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function CPD = update_ess(CPD, fmarginal, evidence, ns, cnodes, hidden_bitv)
% UPDATE_ESS Update the Expected Sufficient Statistics of a hhmm Q node.
% function CPD = update_ess(CPD, fmarginal, evidence, ns, cnodes, idden_bitv)
% Figure out the node numbers associated with each parent
% e.g., D=4, d=3, Qps = all Qs above, so dom = [Q3(t-1) F4(t-1) F3(t-1) Q1(t) Q2(t) Q3(t)].
% so self = Q3(t), old_self = Q3(t-1), CPD.Qps = [1 2], Qps = [Q1(t) Q2(t)]
dom = fmarginal.domain;
self = dom(end);
old_self = dom(1);
Qps = dom(length(dom)-length(CPD.Qps):end-1);
Qsz = CPD.Qsizes(CPD.d);
Qpsz = prod(CPD.Qsizes(CPD.Qps));
% If some of the Q nodes are observed (which happens during supervised training)
% the counts will only be non-zero in positions
% consistent with the evidence. We put the computed marginal responsibilities
% into the appropriate slots of the big counts array.
% (Recall that observed discrete nodes only have a single effective value.)
% (A more general, but much slower, way is to call add_evidence_to_dmarginal.)
% We assume the F nodes are never observed.
obs_self = ~hidden_bitv(self);
obs_Qps = (~isempty(Qps)) & (~any(hidden_bitv(Qps))); % we assume that all or none of the Q parents are observed
if obs_self
self_val = evidence{self};
oldself_val = evidence{old_self};
end
if obs_Qps
Qps_val = subv2ind(Qpsz, cat(1, evidence{Qps}));
if Qps_val == 0
keyboard
end
end
if CPD.d==1 % no Qps from above
if ~CPD.F1toQ1 % no F from self
% marg(Q1(t-1), F2(t-1), Q1(t))
% F2(t-1) P(Q1(t)=j | Q1(t-1)=i)
% 1 delta(i,j)
% 2 transprob(i,j)
if obs_self
hor_counts = zeros(Qsz, Qsz);
hor_counts(oldself_val, self_val) = fmarginal.T(2);
else
marg = reshape(fmarginal.T, [Qsz 2 Qsz]);
hor_counts = squeeze(marg(:,2,:));
end
else
% marg(Q1(t-1), F2(t-1), F1(t-1), Q1(t))
% F2(t-1) F1(t-1) P(Qd(t)=j| Qd(t-1)=i)
% ------------------------------------------------------
% 1 1 delta(i,j)
% 2 1 transprob(i,j)
% 1 2 impossible
% 2 2 startprob(j)
if obs_self
marg = myreshape(fmarginal.T, [1 2 2 1]);
hor_counts = zeros(Qsz, Qsz);
hor_counts(oldself_val, self_val) = marg(1,2,1,1);
ver_counts = zeros(Qsz, 1);
%ver_counts(self_val) = marg(1,2,2,1);
ver_counts(self_val) = marg(1,2,2,1) + marg(1,1,2,1);
else
marg = reshape(fmarginal.T, [Qsz 2 2 Qsz]);
hor_counts = squeeze(marg(:,2,1,:));
%ver_counts = squeeze(sum(marg(:,2,2,:),1)); % sum over i
ver_counts = squeeze(sum(marg(:,2,2,:),1)) + squeeze(sum(marg(:,1,2,:),1)); % sum i,b
end
end % F1toQ1
else % d ~= 1
if CPD.d < CPD.D % general case
% marg(Qd(t-1), Fd+1(t-1), Fd(t-1), Qps(t), Qd(t))
% Fd+1(t-1) Fd(t-1) P(Qd(t)=j| Qd(t-1)=i, Qps(t)=k)
% ------------------------------------------------------
% 1 1 delta(i,j)
% 2 1 transprob(i,k,j)
% 1 2 impossible
% 2 2 startprob(k,j)
if obs_Qps & obs_self
marg = myreshape(fmarginal.T, [1 2 2 1 1]);
k = 1;
hor_counts = zeros(Qsz, Qpsz, Qsz);
hor_counts(oldself_val, Qps_val, self_val) = marg(1, 2,1, k,1);
ver_counts = zeros(Qpsz, Qsz);
%ver_counts(Qps_val, self_val) = marg(1, 2,2, k,1);
ver_counts(Qps_val, self_val) = marg(1, 2,2, k,1) + marg(1, 1,2, k,1);
elseif obs_Qps & ~obs_self
marg = myreshape(fmarginal.T, [Qsz 2 2 1 Qsz]);
k = 1;
hor_counts = zeros(Qsz, Qpsz, Qsz);
hor_counts(:, Qps_val, :) = marg(:, 2,1, k,:);
ver_counts = zeros(Qpsz, Qsz);
%ver_counts(Qps_val, :) = sum(marg(:, 2,2, k,:), 1);
ver_counts(Qps_val, :) = sum(marg(:, 2,2, k,:), 1) + sum(marg(:, 1,2, k,:), 1);
elseif ~obs_Qps & obs_self
error('not yet implemented')
else % everything is hidden
marg = reshape(fmarginal.T, [Qsz 2 2 Qpsz Qsz]);
hor_counts = squeeze(marg(:,2,1,:,:)); % i,k,j
%ver_counts = squeeze(sum(marg(:,2,2,:,:),1)); % sum over i
ver_counts = squeeze(sum(marg(:,2,2,:,:),1)) + squeeze(sum(marg(:,1,2,:,:),1)); % sum over i,b
end
else % d == D, so no F from below
% marg(QD(t-1), FD(t-1), Qps(t), QD(t))
% FD(t-1) P(QD(t)=j | QD(t-1)=i, Qps(t)=k)
% 1 transprob(i,k,j)
% 2 startprob(k,j)
if obs_Qps & obs_self
marg = myreshape(fmarginal.T, [1 2 1 1]);
k = 1;
hor_counts = zeros(Qsz, Qpsz, Qsz);
hor_counts(oldself_val, Qps_val, self_val) = marg(1, 1, k,1);
ver_counts = zeros(Qpsz, Qsz);
ver_counts(Qps_val, self_val) = marg(1, 2, k,1);
elseif obs_Qps & ~obs_self
marg = myreshape(fmarginal.T, [Qsz 2 1 Qsz]);
k = 1;
hor_counts = zeros(Qsz, Qpsz, Qsz);
hor_counts(:, Qps_val, :) = marg(:, 1, k,:);
ver_counts = zeros(Qpsz, Qsz);
ver_counts(Qps_val, :) = sum(marg(:, 2, k, :), 1);
elseif ~obs_Qps & obs_self
error('not yet implemented')
else % everything is hidden
marg = reshape(fmarginal.T, [Qsz 2 Qpsz Qsz]);
hor_counts = squeeze(marg(:,1,:,:));
ver_counts = squeeze(sum(marg(:,2,:,:),1)); % sum over i
end
end
end
CPD.sub_CPD_trans = update_ess_simple(CPD.sub_CPD_trans, hor_counts);
if ~isempty(CPD.sub_CPD_start)
CPD.sub_CPD_start = update_ess_simple(CPD.sub_CPD_start, ver_counts);
end
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