Hostname: page-component-7bb8b95d7b-dtkg6 Total loading time: 0 Render date: 2024-09-15T11:11:38.118Z Has data issue: false hasContentIssue false

Rational interpolation to |x| at the Chebyshev nodes

Published online by Cambridge University Press:  17 April 2009

Lev Brutman
Affiliation:
Department of Mathematics and Computer ScienceUniversity of HaifaHaifa 31905Israel e-mail: [email protected]
Eli Passow
Affiliation:
Department of MathematicsTemple UniversityPhiladelphia PA 19122United States of America e-mail: [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Recently the authors considered Newman-type rational interpolation to |x| induced by arbitrary sets of interpolation nodes and showed that under mild restrictions on the location of the interpolation nodes, the corresponding sequence of rational interpolants converges to |x|. In the present paper we consider the special case of the Chebyshev nodes which are known to be very efficient for polynomial interpolation. It is shown that, in contrast to the polynomial case, the approximation of |x| induced by rational interpolation at the Chebyshev nodes has the same order as rational interpolation at equidistant points.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1997

References

[1]Bernstein, S., ‘Sur la meilleure approximation de |x| par des polynômes de degrés donnés’, Acta Math. 37 (1913), 157.CrossRefGoogle Scholar
[2]Brutman, L. and Passow, E., ‘On rational interpolation to |x|’, Constr. Approx. (to appear).Google Scholar
[3]Byrne, G.J., Mills, T.M. and Smith, S.J., ‘On Lagrange's interpolation with equidistant nodes’, Bull. Austral. Math. Soc. 42 (1990), 8189.CrossRefGoogle Scholar
[4]Gradsteyn, I.S. and Ryzhik, I.M., Table of integrals, series and produds (Academic Press, New York, 1980).Google Scholar
[5]Newman, D., ‘Rational approximation to |x|’, Michigan Math. J. 11 (1964), 1114.CrossRefGoogle Scholar
[6]Rivlin, T.J., Chebyshev polynomials, (2nd ed.) (Wiley, New York, 1990).Google Scholar
[7]Stahl, H., ‘Best uniform rational approximation of |x| on [−1,1]’, Mat. Sb. 183 (1992), 85118.Google Scholar
[8]Werner, H., ‘Rationale Interpolation von |x| in äquidistanten Punkten’, Math. Z. 180 (1982), 85118.CrossRefGoogle Scholar