Saddle-point systems, i.e., structured linear systems with symmetric matrices are considered. A modified implementation of (preconditioned) MINRES is derived which allows to monitor the norms of the subvectors individually. Compared to the implementation from the textbook of [Elman, Sylvester and Wathen, Oxford University Press, 2014], our method requires one extra vector of storage and no additional applications of the preconditioner. Numerical experiments are included.

翻译：考虑采用装配点系统,即结构化线性系统,并配有对称矩阵; 修改(有条件的)MINRES的实施方法,以便能够单独监测次目标的规范; 与[Elman、Sylvester和Wathen,牛津大学出版社,2014年]教科书的实施方法相比,我们的方法需要增加一个存储矢量,而没有附加先决条件的应用; 包括数字实验。