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**Next Page:** Creating an incomplete factorization

A broad class of preconditioners is based on incomplete factorizations
of the coefficient matrix. We call a factorization incomplete if
during the factorization process certain * fill* elements, zero
positions that would be nonzero in an exact factorization, have been
ignored. Such a preconditioner is then given in factored form
with lower and upper triangular. The efficacy of the
preconditioner depends on how well approximates .

- Creating an incomplete factorization
- Point incomplete factorizations
- Block factorization methods
- Incomplete LQ factorizations