A hybrid variant of the BiCOR method for a nonsymmetric linear system with a complex spectrum

A biconjugate A -orthogonal residual method based on the biconjugate A -orthonormalization procedure has been proposed and denoted as BiCOR by Jing, Huang, et al. [Y.-F. Jing, T.-Z. Huang, Y. Zhang, L. Li, G.-H. Cheng, Z.-G. Ren, Y. Duan, T. Sogabe, and B. Carpentieri, Lanczos-type variants of the COCR method for complex nonsymmetric linear systems, J. Comput. Phys. 228 (2009) 6376–6394]. Here, a hybrid variant of BiCOR is presented to avoid generating the transpose of the system matrix and to optimize the convergence of a nonsymmetric linear system with a complex spectrum.