wolffd@0: function CPD = update_CPT(CPD)
wolffd@0: % Compute the big CPT for an HHMM Q node (including F parents) given internal transprob and startprob
wolffd@0: % function CPD = update_CPT(CPD)
wolffd@0: 
wolffd@0: Qsz = CPD.Qsz;
wolffd@0: Qpsz = CPD.Qpsz;
wolffd@0: 
wolffd@0: if ~isempty(CPD.Fbelow_ndx)
wolffd@0:   if ~isempty(CPD.Fself_ndx) % general case
wolffd@0:     % Fb(t-1) Fself(t-1)  P(Q(t)=j| Q(t-1)=i, Qps(t)=k)
wolffd@0:     % ------------------------------------------------------
wolffd@0:     % 1        1         delta(i,j)
wolffd@0:     % 2        1         transprob(i,k,j)
wolffd@0:     % 1        2         impossible
wolffd@0:     % 2        2         startprob(k,j)
wolffd@0:     CPT = zeros(Qsz, 2, 2, Qpsz, Qsz);
wolffd@0:     I = repmat(eye(Qsz), [1 1 Qpsz]); % i,j,k
wolffd@0:     I = permute(I, [1 3 2]); % i,k,j
wolffd@0:     CPT(:, 1, 1, :, :) = I;
wolffd@0:     CPT(:, 2, 1, :, :) = CPD.transprob;
wolffd@0:     CPT(:, 1, 2, :, :) = I;
wolffd@0:     CPT(:, 2, 2, :, :) = repmat(reshape(CPD.startprob, [1 Qpsz Qsz]), ...
wolffd@0: 				[Qsz 1 1]); % replicate  over i 
wolffd@0:   else % no F from self, hence no startprob
wolffd@0:     % Fb(t-1) P(Q(t)=j| Q(t-1)=i, Qps(t)=k)
wolffd@0:     % ------------------------------------------------------
wolffd@0:     % 1       delta(i,j)
wolffd@0:     % 2       transprob(i,k,j)
wolffd@0:     
wolffd@0:     nps = length(CPD.dom_sz)-1; % num parents
wolffd@0:     CPT = 0*myones(CPD.dom_sz);
wolffd@0:     %CPT = zeros(Qsz, 2, Qpsz, Qsz); % assumes CPT(Q(t-1), F(t-1), Qps, Q(t))
wolffd@0:     % but a member of Qps may preceed Q(t-1) or F(t-1) in the ordering
wolffd@0: 
wolffd@0:     for k=1:CPD.Qpsz
wolffd@0:       Qps_vals = ind2subv(CPD.Qpsizes, k);
wolffd@0:       ndx = mk_multi_index(nps+1, [CPD.Fbelow_ndx CPD.Qps_ndx], [1 Qps_vals]);
wolffd@0:       CPT(ndx{:}) = eye(Qsz); % CPT(:,2,k,:) or CPT(:,k,2,:) etc
wolffd@0:     end
wolffd@0:     ndx = mk_multi_index(nps+1, CPD.Fbelow_ndx, 2);
wolffd@0:     CPT(ndx{:}) = CPD.transprob; % we assume transprob is in topo order
wolffd@0:   end
wolffd@0: else % no F signal from below
wolffd@0:   if ~isempty(CPD.Fself_ndx)
wolffd@0:     % Q(t-1), Fself(t-1), Qps, Q(t)
wolffd@0:     
wolffd@0:     % Fself(t-1)  P(Q(t-1)=i, Qps(t)=k -> Q(t)=j)
wolffd@0:     % ------------------------------------------------------
wolffd@0:     % 1         transprob(i,k,j)
wolffd@0:     % 2         startprob(k,j)
wolffd@0:     
wolffd@0:     nps = length(CPD.dom_sz)-1; % num parents
wolffd@0:     CPT = 0*myones(CPD.dom_sz);
wolffd@0:     ndx = mk_multi_index(nps+1, CPD.Fself_ndx, 1);
wolffd@0:     CPT(ndx{:}) = CPD.transprob;
wolffd@0:     if CPD.fullstartprob
wolffd@0:       ndx = mk_multi_index(nps+1, CPD.Fself_ndx, 2);
wolffd@0:       CPT(ndx{:}) = CPD.startprob;
wolffd@0:     else
wolffd@0:       for i=1:CPD.Qsz
wolffd@0: 	ndx = mk_multi_index(nps+1, [CPD.Fself_ndx CPD.old_self_ndx], [2 i]);
wolffd@0: 	CPT(ndx{:}) = CPD.startprob;
wolffd@0:       end
wolffd@0:     end
wolffd@0:   else % no F from self
wolffd@0:     error('An hhmmQ node without any F parents is just a tabular_CPD')
wolffd@0:   end
wolffd@0: end
wolffd@0: 
wolffd@0: CPD = set_fields(CPD, 'CPT', CPT);