Mercurial > hg > camir-aes2014
comparison toolboxes/FullBNT-1.0.7/bnt/CPDs/@hhmmQ_CPD/Old/hhmmQ_CPD.m @ 0:e9a9cd732c1e tip
first hg version after svn
author | wolffd |
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date | Tue, 10 Feb 2015 15:05:51 +0000 |
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-1:000000000000 | 0:e9a9cd732c1e |
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1 function CPD = hhmmQ_CPD(bnet, self, Qnodes, d, D, varargin) | |
2 % HHMMQ_CPD Make the CPD for a Q node at depth D of a D-level hierarchical HMM | |
3 % CPD = hhmmQ_CPD(bnet, self, Qnodes, d, D, ...) | |
4 % | |
5 % Fd(t-1) \ Q1:d-1(t) | |
6 % \ | | |
7 % \ v | |
8 % Qd(t-1) -> Qd(t) | |
9 % / | |
10 % / | |
11 % Fd+1(t-1) | |
12 % | |
13 % We assume parents are ordered (numbered) as follows: | |
14 % Qd(t-1), Fd+1(t-1), Fd(t-1), Q1(t), ..., Qd(t) | |
15 % | |
16 % The parents of Qd(t) can either be just Qd-1(t) or the whole stack Q1:d-1(t) (allQ) | |
17 % In either case, we will call them Qps. | |
18 % If d=1, Qps does not exist. Also, the F1(t-1) -> Q1(t) arc is optional. | |
19 % If the arc is missing, startprob does not need to be specified, | |
20 % since the toplevel is assumed to never reset (F1 does not exist). | |
21 % If d=D, Fd+1(t-1) does not exist (there is no signal from below). | |
22 % | |
23 % optional args [defaults] | |
24 % | |
25 % transprob - transprob(i,k,j) = prob transition from i to j given Qps = k ['leftright'] | |
26 % selfprob - prob of a transition from i to i given Qps=k [0.1] | |
27 % startprob - startprob(k,j) = prob start in j given Qps = k ['leftstart'] | |
28 % startargs - other args to be passed to the sub tabular_CPD for learning startprob | |
29 % transargs - other args will be passed to the sub tabular_CPD for learning transprob | |
30 % allQ - 1 means use all Q nodes above d as parents, 0 means just level d-1 [0] | |
31 % F1toQ1 - 1 means add F1(t-1) -> Q1(t) arc, 0 means level 1 never resets [0] | |
32 % | |
33 % For d=1, startprob(1,j) is only needed if F1toQ1=1 | |
34 % Also, transprob(i,j) can be used instead of transprob(i,1,j). | |
35 % | |
36 % hhmmQ_CPD is a subclass of tabular_CPD so we inherit inference methods like CPD_to_pot, etc. | |
37 % | |
38 % We create isolated tabular_CPDs with no F parents to learn transprob/startprob | |
39 % so we can avail of e.g., entropic or Dirichlet priors. | |
40 % In the future, we will be able to represent the transprob using a tree_CPD. | |
41 % | |
42 % For details, see "Linear-time inference in hierarchical HMMs", Murphy and Paskin, NIPS'01. | |
43 | |
44 | |
45 ss = bnet.nnodes_per_slice; | |
46 %assert(self == Qnodes(d)+ss); | |
47 ns = bnet.node_sizes(:); | |
48 CPD.Qsizes = ns(Qnodes); | |
49 CPD.d = d; | |
50 CPD.D = D; | |
51 allQ = 0; | |
52 | |
53 % find out which parents to use, to get right size | |
54 for i=1:2:length(varargin) | |
55 switch varargin{i}, | |
56 case 'allQ', allQ = varargin{i+1}; | |
57 end | |
58 end | |
59 | |
60 if d==1 | |
61 CPD.Qps = []; | |
62 else | |
63 if allQ | |
64 CPD.Qps = Qnodes(1:d-1); | |
65 else | |
66 CPD.Qps = Qnodes(d-1); | |
67 end | |
68 end | |
69 | |
70 Qsz = ns(self); | |
71 Qpsz = prod(ns(CPD.Qps)); | |
72 | |
73 % set default arguments | |
74 startprob = 'leftstart'; | |
75 transprob = 'leftright'; | |
76 startargs = {}; | |
77 transargs = {}; | |
78 CPD.F1toQ1 = 0; | |
79 selfprob = 0.1; | |
80 | |
81 for i=1:2:length(varargin) | |
82 switch varargin{i}, | |
83 case 'transprob', transprob = varargin{i+1}; | |
84 case 'selfprob', selfprob = varargin{i+1}; | |
85 case 'startprob', startprob = varargin{i+1}; | |
86 case 'startargs', startargs = varargin{i+1}; | |
87 case 'transargs', transargs = varargin{i+1}; | |
88 case 'F1toQ1', CPD.F1toQ1 = varargin{i+1}; | |
89 end | |
90 end | |
91 | |
92 Qps = CPD.Qps + ss; | |
93 old_self = self-ss; | |
94 | |
95 if strcmp(transprob, 'leftright') | |
96 LR = mk_leftright_transmat(Qsz, selfprob); | |
97 transprob = repmat(reshape(LR, [1 Qsz Qsz]), [Qpsz 1 1]); % transprob(k,i,j) | |
98 transprob = permute(transprob, [2 1 3]); % now transprob(i,k,j) | |
99 end | |
100 transargs{end+1} = 'CPT'; | |
101 transargs{end+1} = transprob; | |
102 CPD.sub_CPD_trans = mk_isolated_tabular_CPD([old_self Qps], ns([old_self Qps self]), transargs); | |
103 S = struct(CPD.sub_CPD_trans); | |
104 CPD.transprob = myreshape(S.CPT, [Qsz Qpsz Qsz]); | |
105 | |
106 | |
107 if strcmp(startprob, 'leftstart') | |
108 startprob = zeros(Qpsz, Qsz); | |
109 startprob(:,1) = 1; | |
110 end | |
111 | |
112 if (d==1) & ~CPD.F1toQ1 | |
113 CPD.sub_CPD_start = []; | |
114 CPD.startprob = []; | |
115 else | |
116 startargs{end+1} = 'CPT'; | |
117 startargs{end+1} = startprob; | |
118 CPD.sub_CPD_start = mk_isolated_tabular_CPD(Qps, ns([Qps self]), startargs); | |
119 S = struct(CPD.sub_CPD_start); | |
120 CPD.startprob = myreshape(S.CPT, [Qpsz Qsz]); | |
121 end | |
122 | |
123 CPD = class(CPD, 'hhmmQ_CPD', tabular_CPD(bnet, self)); | |
124 | |
125 CPD = update_CPT(CPD); | |
126 |