petsc-3.7.1 2016-05-15
PCFactorSetFill
Indicate the amount of fill you expect in the factored matrix, fill = number nonzeros in factor/number nonzeros in original matrix.
Synopsis
#include "petscpc.h"
PetscErrorCode PCFactorSetFill(PC pc,PetscReal fill)
Not Collective, each process can expect a different amount of fill Many br
Input Parameters
| pc | - the preconditioner context Many br |
| fill | - amount of expected fill Many br |
Options Database Key
-pc_factor_fill <fill> -Sets fill amount Many br
Many br
Note
For sparse matrix factorizations it is difficult to predict how much Many brfill to expect. By running with the option -info PETSc will print the Many bractual amount of fill used; allowing you to set the value accurately for Many brfuture runs. Default PETSc uses a value of 5.0 Many br
This parameter has NOTHING to do with the levels-of-fill of ILU(). That is set with PCFactorSetLevels() or -pc_factor_levels. Many br
Keywords
PC, set, factorization, direct, fill
Level:intermediate
Location:src/ksp/pc/impls/factor/factor.c
Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages