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:   dps = ps(CPD.dps);
wolffd@0:   k = evidence{dps};
wolffd@0:   if isempty(k)
wolffd@0:     error('gmux node must have observed discrete parent')
wolffd@0:   end
wolffd@0:   m = msg{n}.pi_from_parent{k}; 
wolffd@0:   B = CPD.weights(:,:,k);
wolffd@0:   pi.mu = CPD.mean(:,k) + B * m.mu;
wolffd@0:   pi.Sigma = CPD.cov(:,:,k) + B * m.Sigma * B';
wolffd@0: end