English

On polynomial interpolation in the monomial basis

Numerical Analysis 2025-03-06 v5 Numerical Analysis

Abstract

In this paper, we show that the monomial basis is generally as good as a well-conditioned polynomial basis for interpolation, provided that the condition number of the Vandermonde matrix is smaller than the reciprocal of machine epsilon. This leads to a practical algorithm for piecewise polynomial interpolation over general regions in the complex plane using the monomial basis. Our analysis also yields a new upper bound for the condition number of an arbitrary Vandermonde matrix, which generalizes several previous results.

Keywords

Cite

@article{arxiv.2212.10519,
  title  = {On polynomial interpolation in the monomial basis},
  author = {Zewen Shen and Kirill Serkh},
  journal= {arXiv preprint arXiv:2212.10519},
  year   = {2025}
}

Comments

31 pages, 17 figures. Accepted by SIAM J. Numer. Anal

R2 v1 2026-06-28T07:45:21.454Z