wolffd@0: function CPDpot = convert_dbn_CPDs_to_tables1(bnet, evidence)
wolffd@0: % CONVERT_DBN_CPDS_TO_TABLES Convert CPDs of (possibly instantiated) DBN nodes to tables
wolffd@0: % CPDpot = convert_dbn_CPDs_to_tables(bnet, evidence)
wolffd@0: %
wolffd@0: % CPDpot{n,t} is a table containing P(n,t|pa(n,t), ev)
wolffd@0: % All hidden nodes are assumed to be discrete
wolffd@0: % We assume the observed nodes are the same in every slice
wolffd@0: %
wolffd@0: % Evaluating the conditional likelihood of the evidence can be very slow,
wolffd@0: % so we take pains to vectorize where possible, i.e., we try to avoid
wolffd@0: % calling convert_to_table
wolffd@0: 
wolffd@0: [ss T] = size(evidence);
wolffd@0: %obs_bitv = ~isemptycell(evidence(:));
wolffd@0: obs_bitv = zeros(1, 2*ss);
wolffd@0: obs_bitv(bnet.observed) = 1;
wolffd@0: obs_bitv(bnet.observed+ss) = 1;
wolffd@0: 
wolffd@0: ns = bnet.node_sizes(:);
wolffd@0: CPDpot = cell(ss,T); 
wolffd@0: 
wolffd@0: for n=1:ss
wolffd@0:   % slice 1
wolffd@0:   t = 1;
wolffd@0:   ps = parents(bnet.dag, n);
wolffd@0:   e = bnet.equiv_class(n, 1);
wolffd@0:   if ~any(obs_bitv(ps))
wolffd@0:     CPDpot{n,t} = convert_CPD_to_table_hidden_ps(bnet.CPD{e}, evidence{n,t});
wolffd@0:   else
wolffd@0:     CPDpot{n,t} = convert_to_table(bnet.CPD{e}, [ps n], evidence(:,1));
wolffd@0:   end
wolffd@0:   
wolffd@0:   % slices 2..T
wolffd@0:   debug = 1;
wolffd@0:   if ~obs_bitv(n)
wolffd@0:     CPDpot = helper_hidden_child(bnet, evidence, n, CPDpot, obs_bitv, debug);
wolffd@0:   else
wolffd@0:     CPDpot = helper_obs_child(bnet, evidence, n, CPDpot, obs_bitv, debug);
wolffd@0:   end
wolffd@0: end
wolffd@0: 
wolffd@0: if 0
wolffd@0: CPDpot2 = convert_dbn_CPDs_to_tables_slow(bnet, evidence);
wolffd@0: for t=1:T
wolffd@0:   for n=1:ss
wolffd@0:     if ~approxeq(CPDpot{n,t}, CPDpot2{n,t})
wolffd@0:       fprintf('CPDpot n=%d, t=%d\n',n,t);
wolffd@0:       keyboard
wolffd@0:     end
wolffd@0:   end
wolffd@0: end
wolffd@0: end
wolffd@0: 
wolffd@0: 
wolffd@0: % special cases: c=child, p=parents, d=discrete, h=hidden, 1=1slice
wolffd@0: % if c=h=1 then c=d=1, since hidden nodes must be discrete
wolffd@0: % c=h c=d p=h p=d p=1 method
wolffd@0: % ---------------------------
wolffd@0: % 1   1   1   1   -   replicate CPT
wolffd@0: % 0   1   1   1   1   dhmm
wolffd@0: % 0   0   1   1   1   ghmm
wolffd@0: % -   1   -   1   -   evaluate CPT on evidence
wolffd@0: % other               loop
wolffd@0: 
wolffd@0: %%%%%%%
wolffd@0: function CPDpot = helper_hidden_child(bnet, evidence, n, CPDpot, obs_bitv, debug)
wolffd@0: 
wolffd@0: [ss T] = size(evidence);
wolffd@0: self = n+ss;
wolffd@0: ps = parents(bnet.dag, self);
wolffd@0: e = bnet.equiv_class(n, 2);
wolffd@0: ns = bnet.node_sizes(:);
wolffd@0: if ~any(obs_bitv(ps)) % all parents are hidden (hence discrete)
wolffd@0:   if debug, fprintf('node %d is hidden, all ps are hidden\n', n); end
wolffd@0:   if myismember(n, bnet.dnodes) 
wolffd@0:     %CPT = CPD_to_CPT(bnet.CPD{e});
wolffd@0:     %CPT = reshape(CPT, [prod(ns(ps)) ns(self)]);
wolffd@0:     CPT = convert_CPD_to_table_hidden_ps(bnet.CPD{e}, []);
wolffd@0:     CPDpot(n,2:T) = num2cell(repmat(CPT, [1 1 T-1]), [1 2]);
wolffd@0:   else
wolffd@0:     error(['hidden cts node disallowed'])
wolffd@0:   end
wolffd@0: else % some parents are observed - slow
wolffd@0:   if mysubset(ps, bnet.dnodes) % all parents are discrete
wolffd@0:     % given CPT(p1, p2, p3, p4, c), where p1,p3 are observed
wolffd@0:     % we create CPT([p2 p4 c], [p1 p3]).
wolffd@0:     % We then convert all observed p1,p3 into indices ndx
wolffd@0:     % and return CPT(:, ndx)
wolffd@0:     CPT = CPD_to_CPT(bnet.CPD{e});
wolffd@0:     domain = [ps self];
wolffd@0:     % if dom is [3 7 8] and 3,8 are observed, odom_rel = [1 3], hdom_rel = 2,
wolffd@0:     % odom = [3 8], hdom = 7
wolffd@0:     odom_rel = find(obs_bitv(domain));
wolffd@0:     hdom_rel = find(~obs_bitv(domain));
wolffd@0:     odom = domain(odom_rel);
wolffd@0:     hdom = domain(hdom_rel);
wolffd@0:     CPT = permute(CPT, [hdom_rel odom_rel]);
wolffd@0:     CPT = reshape(CPT, prod(ns(hdom)), prod(ns(odom)));
wolffd@0:     parents_in_same_slice = all(ps > ss);
wolffd@0:     if parents_in_same_slice
wolffd@0:       if debug, fprintf('node %d is hidden, some ps are obs, all ps discrete, 1 slice\n', n); end
wolffd@0:       data = cell2num(evidence(odom-ss,2:T)); %data(i,t) = val of i'th obs parent at t+1
wolffd@0:     else
wolffd@0:       if debug, fprintf('node %d is hidden, some ps are obs, all ps discrete, 2 slice\n', n); end
wolffd@0:       data = zeros(length(odom), T-1);
wolffd@0:       for t=2:T
wolffd@0: 	ev = evidence(:,t-1:t);
wolffd@0: 	data(:,t-1) = cell2num(ev(odom));
wolffd@0:       end
wolffd@0:     end
wolffd@0:     ndx = subv2ind(ns(odom), data'); % ndx(t) encodes data(:,t)
wolffd@0:     CPDpot(n,2:T) = num2cell(CPT(:, ndx), [1 2]);
wolffd@0:   else % some parents are cts - v slow
wolffd@0:     if debug, fprintf('node %d is hidden, some ps are obs, some ps cts\n', n); end
wolffd@0:     for t=2:T
wolffd@0:       CPDpot{n,t} = convert_to_table(bnet.CPD{e}, [ps self], evidence(:,t-1:t));
wolffd@0:     end
wolffd@0:   end
wolffd@0: end
wolffd@0:   
wolffd@0: %%%%%%%
wolffd@0: function CPDpot = helper_obs_child(bnet, evidence, n, CPDpot, obs_bitv, debug)
wolffd@0: 
wolffd@0: [ss T] = size(evidence);
wolffd@0: self = n+ss;
wolffd@0: ps = parents(bnet.dag, self);
wolffd@0: e = bnet.equiv_class(n, 2);
wolffd@0: ns = bnet.node_sizes(:);
wolffd@0: if ~any(obs_bitv(ps)) % all parents are hidden
wolffd@0:   parents_in_same_slice = all(ps > ss);
wolffd@0:   if parents_in_same_slice
wolffd@0:     if debug, fprintf('node %d is obs, all ps are hidden, 1 slice\n', n); end
wolffd@0:     ps1 = ps - ss;
wolffd@0:     if myismember(n, bnet.dnodes) 
wolffd@0:       CPT = CPD_to_CPT(bnet.CPD{e});
wolffd@0:       CPT = reshape(CPT, [prod(ns(ps)) ns(self)]); % what if no parents?
wolffd@0:       obslik = eval_pdf_cond_multinomial(cell2num(evidence(n,2:T)), CPT);
wolffd@0:       CPDpot(n,2:T) = num2cell(obslik, 1);
wolffd@0:     else
wolffd@0:       S = struct(bnet.CPD{e}); 
wolffd@0:       obslik = eval_pdf_cond_gauss(cell2num(evidence(n,2:T)), S.mean, S.cov);
wolffd@0:       CPDpot(n,2:T) = num2cell(obslik, 1);
wolffd@0:     end
wolffd@0:   else % parents span 2 slices - slow
wolffd@0:     if debug, fprintf('node %d is obs, all ps are hidden , 2 slice\n', n); end
wolffd@0:     for t=2:T
wolffd@0:       CPDpot{n,t} = convert_to_table(bnet.CPD{e}, [ps self], evidence(:,t-1:t));
wolffd@0:     end
wolffd@0:   end
wolffd@0: else 
wolffd@0:   if isempty(ps) % observed root
wolffd@0:     if debug, fprintf('node %d is obs, no ps\n', n); end
wolffd@0:     CPT = CPD_to_CPT(bnet.CPD{e});
wolffd@0:     data = cell2num(evidence(n,2:T));
wolffd@0:     CPDpot(n,2:T) = CPT(data);
wolffd@0:   else  % some parents are observed  - slow
wolffd@0:     if debug, fprintf('node %d is obs, some ps are obs\n', n); end
wolffd@0:     for t=2:T
wolffd@0:       CPDpot{n,t} = convert_to_table(bnet.CPD{e}, [ps self], evidence(:,t-1:t));
wolffd@0:     end
wolffd@0:   end
wolffd@0: end