This paper continues the theoretical and numerical study of the so-called factorized sparse approximate inverse (FSAI) preconditionings of symmetric positive-definite matrices and considers two new approaches to improving them. The first one is based on the a posteriori sparsification of an already
Efficient computation of sparse approximate inverses
β Scribed by Thomas K. Huckle
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 101 KB
- Volume
- 5
- Category
- Article
- ISSN
- 1070-5325
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β¦ Synopsis
We investigate different methods for computing a sparse approximate inverse M for a given sparse matrix A by minimizing AM -E in the Frobenius norm. Such methods are very useful for deriving preconditioners in iterative solvers, especially in a parallel environment. We compare different strategies for choosing the sparsity structure of M and different ways for solving the small least squares problem that are related to the computation of each column of M. Especially we show how we can take full advantage of the sparsity of A.
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