annotate _FullBNT/BNT/CPDs/@gaussian_CPD/sample_node.m @ 8:b5b38998ef3b

added all that other stuff
author matthiasm
date Fri, 11 Apr 2014 15:54:25 +0100
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matthiasm@8 1 function y = sample_node(CPD, pev)
matthiasm@8 2 % SAMPLE_NODE Draw a random sample from P(Xi | x(pi_i), theta_i) (gaussian)
matthiasm@8 3 % y = sample_node(CPD, parent_evidence)
matthiasm@8 4 %
matthiasm@8 5 % pev{i} is the value of the i'th parent (if there are any parents)
matthiasm@8 6 % y is the sampled value (a scalar or vector)
matthiasm@8 7
matthiasm@8 8 if length(CPD.dps)==0
matthiasm@8 9 i = 1;
matthiasm@8 10 else
matthiasm@8 11 dpvals = cat(1, pev{CPD.dps});
matthiasm@8 12 i = subv2ind(CPD.sizes(CPD.dps), dpvals(:)');
matthiasm@8 13 end
matthiasm@8 14
matthiasm@8 15 if length(CPD.cps) == 0
matthiasm@8 16 y = gsamp(CPD.mean(:,i), CPD.cov(:,:,i), 1);
matthiasm@8 17 else
matthiasm@8 18 pev = pev(:);
matthiasm@8 19 x = cat(1, pev{CPD.cps});
matthiasm@8 20 y = gsamp(CPD.mean(:,i) + CPD.weights(:,:,i)*x(:), CPD.cov(:,:,i), 1);
matthiasm@8 21 end
matthiasm@8 22 y = y(:);