Sharp Oracle Inequalities for Aggregation of Affine Estimators

Autor: Arnak S. Dalalyan, Joseph Salmon
Přispěvatelé: Centre de Recherche en Économie et Statistique (CREST), Ecole Nationale de la Statistique et de l'Analyse de l'Information [Bruz] (ENSAI)-École polytechnique (X)-École Nationale de la Statistique et de l'Administration Économique (ENSAE Paris)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Probabilités et Modèles Aléatoires (LPMA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Statistics and Probability
Statistics::Theory
model selection
Heteroscedasticity
Mathematics - Statistics Theory
Statistics Theory (math.ST)
02 engineering and technology
[STAT.OT]Statistics [stat]/Other Statistics [stat.ML]
01 natural sciences
010104 statistics & probability
symbols.namesake
62G08
[MATH.MATH-ST]Mathematics [math]/Statistics [math.ST]
minimax risk
FOS: Mathematics
0202 electrical engineering
electronic engineering
information engineering

oracle inequalities
Applied mathematics
62G05
0101 mathematics
62G20
Mathematics
62C20
Model selection
aggregation
Estimator
020206 networking & telecommunications
Regression analysis
[STAT.TH]Statistics [stat]/Statistics Theory [stat.TH]
exponential weights
Minimax
AMS 62G08
exponentially weighted aggregation
Gaussian noise
Adaptive estimator
symbols
regression
Affine transformation
Statistics
Probability and Uncertainty
Zdroj: Annals of Statistics
Annals of Statistics, Institute of Mathematical Statistics, 2012, 40 (4), pp.2327-2355. ⟨10.1214/12-AOS1038⟩
Ann. Statist. 40, no. 4 (2012), 2327-2355
Annals of Statistics, 2012, 40 (4), pp.2327-2355. ⟨10.1214/12-AOS1038⟩
ISSN: 0090-5364
2168-8966
DOI: 10.1214/12-AOS1038⟩
Popis: International audience; We consider the problem of combining a (possibly uncountably infinite) set of affine estimators in non-parametric regression model with heteroscedastic Gaussian noise. Focusing on the exponentially weighted aggregate, we prove a PAC-Bayesian type inequality that leads to sharp oracle inequalities in discrete but also in continuous settings. The framework is general enough to cover the combinations of various procedures such as least square regression, kernel ridge regression, shrinking estimators and many other estimators used in the literature on statistical inverse problems. As a consequence, we show that the proposed aggregate provides an adaptive estimator in the exact minimax sense without neither discretizing the range of tuning parameters nor splitting the set of observations. We also illustrate numerically the good performance achieved by the exponentially weighted aggregate.
Databáze: OpenAIRE