comparison toolboxes/FullBNT-1.0.7/HMM/dhmm_logprob_brute_force.m @ 0:e9a9cd732c1e tip

first hg version after svn

+function logp = enumerate_HMM_loglik(prior, transmat, obsmat)
+% ENUMERATE_HMM_LOGLIK Compute the log likelihood of a sequence by exhaustive (O(Q^T)) enumeration.
+% logp = enumerate_HMM_loglik(prior, transmat, obsmat)
+%
+% Inputs:
+% prior(i) = Pr(Q(1) = i)
+% transmat(i,j) = Pr(Q(t+1)=j | Q(t)=i)
+% obsmat(i,t) = Pr(y(t) | Q(t)=i)
+
+Q = length(prior);
+T = size(obsmat, 2);
+sizes = repmat(Q, 1, T);
+
+psum = 0;
+for i=1:Q^T
+  qs = ind2subv(sizes, i); % make the state sequence 
+  psum = psum + prob_path(prior, transmat, obsmat, qs);
+end
+logp = log(psum)
+
+