PCCholeskySetShift
specify whether to use Manteuffel shifting of Cholesky. If an Cholesky factorisation breaks down because of nonpositive pivots, adding sufficient identity to the diagonal will remedy this. Setting this causes a bisection method to find the minimum shift that will lead to a well-defined Cholesky.
Synopsis
#include "petscpc.h"
PetscErrorCode PCCholeskySetShift(PC pc,PetscTruth shift)
Input parameters
Options Database Key
-pc_ilu_shift -Activate PCCholeskySetShift()
Keywords
PC, indefinite, factorization, incomplete, Cholesky
See Also
PCILUSetShift()
Level:intermediate
Location:src/ksp/pc/impls/cholesky/cholesky.c
Index of all PC routines
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Index of all manual pages