wolffd@0: function M = unroll_higher_order_topology(intra, inter, T, intra1)
wolffd@0: % UNROLL_DBN_TOPOLOGY Make the block diagonal adjacency matrix for a DBN consisting of T slices
wolffd@0: % M = unroll_dbn_topology(intra, inter, T, intra1)
wolffd@0: %
wolffd@0: % intra is the connectivity within a slice, inter between two slices.
wolffd@0: % M will have intra along the diagonal, and inter one above the diagonal.
wolffd@0: % intra1 is an optional argumnet, in case the intra is different for the first slice.
wolffd@0: 
wolffd@0: if nargin < 4 
wolffd@0:     intra1 = intra; 
wolffd@0: end;
wolffd@0: 
wolffd@0: 
wolffd@0: ss = length(intra); % slice size
wolffd@0: M = sparse(ss*T, ss*T);
wolffd@0: [rows,columns,order] = size(inter);
wolffd@0: for t1 = 1:T
wolffd@0:   b = 1 + (t1 - 1)*ss : t1*ss;
wolffd@0:   if t1 == 1
wolffd@0:       M(b,b) = intra1;
wolffd@0:   else
wolffd@0:       M(b,b) = intra;
wolffd@0:   end
wolffd@0:   for t2 = 1:order
wolffd@0:     if t1 + t2 <= T
wolffd@0:       M(b,b+t2*ss) = inter(:,:,t2);
wolffd@0:     end
wolffd@0:   end
wolffd@0: end
wolffd@0: