Refined and refined harmonic Jacobi--Davidson methods for computing several GSVD components of a large regular matrix pair
Jinzhi Huang, Zhongxiao Jia
TL;DR
This work addresses computing multiple GSVD components of a large regular matrix pair $(A,B)$ by introducing three refined Jacobi–Davidson–type methods: RCPF-JDGSVD, RCPF-HJDGSVD, and RIF-HJDGSVD. The authors fuse refined extraction with cross product-free and harmonic extraction strategies and embed them in thick-restart schemes with deflation and purgation to robustly extract several components near a target $\tau$, handling both extreme and interior GSVD components. Empirical results on large sparse matrix pairs show that RCPF-JDGSVD excels for extreme components, while RCPF-HJDGSVD and RIF-HJDGSVD offer superior performance and reliability for interior components, demonstrating improved convergence and efficiency over prior CPF/IF-HJDGSVD methods. The approach thus provides a practical, scalable framework for reliable partial GSVD computations in large-scale applications, with future work focusing on specialized solvers and preconditioners for the correction equations.
Abstract
Three refined and refined harmonic extraction-based Jacobi--Davidson (JD) type methods are proposed, and their thick-restart algorithms with deflation and purgation are developed to compute several generalized singular value decomposition (GSVD) components of a large regular matrix pair. The new methods are called refined cross product-free (RCPF), refined cross product-free harmonic (RCPF-harmonic) and refined inverse-free harmonic (RIF-harmonic) JDGSVD algorithms, abbreviated as RCPF-JDGSVD, RCPF-HJDGSVD and RIF-HJDGSVD, respectively. The new JDGSVD methods are more efficient than the corresponding standard and harmonic extraction-based JDSVD methods proposed previously by the authors, and can overcome the erratic behavior and intrinsic possible non-convergence of the latter ones. Numerical experiments illustrate that RCPF-JDGSVD performs better for the computation of extreme GSVD components while RCPF-HJDGSVD and RIF-HJDGSVD suit better for that of interior GSVD components.
