wolffd@0: function pi = CPD_to_pi(CPD, msg_type, n, ps, msg, evidence)
wolffd@0: % COMPUTE_PI Compute pi vector (discrete) 
wolffd@0: % pi = compute_pi(CPD, msg_type, n, ps, msg, evidence)
wolffd@0: % Pearl p183 eq 4.51
wolffd@0: 
wolffd@0: switch msg_type
wolffd@0:   case 'd',
wolffd@0:    T = prod_CPT_and_pi_msgs(CPD, n, ps, msg);
wolffd@0:    pi = pot_to_marginal(marginalize_pot(T, n));
wolffd@0:    pi = pi.T(:);                   
wolffd@0:  case 'g', 
wolffd@0:   error('can only convert discrete CPD to Gaussian pi if observed')
wolffd@0: end