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function pi = CPD_to_pi(CPD, msg_type, n, ps, msg, evidence)
% CPD_TO_PI Compute the pi vector (gaussian)
% function pi = CPD_to_pi(CPD, msg_type, n, ps, msg, evidence)
switch msg_type
case 'd',
error('gaussian_CPD can''t create discrete msgs')
case 'g',
[m, Q, W] = gaussian_CPD_params_given_dps(CPD, [ps n], evidence);
cps = ps(CPD.cps);
cpsizes = CPD.sizes(CPD.cps);
pi.mu = m;
pi.Sigma = Q;
for k=1:length(cps) % only get pi msgs from cts parents
%bk = block(k, cpsizes);
bk = CPD.cps_block_ndx{k};
Bk = W(:, bk);
m = msg{n}.pi_from_parent{k};
pi.Sigma = pi.Sigma + Bk * m.Sigma * Bk';
pi.mu = pi.mu + Bk * m.mu; % m.mu = u(k)
end
end
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