Variable s-step technique for Planar algorithms in solving indefinite linear systems
摘要
The conjugate gradient (CG) method is specifically designed for solving symmetric positive definite (SPD) linear systems. However, when addressing linear systems with an indefinite matrix, a category of algorithms known as Planar algorithms comes into play. One notable member of these Planar CG algorithms is the FLR algorithm. The FLR algorithm paved the way for the introduction of two simplified and more cost-effective algorithms, namely the Alg-F and Alg-ML algorithms. The focus of this article is to incorporate the s-step technique into these three aforementioned algorithms, enabling the adjustment of the parameter s in each iteration. Through the execution of several numerical tests, the performance outcomes of these algorithms are systematically compared.