نتایج جستجو برای: preconditioned matrix

تعداد نتایج: 367346  

Journal: :Numerical Lin. Alg. with Applic. 2006
Srinivasa M. Salapaka A. Peirce

This paper proposes and studies the performance of a preconditioner suitable for solving a class of symmetric positive de nite systems, Âx = b, which we call p-level lower rank extracted systems (p-level LRES), by the preconditioned conjugate gradient method. The study of these systems is motivated by the numerical approximation of integral equations with convolution kernels de ned on arbitrary...

1997
Hao Lu Owe Axelsson H. Lu O. Axelsson

The paper deals with eigenvalue estimates for block incomplete factorization methods for symmetric matrices. First, some previous results on upper bounds for the maximum eigenvalue of preconditioned matrices are generalized to each eigenvalue. Second, upper bounds for the maximum eigenvalue of the preconditioned matrix are further estimated, which presents a substantial improvement of earlier r...

2001
ANDREW V. KNYAZEV KLAUS NEYMEYR

We present a short survey of multigrid–based solvers for symmetric eigenvalue problems. We concentrate our attention on “of the shelf” and “black box” methods, which should allow solving eigenvalue problems with minimal, or no, effort on the part of the developer, taking advantage of already existing algorithms and software. We consider a class of such methods, where the multigrid only appears ...

2012
Li Jiang Baoguang Tian Guang-Hui Cheng

In this paper, we present the preconditioned mixed-type splitting iterative method for solving the linear systems, Ax = b, where A is a Z-matrix. And we give some comparison theorems to show that the convergence rate of the preconditioned mixed-type splitting iterative method is faster than that of the mixed-type splitting iterative method. Finally, we give a numerical example to illustrate our...

2009
Alfred O. Hero Mohammad Usman Anne C. Sauve Jeffrey A. Fessler Michael P. Clark

Computation of the Cramer-Rao bound (CRB) on estimator variance requires the inverse or the pseudo-inverse Fisher information matrix (FIM). Direct matrix inversion can be computationally intractable when the number of unknown parameters is large. In this correspondence, we compare several iterative methods for approximating the CRB using matrix splitting and preconditioned conjugate gradient al...

2015
Noriyuki Kushida

The present paper introduces a condition number estimation method for preconditioned matrices. The newly developed method provides reasonable results, while the conventional method which is based on the Lanczos connection gives meaningless results. The Lanczos connection based method provides the condition numbers of coefficient matrices of systems of linear equations with information obtained ...

Journal: :J. Applied Mathematics 2012
Shi-Liang Wu Feng Chen Xiao-Qi Niu

We consider the SIMPLE preconditioning for block two-by-two generalized saddle point problems; this is the general nonsymmetric, nonsingular case where the 1,2 block needs not to equal the transposed 2,1 block, and the 2,2 block may not be zero. The eigenvalue analysis of the SIMPLE preconditioned matrix is presented. The relationship between the two different formulations spectrum of the SIMPL...

Journal: :Numerical Lin. Alg. with Applic. 2009
Stefania Bellavia Jacek Gondzio Benedetta Morini

A regularized Newton-like method for solving nonnegative least-squares problems is proposed and analysed in this paper. A preconditioner for KKT systems arising in the method is introduced and spectral properties of the preconditioned matrix are analysed. A bound on the condition number of the preconditioned matrix is provided. The bound does not depend on the interior-point scaling matrix. Pre...

Journal: :Computers & Mathematics with Applications 2017
Davod Khojasteh Salkuyeh Maryam Rahimian

A modification of the generalized shift-splitting (GSS) method is presented for solving singular saddle point problems. In this kind of modification, the diagonal shift matrix is replaced by a block diagonal matrix which is symmetric positive definite. Semiconvergence of the proposed method is investigated. The induced preconditioner is applied to the saddle point problem and the preconditioned...

Journal: :IEEE Trans. Signal Processing 1997
Alfred O. Hero Mohammad Usman Anne C. Sauve Jeffrey A. Fessler

Computation of the Cramer-Rao bound (CRB) on estimator variance requires the inverse or the pseudo-inverse Fisher information matrix (FIM). Direct matrix inversion can be computationally intractable when the number of unknown parameters is large. In this correspondence, we compare several iterative methods for approximating the CRB using matrix splitting and preconditioned conjugate gradient al...

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