/*@
MatCreateComposite - Creates a matrix as the sum of zero or more matrices
Collective on MPI_Comm
Input Parameters:
+ comm - MPI communicator
. nmat - number of matrices to put in
- mats - the matrices
Output Parameter:
. A - the matrix
Level: advanced
Notes:
Alternative construction
$ MatCreate(comm,&mat);
$ MatSetSizes(mat,m,n,M,N);
$ MatSetType(mat,MATCOMPOSITE);
$ MatCompositeAddMat(mat,mats[0]);
$ ....
$ MatCompositeAddMat(mat,mats[nmat-1]);
$ MatAssemblyBegin(mat,MAT_FINAL_ASSEMBLY);
$ MatAssemblyEnd(mat,MAT_FINAL_ASSEMBLY);
For the multiplicative form the product is mat[nmat-1]*mat[nmat-2]*....*mat[0]
.seealso: MatDestroy(), MatMult(), MatCompositeAddMat(), MatCompositeMerge(), MatCompositeSetType(), MatCompositeType
@*/
PetscErrorCode MatCreateComposite(MPI_Comm comm,PetscInt nmat,const Mat *mats,Mat *mat)
{
PetscErrorCode ierr;
PetscInt m,n,M,N,i;
PetscFunctionBegin;
if (nmat < 1) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Must pass in at least one matrix");
PetscValidPointer(mat,3);
ierr = MatGetLocalSize(mats[0],&m,&n);CHKERRQ(ierr);
ierr = MatGetSize(mats[0],&M,&N);CHKERRQ(ierr);
ierr = MatCreate(comm,mat);CHKERRQ(ierr);
ierr = MatSetSizes(*mat,m,n,M,N);CHKERRQ(ierr);
ierr = MatSetType(*mat,MATCOMPOSITE);CHKERRQ(ierr);
for (i=0; i<nmat; i++) {
ierr = MatCompositeAddMat(*mat,mats[i]);CHKERRQ(ierr);
}
ierr = MatAssemblyBegin(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
ierr = MatAssemblyEnd(*mat,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
PETSC_EXTERN void PETSC_STDCALL matcompositeaddmat_(Mat mat,Mat smat, int *__ierr ){
*__ierr = MatCompositeAddMat(
(Mat)PetscToPointer((mat) ),
(Mat)PetscToPointer((smat) ));
}
