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