Indicate the amount of fill you expect in the factored matrix, fill = number nonzeros in factor/number nonzeros in original matrix.


#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


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()






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