Best L1 approximation of Heaviside-type functions from Chebyshev and weak-Chebyshev spaces

被引:2
|
作者
Gajny, Laurent [1 ]
Gibaru, Olivier [1 ,2 ]
Nyiri, Eric [1 ]
Fang, Shu-Cherng [3 ]
机构
[1] CNRS, UMR 7296, LSIS, Arts & Metiers ParisTech, 8 Blvd Louis XIV, F-59046 Lille, France
[2] INRIA Lille Nord Europe, NON A Res Team, 40 Ave Halley, F-59650 Villeneuve Dascq, France
[3] North Carolina State Univ, Edward P Fitts Dept Ind & Syst Engn, Raleigh, NC 27695 USA
关键词
Best approximation; L-1; norm; Heaviside function; Polynomials; Polynomial splines; Chebyshev space; Weak-Chebyshev space;
D O I
10.1007/s11075-016-0222-8
中图分类号
O29 [应用数学];
学科分类号
070104 ;
摘要
In this article, we study the problem of best L-1 approximation of Heaviside-type functions from Chebyshev and weak-Chebyshev spaces. We extend the Hobby-Rice theorem (Proc. Am. Math. Soc., 16, 665-670, 1965) into an appropriate framework and prove the unicity of best L-1 approximation of Heaviside-type functions from an even-dimensional Chebyshev space under some assumptions on the dimension of the subspaces composed of the odd and even functions. We also apply the results to compute best L-1 approximations of Heaviside-type functions by polynomials and Hermite polynomial splines with fixed knots.
引用
收藏
页码:827 / 843
页数:17
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