_engine, i+ss);endengine.jtree_struct = struct(engine.jtree_engine); % violate object privacy% stuff needed by marginal_nodesengine.clpot = [];engine.maximize = [];engine.T = [];engine = class(engine, 'jtree_dbn_inf_engine', inf_engine(bnet));