THE DESIGN OF MA48 - A CODE FOR THE DIRECT SOLUTION OF SPARSE UNSYMMETRIC LINEAR-SYSTEMS OF EQUATIONS

We describe the design of a new code for the direct solution of sparse unsymmetric linear systems of equations. The new code utilizes a nove l restructuring of the symbolic and numerical phases, which increases speed and saves storage without sacrifice of numerical stability. Othe r features include switching to full-matrix processing in all phases o f the computation enabling the use of all three levels of BLAS, treatm ent of rectangular or rank-deficient matrices, partial factorization, and integrated facilities for iterative refinement and error estimatio n.