Mauch MIREX 2010

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)

%

% we assume if one of the Qps is observed, all of them are 

% We assume the F nodes are already hidden 

% Figure out the node numbers associated with each parent

dom = fmarginal.domain;

self = dom(end);

old_self = dom(CPD.old_self_ndx);

%Fself = dom(CPD.Fself_ndx);

%Fbelow = dom(CPD.Fbelow_ndx);

Qps = dom(CPD.Qps_ndx);

Qsz = CPD.Qsz;

Qpsz = CPD.Qpsz;

% hor_counts(old_self, Qps, self),

% fmarginal(old_self, Fbelow, Fself, Qps, self)

% hor_counts(i,k,j) = fmarginal(i,2,1,k,j) % below has finished, self has not

% ver_counts(i,k,j) = fmarginal(i,2,2,k,j) % below has finished, and so has self (reset)

% Since any of i,j,k may be observed, we write

% hor_counts(i_counts_ndx, kndx, jndx) = fmarginal(i_fmarg_ndx...)

% where i_fmarg_ndx = 1 and i_counts_ndx = i if old_self is observed to have value i,

% i_fmarg_ndx = 1:Qsz and i_counts_ndx = 1:Qsz if old_self is hidden, etc.

if hidden_bitv(old_self)

  i_counts_ndx = 1:Qsz;

  eff_oldQsz = Qsz;

else

  i_counts_ndx = evidence{old_self};

  eff_oldQsz = 1;

end

if all(hidden_bitv(Qps)) % we assume all are hidden or all are observed

  k_counts_ndx = 1:Qpsz;

  eff_Qpsz = Qpsz;

else

  k_counts_ndx = subv2ind(Qpsz, cat(1, evidence{Qps}));

  eff_Qpsz = 1;

end

if hidden_bitv(self)

  j_counts_ndx = 1:Qsz;

  eff_Qsz = Qsz;

else

  j_counts_ndx = evidence{self};

  eff_Qsz = 1;

end

hor_counts = zeros(Qsz, Qpsz, Qsz);

ver_counts = zeros(Qpsz, Qsz);

if ~isempty(CPD.Fbelow_ndx)

  if ~isempty(CPD.Fself_ndx) % general case

    fmarg = myreshape(fmarginal.T, [eff_oldQsz 2 2 eff_Qpsz eff_Qsz]);

    hor_counts(i_counts_ndx, k_counts_ndx, j_counts_ndx) =  fmarg(:, 2, 1, :, :);

    ver_counts(k_counts_ndx, j_counts_ndx) = ... % sum over Fbelow and Qold

	sumv(fmarg(:, :,  2, :, :), [1 2]); % require Fself=2

  else % no F from self, hence no startprob

    fmarg = myreshape(fmarginal.T, [eff_oldQsz 2 eff_Qpsz eff_Qsz]);

    hor_counts(i_counts_ndx, k_counts_ndx, j_counts_ndx) = ...

	fmarg(:, 2, :, :); % require Fbelow = 2

  end

else % no F signal from below

  if ~isempty(CPD.Fself_ndx) % self F

    fmarg = myreshape(fmarginal.T, [eff_oldQsz 2 eff_Qpsz eff_Qsz]);

    hor_counts(i_counts_ndx, k_counts_ndx, j_counts_ndx) =  fmarg(:, 1, :, :);

    ver_counts(k_counts_ndx, j_counts_ndx) = ... % sum over Qold

	squeeze(sum(fmarg(:, 2, :, :), 1)); % Fself=2

  else % no F from self

    error('An hhmmQ node without any F parents is just a tabular_CPD')

  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