论文标题

数值集成规则,其准确度已接近奇异性

Numerical integration rules with improved accuracy close to singularities

论文作者

Amat, Sergio, Li, Zhilin, Ruiz-Alvarez, Juan, Solano, Concepcion, Trillo, Juan C.

论文摘要

有时,有必要仅使用离散数据获得数值集成。在某些情况下,数据包含已知位置的奇异性,但与离散点不一致,并且该函数及其导数的跳跃在这些位置上可用。本文的动机是使用先前的信息获得数值正交公式,该公式允许准确地超过某些间隔的离散数据积分。这项工作致力于对新的非线性技术的构建和分析,该技术允许使用包含奇异性的数据以及仅在网格点上知道集成的数据的任何顺序的准确数值集成。该技术的新颖性在于包含校正术语,其封闭表达取决于函数跳跃的大小及其在奇异性下的衍生物的大小,这应该是已知的。这些术语的添加允许恢复经典数值集成公式的准确性,甚至接近奇异性,因为这些校正术语说明了经典集成公式在平滑区域的准确性。因此,可以在集成期间或作为后处理过程中添加校正项,如果已经使用经典公式完成了积分的主要计算,这将很有用。执行的数值实验使我们能够确认本文中得出的理论结论。

Sometimes it is necessary to obtain a numerical integration using only discretised data. In some cases, the data contains singularities which position is known but does not coincide with a discretisation point, and the jumps in the function and its derivatives are available at these positions. The motivation of this paper is to use the previous information to obtain numerical quadrature formulas that allow approximating the integral of the discrete data over certain intervals accurately. This work is devoted to the construction and analysis of a new nonlinear technique that allows to obtain accurate numerical integrations of any order using data that contains singularities, and when the integrand is only known at grid points. The novelty of the technique consists in the inclusion of correction terms with a closed expression that depends on the size of the jumps of the function and its derivatives at the singularities, that are supposed to be known. The addition of these terms allows recovering the accuracy of classical numerical integration formulas even close to the singularities, as these correction terms account for the error that the classical integration formulas commit up to their accuracy at smooth zones. Thus, the correction terms can be added during the integration or as post-processing, which is useful if the main calculation of the integral has been already done using classical formulas. The numerical experiments performed allow us to confirm the theoretical conclusions reached in this paper.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源