Vector computations for sparse linear systems

We are interested in the development of algorithms, based on iterative methods, and software for the solution of large sparse systems of linear algebraic equations with emphasis on systems arising in the numerical solution of partial differential equations. The objective is to develop algorithms and software which are effective when used with a vector computer such as the Control Data CYBER 205 or the CRAY 1. A package of programs, known as ITPACK, has been developed for use on conventional, or scalar machines. A number of “short-range” modifications to ITPACK, including changes in the data storage format and changes in the programming, but not in the algorithms used, have been made and tested on a number of numerical examples. Preliminary work is described on “long-range” modifications which will involve extensive changes in the basic algorithms in order to achieve efficient vectorization.