/*@
MatDiagonalSet - Computes Y = Y + D, where D is a diagonal matrix
that is represented as a vector. Or Y[i,i] = D[i] if InsertMode is
INSERT_VALUES.
Input Parameters:
+ Y - the input matrix
. D - the diagonal matrix, represented as a vector
- i - INSERT_VALUES or ADD_VALUES
Neighbor-wise Collective on Mat and Vec
Level: intermediate
.keywords: matrix, add, shift, diagonal
.seealso: MatShift()
@*/
PetscErrorCode MatDiagonalSet(Mat Y,Vec D,InsertMode is)
{
PetscErrorCode ierr;
PetscFunctionBegin;
PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
PetscValidHeaderSpecific(D,VEC_CLASSID,2);
if (Y->ops->diagonalset) {
ierr = (*Y->ops->diagonalset)(Y,D,is);CHKERRQ(ierr);
} else {
ierr = MatDiagonalSet_Default(Y,D,is);CHKERRQ(ierr);
}
PetscFunctionReturn(0);
}
/*@
MatDiagonalSet - Computes Y = Y + D, where D is a diagonal matrix
that is represented as a vector. Or Y[i,i] = D[i] if InsertMode is
INSERT_VALUES.
Input Parameters:
+ Y - the input matrix
. D - the diagonal matrix, represented as a vector
- i - INSERT_VALUES or ADD_VALUES
Neighbor-wise Collective on Mat and Vec
Notes: If the matrix Y is missing some diagonal entries this routine can be very slow. To make it fast one should initially
fill the matrix so that all diagonal entries have a value (with a value of zero for those locations that would not have an
entry).
Level: intermediate
.keywords: matrix, add, shift, diagonal
.seealso: MatShift()
@*/
PetscErrorCode MatDiagonalSet(Mat Y,Vec D,InsertMode is)
{
PetscErrorCode ierr;
PetscInt matlocal,veclocal;
PetscFunctionBegin;
PetscValidHeaderSpecific(Y,MAT_CLASSID,1);
PetscValidHeaderSpecific(D,VEC_CLASSID,2);
ierr = MatGetLocalSize(Y,&matlocal,NULL);CHKERRQ(ierr);
ierr = VecGetLocalSize(D,&veclocal);CHKERRQ(ierr);
if (matlocal != veclocal) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_INCOMP,"Number local rows of matrix %D does not match that of vector for diagonal %D",matlocal,veclocal);
if (Y->ops->diagonalset) {
ierr = (*Y->ops->diagonalset)(Y,D,is);CHKERRQ(ierr);
} else {
ierr = MatDiagonalSet_Default(Y,D,is);CHKERRQ(ierr);
}
PetscFunctionReturn(0);
}