Mercurial > hg > camir-aes2014
diff 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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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/toolboxes/FullBNT-1.0.7/bnt/CPDs/@hhmmQ_CPD/Old/hhmmQ_CPD.m Tue Feb 10 15:05:51 2015 +0000 @@ -0,0 +1,126 @@ +function CPD = hhmmQ_CPD(bnet, self, Qnodes, d, D, varargin) +% HHMMQ_CPD Make the CPD for a Q node at depth D of a D-level hierarchical HMM +% CPD = hhmmQ_CPD(bnet, self, Qnodes, d, D, ...) +% +% Fd(t-1) \ Q1:d-1(t) +% \ | +% \ v +% Qd(t-1) -> Qd(t) +% / +% / +% Fd+1(t-1) +% +% We assume parents are ordered (numbered) as follows: +% Qd(t-1), Fd+1(t-1), Fd(t-1), Q1(t), ..., Qd(t) +% +% The parents of Qd(t) can either be just Qd-1(t) or the whole stack Q1:d-1(t) (allQ) +% In either case, we will call them Qps. +% If d=1, Qps does not exist. Also, the F1(t-1) -> Q1(t) arc is optional. +% If the arc is missing, startprob does not need to be specified, +% since the toplevel is assumed to never reset (F1 does not exist). +% If d=D, Fd+1(t-1) does not exist (there is no signal from below). +% +% optional args [defaults] +% +% transprob - transprob(i,k,j) = prob transition from i to j given Qps = k ['leftright'] +% selfprob - prob of a transition from i to i given Qps=k [0.1] +% startprob - startprob(k,j) = prob start in j given Qps = k ['leftstart'] +% startargs - other args to be passed to the sub tabular_CPD for learning startprob +% transargs - other args will be passed to the sub tabular_CPD for learning transprob +% allQ - 1 means use all Q nodes above d as parents, 0 means just level d-1 [0] +% F1toQ1 - 1 means add F1(t-1) -> Q1(t) arc, 0 means level 1 never resets [0] +% +% For d=1, startprob(1,j) is only needed if F1toQ1=1 +% Also, transprob(i,j) can be used instead of transprob(i,1,j). +% +% hhmmQ_CPD is a subclass of tabular_CPD so we inherit inference methods like CPD_to_pot, etc. +% +% We create isolated tabular_CPDs with no F parents to learn transprob/startprob +% so we can avail of e.g., entropic or Dirichlet priors. +% In the future, we will be able to represent the transprob using a tree_CPD. +% +% For details, see "Linear-time inference in hierarchical HMMs", Murphy and Paskin, NIPS'01. + + +ss = bnet.nnodes_per_slice; +%assert(self == Qnodes(d)+ss); +ns = bnet.node_sizes(:); +CPD.Qsizes = ns(Qnodes); +CPD.d = d; +CPD.D = D; +allQ = 0; + +% find out which parents to use, to get right size +for i=1:2:length(varargin) + switch varargin{i}, + case 'allQ', allQ = varargin{i+1}; + end +end + +if d==1 + CPD.Qps = []; +else + if allQ + CPD.Qps = Qnodes(1:d-1); + else + CPD.Qps = Qnodes(d-1); + end +end + +Qsz = ns(self); +Qpsz = prod(ns(CPD.Qps)); + +% set default arguments +startprob = 'leftstart'; +transprob = 'leftright'; +startargs = {}; +transargs = {}; +CPD.F1toQ1 = 0; +selfprob = 0.1; + +for i=1:2:length(varargin) + switch varargin{i}, + case 'transprob', transprob = varargin{i+1}; + case 'selfprob', selfprob = varargin{i+1}; + case 'startprob', startprob = varargin{i+1}; + case 'startargs', startargs = varargin{i+1}; + case 'transargs', transargs = varargin{i+1}; + case 'F1toQ1', CPD.F1toQ1 = varargin{i+1}; + end +end + +Qps = CPD.Qps + ss; +old_self = self-ss; + +if strcmp(transprob, 'leftright') + LR = mk_leftright_transmat(Qsz, selfprob); + transprob = repmat(reshape(LR, [1 Qsz Qsz]), [Qpsz 1 1]); % transprob(k,i,j) + transprob = permute(transprob, [2 1 3]); % now transprob(i,k,j) +end +transargs{end+1} = 'CPT'; +transargs{end+1} = transprob; +CPD.sub_CPD_trans = mk_isolated_tabular_CPD([old_self Qps], ns([old_self Qps self]), transargs); +S = struct(CPD.sub_CPD_trans); +CPD.transprob = myreshape(S.CPT, [Qsz Qpsz Qsz]); + + +if strcmp(startprob, 'leftstart') + startprob = zeros(Qpsz, Qsz); + startprob(:,1) = 1; +end + +if (d==1) & ~CPD.F1toQ1 + CPD.sub_CPD_start = []; + CPD.startprob = []; +else + startargs{end+1} = 'CPT'; + startargs{end+1} = startprob; + CPD.sub_CPD_start = mk_isolated_tabular_CPD(Qps, ns([Qps self]), startargs); + S = struct(CPD.sub_CPD_start); + CPD.startprob = myreshape(S.CPT, [Qpsz Qsz]); +end + +CPD = class(CPD, 'hhmmQ_CPD', tabular_CPD(bnet, self)); + +CPD = update_CPT(CPD); +