MA48: A FORTRAN code for direct solution of sparse unsymmetric linear systems of equations
Iain S. Duff, John K. Reid · 1993
We describe the design of a new code that supersedes the Harwell Subroutine Library (HSL) code MA28 for the direct solution of sparse unsymmetric linear systems of equations. The principal differences lie in a new factorization entry that includes row permutations for stability without an overhead of greater complexity than that of the factorization itself, switching to full processing including the use of all three levels of BLAS, better treatment of rectangular or rank-deficient matrices, partial refactorization, and integrated facilities for iterative refinement and error estimation.