Eigenvalue problems to compute almost optimal points for rational interpolation with prescribed poles

✍ Scribed by Van Deun J.

• Year: 2007
• Tongue: English
• Leaves: 11
• Category: Library

✦ Synopsis

Explicit formulas exist for the (n,m) rational function with monic numerator and prescribed poles that has the smallest possible Chebyshev norm. In this paper we derive two different eigenvalue problems to obtain the zeros of this extremal function. The first one is an ordinary tridiagonal eigenvalue problem based on a representation in terms of Chebyshev polynomials. The second is a generalised tridiagonal eigenvalue problem which we derive using a connection with orthogonal rational functions. In the polynomial case (m = 0) both problems reduce to the tridiagonal eigenvalue problem associated with the Chebyshev polynomials of the first kind.

✦ Table of Contents

Introduction......Page 1
Preliminaries......Page 2
Ordinary eigenvalue problem......Page 5
Generalised eigenvalue problem......Page 6
Examples......Page 8
Concluding remarks......Page 10
References......Page 11