Number of the records: 1

Limiting Accuracy of Segregated Solution Methods for Nonsymmetric Saddle Point Problems

SYSNO ASEP	0042846
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	Limiting Accuracy of Segregated Solution Methods for Nonsymmetric Saddle Point Problems
Title	Limitní přesnost segregovaných iteračních metod pro nesymetrické sedlobodové soustavy
Author(s)	Jiránek, P. (CZ) Rozložník, Miroslav (UIVT-O)_{SAI, RID, ORCID}
Source Title	Journal of Computational and Applied Mathematics. - : Elsevier - ISSN 0377-0427 Roc. 215, c. 1 (2008), s. 28-37
Number of pages	10 s.
Language	eng - English
Country	NL - Netherlands
Keywords	saddle point problems ; Schur complement reduction method ; null-space projection method ; rounding error analysis
Subject RIV	BA - General Mathematics
R&D Projects	1M0554 GA MŠMT - Ministry of Education, Youth and Sports (MEYS)
	1ET400300415 GA AV ČR - Academy of Sciences of the Czech Republic (AV ČR)
CEZ	AV0Z10300504 - UIVT-O (2005-2011)
UT WOS	000254808700003
EID SCOPUS	39849085834
DOI	10.1016/j.cam.2007.03.021
Annotation	Nonsymmetric saddle point problems arise in a wide variety of applications in computational science and engineering. The aim of this paper is to discuss numerical behavior of several nonsymmetric iterative methods applied for solving the saddle point systems via the Schur complement reduction or the null-space projection approach. Krylov subspace methods often produce the iterates which fluctuate rather strongly. Here we address the question whether large intermediate approximate solutions reduce the final accuracy of these two-level (inner-outer) iteration algorithms. We extend our previous analysis obtained for symmetric saddle point problems and distinguish between three mathematically equivalent back-substitution schemes which lead to a different numerical behavior when applied in finite precision arithmetic. Theoretical results are then illustrated on a simple model example.
Workplace	Institute of Computer Science
Contact	Tereza Šírová, sirova@cs.cas.cz, Tel.: 266 053 800
Year of Publishing	2008

Number of the records: 1