PCFactorSetShiftAmount#

adds a quantity to the diagonal of the matrix during numerical factorization, thus the matrix has nonzero pivots

Synopsis#

#include "petscpc.h" 
PetscErrorCode PCFactorSetShiftAmount(PC pc, PetscReal shiftamount)

Logically Collective

Input Parameters#

  • pc - the preconditioner context

  • shiftamount - amount of shift or PETSC_DECIDE for the default

Options Database Key#

  • -pc_factor_shift_amount - Sets shift amount or -1 for the default

See Also#

KSP: Linear System Solvers, PCCHOLESKY, PCLU, ``PCFactorSetZeroPivot(), PCFactorSetShiftType()`

Level#

intermediate

Location#

src/ksp/pc/impls/factor/factor.c

Implementations#

PCFactorSetShiftAmount_Factor() in src/ksp/pc/impls/factor/factimpl.c


Index of all PC routines
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Index of all manual pages