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function CPD = update_ess(CPD, fmarginal, evidence, ns, cnodes, hidden_bitv)
% UPDATE_ESS Update the Expected Sufficient Statistics of a hhmmF node.
% function CPD = update_ess(CPD, fmarginal, evidence, ns, cnodes, hidden_bitv)
% Figure out the node numbers associated with each parent
% so we extract evidence from the right place
dom = fmarginal.domain; % Q(1) .. Q(d) F(d+1) F(d)
Qps = fmarginal.domain(1:end-2);
Q = Qps(end);
Qps = Qps(1:end-1);
Qsz = CPD.Qsizes(CPD.Q);
Qpsz = prod(CPD.Qsizes(CPD.Qps)); % may be 1
% We assume the F node are always hidden, but allow some of the Q nodes
% to be observed. We do case analysis for speed.
%We only extract prob from fmarginal.T when F(d+1)=2 i.e., model below has finished.
% wrong -> % We sum over the possibilities that F(d+1) = 1 or 2
obs_self = ~hidden_bitv(Q);
if obs_self
self_val = evidence{Q};
end
if isempty(Qps) % independent of parent context
counts = zeros(Qsz, 2);
%fmarginal.T(Q(d), F(d+1), F(d))
if obs_self
marg = myreshape(fmarginal.T, [1 2 2]);
counts(self_val,:) = marg(1,2,:);
%counts(self_val,:) = marg(1,1,:) + marg(1,2,:);
else
marg = myreshape(fmarginal.T, [Qsz 2 2]);
counts = squeeze(marg(:,2,:));
%counts = squeeze(marg(:,2,:)) + squeeze(marg(:,1,:));
end
else
counts = zeros(Qpsz, Qsz, 2);
%fmarginal.T(Q(1:d-1), Q(d), F(d+1), F(d))
obs_Qps = ~any(hidden_bitv(Qps)); % we assume that all or none of the Q parents are observed
if obs_Qps
Qps_val = subv2ind(Qpsz, cat(1, evidence{Qps}));
end
if obs_self & obs_Qps
marg = myreshape(fmarginal.T, [1 1 2 2]);
counts(Qps_val, self_val, :) = squeeze(marg(1,1,2,:));
%counts(Qps_val, self_val, :) = squeeze(marg(1,1,2,:)) + squeeze(marg(1,1,1,:));
elseif ~obs_self & obs_Qps
marg = myreshape(fmarginal.T, [1 Qsz 2 2]);
counts(Qps_val, :, :) = squeeze(marg(1,:,2,:));
%counts(Qps_val, :, :) = squeeze(marg(1,:,2,:)) + squeeze(marg(1,:,1,:));
elseif obs_self & ~obs_Qps
error('not yet implemented')
else
marg = myreshape(fmarginal.T, [Qpsz Qsz 2 2]);
counts(:, :, :) = squeeze(marg(:,:,2,:));
%counts(:, :, :) = squeeze(marg(:,:,2,:)) + squeeze(marg(:,:,1,:));
end
end
CPD.sub_CPD_term = update_ess_simple(CPD.sub_CPD_term, counts);
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