MatSetUnfactored#
Resets a factored matrix to be treated as unfactored.
Synopsis#
#include "petscmat.h"
PetscErrorCode MatSetUnfactored(Mat mat)
Logically Collective
Input Parameter#
mat - the factored matrix to be reset
Notes#
This routine should be used only with factored matrices formed by in-place
factorization via ILU(0) (or by in-place LU factorization for the MATSEQDENSE
format). This option can save memory, for example, when solving nonlinear
systems with a matrix-free Newton-Krylov method and a matrix-based, in-place
ILU(0) preconditioner.
One can specify in-place ILU(0) factorization by calling
or by using the options -pc_type ilu -pc_factor_in_place
In-place factorization ILU(0) can also be used as a local solver for the blocks within the block Jacobi or additive Schwarz methods (runtime option: -sub_pc_factor_in_place). See Users-Manual: ch_pc for details on setting local solver options.
Most users should employ the KSP
interface for linear solvers
instead of working directly with matrix algebra routines such as this.
See, e.g., KSPCreate()
.
See Also#
Matrices, Mat
, PCFactorSetUseInPlace()
, PCFactorGetUseInPlace()
Level#
developer
Location#
Implementations#
MatSetUnfactored_MPIAIJ() in src/mat/impls/aij/mpi/mpiaij.c
MatSetUnfactored_MPIBAIJ() in src/mat/impls/baij/mpi/mpibaij.c
MatSetUnfactored_MPISBAIJ() in src/mat/impls/sbaij/mpi/mpisbaij.c
MatSetUnfactored_MPISELL() in src/mat/impls/sell/mpi/mpisell.c
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