P SPARSLIB Working Note No. 2

The Iterative Solvers Module ?

Youcef Saad and Kesheng Wu

University of Minnesota

Department of Computer Science

November 17, 1993

Abstract

P SPARSLIBis a library of portable FORTRAN routines for sparse matrix compuations. The current thrust of the library is in iterative solution techniques. In this note we present the `accelerators' part of the library, which consists of the best known of Krylov subspace techniques. This iterative solution module is implemented in reverse communication mode so as to allow any preconditioned to be combined with the pacgake. In addition, this mechanism allows us to ensure portability, since the communication calls required in the iterative solution process are hidden in the dot product and the matrix-vector product and preconditioning operatins.

1 Introduction

Solving linear systems
Ax = b
?Work supported in part by ARPA under grant number NIST 60NANB2D1272, in part by NSF under grant number NSF/CCR-9214116, and in part by AHPCRC (University of Minnesota) under Army Research Office grant number DAAL03-89-C-0038