Open Access
Translator Disclaimer
December 1997 Optimal pointwise adaptive methods in nonparametric estimation
O. V. Lepski, V. G. Spokoiny
Ann. Statist. 25(6): 2512-2546 (December 1997). DOI: 10.1214/aos/1030741083


The problem of optimal adaptive estimation of a function at a given point from noisy data is considered. Two procedures are proved to be asymptotically optimal for different settings.

First we study the problem of bandwidth selection for nonparametric pointwise kernel estimation with a given kernel. We propose a bandwidth selection procedure and prove its optimality in the asymptotic sense. Moreover, this optimality is stated not only among kernel estimators with a variable bandwidth. The resulting estimator is asymptotically optimal among all feasible estimators. The important feature of this procedure is that it is fully adaptive and it "works" for a very wide class of functions obeying a mild regularity restriction. With it the attainable accuracy of estimation depends on the function itself and is expressed in terms of the "ideal adaptive bandwidth" corresponding to this function and a given kernel.

The second procedure can be considered as a specialization of the first one under the qualitative assumption that the function to be estimated belongs to some Hölder class $\Sigma (\beta, L)$ with unknown parameters $\beta, L$. This assumption allows us to choose a family of kernels in an optimal way and the resulting procedure appears to be asymptotically optimal in the adaptive sense in any range of adaptation with $\beta \leq 2$.


Download Citation

O. V. Lepski. V. G. Spokoiny. "Optimal pointwise adaptive methods in nonparametric estimation." Ann. Statist. 25 (6) 2512 - 2546, December 1997.


Published: December 1997
First available in Project Euclid: 30 August 2002

zbMATH: 0894.62041
MathSciNet: MR1604408
Digital Object Identifier: 10.1214/aos/1030741083

Primary: 62G07
Secondary: 62G20

Keywords: Bandwidth selection , Hölder-type constraints , pointwise adaptive estimation

Rights: Copyright © 1997 Institute of Mathematical Statistics


Vol.25 • No. 6 • December 1997
Back to Top