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Iterated Gauss-Seidel GMRES

The result's identifiers

  • Result code in IS VaVaI

    <a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985840%3A_____%2F24%3A00585518" target="_blank" >RIV/67985840:_____/24:00585518 - isvavai.cz</a>

  • Alternative codes found

    RIV/00216208:11320/24:10493576

  • Result on the web

    <a href="https://doi.org/10.1137/22M1491241" target="_blank" >https://doi.org/10.1137/22M1491241</a>

  • DOI - Digital Object Identifier

    <a href="http://dx.doi.org/10.1137/22M1491241" target="_blank" >10.1137/22M1491241</a>

Alternative languages

  • Result language

    angličtina

  • Original language name

    Iterated Gauss-Seidel GMRES

  • Original language description

    The GMRES algorithm of Saad and Schultz [SIAM J. Sci. Stat. Comput., 7 (1986), pp. 856--869] is an iterative method for approximately solving linear systems Ax = b, with initial guess x0 and residual r0 = b- Ax0. The algorithm employs the Arnoldi process to generate the Krylov basis vectors (the columns of Vk). It is well known that this process can be viewed as a QR factorization of the matrix Bk = [r0,AVk ] at each iteration. Despite an O(varepsilon)kappa(Bk) loss of orthogonality, for unit roundoff varepsilon and condition number kappa , the modified Gram-Schmidt formulation was shown to be backward stable in the seminal paper by Paige et al. [SIAM J. Matrix Anal. Appl., 28 (2006), pp. 264--284]. We present an iterated Gauss--Seidel formulation of the GMRES algorithm (IGS-GMRES) based on the ideas of Ruhe [Linear Algebra Appl., 52 (1983), pp. 591--601] and S'wirydowicz et al. [Numer. Linear Algebra Appl., 28 (2020), pp. 1--20]. IGS-GMRES maintains orthogonality to the level O(varepsilon)kappa(Bk) or O(varepsilon), depending on the choice of one or two iterations, for two Gauss--Seidel iterations, the computed Krylov basis vectors remain orthogonal to working accuracy and the smallest singular value of Vk remains close to one. The resulting GMRES method is thus backward stable. We show that IGS-GMRES can be implemented with only a single synchronization point per iteration, making it relevant to large-scale parallel computing environments. We also demonstrate that, unlike MGS-GMRES, in IGS-GMRES the relative Arnoldi residual corresponding to the computed approximate solution no longer stagnates above machine precision even for highly nonnormal systems.

  • Czech name

  • Czech description

Classification

  • Type

    J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database

  • CEP classification

  • OECD FORD branch

    10101 - Pure mathematics

Result continuities

  • Project

    <a href="/en/project/GA23-06159S" target="_blank" >GA23-06159S: Vortical structures: advanced identification and efficient numerical simulation</a><br>

  • Continuities

    I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Others

  • Publication year

    2024

  • Confidentiality

    S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Data specific for result type

  • Name of the periodical

    SIAM Journal on Scientific Computing

  • ISSN

    1064-8275

  • e-ISSN

    1095-7197

  • Volume of the periodical

    46

  • Issue of the periodical within the volume

    2

  • Country of publishing house

    US - UNITED STATES

  • Number of pages

    26

  • Pages from-to

    "S254"-"S279"

  • UT code for WoS article

    001308408900002

  • EID of the result in the Scopus database

    2-s2.0-85192678897