A Projection Strategy for Improving the Preconditioner in the LOBPCG

The computational methods for solving the generalized eigenvalue problems of real symmetric matrices are crucial in fields such as structural dynamics analysis. As the scale of the problems to be solved increases, higher efficiency in solving eigenvalue problems is demanded. The LOBPCG (locally opti...

Full description

Saved in:
Bibliographic Details
Main Authors: Ma Tailai, Sun Shuli, Zheng Fangyi, Chen Pu
Format: Article
Language:English
Published: Sciendo 2025-06-01
Series:International Journal of Applied Mathematics and Computer Science
Subjects:
Online Access:https://doi.org/10.61822/amcs-2025-0020
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849431594207543296
author Ma Tailai
Sun Shuli
Zheng Fangyi
Chen Pu
author_facet Ma Tailai
Sun Shuli
Zheng Fangyi
Chen Pu
author_sort Ma Tailai
collection DOAJ
description The computational methods for solving the generalized eigenvalue problems of real symmetric matrices are crucial in fields such as structural dynamics analysis. As the scale of the problems to be solved increases, higher efficiency in solving eigenvalue problems is demanded. The LOBPCG (locally optimal block preconditioned conjugate gradient) method is a promising iterative algorithm suitable for solving large-scale eigenvalue problems, capable of quickly solving multiple extreme eigenpairs. In the LOBPCG, the preconditioner can be executed by calling the truncated PCG to approximately solve the ‘inner’ linear system. However, the convergence rate of the LOBPCG is highly sensitive to the quality of its preconditioner. Only when paired with an appropriate preconditioner, the LOBPCG is notably efficient in minimizing the iterations needed for convergence. This paper proposed a projection strategy which can enhance the quality of the preconditioner, thus improving the overall efficiency and stability of the LOBPCG. The projection strategy first utilizes intermediate vectors from the PCG iterations to construct search subspaces and constraint subspaces for oblique projection, and then executes the oblique projection in truncated PCG when solving inner linear system. This oblique projection technique can find a more accurate approximate solution which minimizes the 2-norm residuals in the search subspace without significantly increasing computational cost, thereby improving the quality of the preconditioner, thus accelerating convergence of the LOBPCG.Numerical experiments show that the projection strategy can improve the LOBPCG algorithm significantly in terms of efficiency and stability.
format Article
id doaj-art-fbb0de90bd9c401ebb227c995b8a5a39
institution Kabale University
issn 2083-8492
language English
publishDate 2025-06-01
publisher Sciendo
record_format Article
series International Journal of Applied Mathematics and Computer Science
spelling doaj-art-fbb0de90bd9c401ebb227c995b8a5a392025-08-20T03:27:36ZengSciendoInternational Journal of Applied Mathematics and Computer Science2083-84922025-06-0135228129210.61822/amcs-2025-0020A Projection Strategy for Improving the Preconditioner in the LOBPCGMa Tailai0Sun Shuli1Zheng Fangyi2Chen Pu31Department of Mechanics and Engineering Science, Peking University, Yiheyuan Road No. 5, 100871Beijing, China1Department of Mechanics and Engineering Science, Peking University, Yiheyuan Road No. 5, 100871Beijing, China2Intelligent Science & Technology Academy of CASIC, Fucheng Road No. 8, 100830Beijing, China1Department of Mechanics and Engineering Science, Peking University, Yiheyuan Road No. 5, 100871Beijing, ChinaThe computational methods for solving the generalized eigenvalue problems of real symmetric matrices are crucial in fields such as structural dynamics analysis. As the scale of the problems to be solved increases, higher efficiency in solving eigenvalue problems is demanded. The LOBPCG (locally optimal block preconditioned conjugate gradient) method is a promising iterative algorithm suitable for solving large-scale eigenvalue problems, capable of quickly solving multiple extreme eigenpairs. In the LOBPCG, the preconditioner can be executed by calling the truncated PCG to approximately solve the ‘inner’ linear system. However, the convergence rate of the LOBPCG is highly sensitive to the quality of its preconditioner. Only when paired with an appropriate preconditioner, the LOBPCG is notably efficient in minimizing the iterations needed for convergence. This paper proposed a projection strategy which can enhance the quality of the preconditioner, thus improving the overall efficiency and stability of the LOBPCG. The projection strategy first utilizes intermediate vectors from the PCG iterations to construct search subspaces and constraint subspaces for oblique projection, and then executes the oblique projection in truncated PCG when solving inner linear system. This oblique projection technique can find a more accurate approximate solution which minimizes the 2-norm residuals in the search subspace without significantly increasing computational cost, thereby improving the quality of the preconditioner, thus accelerating convergence of the LOBPCG.Numerical experiments show that the projection strategy can improve the LOBPCG algorithm significantly in terms of efficiency and stability.https://doi.org/10.61822/amcs-2025-0020lobpcgpreconditionerpreconditioned conjugate gradient (pcg)projection method
spellingShingle Ma Tailai
Sun Shuli
Zheng Fangyi
Chen Pu
A Projection Strategy for Improving the Preconditioner in the LOBPCG
International Journal of Applied Mathematics and Computer Science
lobpcg
preconditioner
preconditioned conjugate gradient (pcg)
projection method
title A Projection Strategy for Improving the Preconditioner in the LOBPCG
title_full A Projection Strategy for Improving the Preconditioner in the LOBPCG
title_fullStr A Projection Strategy for Improving the Preconditioner in the LOBPCG
title_full_unstemmed A Projection Strategy for Improving the Preconditioner in the LOBPCG
title_short A Projection Strategy for Improving the Preconditioner in the LOBPCG
title_sort projection strategy for improving the preconditioner in the lobpcg
topic lobpcg
preconditioner
preconditioned conjugate gradient (pcg)
projection method
url https://doi.org/10.61822/amcs-2025-0020
work_keys_str_mv AT matailai aprojectionstrategyforimprovingthepreconditionerinthelobpcg
AT sunshuli aprojectionstrategyforimprovingthepreconditionerinthelobpcg
AT zhengfangyi aprojectionstrategyforimprovingthepreconditionerinthelobpcg
AT chenpu aprojectionstrategyforimprovingthepreconditionerinthelobpcg
AT matailai projectionstrategyforimprovingthepreconditionerinthelobpcg
AT sunshuli projectionstrategyforimprovingthepreconditionerinthelobpcg
AT zhengfangyi projectionstrategyforimprovingthepreconditionerinthelobpcg
AT chenpu projectionstrategyforimprovingthepreconditionerinthelobpcg