Entropy 2013, 15(5), 1609-1623; doi:10.3390/e15051609

A Novel Nonparametric Distance Estimator for Densities with Error Bounds

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Received: 19 December 2012; in revised form: 25 April 2013 / Accepted: 28 April 2013 / Published: 6 May 2013
(This article belongs to the Special Issue Estimating Information-Theoretic Quantities from Data)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: The use of a metric to assess distance between probability densities is an important practical problem. In this work, a particular metric induced by an α-divergence is studied. The Hellinger metric can be interpreted as a particular case within the framework of generalized Tsallis divergences and entropies. The nonparametric Parzen’s density estimator emerges as a natural candidate to estimate the underlying probability density function, since it may account for data from different groups, or experiments with distinct instrumental precisions, i.e., non-independent and identically distributed (non-i.i.d.) data. However, the information theoretic derived metric of the nonparametric Parzen’s density estimator displays infinite variance, limiting the direct use of resampling estimators. Based on measure theory, we present a change of measure to build a finite variance density allowing the use of resampling estimators. In order to counteract the poor scaling with dimension, we propose a new nonparametric two-stage robust resampling estimator of Hellinger’s metric error bounds for heterocedastic data. The approach presents very promising results allowing the use of different covariances for different clusters with impact on the distance evaluation.
Keywords: generalized differential entropies; generalized differential divergences; Tsallis entropy; Hellinger metric; nonparametric estimators; heterocedastic data
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MDPI and ACS Style

Carvalho, A.R.; Tavares, J.M.R.S.; Principe, J.C. A Novel Nonparametric Distance Estimator for Densities with Error Bounds. Entropy 2013, 15, 1609-1623.

AMA Style

Carvalho AR, Tavares JMRS, Principe JC. A Novel Nonparametric Distance Estimator for Densities with Error Bounds. Entropy. 2013; 15(5):1609-1623.

Chicago/Turabian Style

Carvalho, Alexandre R.; Tavares, João M.R.S.; Principe, Jose C. 2013. "A Novel Nonparametric Distance Estimator for Densities with Error Bounds." Entropy 15, no. 5: 1609-1623.

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