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
Input Parameters#
pc - the preconditioner context
fill - amount of expected fill
Options Database Key#
-pc_factor_fill
- Sets fill amount
Notes#
For sparse matrix factorizations it is difficult to predict how much fill to expect. By running with the option -info PETSc will print the actual amount of fill used; allowing you to set the value accurately for future runs. Default PETSc uses a value of 5.0
This is ignored for most solver packages
This parameter has NOTHING to do with the levels-of-fill of ILU(). That is set with PCFactorSetLevels() or -pc_factor_levels.
See Also#
KSP: Linear System Solvers, PCLU, PCCHOLESKY, PCILU, PCICC, PCFactorSetReuseFill()
Level#
intermediate
Location#
Implementations#
PCFactorSetFill_Factor() in src/ksp/pc/impls/factor/factimpl.c
Index of all PC routines
Table of Contents for all manual pages
Index of all manual pages