A COCR method for solving complex symmetric linear systems. (English) Zbl 1108.65028

Summary: The conjugate orthogonal conjugate gradient (COCG) method has been recognized as an attractive Lanczos-type Krylov subspace method for solving complex symmetric linear systems; however, it sometimes shows irregular convergence behavior in practical applications. In the present paper, we propose a conjugate A-orthogonal conjugate residual (COCR) method, which can be regarded as an extension of the conjugate residual (CR) method. Numerical examples show that COCR often gives smoother convergence behavior than COCG.


65F10 Iterative numerical methods for linear systems
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