摘要
The present paper constructs a set of nodes which can generate a rationalinterpolating function to approximate |x|at the rate of O(1/(nk log n))for any givennatural number κ.More importantly.this construction reveals the fact that the higherdensity the distribution of a set of nodes has to zero (that is the singular point of thefunction |x|!),the better the rational interpolation approximation behaves.This probablyalso provides an idea to construct more valuable sets of nodes in the future.
本文中我们构造了一个结点组,基于它定义的有理插值函数,对于任意给定的自然数k,对|x|的逼近能达到精确阶O(1/(nblogn)).更重要的是,这样的构造揭示了一个本质:当结点向(|x|的唯一奇异点)零点集中时,|x|的有理插值逼近阶也随之更佳,这或许为将来本质性的自然结点组的构造提供了一种思路.
基金
Supported in part by National and Provincial Natural Science Foundations(under grant numbers 10141001 and 101009)
by Ningbo Key Doctoral Funds.
