/*@C
MatCreateScatter - Creates a new matrix based on a VecScatter
Collective on MPI_Comm
Input Parameters:
+ comm - MPI communicator
- scatter - a VecScatterContext
Output Parameter:
. A - the matrix
Level: intermediate
PETSc requires that matrices and vectors being used for certain
operations are partitioned accordingly. For example, when
creating a scatter matrix, A, that supports parallel matrix-vector
products using MatMult(A,x,y) the user should set the number
of local matrix rows to be the number of local elements of the
corresponding result vector, y. Note that this is information is
required for use of the matrix interface routines, even though
the scatter matrix may not actually be physically partitioned.
.keywords: matrix, scatter, create
.seealso: MatScatterSetVecScatter(), MatScatterGetVecScatter(), MATSCATTER
@*/
PetscErrorCode MatCreateScatter(MPI_Comm comm,VecScatter scatter,Mat *A)
{
PetscErrorCode ierr;
PetscFunctionBegin;
ierr = MatCreate(comm,A);
CHKERRQ(ierr);
ierr = MatSetSizes(*A,scatter->to_n,scatter->from_n,PETSC_DETERMINE,PETSC_DETERMINE);
CHKERRQ(ierr);
ierr = MatSetType(*A,MATSCATTER);
CHKERRQ(ierr);
ierr = MatScatterSetVecScatter(*A,scatter);
CHKERRQ(ierr);
ierr = MatSetUp(*A);
CHKERRQ(ierr);
PetscFunctionReturn(0);
}
EXTERN_C_END
#undef __FUNCT__
#define __FUNCT__ "MatCreateScatter"
/*@C
MatCreateScatter - Creates a new matrix based on a VecScatter
Collective on MPI_Comm
Input Parameters:
+ comm - MPI communicator
- scatter - a VecScatterContext
Output Parameter:
. A - the matrix
Level: intermediate
PETSc requires that matrices and vectors being used for certain
operations are partitioned accordingly. For example, when
creating a scatter matrix, A, that supports parallel matrix-vector
products using MatMult(A,x,y) the user should set the number
of local matrix rows to be the number of local elements of the
corresponding result vector, y. Note that this is information is
required for use of the matrix interface routines, even though
the scatter matrix may not actually be physically partitioned.
For example,
.keywords: matrix, scatter, create
.seealso: MatScatterSetVecScatter(), MatScatterGetVecScatter(), MATSCATTER
@*/
PetscErrorCode PETSCMAT_DLLEXPORT MatCreateScatter(MPI_Comm comm,VecScatter scatter,Mat *A)
{
PetscErrorCode ierr;
PetscFunctionBegin;
ierr = MatCreate(comm,A);CHKERRQ(ierr);
ierr = MatSetSizes(*A,scatter->to_n,scatter->from_n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
ierr = MatSetType(*A,MATSCATTER);CHKERRQ(ierr);
ierr = MatScatterSetVecScatter(*A,scatter);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
PETSC_EXTERN void PETSC_STDCALL matscattersetvecscatter_(Mat mat,VecScatter scatter, int *__ierr ){
*__ierr = MatScatterSetVecScatter(
(Mat)PetscToPointer((mat) ),
(VecScatter)PetscToPointer((scatter) ));
}
