Daniel@0: function lam_msg = CPD_to_lambda_msg(CPD, msg_type, n, ps, msg, p, evidence)
Daniel@0: % CPD_TO_LAMBDA_MSG Compute lambda message (discrete)
Daniel@0: % lam_msg = compute_lambda_msg(CPD, msg_type, n, ps, msg, p, evidence)
Daniel@0: % Pearl p183 eq 4.52
Daniel@0: 
Daniel@0: switch msg_type
Daniel@0:   case 'd',
Daniel@0:    T = prod_CPT_and_pi_msgs(CPD, n, ps, msg, p);
Daniel@0:    mysize = length(msg{n}.lambda);
Daniel@0:    lambda = dpot(n, mysize, msg{n}.lambda);
Daniel@0:    T = multiply_by_pot(T, lambda);
Daniel@0:    lam_msg = pot_to_marginal(marginalize_pot(T, p));
Daniel@0:    lam_msg = lam_msg.T;           
Daniel@0:  case 'g',
Daniel@0:   error('discrete_CPD can''t create Gaussian msgs')
Daniel@0: end