Communications on Applied Mathematics and Computation ›› 2019, Vol. 1 ›› Issue (3): 449-466.doi: 10.1007/s42967-019-00028-7

• ORIGINAL PAPER • 上一篇    下一篇

Sequential Approximation of Functions in Sobolev Spaces Using Random Samples

Kailiang Wu, Dongbin Xiu   

  1. Department of Mathematics, The Ohio State University, Columbus, OH 43210, USA
  • 收稿日期:2018-08-27 修回日期:2018-12-03 出版日期:2019-09-20 发布日期:2019-09-09
  • 通讯作者: Dongbin Xiu, Kailiang Wu E-mail:xiu.16@osu.edu;wu.3423@osu.edu

Sequential Approximation of Functions in Sobolev Spaces Using Random Samples

Kailiang Wu, Dongbin Xiu   

  1. Department of Mathematics, The Ohio State University, Columbus, OH 43210, USA
  • Received:2018-08-27 Revised:2018-12-03 Online:2019-09-20 Published:2019-09-09

摘要: We present an iterative algorithm for approximating an unknown function sequentially using random samples of the function values and gradients. This is an extension of the recently developed sequential approximation (SA) method, which approximates a target function using samples of function values only. The current paper extends the development of the SA methods to the Sobolev space and allows the use of gradient information naturally. The algorithm is easy to implement, as it requires only vector operations and does not involve any matrices. We present tight error bound of the algorithm, and derive an optimal sampling probability measure that results in fastest error convergence. Numerical examples are provided to verify the theoretical error analysis and the effectiveness of the proposed SA algorithm.

关键词: Approximation theory, Sequential approximation, Randomized algorithm, Sobolev space, Optimal sampling probability measure

Abstract: We present an iterative algorithm for approximating an unknown function sequentially using random samples of the function values and gradients. This is an extension of the recently developed sequential approximation (SA) method, which approximates a target function using samples of function values only. The current paper extends the development of the SA methods to the Sobolev space and allows the use of gradient information naturally. The algorithm is easy to implement, as it requires only vector operations and does not involve any matrices. We present tight error bound of the algorithm, and derive an optimal sampling probability measure that results in fastest error convergence. Numerical examples are provided to verify the theoretical error analysis and the effectiveness of the proposed SA algorithm.

Key words: Approximation theory, Sequential approximation, Randomized algorithm, Sobolev space, Optimal sampling probability measure