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

first hg version after svn
author wolffd
date Tue, 10 Feb 2015 15:05:51 +0000
parents
children
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolboxes/FullBNT-1.0.7/bnt/CPDs/@gaussian_CPD/sample_node.m	Tue Feb 10 15:05:51 2015 +0000
@@ -0,0 +1,22 @@
+function y = sample_node(CPD, pev)
+% SAMPLE_NODE Draw a random sample from P(Xi | x(pi_i), theta_i)  (gaussian)
+% y = sample_node(CPD, parent_evidence)
+%
+% pev{i} is the value of the i'th parent (if there are any parents)
+% y is the sampled value (a scalar or vector)
+
+if length(CPD.dps)==0
+  i = 1;
+else
+  dpvals = cat(1, pev{CPD.dps});
+  i = subv2ind(CPD.sizes(CPD.dps), dpvals(:)');
+end
+
+if length(CPD.cps) == 0 
+  y = gsamp(CPD.mean(:,i), CPD.cov(:,:,i), 1);
+else
+  pev = pev(:);
+  x = cat(1, pev{CPD.cps});
+  y = gsamp(CPD.mean(:,i) + CPD.weights(:,:,i)*x(:), CPD.cov(:,:,i), 1);
+end
+y = y(:);