wolffd@0: function pi = CPD_to_pi(CPD, msg_type, n, ps, msg, evidence)
wolffd@0: % CPD_TO_PI Compute the pi vector (gaussian)
wolffd@0: % function pi = CPD_to_pi(CPD, msg_type, n, ps, msg, evidence)
wolffd@0: 
wolffd@0: switch msg_type
wolffd@0:  case 'd',
wolffd@0:   error('gaussian_CPD can''t create discrete msgs')
wolffd@0:  case 'g',
wolffd@0:   [m, Q, W] = gaussian_CPD_params_given_dps(CPD, [ps n], evidence);
wolffd@0:   cps = ps(CPD.cps);
wolffd@0:   cpsizes = CPD.sizes(CPD.cps);
wolffd@0:   pi.mu = m;
wolffd@0:   pi.Sigma = Q;
wolffd@0:   for k=1:length(cps) % only get pi msgs from cts parents
wolffd@0:     %bk = block(k, cpsizes);
wolffd@0:     bk = CPD.cps_block_ndx{k};
wolffd@0:     Bk = W(:, bk);
wolffd@0:     m = msg{n}.pi_from_parent{k}; 
wolffd@0:     pi.Sigma = pi.Sigma + Bk * m.Sigma * Bk';
wolffd@0:     pi.mu = pi.mu + Bk * m.mu; % m.mu = u(k)
wolffd@0:   end
wolffd@0: end