Results 11 to 20 of about 713 (182)

Weighted Inner Products for GMRES and GMRES-DR [PDF]

open access: yesSIAM Journal on Scientific Computing, 2017
Revision containing edits to the text, corrections, and removal of the section on Arnoldi in weighted inner products (to reduce the manuscript's length)
Embree, Mark   +2 more
openaire   +3 more sources

Iterated Gauss–Seidel GMRES

open access: yesSIAM Journal on Scientific Computing, 2023
The GMRES algorithm of Saad and Schultz (1986) is an iterative method for approximately solving linear systems $A{\bf x}={\bf b}$, with initial guess ${\bf x}_0$ and residual ${\bf r}_0 = {\bf b} - A{\bf x}_0$. The algorithm employs the Arnoldi process to generate the Krylov basis vectors (the columns of $V_k$).
Stephen Thomas   +4 more
openaire   +4 more sources

Toward efficient polynomial preconditioning for GMRES [PDF]

open access: yesNumerical Linear Algebra with Applications, 2021
AbstractWe present a polynomial preconditioner for solving large systems of linear equations. The polynomial is derived from the minimum residual polynomial (the GMRES polynomial) and is more straightforward to compute and implement than many previous polynomial preconditioners. Our current implementation of this polynomial using its roots is naturally
Jennifer A. Loe, Ronald B. Morgan
openaire   +2 more sources

GMRES and Integral Operators [PDF]

open access: yesSIAM Journal on Scientific Computing, 1996
The purpose of this paper is to show how the generalized minimal residual (GMRES) method can be modified to incorporate Nyström interpolation at a small cost in both computational effort and algorithmic complexity. The result is an algorithm that has the convergence property of Broyden's method.
Kelley, C. T., Xue, Z. Q.
openaire   +1 more source

Multipreconditioned Gmres for Shifted Systems [PDF]

open access: yesSIAM Journal on Scientific Computing, 2017
An implementation of GMRES with multiple preconditioners (MPGMRES) is proposed for solving shifted linear systems with shift-and-invert preconditioners. With this type of preconditioner, the Krylov subspace can be built without requiring the matrix-vector product with the shifted matrix.
Bakhos, T.   +4 more
openaire   +4 more sources

Adaptive version of Simpler GMRES [PDF]

open access: yesNumerical Algorithms, 2009
The authors propose and theoretically analyze a stable version of simpler generalized minimal residual (GMRES) algorithm, based on an adaptive choice of the Krylov subspace basis at a given iteration step. They show that this adaptive choice of direction vectors keeps the basis well-conditioned and that the condition number grows at most linearly with ...
Jiránek, P., Rozložník, M. (Miroslav)
openaire   +2 more sources

Properties of Worst-Case GMRES [PDF]

open access: yesSIAM Journal on Matrix Analysis and Applications, 2013
In the convergence analysis of the GMRES method for a given matrix $A$, one quantity of interest is the largest possible residual norm that can be attained, at a given iteration step $k$, over all unit norm initial vectors. This quantity is called the worst-case GMRES residual norm for $A$ and $k$.
Faber, Vance   +2 more
openaire   +3 more sources

Complete stagnation of gmres

open access: yesLinear Algebra and its Applications, 2003
In their introduction, the authors state, ``We study an oddity: the class of problems for which the generalized minimal residual (GMRES) algorithm, when started with the initial guess \(x^{(0)}=0\) and using exact arithmetic, computes \(m\) iterates \(x^{(1)}=\cdots=x^{(m)}=0\) without making any progress at all.
Zavorin, Ilya   +2 more
openaire   +2 more sources

DAPHNE-3D: A NEW TRANSPORT SOLVER FOR UNSTRUCTURED TETRAHEDRAL MESHES [PDF]

open access: yesEPJ Web of Conferences, 2021
A new Discrete Ordinates transport solver for unstructured tetrahedral meshes is presented. The solver uses the Discontinuous Galërkin Finite Element Method with linear or quadratic expansion of the flux within each cell.
Diamantopoulou Evangelia   +1 more
doaj   +1 more source

A relaxed block splitting preconditioner for complex symmetric indefinite linear systems

open access: yesOpen Mathematics, 2018
In this paper, we propose a relaxed block splitting preconditioner for a class of complex symmetric indefinite linear systems to accelerate the convergence rate of the Krylov subspace iteration method and the relaxed preconditioner is much closer to the ...
Huang Yunying, Chen Guoliang
doaj   +1 more source

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