Incomplete Cholesky factorization preconditioners.

Options Database Keys

-pc_factor_levels <k> - number of levels of fill for ICC(k)
-pc_factor_in_place - only for ICC(0) with natural ordering, reuses the space of the matrix for its factorization (overwrites original matrix)
-pc_factor_fill <nfill> - expected amount of fill in factored matrix compared to original matrix, nfill > 1
-pc_factor_mat_ordering_type <natural,nd,1wd,rcm,qmd> - set the row/column ordering of the factored matrix
-pc_factor_shift_nonzero <shift> - Sets shift amount or PETSC_DECIDE for the default
-pc_factor_shift_positive_definite [PETSC_TRUE/PETSC_FALSE] - Activate/Deactivate PCFactorSetShiftPd(); the value is optional with PETSC_TRUE being the default

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

For BAIJ matrices this implements a point block ICC.

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

By default, the Manteuffel is applied (for matrices with block size 1). Call PCFactorSetShiftPd(pc,PETSC_FALSE); to turn off the shift.

See Also

PCCreate(), PCSetType(), PCType (for list of available types), PC, PCSOR, MatOrderingType,
PCFactorSetZeroPivot(), PCFactorSetShiftNonzero(), PCFactorSetShiftPd(), PCFactorSetFill(), PCFactorSetMatOrdering(), PCFactorSetReuseOrdering(), PCFactorSetLevels(),PCFactorSetShiftNonzero(),PCFactorSetShiftPd(),

Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages