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ILUPreconditioning problem
Posted:
Dec 6, 1996 8:41 AM


Dear netters,
I run into a problem in the context of the iterative solution of a linear system. It appears during the construction of the incomplete LUfactorization of the matrix, is caused by the structure of the matrix and leads to failure due to division by zero. It is sure that the matrix is regular as Gauss' algorithm works without any problems. However, Gauss' algorithm applies row interchangings which I could not apply successfully in the context of the ILU decomposition. The linear systems are relativly small, so row interchangings do not cause Too much trouble. On the other hand, the system has to be solved repeatedly, what makes an iterative solution interesting.
Now the question: What could I do to get an effective preconditioning? Are there other preconditioners, which do not require any row interchanging?
I heard about IQRdecomposition, but do not know of its features.
Thank you in advance,  Michael Hiegemann email: University of Dortmund, CTEPT hiegeman@chemietechnik.unidortmund.de D44221 Dortmund phone: +49 231 755 3403 Federal Republic of Germany fax: +49 231 755 3209  Michael Hiegemann email: University of Dortmund, CTEPT hiegeman@chemietechnik.unidortmund.de D44221 Dortmund phone: +49 231 755 3403 Federal Republic of Germany fax: +49 231 755 3209



