|
wolffd@0
|
1 function [transprob, termprob] = remove_hhmm_end_state(A)
|
|
wolffd@0
|
2 % REMOVE_END_STATE Infer transition and termination probabilities from automaton with an end state
|
|
wolffd@0
|
3 % [transprob, termprob] = remove_end_state(A)
|
|
wolffd@0
|
4 %
|
|
wolffd@0
|
5 % A(i,k,j) = Pr( i->j | Qps=k), where i in 1:Q, j in 1:(Q+1), and Q+1 is the end state
|
|
wolffd@0
|
6 % This implements the equation in footnote 3 of my NIPS 01 paper,
|
|
wolffd@0
|
7 % transprob(i,k,j) = \tilde{A}_k(i,j)
|
|
wolffd@0
|
8 % termprob(k,j) = \tau_k(j)
|
|
wolffd@0
|
9 %
|
|
wolffd@0
|
10 % For the top level, the k index is missing.
|
|
wolffd@0
|
11
|
|
wolffd@0
|
12 Q = size(A,1);
|
|
wolffd@0
|
13 toplevel = (ndims(A)==2);
|
|
wolffd@0
|
14 if toplevel
|
|
wolffd@0
|
15 Qk = 1;
|
|
wolffd@0
|
16 A = reshape(A, [Q 1 Q+1]);
|
|
wolffd@0
|
17 else
|
|
wolffd@0
|
18 Qk = size(A, 2);
|
|
wolffd@0
|
19 end
|
|
wolffd@0
|
20
|
|
wolffd@0
|
21 transprob = A(:, :, 1:Q);
|
|
wolffd@0
|
22 term = A(:,:,Q+1)'; % term(k,j) = P(Qj -> end | k)
|
|
wolffd@0
|
23 termprob = term;
|
|
wolffd@0
|
24 %termprob = zeros(Qk, Q, 2);
|
|
wolffd@0
|
25 %termprob(:,:,2) = term;
|
|
wolffd@0
|
26 %termprob(:,:,1) = 1-term;
|
|
wolffd@0
|
27
|
|
wolffd@0
|
28 for k=1:Qk
|
|
wolffd@0
|
29 for i=1:Q
|
|
wolffd@0
|
30 for j=1:Q
|
|
wolffd@0
|
31 denom = (1-termprob(k,i));
|
|
wolffd@0
|
32 denom = denom + (denom==0)*eps;
|
|
wolffd@0
|
33 transprob(i,k,j) = transprob(i,k,j) / denom;
|
|
wolffd@0
|
34 end
|
|
wolffd@0
|
35 end
|
|
wolffd@0
|
36 end
|
|
wolffd@0
|
37
|
|
wolffd@0
|
38 if toplevel
|
|
wolffd@0
|
39 termprob = squeeze(termprob);
|
|
wolffd@0
|
40 transprob = squeeze(transprob);
|
|
wolffd@0
|
41 end
|
