ILUS - AN INCOMPLETE LU PRECONDITIONER IN SPARSE SKYLINE FORMAT

Incomplete LU factorizations are among the most effective precondition ers for solving general large, sparse linear systems arising from prac tical engineering problems. This paper shows how an ILU factorization may be easily computed in sparse skyline storage format, as opposed to traditional row-by-row schemes. This organization of the factorizatio n has many advantages, including its amenability when the original mat rix is in skyline format, the ability to dynamically monitor the stabi lity of the factorization and the fact that factorizations may be prod uced with symmetric structure. Numerical results are presented for Gal erkin finite element matrices arising from the standard square lid-dri ven cavity problem. (C) 1997 John Wiley & Sons, Ltd.