Physics – Condensed Matter – Statistical Mechanics
Scientific paper
2003-05-28
Physics
Condensed Matter
Statistical Mechanics
16 pages, including 18 figures
Scientific paper
10.1103/PhysRevE.69.066138
We present two classes of improved estimators for mutual information $M(X,Y)$, from samples of random points distributed according to some joint probability density $\mu(x,y)$. In contrast to conventional estimators based on binnings, they are based on entropy estimates from $k$-nearest neighbour distances. This means that they are data efficient (with $k=1$ we resolve structures down to the smallest possible scales), adaptive (the resolution is higher where data are more numerous), and have minimal bias. Indeed, the bias of the underlying entropy estimates is mainly due to non-uniformity of the density at the smallest resolved scale, giving typically systematic errors which scale as functions of $k/N$ for $N$ points. Numerically, we find that both families become {\it exact} for independent distributions, i.e. the estimator $\hat M(X,Y)$ vanishes (up to statistical fluctuations) if $\mu(x,y) = \mu(x) \mu(y)$. This holds for all tested marginal distributions and for all dimensions of $x$ and $y$. In addition, we give estimators for redundancies between more than 2 random variables. We compare our algorithms in detail with existing algorithms. Finally, we demonstrate the usefulness of our estimators for assessing the actual independence of components obtained from independent component analysis (ICA), for improving ICA, and for estimating the reliability of blind source separation.
Grassberger Peter
Kraskov Alexander
Stoegbauer Harald
No associations
LandOfFree
Estimating Mutual Information does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Estimating Mutual Information, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Estimating Mutual Information will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-648629