2013/12/18 by Felicja Okulicka-Dłużewska, Okulicka-Dłużewska, Felicja, Alicja Smoktunowicz +1 · 14 citations
Computer Science · Mathematics · Physics and Astronomy · #15A12 #15A23 #15A60 #65H10 #Electromagnetic Scattering and Analysis #FOS: Mathematics #Matrix Theory and Algorithms #Numerical Analysis (math.NA) #Numerical methods for differential equations
paper · pdf · doi:10.48550/arxiv.1312.5277
openalex publication_date 2013/12/18 · openalex created_date 2022/10/04 · openalex updated_date 2026/07/28
Saddle point problems arise in many important practical applications. In this paper we propose and analyze some algorithms for solving symmetric saddle point problems which are based upon the block Gram-Schmidt method. In particular, we prove that the algorithm BCGS2 (Reorthogonalized Block Classical Gram-Schmidt) using Householder Q-R decomposition implemented in floating point arithmetic is backward stable, under a mild assumption on the matrix M. This means that the computed vector z is the exact solution to a slightly perturbed linear system of equations Mz = f.