MatNullSpaceCreate#
Creates a MatNullSpace
data structure used to project vectors out of null spaces.
Synopsis#
#include "petscmat.h"
PetscErrorCode MatNullSpaceCreate(MPI_Comm comm, PetscBool has_cnst, PetscInt n, const Vec vecs[], MatNullSpace *SP)
Collective
Input Parameters#
comm - the MPI communicator associated with the object
has_cnst -
PETSC_TRUE
if the null space contains the constant vector; otherwisePETSC_FALSE
n - number of vectors (excluding constant vector) in null space
vecs - the vectors that span the null space (excluding the constant vector); these vectors must be orthonormal. These vectors are NOT copied, so do not change them after this call. You should free the array that you pass in and destroy the vectors (this will reduce the reference count for them by one).
Output Parameter#
SP - the null space context
Notes#
See MatNullSpaceSetFunction()
as an alternative way of providing the null space information instead of providing the vectors.
If has_cnst is PETSC_TRUE
you do not need to pass a constant vector in as a fourth argument to this routine, nor do you
need to pass in a function that eliminates the constant function into MatNullSpaceSetFunction()
.
See Also#
Matrices, Mat
, MatNullSpace
, MatNullSpaceDestroy()
, MatNullSpaceRemove()
, MatSetNullSpace()
, MatNullSpaceSetFunction()
Level#
advanced
Location#
Examples#
src/ts/tutorials/ex50.c
src/ts/tutorials/ex77.c
src/dm/impls/stag/tutorials/ex4.c
src/ts/tutorials/ex30.c
src/ksp/ksp/tutorials/ex72.c
src/ts/tutorials/ex46.c
src/ksp/ksp/tutorials/ex32.c
src/dm/impls/stag/tutorials/ex2.c
src/dm/impls/stag/tutorials/ex3.c
src/ts/tutorials/ex76.c
Index of all Mat routines
Table of Contents for all manual pages
Index of all manual pages