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Local linear smoothing for regression surfaces on the simplex using Dirichlet kernels

Statistics Theory 2025-07-22 v4 Applications Methodology Statistics Theory

Abstract

This paper introduces a local linear smoother for regression surfaces on the simplex. The estimator solves a least-squares regression problem weighted by a locally adaptive Dirichlet kernel, ensuring good boundary properties. Asymptotic results for the bias, variance, mean squared error, and mean integrated squared error are derived, generalizing the univariate results of Chen [Ann. Inst. Statist. Math., 54(2) (2002), pp. 312-323]. A simulation study shows that the proposed local linear estimator with Dirichlet kernel outperforms its only direct competitor in the literature, the Nadaraya-Watson estimator with Dirichlet kernel due to Bouzebda, Nezzal and Elhattab [AIMS Math., 9(9) (2024), pp. 26195-26282].

Keywords

Cite

@article{arxiv.2408.07209,
  title  = {Local linear smoothing for regression surfaces on the simplex using Dirichlet kernels},
  author = {Christian Genest and Frédéric Ouimet},
  journal= {arXiv preprint arXiv:2408.07209},
  year   = {2025}
}

Comments

25 pages, 4 tables, 3 figures

R2 v1 2026-06-28T18:12:19.411Z