Error Norm Estimation in the Conjugate Gradient Algorithm
Error Norm Estimation in the Conjugate Gradient Algorithm

Author: Gérard Meurant

Publisher: SIAM

Published: 2024-01-30

Total Pages: 138

ISBN-13: 161197786X

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The conjugate gradient (CG) algorithm is almost always the iterative method of choice for solving linear systems with symmetric positive definite matrices. This book describes and analyzes techniques based on Gauss quadrature rules to cheaply compute bounds on norms of the error. The techniques can be used to derive reliable stopping criteria. How to compute estimates of the smallest and largest eigenvalues during CG iterations is also shown. The algorithms are illustrated by many numerical experiments, and they can be easily incorporated into existing CG codes. The book is intended for those in academia and industry who use the conjugate gradient algorithm, including the many branches of science and engineering in which symmetric linear systems have to be solved.

Preconditioning and the Conjugate Gradient Method in the Context of Solving PDEs
Preconditioning and the Conjugate Gradient Method in the Context of Solving PDEs

Author: Josef Malek

Publisher: SIAM

Published: 2014-12-22

Total Pages: 106

ISBN-13: 161197383X

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Preconditioning and the Conjugate Gradient Method in the Context of Solving PDEs?is about the interplay between modeling, analysis, discretization, matrix computation, and model reduction. The authors link PDE analysis, functional analysis, and calculus of variations with matrix iterative computation using Krylov subspace methods and address the challenges that arise during formulation of the mathematical model through to efficient numerical solution of the algebraic problem. The book?s central concept, preconditioning of the conjugate gradient method, is traditionally developed algebraically using the preconditioned finite-dimensional algebraic system. In this text, however, preconditioning is connected to the PDE analysis, and the infinite-dimensional formulation of the conjugate gradient method and its discretization and preconditioning are linked together. This text challenges commonly held views, addresses widespread misunderstandings, and formulates thought-provoking open questions for further research.?

The Lanczos and Conjugate Gradient Algorithms
The Lanczos and Conjugate Gradient Algorithms

Author: Gerard Meurant

Publisher: SIAM

Published: 2006-08-01

Total Pages: 374

ISBN-13: 0898716160

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The most comprehensive and up-to-date discussion available of the Lanczos and CG methods for computing eigenvalues and solving linear systems.

Matrices, Moments and Quadrature with Applications
Matrices, Moments and Quadrature with Applications

Author: Gene H. Golub

Publisher: Princeton University Press

Published: 2009-12-07

Total Pages: 376

ISBN-13: 1400833884

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This computationally oriented book describes and explains the mathematical relationships among matrices, moments, orthogonal polynomials, quadrature rules, and the Lanczos and conjugate gradient algorithms. The book bridges different mathematical areas to obtain algorithms to estimate bilinear forms involving two vectors and a function of the matrix. The first part of the book provides the necessary mathematical background and explains the theory. The second part describes the applications and gives numerical examples of the algorithms and techniques developed in the first part. Applications addressed in the book include computing elements of functions of matrices; obtaining estimates of the error norm in iterative methods for solving linear systems and computing parameters in least squares and total least squares; and solving ill-posed problems using Tikhonov regularization. This book will interest researchers in numerical linear algebra and matrix computations, as well as scientists and engineers working on problems involving computation of bilinear forms.

Iterative Solution Methods
Iterative Solution Methods

Author: Owe Axelsson

Publisher: Cambridge University Press

Published: 1996-03-29

Total Pages: 676

ISBN-13: 9780521555692

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This book deals primarily with the numerical solution of linear systems of equations by iterative methods. The first part of the book is intended to serve as a textbook for a numerical linear algebra course. The material assumes the reader has a basic knowledge of linear algebra, such as set theory and matrix algebra, however it is demanding for students who are not afraid of theory. To assist the reader, the more difficult passages have been marked, the definitions for each chapter are collected at the beginning of the chapter, and numerous exercises are included throughout the text. The second part of the book serves as a monograph introducing recent results in the iterative solution of linear systems, mainly using preconditioned conjugate gradient methods. This book should be a valuable resource for students and researchers alike wishing to learn more about iterative methods.

The Lanczos and Conjugate Gradient Algorithms
The Lanczos and Conjugate Gradient Algorithms

Author: Gerard Meurant

Publisher: SIAM

Published: 2006-01-01

Total Pages: 380

ISBN-13: 9780898718140

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The Lanczos and conjugate gradient (CG) algorithms are fascinating numerical algorithms. This book presents the most comprehensive discussion to date of the use of these methods for computing eigenvalues and solving linear systems in both exact and floating point arithmetic. The author synthesizes the research done over the past 30 years, describing and explaining the "average" behavior of these methods and providing new insight into their properties in finite precision. Many examples are given that show significant results obtained by researchers in the field. The author emphasizes how both algorithms can be used efficiently in finite precision arithmetic, regardless of the growth of rounding errors that occurs. He details the mathematical properties of both algorithms and demonstrates how the CG algorithm is derived from the Lanczos algorithm. Loss of orthogonality involved with using the Lanczos algorithm, ways to improve the maximum attainable accuracy of CG computations, and what modifications need to be made when the CG method is used with a preconditioner are addressed.

Domain Decomposition Methods in Science and Engineering XXIII
Domain Decomposition Methods in Science and Engineering XXIII

Author: Chang-Ock Lee

Publisher: Springer

Published: 2017-03-15

Total Pages: 419

ISBN-13: 3319523899

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This book is a collection of papers presented at the 23rd International Conference on Domain Decomposition Methods in Science and Engineering, held on Jeju Island, Korea on July 6-10, 2015. Domain decomposition methods solve boundary value problems by splitting them into smaller boundary value problems on subdomains and iterating to coordinate the solution between adjacent subdomains. Domain decomposition methods have considerable potential for a parallelization of the finite element methods, and serve a basis for distributed, parallel computations.