Mercurial > hg > camir-aes2014
annotate toolboxes/FullBNT-1.0.7/HMM/mc_sample_endstate.m @ 0:e9a9cd732c1e tip
first hg version after svn
author | wolffd |
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date | Tue, 10 Feb 2015 15:05:51 +0000 |
parents | |
children |
rev | line source |
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wolffd@0 | 1 function S = sample_mc_endstate(startprob, trans, endprob) |
wolffd@0 | 2 % SAMPLE_MC_ENDSTATE Generate a random sequence from a Markov chain until enter the endstate. |
wolffd@0 | 3 % seq = sample_mc(startprob, trans, endprob) |
wolffd@0 | 4 |
wolffd@0 | 5 % add an end state |
wolffd@0 | 6 Q = size(trans,1); |
wolffd@0 | 7 transprob = zeros(Q,Q+1); |
wolffd@0 | 8 end_state = Q+1; |
wolffd@0 | 9 for i=1:Q |
wolffd@0 | 10 for j=1:Q |
wolffd@0 | 11 transprob(i,j) = (1-endprob(i)) * trans(i,j); |
wolffd@0 | 12 end |
wolffd@0 | 13 transprob(i,end_state) = endprob(i); |
wolffd@0 | 14 %assert(approxeq(sum(transprob(i,:)), 1)) |
wolffd@0 | 15 end |
wolffd@0 | 16 |
wolffd@0 | 17 S = []; |
wolffd@0 | 18 S(1) = sample_discrete(startprob); |
wolffd@0 | 19 t = 1; |
wolffd@0 | 20 p = endprob(S(t)); |
wolffd@0 | 21 stop = (S(1) == end_state); |
wolffd@0 | 22 while ~stop |
wolffd@0 | 23 S(t+1) = sample_discrete(transprob(S(t),:)); |
wolffd@0 | 24 stop = (S(t+1) == end_state); |
wolffd@0 | 25 t = t + 1; |
wolffd@0 | 26 end |
wolffd@0 | 27 S = S(1:end-1); % don't include end state |