petsc-3.10.5 2019-03-28
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# MatGetColumnIJ

Returns the compressed column storage i and j indices for sequential matrices.

### Synopsis

    #include "petscmat.h"
    PetscErrorCode MatGetColumnIJ(Mat mat,PetscInt shift,PetscBool symmetric,PetscBool inodecompressed,PetscInt *n,const PetscInt *ia[],const PetscInt *ja[],PetscBool  *done)

Collective on Mat

### Input Parameters

| mat | - the matrix
| shift | - 1 or zero indicating we want the indices starting at 0 or 1
| symmetric | - PETSC_TRUE or PETSC_FALSE indicating the matrix data structure should be symmetrized
| inodecompressed | - PETSC_TRUE or PETSC_FALSE indicating if the nonzero structure of the inodes or the nonzero elements is wanted. For BAIJ matrices the compressed version is always used.
| n | - number of columns in the (possibly compressed) matrix
| ia | - the column pointers
| ja | - the row indices

### Output Parameters

done -PETSC_TRUE or PETSC_FALSE, indicating whether the values have been returned

### Note

This routine zeros out n, ia, and ja. This is to prevent accidental us of the array after it has been restored. If you pass NULL, it will not zero the pointers. Use of ia or ja after MatRestoreColumnIJ() is invalid.

### See Also

MatGetRowIJ(), MatRestoreColumnIJ()

### Level

developer

### Location

src/mat/interface/matrix.c

### Implementations

MatGetColumnIJ_SeqAIJ in src/mat/impls/aij/seq/aij.c
MatGetColumnIJ_SeqAIJ_Color in src/mat/impls/aij/seq/aij.c
MatGetColumnIJ_SeqAIJ_Inode_Nonsymmetric in src/mat/impls/aij/seq/inode.c
MatGetColumnIJ_SeqAIJ_Inode in src/mat/impls/aij/seq/inode.c
MatGetColumnIJ_SeqBAIJ in src/mat/impls/baij/seq/baij.c
MatGetColumnIJ_SeqBAIJ_Color in src/mat/impls/baij/seq/baij.c
MatGetColumnIJ_SeqSELL_Color in src/mat/impls/sell/seq/fdsell.c
Index of all Mat routines
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Index of all manual pages