wolffd@0: function pot = convert_to_pot(CPD, pot_type, domain, evidence)
wolffd@0: % CONVERT_TO_POT Convert a discrete CPD to a potential
wolffd@0: % pot = convert_to_pot(CPD, pot_type, domain, evidence)
wolffd@0: %
wolffd@0: % pots = CPD evaluated using evidence(domain)
wolffd@0: 
wolffd@0: ncases = size(domain,2);
wolffd@0: assert(ncases==1); % not yet vectorized
wolffd@0: 
wolffd@0: sz = dom_sizes(CPD);
wolffd@0: ns = zeros(1, max(domain));
wolffd@0: ns(domain) = sz;
wolffd@0: 
wolffd@0: CPT1 = CPD_to_CPT(CPD);
wolffd@0: spar = issparse(CPT1);
wolffd@0: odom = domain(~isemptycell(evidence(domain)));
wolffd@0: if spar
wolffd@0:    T = convert_to_sparse_table(CPD, domain, evidence);
wolffd@0: else 
wolffd@0:    T = convert_to_table(CPD, domain, evidence);
wolffd@0: end
wolffd@0: 
wolffd@0: switch pot_type
wolffd@0:  case 'u',
wolffd@0:   pot = upot(domain, sz, T, 0*myones(sz));  
wolffd@0:  case 'd',
wolffd@0:   ns(odom) = 1;
wolffd@0:   pot = dpot(domain, ns(domain), T);          
wolffd@0:  case {'c','g'},
wolffd@0:   % Since we want the output to be a Gaussian, the whole family must be observed.
wolffd@0:   % In other words, the potential is really just a constant.
wolffd@0:   p = T;
wolffd@0:   %p = prob_node(CPD, evidence(domain(end)), evidence(domain(1:end-1)));
wolffd@0:   ns(domain) = 0;
wolffd@0:   pot = cpot(domain, ns(domain), log(p));       
wolffd@0: 
wolffd@0:  case 'cg',
wolffd@0:   T = T(:);
wolffd@0:   ns(odom) = 1;
wolffd@0:   can = cell(1, length(T));
wolffd@0:   for i=1:length(T)
wolffd@0:     if T(i) == 0 
wolffd@0:       can{i} = cpot([], [], -Inf); % bug fix by Bob Welch 20/2/04
wolffd@0:     else
wolffd@0:       can{i} = cpot([], [], log(T(i)));
wolffd@0:     end;
wolffd@0:   end
wolffd@0:   pot = cgpot(domain, [], ns, can); 
wolffd@0:   
wolffd@0:  case 'scg'
wolffd@0:   T = T(:);
wolffd@0:   ns(odom) = 1;
wolffd@0:   pot_array = cell(1, length(T));
wolffd@0:   for i=1:length(T)
wolffd@0:     pot_array{i} = scgcpot([], [], T(i));
wolffd@0:   end
wolffd@0:   pot = scgpot(domain, [], [], ns, pot_array);   
wolffd@0: 
wolffd@0:  otherwise,
wolffd@0:   error(['unrecognized pot type ' pot_type])
wolffd@0: end
wolffd@0: