Skip to main content
Top
Published in: Calcolo 3/2019

01-09-2019

Conditioning of polynomial Fourier sums

Authors: J. M. Carnicer, Y. Khiar, J. M. Peña

Published in: Calcolo | Issue 3/2019

Login to get access

Activate our intelligent search to find suitable subject content or patents.

search-config
loading …

Abstract

In order to measure the stability properties of Fourier sums, we introduce a conditioning of a representation of the solution of the least squares problem. We relate the conditioning of the discrete polynomial Fourier sums with the corresponding continuous one. We study the asymptotic growth of the conditioning in terms of the degree n. For Fourier–Legendre sums, it is \(O(n^{3/2})\). In the case of Fourier–Chebyshev sums, it is linear in the degree. For Fourier sums with Chebyshev polynomials of the second kind, it is \(O(n^2)\).
Literature
1.
go back to reference Abramowitz, M., Stegun, I.: Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables, vol. 55. National Bureau of Standards Applied Mathematics Series, Washington (1972)MATH Abramowitz, M., Stegun, I.: Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables, vol. 55. National Bureau of Standards Applied Mathematics Series, Washington (1972)MATH
2.
go back to reference Beals, R., Wong, R.: Special Functions and Orthogonal Polynomials. Cambridge University Press, Cambridge (2016)CrossRef Beals, R., Wong, R.: Special Functions and Orthogonal Polynomials. Cambridge University Press, Cambridge (2016)CrossRef
3.
go back to reference Carnicer, J.M., Khiar, Y., Peña, J.M.: Optimal stability of the Lagrange formula and conditioning of the Newton formula. J. Approx. Theory 238, 52–66 (2019)MathSciNetCrossRef Carnicer, J.M., Khiar, Y., Peña, J.M.: Optimal stability of the Lagrange formula and conditioning of the Newton formula. J. Approx. Theory 238, 52–66 (2019)MathSciNetCrossRef
4.
go back to reference Cheney, E.W.: Introduction to Approximation Theory, 2nd edn. AMS Chelsea Publishing, Providence (1982)MATH Cheney, E.W.: Introduction to Approximation Theory, 2nd edn. AMS Chelsea Publishing, Providence (1982)MATH
5.
go back to reference Cheney, E.W., Light, W.: A Course in Approximation Theory. Brooks/Cole Publishing Company, Pacific Groove (2000)MATH Cheney, E.W., Light, W.: A Course in Approximation Theory. Brooks/Cole Publishing Company, Pacific Groove (2000)MATH
7.
go back to reference Faber, G.: Über die interpolatorische Darstellung stetiger Funktionen. DMV 23, 192–210 (1914)MATH Faber, G.: Über die interpolatorische Darstellung stetiger Funktionen. DMV 23, 192–210 (1914)MATH
8.
go back to reference Lebesgue, H.: Sur les intégrales singulières. Ann. Fac. Sci. Toulouse Sci. Math. Sci. Phys. 1, 25–117 (1909)MathSciNetMATH Lebesgue, H.: Sur les intégrales singulières. Ann. Fac. Sci. Toulouse Sci. Math. Sci. Phys. 1, 25–117 (1909)MathSciNetMATH
9.
go back to reference Nikolaev, V.F.: Concerning the approximation of continuous functions by polynomials. Doklady Akad. Nauk SSSR 61, 201–204 (1948)MathSciNet Nikolaev, V.F.: Concerning the approximation of continuous functions by polynomials. Doklady Akad. Nauk SSSR 61, 201–204 (1948)MathSciNet
10.
go back to reference Rivlin, T.J.: Chebyshev Polynomials. From Approximation Theory to Algebra and Number Theory, Pure and Applied Mathematics (New York). Wiley, New York (1990) Rivlin, T.J.: Chebyshev Polynomials. From Approximation Theory to Algebra and Number Theory, Pure and Applied Mathematics (New York). Wiley, New York (1990)
11.
go back to reference Rudin, W.: Real and Complex Analysis. Mac Graw-Hill, London (1970)MATH Rudin, W.: Real and Complex Analysis. Mac Graw-Hill, London (1970)MATH
Metadata
Title
Conditioning of polynomial Fourier sums
Authors
J. M. Carnicer
Y. Khiar
J. M. Peña
Publication date
01-09-2019
Publisher
Springer International Publishing
Published in
Calcolo / Issue 3/2019
Print ISSN: 0008-0624
Electronic ISSN: 1126-5434
DOI
https://doi.org/10.1007/s10092-019-0323-6

Other articles of this Issue 3/2019

Calcolo 3/2019 Go to the issue

Premium Partner