diff toolboxes/FullBNT-1.0.7/KPMstats/KLgauss.m @ 0:e9a9cd732c1e tip

first hg version after svn
author wolffd
date Tue, 10 Feb 2015 15:05:51 +0000
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolboxes/FullBNT-1.0.7/KPMstats/KLgauss.m	Tue Feb 10 15:05:51 2015 +0000
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+function kl = KLgauss(P, Q)
+%The following computes D(P||Q), the KL divergence between two zero-mean
+%Gaussians with covariance P and Q:
+%  klDiv = -0.5*(log(det(P*inv(Q))) + trace(eye(N)-P*inv(Q)));
+
+R = P*inv(Q);
+kl = -0.5*(log(det(R))) + trace(eye(length(P))-R);
+
+%To get MI, just set P=cov(X,Y) and Q=blockdiag(cov(X),cov(Y)).