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Block Gram-Schmidt Algorithms and Their Stability Properties

Journal Article · · Linear Algebra and its Applications

Block Gram-Schmidt algorithms serve as essential kernels in many scientific computing applications, but for many commonly used variants, a rigorous treatment of their stability properties remains open. This work provides a comprehensive categorization of block Gram-Schmidt algorithms, particularly those used in Krylov subspace methods to build orthonormal bases one block vector at a time. Known stability results are assembled, and new results are summarized or conjectured for important communication-reducing variants. Additionally, new block versions of low-synchronization variants are derived, and their efficacy and stability are demonstrated for a wide range of challenging examples. Numerical examples are computed with a versatile Matlab package hosted at https://github.com/katlund/BlockStab, and scripts for reproducing all results in the paper are provided. Block Gram-Schmidt implementations in popular software packages are discussed, along with a number of open problems. An appendix containing all algorithms type-set in a uniform fashion is provided.

Research Organization:
National Renewable Energy Laboratory (NREL), Golden, CO (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR) (SC-21)
DOE Contract Number:
AC36-08GO28308
OSTI ID:
1841142
Report Number(s):
NREL/JA-2C00-80324; MainId:42527; UUID:a7eaad28-5513-4750-84b8-631d1fb70f33; MainAdminID:63642
Journal Information:
Linear Algebra and its Applications, Journal Name: Linear Algebra and its Applications Vol. 638
Country of Publication:
United States
Language:
English

References (42)

Block Gram–Schmidt Orthogonalization journal January 2008
A Storage-Efficient $WY$ Representation for Products of Householder Transformations journal January 1989
Iterative algorithms for Gram-Schmidt orthogonalization journal December 1989
A projection method for generalized eigenvalue problems using numerical integration journal October 2003
Toward the Optimal Preconditioned Eigensolver: Locally Optimal Block Preconditioned Conjugate Gradient Method journal January 2001
Updating the QR decomposition of block tridiagonal and block Hessenberg matrices journal June 2008
The Stability of Block Variants of Classical Gram--Schmidt journal January 2021
Modified Gram-Schmidt (MGS), Least Squares, and Backward Stability of MGS-GMRES journal January 2006
Enlarged Krylov Subspace Conjugate Gradient Methods for Reducing Communication journal January 2016
Deflated Restarting for Matrix Functions journal April 2011
Reorthogonalized block classical Gram–Schmidt journal September 2012
Round off error analysis for Gram-Schmidt method and solution of linear least squares problems journal December 1971
Rational Krylov approximation of matrix functions: Numerical methods and optimal pole selection journal August 2013
Mixed-Precision Cholesky QR Factorization and Its Case Studies on Multicore CPU with Multiple GPUs journal January 2015
Efficient and Stable Arnoldi Restarts for Matrix Functions Based on Quadrature journal January 2014
A Krylov--Schur Algorithm for Large Eigenproblems journal January 2002
Recycling Krylov Subspaces for Sequences of Linear Systems journal January 2006
Rounding error analysis of the classical Gram-Schmidt orthogonalization process journal May 2005
Low synchronization Gram–Schmidt and generalized minimal residual algorithms journal October 2020
Communication lower bounds and optimal algorithms for numerical linear algebra journal May 2014
Loss and Recapture of Orthogonality in the Modified Gram–Schmidt Algorithm journal January 1992
KSPHPDDM and PCHPDDM: Extending PETSc with advanced Krylov methods and robust multilevel overlapping Schwarz preconditioners journal February 2021
Stability Analysis and Improvement of the Block Gram–Schmidt Algorithm journal September 1991
Convergence properties of block GMRES and matrix polynomials journal November 1996
Solving linear least squares problems by Gram-Schmidt orthogonalization journal March 1967
Communication-optimal Parallel and Sequential QR and LU Factorizations journal January 2012
An accurate parallel block Gram-Schmidt algorithm without reorthogonalization journal January 2000
An adaptive $s$-step conjugate gradient algorithm with dynamic basis updating [english] journal February 2020
Gram-Schmidt orthogonalization: 100 years and more: GRAM-SCHMIDT ORTHOGONALIZATION: 100 YEARS AND MORE journal June 2012
Restarted block-GMRES with deflation of eigenvalues journal July 2005
Backward error analysis of the AllReduce algorithm for householder QR decomposition journal December 2011
Implementation of the GMRES Method Using Householder Transformations journal January 1988
Block Modified Gram--Schmidt Algorithms and Their Analysis journal January 2019
A note on the error analysis of classical Gram–Schmidt journal November 2006
Numerical aspects of Gram-Schmidt orthogonalization of vectors journal July 1983
Block-Arnoldi and Davidson methods for unsymmetric large eigenvalue problems journal December 1993
Block Krylov Subspace Methods for Functions of Matrices II: Modified Block FOM journal January 2020
On Improving Linear Solver Performance: A Block Variant of GMRES journal January 2006
Convergence of Restarted Krylov Subspace Methods for Stieltjes Functions of Matrices journal January 2014
The block conjugate gradient algorithm and related methods journal February 1980
Shifted Cholesky QR for Computing the QR Factorization of Ill-Conditioned Matrices journal January 2020
When modified Gram-Schmidt generates a well-conditioned set of vectors journal October 2002

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