diff toolboxes/FullBNT-1.0.7/bnt/CPDs/@gaussian_CPD/CPD_to_pi.m @ 0:e9a9cd732c1e tip

first hg version after svn

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolboxes/FullBNT-1.0.7/bnt/CPDs/@gaussian_CPD/CPD_to_pi.m	Tue Feb 10 15:05:51 2015 +0000
@@ -0,0 +1,22 @@
+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