Hostname: page-component-586b7cd67f-gb8f7 Total loading time: 0 Render date: 2024-11-30T19:58:30.793Z Has data issue: false hasContentIssue false

Local polynomial estimation of the mean function and itsderivatives based on functional data and regular designs

Published online by Cambridge University Press:  29 October 2014

Karim Benhenni
Affiliation:
Laboratoire LJK UMR CNRS 5224, Université de Grenoble, 38040 Grenoble, France. [email protected]
David Degras
Affiliation:
Department of Mathematical Sciences, DePaul University, Chicago 60614, Illinois, USA; [email protected]
Get access

Abstract

We study the estimation of the mean function of a continuous-time stochastic process andits derivatives. The covariance function of the process is assumed to be nonparametric andto satisfy mild smoothness conditions. Assuming that n independent realizationsof the process are observed at a sampling design of size N generated by a positivedensity, we derive the asymptotic bias and variance of the local polynomial estimator asn,Nincrease to infinity. We deduce optimal sampling densities, optimal bandwidths, andpropose a new plug-in bandwidth selection method. We establish the asymptotic performanceof the plug-in bandwidth estimator and we compare, in a simulation study, its performancefor finite sizes n,N to the cross-validation and the optimalbandwidths. A software implementation of the plug-in method is available in the Renvironment.

Type
Research Article
Copyright
© EDP Sciences, SMAI 2014

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Benhenni, K. and Cambanis, S., Sampling designs for estimating integrals of stochastic processes. Ann. Statist. 20 (1992) 161194. Google Scholar
Benhenni, K. and Rachdi, M., Nonparametric estimation of the regression function from quantized observations. Comput. Statist. Data Anal. 50 (2006) 30673085. Google Scholar
Benhenni, K. and Rachdi, M., Nonparametric estimation of average growth curve with general nonstationary error process. Comm. Statist. Theory Methods 36 (2007) 11731186. Google Scholar
S. Cambanis, Sampling designs for time series, in Time Series in the Time Domain. Edited by P.R. Krishnaiah E.J. Hannan and M.M. Rao, vol. 5 of Handbook of Statistics. Elsevier (1985) 337–362
Cardot, H., Nonparametric estimation of smoothed principal components analysis of sampled noisy functions. J. Nonparametr. Statist. 12 (2000) 503538. Google Scholar
Degras, D., Asymptotics for the nonparametric estimation of the mean function of a random process. Statist. Probab. Lett. 78 (2008) 29762980. Google Scholar
Degras, D., Simultaneous confidence bands for nonparametric regression with functional data. Statist. Sinica 21 (2011) 17351765. Google Scholar
J. Fan and I. Gijbels, Local polynomial modelling and its applications. Vol. 66 of Monogr. Stat. Appl. Probab. Chapman & Hall, London (1996).
Fan, J., Gijbels, I., Hu, T.C. and Huang, L.S., A study of variable bandwidth selection for local polynomial regression. Statist. Sinica 6 (1996) 113127. Google Scholar
Fan, J. and Marron, J.S., Fast implementations of nonparametric curve estimators. J. Comput. Graph. Statist. 3 (1994) 3556. Google Scholar
Ferreira, E., Núñez–Antón, V. and Rodríguez–Póo, J., Kernel regression estimates of growth curves using nonstationary correlated errors. Statist. Probab. Lett. 34 (1997) 413423. Google Scholar
Francisco–Fernández, M., Opsomer, J. and Vilar–Fernández, J. M., Plug-in bandwidth selector for local polynomial regression estimator with correlated errors. J. Nonparametr. Stat. 16 (2004) 127151. Google Scholar
Francisco–Fernández, M. and Vilar–Fernández, J.M., Local polynomial regression estimation with correlated errors. Comm. Statist. Theory Methods 30 (2001) 12711293. Google Scholar
Hall, P., Nath Lahiri, S. and Polzehl, J., On bandwidth choice in nonparametric regression with both short- and long-range dependent errors. Ann. Statist. 23 (1995) 19211936. Google Scholar
Hart, J.D. and Wehrly, T.E., Kernel regression estimation using repeated measurements data. J. Amer. Statist. Assoc. 81 (1986) 10801088. Google Scholar
Hart, J.D. and Wehrly, T.E., Consistency of cross-validation when the data are curves. Stoch. Process. Appl. 45 (1993) 351361. Google Scholar
Masry, E., Local polynomial fitting under association. J. Multivariate Anal. 86 (2003) 330359. Google Scholar
Masry, E. and Fan, J., Local polynomial estimation of regression functions for mixing processes. Scand. J. Statist. 24 (1997) 165179. Google Scholar
Opsomer, J., Wang, Y. and Yang, Y., Nonparametric regression with correlated errors. Statist. Sci. 16 (2001) 134153. Google Scholar
Pérez–González, A., Vilar–Fernández, J.M. and González–Manteiga, W., Asymptotic properties of local polynomial regression with missing data and correlated errors. Ann. Inst. Statist. Math. 61 (2009) 85109. Google Scholar
Perrin, O., Quadratic variation for Gaussian processes and application to time deformation. Stoch. Process. Appl. 82 (1999) 293305. Google Scholar
R. Core Team, R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, Austria (2013).
J.O. Ramsay and B.W. Silverman, Functional data analysis. Springer Ser. Statist., 2nd edition. Springer, New York (2005).
Rice, J.A. and Silverman, B.W., Estimating the mean and covariance structure nonparametrically when the data are curves. J. Roy. Statist. Soc. Ser. B 53 (1991) 233243. Google Scholar
Ruppert, D., Empirical-bias bandwidths for local polynomial nonparametric regression and density estimation. J. Amer. Statist. Assoc. 92 (1997) 10491062. Google Scholar
Ruppert, D., Sheather, S.J. and Wand, M.P., An effective bandwidth selector for local least squares regression. J. Amer. Statist. Assoc. 90 (1995) 12571270. Google Scholar
M.P. Wand and M.C. Jones, Kernel smoothing. Vol. 60 of Monogr. Statist. Appl. Probab. Chapman and Hall Ltd., London (1995).
Yao, F., Asymptotic distributions of nonparametric regression estimators for longitudinal or functional data. J. Multivariate Anal. 98 (2007) 4056. Google Scholar