wolffd@0: function marginal = marginal_family(engine, i, t, add_ev)
wolffd@0: % MARGINAL_FAMILY Compute the marginal on the specified family (hmm)
wolffd@0: % marginal = marginal_family(engine, i, t, add_ev)
wolffd@0: 
wolffd@0: if nargin < 3, t = 1; end
wolffd@0: if nargin < 4, add_ev = 0; end
wolffd@0: 
wolffd@0: ns = engine.eff_node_sizes(:);
wolffd@0: ss = engine.slice_size;
wolffd@0: 
wolffd@0: if t==1 | ~engine.persist_bitv(i)
wolffd@0:   bigT = engine.one_slice_marginal(:,t);
wolffd@0:   ps = engine.parents{i};
wolffd@0:   dom = [ps i] + (t-1)*ss;
wolffd@0:   bigdom = 1:ss;
wolffd@0:   bigsz = ns(bigdom);
wolffd@0:   bigdom = bigdom + (t-1)*ss;
wolffd@0: else % some parents are in previous slice
wolffd@0:   bigT = engine.two_slice_marginal(:,t-1); % t-1 and t
wolffd@0:   ps = engine.parents{i+ss};
wolffd@0:   dom = [ps i+ss] + (t-2)*ss; 
wolffd@0:   bigdom = 1:(2*ss); % domain of xi(:,:,t)
wolffd@0:   bigsz = ns(bigdom);
wolffd@0:   bigdom = bigdom + (t-2)*ss;
wolffd@0: end
wolffd@0: marginal.domain = dom;
wolffd@0: 
wolffd@0: marginal.T = marg_table(bigT, bigdom, bigsz, dom, engine.maximize); 
wolffd@0: marginal.mu = []; 
wolffd@0: marginal.Sigma = [];
wolffd@0: 
wolffd@0: if add_ev
wolffd@0:   marginal = add_ev_to_dmarginal(marginal, engine.evidence, engine.node_sizes);
wolffd@0: end    
wolffd@0: