wolffd@0: function L = log_prior(CPD)
wolffd@0: % LOG_PRIOR Return log P(theta) for a tabular CPD 
wolffd@0: % L = log_prior(CPD)
wolffd@0: 
wolffd@0: switch CPD.prior_type
wolffd@0:  case 'none',
wolffd@0:   L = 0;
wolffd@0:  case 'dirichlet',
wolffd@0:   D = CPD.dirichlet(:);
wolffd@0:   L = sum(log(D + (D==0)));
wolffd@0:  case 'entropic',
wolffd@0:   % log-prior = log exp(-H(theta)) = sum_i theta_i log (theta_i)
wolffd@0:   fam_sz = CPD.sizes;
wolffd@0:   psz = prod(fam_sz(1:end-1));
wolffd@0:   ssz = fam_sz(end);
wolffd@0:   C = reshape(CPD.CPT, psz, ssz);
wolffd@0:   L = sum(sum(C .* log(C + (C==0))));
wolffd@0: end