A Hilbert transform representation of the error in Lagrange interpolation

被引:3
作者
Kubayi, DG
Lubinsky, DS
机构
[1] Georgia Inst Technol, Sch Math, Atlanta, GA 30332 USA
[2] Univ Witwatersrand, Sch Math, ZA-2050 Wits, South Africa
关键词
Lagrange interpolation; Hilbert tranform;
D O I
10.1016/j.jat.2004.05.002
中图分类号
O1 [数学];
学科分类号
0701 ; 070101 ;
摘要
Let L-n[f] denote the Lagrange interpolation polynomial to a function f at the zeros of a polynomial P-n with distinct real zeros. We show that f - L-n [f] = -PnHc [H[f]/(P-n) over bar], where H denotes the Hilbert transform, and H-e is an extension of it. We use this to prove convergence of Lagrange interpolation for certain functions analytic in (-1, 1) that are not assumed analytic in any ellipse with foci at (-1, 1). (C) 2004 Elsevier Inc. All rights reserved.
引用
收藏
页码:94 / 100
页数:7
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