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AAA-最小二乘有理逼近和拉普拉斯问题的解

AAA-least squares rational approximation and solution of Laplace problems
课程网址: http://videolectures.net/8ecm2021_trefethen_aaa_squares/  
主讲教师: Nick Trefethen
开课单位: 牛津大学
开课时间: 2021-07-06
课程语种: 英语
中文简介:
在过去的五年中,随着用于重心有理逼近的 AAA 算法的引入以及针对拉普拉斯、斯托克斯和亥姆霍兹问题的闪电最小二乘求解器的引入,有理函数的计算取得了长足的进步。 在这里,我们将这些方法组合成解决平面拉普拉斯问题的两步法。 首先,边界数据的复杂有理逼近由 AAA 逼近确定,局部靠近每个角或其他奇点。 然后收集问题域之外的这些近似值的极点,并用于全局最小二乘拟合解决方案。 典型问题可在笔记本电脑的一秒内解决,精度达到 8 位,一直到角落。 这是与 Stefano Costa 的联合工作。
课程简介: In the past five years, computation with rational functions has advanced greatly with the introduction of the AAA algorithm for barycentric rational approximation and of lightning least-squares solvers for Laplace, Stokes, and Helmholtz problems. Here we combine these methods into a two-step method for solving planar Laplace problems. First, complex rational approximations to the boundary data are determined by AAA approximation, locally near each corner or other singularity. The poles of these approximations outside the problem domain are then collected and used for a global least-squares fit to the solution. Typical problems are solved in a second of laptop time to 8-digit accuracy, all the way up to the corners. This is joint work with Stefano Costa.
关 键 词: AAA算法; 最小二乘; 有理函数
课程来源: 视频讲座网
数据采集: 2022-03-27:hqh
最后编审: 2022-03-27:hqh
阅读次数: 31