English

Influence of sampling on the convergence rates of greedy algorithms for parameter-dependent random variables

Numerical Analysis 2021-09-24 v2 Numerical Analysis

Abstract

The main focus of this article is to provide a mathematical study of the algorithm proposed in \cite{boyaval2010variance} where the authors proposed a variance reduction technique for the computation of parameter-dependent expectations using a reduced basis paradigm. We study the effect of Monte-Carlo sampling on the theoretical properties of greedy algorithms. In particular, using concentration inequalities for the empirical measure in Wasserstein distance proved in \cite{fournier2015rate}, we provide sufficient conditions on the number of samples used for the computation of empirical variances at each iteration of the greedy procedure to guarantee that the resulting method algorithm is a weak greedy algorithm with high probability. These theoretical results are not fully practical and we therefore propose a heuristic procedure to choose the number of Monte-Carlo samples at each iteration, inspired from this theoretical study, which provides satisfactory results on several numerical test cases.

Keywords

Cite

@article{arxiv.2105.14091,
  title  = {Influence of sampling on the convergence rates of greedy algorithms for parameter-dependent random variables},
  author = {Mohamed-Raed Blel and Virginie Ehrlacher and Tony Lelièvre},
  journal= {arXiv preprint arXiv:2105.14091},
  year   = {2021}
}