Mercurial > hg > camir-aes2014
diff toolboxes/FullBNT-1.0.7/bnt/CPDs/@softmax_CPD/update_ess.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/@softmax_CPD/update_ess.m Tue Feb 10 15:05:51 2015 +0000 @@ -0,0 +1,97 @@ +function CPD = update_ess(CPD, fmarginal, evidence, ns, cnodes, hidden_bitv) +% UPDATE_ESS Update the Expected Sufficient Statistics of a softmax node +% function CPD = update_ess(CPD, fmarginal, evidence, ns, cnodes, hidden_bitv) +% +% fmarginal = overall posterior distribution of self and its parents +% fmarginal(i1,i2...,ik,s)=prob(Pa1=i1,...,Pak=ik, self=s| X) +% +% => 1) prob(self|Pa1,...,Pak)=fmarginal/prob(Pa1,...,Pak) with prob(Pa1,...,Pak)=sum{s,fmarginal} +% [self estimation -> CPD.self_vals] +% 2) prob(Pa1,...,Pak) [WIRLS weights -> CPD.eso_weights] +% +% Hidden_bitv is ignored + +% Written by Pierpaolo Brutti + +if ~adjustable_CPD(CPD), return; end + +domain = fmarginal.domain; +self = domain(end); +ps = domain(1:end-1); +cnodes = domain(CPD.cpndx); +cps = myintersect(domain, cnodes); +dps = mysetdiff(ps, cps); +dn_use = dps; +if isempty(evidence{self}) dn_use = [dn_use self]; end % if self is hidden we must consider its dimension +dps_as_cps = domain(CPD.dps_as_cps.ndx); +odom = domain(~isemptycell(evidence(domain))); + +ns = zeros(1, max(domain)); +ns(domain) = CPD.sizes; % CPD.sizes = bnet.node_sizes([ps self]); +ens = ns; % effective node sizes +ens(odom) = 1; +dpsize = prod(ns(dps)); + +% Extract the params compatible with the observations (if any) on the discrete parents (if any) +dops = myintersect(dps, odom); +dpvals = cat(1, evidence{dops}); + +subs = ind2subv(ens(dn_use), 1:prod(ens(dn_use))); +dpmap = find_equiv_posns(dops, dn_use); +if ~isempty(dpmap), subs(:,dpmap) = subs(:,dpmap)+repmat(dpvals(:)',[size(subs,1) 1])-1; end +supportedQs = subv2ind(ns(dn_use), subs); subs=subs(1:prod(ens(dps)),1:length(dps)); +Qarity = prod(ns(dn_use)); +if isempty(dn_use), Qarity = 1; end + +fullm.T = zeros(Qarity, 1); +fullm.T(supportedQs) = fmarginal.T(:); +rs_dim = CPD.sizes; rs_dim(CPD.cpndx) = 1; % +if ~isempty(evidence{self}), rs_dim(end)=1; end % reshaping the marginal +fullm.T = reshape(fullm.T, rs_dim); % + +% --------------------------------------------------------------------------------UPDATE-- + +CPD.nsamples = CPD.nsamples + 1; + +% 1) observations vector -> CPD.parents_vals --------------------------------------------- +cpvals = cat(1, evidence{cps}); + +if ~isempty(dps_as_cps), % ...get in the dp_as_cp parents... + separator = CPD.dps_as_cps.separator; + dp_as_cpmap = find_equiv_posns(dps_as_cps, dps); + for i=1:dpsize, + dp_as_cpvals=zeros(1,sum(ns(dps_as_cps))); + possible_vals = ind2subv(ns(dps),i); + ll=find(ismember(subs(:,dp_as_cpmap), possible_vals(dp_as_cpmap), 'rows')==1); + if ~isempty(ll), + where_one = separator + possible_vals(dp_as_cpmap); + dp_as_cpvals(where_one)=1; + end + CPD.parent_vals(CPD.nsamples,:,i) = [dp_as_cpvals(:); cpvals(:)]'; + end +else + CPD.parent_vals(CPD.nsamples,:) = cpvals(:)'; +end + +% 2) weights vector -> CPD.eso_weights ---------------------------------------------------- +if isempty(evidence{self}), % self is hidden + pesi=reshape(sum(fullm.T, length(rs_dim)),[dpsize,1]); +else + pesi=reshape(fullm.T,[dpsize,1]); +end +assert(approxeq(sum(pesi),1)); % check + +% 3) estimate (if R is hidden) or recover (if R is obs) self'value------------------------- +if isempty(evidence{self}) % P(self|Pa1,...,Pak)=fmarginal/prob(Pa1,...,Pak) + r=reshape(mk_stochastic(fullm.T), [dpsize ns(self)]); % matrix size: prod{j,ns(Paj)} x ns(self) +else + r = zeros(dpsize,ns(self)); + for i=1:dpsize, if pesi(i)~=0, r(i,evidence{self}) = 1; end; end +end +for i=1:dpsize, if pesi(i)~=0, assert(approxeq(sum(r(i,:)),1)); end; end % check + +% 4) save the previous values -------------------------------------------------------------- +for i=1:dpsize + CPD.eso_weights(CPD.nsamples,:,i)=pesi(i); + CPD.self_vals(CPD.nsamples,:,i) = r(i,:); +end