• 中国计算机学会会刊
  • 中国科技核心期刊
  • 中文核心期刊

J4 ›› 2008, Vol. 30 ›› Issue (10): 85-86.

• 论文 • 上一篇    下一篇

数值求导的离散正则化方法

宛艳萍 孙曙光 肖庭延   

  • 出版日期:2008-10-01 发布日期:2010-05-19

  • Online:2008-10-01 Published:2010-05-19

摘要:

数值微分作为一个典型的反问题,在Hadamard意义下是不适定的,即在求导中函数的微小扰动就可能导致计算上很大的误差。本文首次利用目前处理不适定问题的、广为采用且相当有效的Tikhonov 正则化方法,讨论了用离散正则化方法处理数值求导的有关理论和技术问题,包括离散正则解的收敛性、稳定性以及在原始数据误差水平已知和未知 情况下的正则参数选取问题,给出了稳定和有效的算法,并在Matlab环境下加以实现,而且进行了成功的数值试验和对比试验研究。理论分析和数值试验表明:利用本文所给 给的离散正则化算法求导,具有精度高和数值稳定性好、抗干扰性能强等优点。

关键词: 数值微分 不适定性 离散正则化方法 正则参数 偏差原理

Abstract:

Numerical differentiation is a typical inverse problem. It is known to be ill-posed in the sense of Hadamard that small perturbations in the function   to be differentiated may lead to large errors in the computed derivative. For the first time Tikhonov' s regularizing method is used to discuss some th heoretical and technical problems of applying the discrete regularization method to do the problem of numerical differentiation, among which, the analys  is of convergence and stability of discrete regularization solution, the selection of regularization parameters with and without knowing the error level   of the input data, the development of the stable algorithms, are concerned and presented, and the numerical tests with comparison are also Given. A the   oretical analysis and numeri- cal test shows that using the discrete regularization method given in this paper on numerical differentiation possesses th   e advantages of wide application, high accuracy and good numerical stability.

Key words: numerical differentiation, ill-posed, discrete regularization method, regularization parameter, dis crepancy principle