Tangential frequency filtering decompositions for unsymmetric matrices. (English) Zbl 0890.65031

This paper is a generalization for nonsymmetric matrices of the tangential frequency filtering decomposition (TFFD) of a symmetric matrix considered by the author in Numer. Math. 78, No. 1, 119-142 (1997; reviewed above). Existence of TFFD and convergence rates of the induced iterative algorithm are presented. The convergence rates of an iterative scheme which uses a sequence of TFFDs as preconditioners are independent of the number of unknowns for a certain class of nonsymmetric matrices. Numerical experiments with linear systems arising from the discretization of convection-diffusion equations are presented.
Reviewer: W.Gander (Zürich)


65F10 Iterative numerical methods for linear systems
35J15 Second-order elliptic equations
65N06 Finite difference methods for boundary value problems involving PDEs


Zbl 0890.65030
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