comparison toolboxes/FullBNT-1.0.7/bnt/CPDs/@hhmmQ_CPD/maximize_params.m @ 0:e9a9cd732c1e tip

first hg version after svn

+function CPD = maximize_params(CPD, temp)
+% MAXIMIZE_PARAMS Set the params of a hhmmQ node to their ML/MAP values.
+% CPD = maximize_params(CPD, temperature)
+
+Qsz = CPD.Qsz;
+Qpsz = CPD.Qpsz;
+
+if ~isempty(CPD.sub_CPD_start)
+  CPD.sub_CPD_start = maximize_params(CPD.sub_CPD_start, temp);
+  S = struct(CPD.sub_CPD_start);
+  CPD.startprob = myreshape(S.CPT, [Qpsz Qsz]);
+  %CPD.startprob = S.CPT;
+end
+
+if 1
+  % If we are in a state that can only go the end state,
+  % we will never see a transition to another (non-end) state,
+  % so counts(i,k,j)=0 (and termprob(k,i)=1).
+  % We set counts(i,k,i)=1 in this case.
+  % This will cause remove_hhmm_end_state to return a
+  % stochastic matrix, but otherwise has no effect on EM.
+  counts = get_field(CPD.sub_CPD_trans, 'counts');
+  counts = reshape(counts, [Qsz Qpsz Qsz]);
+  for k=1:Qpsz
+    for i=1:Qsz
+      if sum(counts(i,k,:))==0 % never witnessed a transition out of i
+	counts(i,k,i)=1; % add self loop 
+	%fprintf('CPDQ d=%d i=%d k=%d\n', CPD.d, i, k);
+      end
+    end
+  end
+  CPD.sub_CPD_trans = set_fields(CPD.sub_CPD_trans, 'counts', counts(:)); 
+end
+ 
+CPD.sub_CPD_trans = maximize_params(CPD.sub_CPD_trans, temp);
+S = struct(CPD.sub_CPD_trans);
+%CPD.transprob = S.CPT;
+CPD.transprob = myreshape(S.CPT, [Qsz Qpsz Qsz]);
+
+CPD = update_CPT(CPD);