Mercurial > hg > camir-aes2014
annotate toolboxes/FullBNT-1.0.7/HMM/dhmm_logprob_brute_force.m @ 0:e9a9cd732c1e tip
first hg version after svn
| author | wolffd |
|---|---|
| date | Tue, 10 Feb 2015 15:05:51 +0000 |
| parents | |
| children |
| rev | line source |
|---|---|
| wolffd@0 | 1 function logp = enumerate_HMM_loglik(prior, transmat, obsmat) |
| wolffd@0 | 2 % ENUMERATE_HMM_LOGLIK Compute the log likelihood of a sequence by exhaustive (O(Q^T)) enumeration. |
| wolffd@0 | 3 % logp = enumerate_HMM_loglik(prior, transmat, obsmat) |
| wolffd@0 | 4 % |
| wolffd@0 | 5 % Inputs: |
| wolffd@0 | 6 % prior(i) = Pr(Q(1) = i) |
| wolffd@0 | 7 % transmat(i,j) = Pr(Q(t+1)=j | Q(t)=i) |
| wolffd@0 | 8 % obsmat(i,t) = Pr(y(t) | Q(t)=i) |
| wolffd@0 | 9 |
| wolffd@0 | 10 Q = length(prior); |
| wolffd@0 | 11 T = size(obsmat, 2); |
| wolffd@0 | 12 sizes = repmat(Q, 1, T); |
| wolffd@0 | 13 |
| wolffd@0 | 14 psum = 0; |
| wolffd@0 | 15 for i=1:Q^T |
| wolffd@0 | 16 qs = ind2subv(sizes, i); % make the state sequence |
| wolffd@0 | 17 psum = psum + prob_path(prior, transmat, obsmat, qs); |
| wolffd@0 | 18 end |
| wolffd@0 | 19 logp = log(psum) |
| wolffd@0 | 20 |
| wolffd@0 | 21 |