WSMP: Watson Sparse Matrix Package. Part III: Iterative Solution of Sparse Systems. Version 7.11

TheWatson Sparse Matrix Package, WSMP, is a high-performance, robust, and easy to use software package for solving large sparse systems of linear equations using a direct method. It can be used as a serial package, or in a shared-memory multiprocessor environment, or as a scalable parallel solver in a message-passing environment, where each node can either be a uniprocessor or a shared-memory multiprocessor. WSMP is comprised of three parts. Part I uses direct factorization for solving symmetric systems without numerical pivoting. Part II sparse LU factorization with pivoting for numerical stability to solve general systems. This document describes the iterative solution of sparse systems of linear equations in WSMP. Parts I and II of User’s Guide [6] can be obtained from http://www.cs.umn.edu/˜agupta/wsmp.html, along with some example programs and technical papers related to the software. A current list of known bugs and issues is also maintained at this web site.

Note 1.1 The current version supports iterative solution of linear systems only in the serial/multithreaded mode. The distributed-memory parallel solvers will be made available shortly. Please disregard any portions of this document that refer to distributed-memory/message-passing parallelism.

Note 1.2 Although WSMP and PWSMP libraries contain multithreaded code, the libraries themselves are not threadsafe. Therefore, the calling program cannot invoke multiple instances of the routines contained in WSMP and PWSMP libraries from different threads at the same time.

The organization of this document is as follows. Section 2 lists the various libraries that are available and describe how to obtain and use the libraries. Section 3 describes the functionality of the main serial/multithreaded routine that provides an advanced single-routine interface to the entire software. This section also describes the input data structures for the serial and multithreaded cases. Section 4 describes a few utility routines available to the users. Section 5 gives a brief description of the double-complex data type interface of WSMP. Section 6 contains the terms and conditions that all users of the package must adhere to.