Minimax estimation of Functional Principal Components from noisy discretized functional data

Fuente: arXiv
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Main Authors: Belhakem, Ryad, Picard, Franck, Rivoirard, Vincent, Roche, Angelina
Format: Preprint
Published: 2021
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author Belhakem, Ryad
Picard, Franck
Rivoirard, Vincent
Roche, Angelina
author_facet Belhakem, Ryad
Picard, Franck
Rivoirard, Vincent
Roche, Angelina
contents Functional Principal Component Analysis is a reference method for dimension reduction of curve data. Its theoretical properties are now well understood in the simplified case where the sample curves are fully observed without noise. However, functional data are noisy and necessarily observed on a finite discretization grid. Common practice consists in smoothing the data and then to compute the functional estimates, but the impact of this denoising step on the procedure's statistical performance are rarely considered. Here we prove new convergence rates for functional principal component estimators. We introduce a double asymptotic framework: one corresponding to the sampling size and a second to the size of the grid. We prove that estimates based on projection onto histograms show optimal rates in a minimax sense. Theoretical results are illustrated on simulated data and the method is applied to the visualization of genomic data.
format Preprint
id arxiv_https___arxiv_org_abs_2110_12739
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle Minimax estimation of Functional Principal Components from noisy discretized functional data
Belhakem, Ryad
Picard, Franck
Rivoirard, Vincent
Roche, Angelina
Methodology
Functional Principal Component Analysis is a reference method for dimension reduction of curve data. Its theoretical properties are now well understood in the simplified case where the sample curves are fully observed without noise. However, functional data are noisy and necessarily observed on a finite discretization grid. Common practice consists in smoothing the data and then to compute the functional estimates, but the impact of this denoising step on the procedure's statistical performance are rarely considered. Here we prove new convergence rates for functional principal component estimators. We introduce a double asymptotic framework: one corresponding to the sampling size and a second to the size of the grid. We prove that estimates based on projection onto histograms show optimal rates in a minimax sense. Theoretical results are illustrated on simulated data and the method is applied to the visualization of genomic data.
title Minimax estimation of Functional Principal Components from noisy discretized functional data
topic Methodology
url https://arxiv.org/abs/2110.12739