Skip to Main Content

Mathematics of Computation

Published by the American Mathematical Society since 1960 (published as Mathematical Tables and other Aids to Computation 1943-1959), Mathematics of Computation is devoted to research articles of the highest quality in computational mathematics.

ISSN 1088-6842 (online) ISSN 0025-5718 (print)

The 2020 MCQ for Mathematics of Computation is 1.78.

What is MCQ? The Mathematical Citation Quotient (MCQ) measures journal impact by looking at citations over a five-year period. Subscribers to MathSciNet may click through for more detailed information.

 

Generalized sampling and the stable and accurate reconstruction of piecewise analytic functions from their Fourier coefficients
HTML articles powered by AMS MathViewer

by Ben Adcock and Anders C. Hansen PDF
Math. Comp. 84 (2015), 237-270 Request permission

Abstract:

Suppose that the first $m$ Fourier coefficients of a piecewise analytic function are given. Direct expansion in a Fourier series suffers from the Gibbs phenomenon and lacks uniform convergence. Nonetheless, in this paper we show that, under very broad conditions, it is always possible to recover an $n$-term expansion in a different system of functions using only these coefficients. Such an expansion can be made arbitrarily close to the best possible $n$-term expansion in the given system. Thus, if a piecewise polynomial basis is employed, for example, exponential convergence can be restored. The resulting method is linear, numerically stable and can be implemented efficiently in only $\mathcal {O} \left (n m\right )$ operations.

A key issue is how the parameter $m$ must scale in comparison to $n$ to ensure such recovery. We derive analytical estimates for this scaling for large classes of polynomial and piecewise polynomial bases. In particular, we show that in many important cases, including the case of piecewise Chebyshev polynomials, this scaling is quadratic: $m=\mathcal {O}\left (n^2\right )$. Therefore, with a system of polynomials that the user is essentially free to choose, one can restore exponential accuracy in $n$ and root-exponential accuracy in $m$. This generalizes a result proved recently for piecewise Legendre polynomials.

References
Similar Articles
  • Retrieve articles in Mathematics of Computation with MSC (2010): 41A10, 41A25, 42A10
  • Retrieve articles in all journals with MSC (2010): 41A10, 41A25, 42A10
Additional Information
  • Ben Adcock
  • Affiliation: Department of Mathematics, Purdue University, West Lafayette, Indiana 47907
  • Anders C. Hansen
  • Affiliation: DAMTP, Centre for Mathematical Sciences, University of Cambridge, United Kingdom
  • Received by editor(s): November 21, 2011
  • Received by editor(s) in revised form: May 13, 2013
  • Published electronically: May 27, 2014
  • © Copyright 2014 American Mathematical Society
  • Journal: Math. Comp. 84 (2015), 237-270
  • MSC (2010): Primary 41A10, 41A25, 42A10
  • DOI: https://doi.org/10.1090/S0025-5718-2014-02860-3
  • MathSciNet review: 3266959