Summary: We consider the SIMPLE preconditioning for block two-by-two generalized saddle point problems; this is the general nonsymmetric, nonsingular case where the
block needs not to equal the transposed
block, and the
block may not be zero. The eigenvalue analysis of the SIMPLE preconditioned matrix is presented. The relationship between the two different formulations spectrum of the SIMPLE preconditioned matrix is established by using the theory of matrix eigenvalue, and some corresponding results in recent article by C. Li
and C. Vuik
[Numer. Linear Algebra Appl. 11, No. 5-6, 511–523 (2004; Zbl 1164.65398
)] are extended.