0


拉普拉斯问题的AAA最小二乘有理逼近与求解

AAA-least squares rational approximation and solution of Laplace problems
课程网址: https://videolectures.net/8ecm2021_trefethen_aaa_squares/  
主讲教师: Nick Trefethen
开课单位: 8ECM会议
开课时间: 2021-07-06
课程语种: 英语
中文简介:
在过去的五年里,随着重心有理逼近的AAA算法和拉普拉斯、斯托克斯和亥姆霍兹问题的闪电最小二乘解算器的引入,有理函数的计算有了很大的进步。在这里,我们将这些方法组合成求解平面拉普拉斯问题的两步方法。首先,通过AAA近似确定边界数据的复有理近似,局部靠近每个角点或其他奇异点。然后收集这些近似在问题域之外的极点,并将其用于求解的全局最小二乘拟合。典型的问题在笔记本电脑的一秒钟内解决,精确到8位数,一直到角落。这是与斯特凡诺·科斯塔的合作。
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; 拉普拉斯; 斯托克斯
课程来源: 视频讲座网
数据采集: 2024-05-22:liyq
最后编审: 2024-05-22:liyq
阅读次数: 6