Public Domain Software: GMRES

A Set of GMRES Routines for Real and Complex Arithmetics.

by   V. Frayssé    L. Giraud    S. Gratton    J. Langou

Last Release: Jul 2007 - Version 2.1
We propose an implementation of the GMRES algorithm (Saad and Schultz, 1986) for real and complex, single and double precision arithmetics suitable for serial, shared memory and distributed memory computers. For the sake of simplicity, flexibility and efficiency, the GMRES solvers have been implemented using the reverse communication mechanism for the matrix-vector product, the preconditioning and the dot product computations. The code is written in Fortran 77. For distributed memory computation several orthogonalisation procedures have been implemented to reduce the cost of the dot product calculation, that is a well-known bottleneck of efficiency for the Krylov methods (related CERFACS technical report - TR/PA/98/07 (Gzipped PostCript 54 kB)). Finally the implemented stopping criterion is based on a normwise backward error.

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Last Update: Aug 13, 2001