petsc-3.7.1 2016-05-15
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PCICC

Incomplete Cholesky factorization preconditioners.

Options Database Keys

-pc_factor_levels <k> - number of levels of fill for ICC(k) Many br
-pc_factor_in_place - only for ICC(0) with natural ordering, reuses the space of the matrix for Many brits factorization (overwrites original matrix) Many br
-pc_factor_fill <nfill> - expected amount of fill in factored matrix compared to original matrix, nfill > 1 Many br
-pc_factor_mat_ordering_type <natural,nd,1wd,rcm,qmd> - set the row/column ordering of the factored matrix Many br

Many br

Notes: Only implemented for some matrix formats. Not implemented in parallel. Many br

For BAIJ matrices this implements a point block ICC. Many br

The Manteuffel shift is only implemented for matrices with block size 1 Many br

By default, the Manteuffel is applied (for matrices with block size 1). Call PCFactorSetShiftType(pc,MAT_SHIFT_POSITIVE_DEFINITE); Many brto turn off the shift. Many br

References

1. -TONY F. CHAN AND HENK A. VAN DER VORST, Review article: APPROXIMATE AND INCOMPLETE FACTORIZATIONS, Many brChapter in Parallel Numerical Algorithms, edited by D. Keyes, A. Semah, V. Venkatakrishnan, ICASE/LaRC Interdisciplinary Series in Many brScience and Engineering, Kluwer. Many br

See Also

PCCreate(), PCSetType(), PCType (for list of available types), PC, PCSOR, MatOrderingType,
PCFactorSetZeroPivot(), PCFactorSetShiftType(), PCFactorSetShiftAmount(), Many brPCFactorSetFill(), PCFactorSetMatOrderingType(), PCFactorSetReuseOrdering(), Many brPCFactorSetLevels() Many br

Level:beginner
Location:
src/ksp/pc/impls/factor/icc/icc.c
Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages

Examples

src/ksp/pc/examples/tutorials/ex2.c.html