view toolboxes/FullBNT-1.0.7/bnt/CPDs/@gaussian_CPD/Old/log_prob_node.m @ 0:e9a9cd732c1e tip

first hg version after svn

function L = log_prob_node(CPD, self_ev, pev)
% LOG_PROB_NODE Compute prod_m log P(x(i,m)| x(pi_i,m), theta_i) for node i (gaussian)
% L = log_prob_node(CPD, self_ev, pev)
%
% self_ev(m) is the evidence on this node in case m.
% pev(i,m) is the evidence on the i'th parent in case m (if there are any parents).
% (These may also be cell arrays.)

if iscell(self_ev), usecell = 1; else usecell = 0; end

use_log = 1;
ncases = length(self_ev);
nparents = length(CPD.sizes)-1;
assert(ncases == size(pev, 2));

if ncases == 0
  L = 0;
  return;
end

if length(CPD.dps)==0 % no discrete parents, so we can vectorize
  i = 1;
  if usecell
    Y = cell2num(self_ev);
  else
    Y = self_ev;
  end
  if length(CPD.cps) == 0 
    L = gaussian_prob(Y, CPD.mean(:,i), CPD.cov(:,:,i), use_log);
  else
    if usecell
      X = cell2num(pev);
    else
      X = pev;
    end
    L = gaussian_prob(Y, CPD.mean(:,i) + CPD.weights(:,:,i)*X, CPD.cov(:,:,i), use_log);
  end
else % each case uses a (potentially) different set of parameters
  L = 0;
  for m=1:ncases
    if usecell
      dpvals = cat(1, pev{CPD.dps, m});
    else
      dpvals = pev(CPD.dps, m);
    end
    i = subv2ind(CPD.sizes(CPD.dps), dpvals(:)');
    y = self_ev{m};
    if length(CPD.cps) == 0 
      L = L + gaussian_prob(y, CPD.mean(:,i), CPD.cov(:,:,i), use_log);
    else
      if usecell
	x = cat(1, pev{CPD.cps, m});
      else
	x = pev(CPD.cps, m);
      end
      L = L + gaussian_prob(y, CPD.mean(:,i) + CPD.weights(:,:,i)*x, CPD.cov(:,:,i), use_log);
    end
  end
end