MatGetOwnershipRangeColumn#
Returns the range of matrix columns associated with rows of a vector one multiplies this matrix by that are owned by this processor.
Synopsis#
#include "petscmat.h"
PetscErrorCode MatGetOwnershipRangeColumn(Mat mat, PetscInt *m, PetscInt *n)
Not Collective, unless matrix has not been allocated, then collective
Input Parameter#
mat - the matrix
Output Parameters#
m - the global index of the first local column, use
NULL
to not obtain this valuen - one more than the global index of the last local column, use
NULL
to not obtain this value
Notes#
If the Mat
was obtained from a DM
with DMCreateMatrix()
, then the range values are determined by the specific DM
.
If the Mat
was created directly the range values are determined by the local size passed to MatSetSizes()
or MatCreateAIJ()
.
If PETSC_DECIDE
was passed as the local size, then the vector uses default values for the range using PetscSplitOwnership()
.
For certain DM
, such as DMDA
, it is better to use DM
specific routines, such as DMDAGetGhostCorners()
, to determine
the local values in the matrix.
Returns the columns of the “diagonal block” for most sparse matrix formats. See Matrix Layouts for details on matrix layouts.
See Also#
Matrices, Mat
, MatGetOwnershipRange()
, MatGetOwnershipRanges()
, MatGetOwnershipRangesColumn()
, PetscLayout
,
MatSetSizes()
, MatCreateAIJ()
, DMDAGetGhostCorners()
, DM
Level#
developer
Location#
Examples#
src/ksp/ksp/tutorials/ex27.c
src/snes/tutorials/ex48.c
src/mat/tutorials/ex10.c
src/ksp/ksp/tutorials/ex85.c
Index of all Mat routines
Table of Contents for all manual pages
Index of all manual pages