N = 1; % single chain = HMM - should give exact answersQ = 2;rand('state', 0);randn('state', 0);discrete = 1;if discrete  Y = 2; % size of output alphabetelse  Y = 1;endcoupled = 1;bnet  = mk_chmm(N, Q, Y, discrete, coupled);ss = N*2;T = 3;engine = {};engine{end+1} = jtree_dbn_inf_engine(bnet); engine{end+1} = jtree_unrolled_dbn_inf_engine(bnet, T); engine{end+1} = pearl_unrolled_dbn_inf_engine(bnet, 'protocol', 'tree');  inf_time = cmp_inference_dbn(bnet, engine, T)learning_time = cmp_learning_dbn(bnet, engine, T)