Hyperinterpolation on the square

[摘要] We show that hyperinterpolation at (near) minimal cubature points for the product Chebyshev measure, along with Xu compact formula for the corresponding reproducing kernel, provide a simple and powerful polynomial approximation formula in the uniform norm on the square. The Lebesgue constant of the hyperinterpolation operator grows like log(2) of the degree, as that of quasi-optimal interpolation sets recently proposed in the literature. Moreover, we give an accurate implementation of the hyperinterpolation formula with linear cost in the number of cubature points, and we compare it with interpolation formulas at the same set of points. (C) 2006 Published by Elsevier B.V.

[发布日期] 2007-12-31

[效力级别]  Proceedings Paper

[关键词] hyperinterpolation;square;Xu points;minimal cubature formulas;Lebesgue constant