static PetscErrorCode TestMatrix(Mat A,Vec X,Vec Y,Vec Z)
{
PetscErrorCode ierr;
Vec W1,W2;
Mat E;
const char *mattypename;
PetscViewer viewer = PETSC_VIEWER_STDOUT_WORLD;
PetscFunctionBegin;
ierr = VecDuplicate(X,&W1);
CHKERRQ(ierr);
ierr = VecDuplicate(X,&W2);
CHKERRQ(ierr);
ierr = MatScale(A,31);
CHKERRQ(ierr);
ierr = MatShift(A,37);
CHKERRQ(ierr);
ierr = MatDiagonalScale(A,X,Y);
CHKERRQ(ierr);
ierr = MatScale(A,41);
CHKERRQ(ierr);
ierr = MatDiagonalScale(A,Y,Z);
CHKERRQ(ierr);
ierr = MatComputeExplicitOperator(A,&E);
CHKERRQ(ierr);
ierr = PetscObjectGetType((PetscObject)A,&mattypename);
CHKERRQ(ierr);
ierr = PetscViewerASCIIPrintf(viewer,"Matrix of type: %s\n",mattypename);
CHKERRQ(ierr);
ierr = MatView(E,viewer);
CHKERRQ(ierr);
ierr = MatMult(A,Z,W1);
CHKERRQ(ierr);
ierr = MatMultTranspose(A,W1,W2);
CHKERRQ(ierr);
ierr = VecView(W2,viewer);
CHKERRQ(ierr);
ierr = MatGetDiagonal(A,W2);
CHKERRQ(ierr);
ierr = VecView(W2,viewer);
CHKERRQ(ierr);
ierr = MatDestroy(&E);
CHKERRQ(ierr);
ierr = VecDestroy(&W1);
CHKERRQ(ierr);
ierr = VecDestroy(&W2);
CHKERRQ(ierr);
PetscFunctionReturn(0);
}
/*@
MatSchurComplementGetAinvType - get the type of approximation for the inverse of the (0,0) block used in forming Sp in MatSchurComplementGetPmat()
Not collective.
Input Parameter:
. S - matrix obtained with MatCreateSchurComplement() (or equivalent) and implementing the action of A11 - A10 ksp(A00,Ap00) A01
Output Parameter:
. ainvtype - type of approximation used to form A00inv from A00 when assembling Sp = A11 - A10 A00inv A01:
MAT_SCHUR_COMPLEMENT_AINV_DIAG or MAT_SCHUR_COMPLEMENT_AINV_LUMP
Note:
Since the real Schur complement is usually dense, providing a good approximation to newpmat usually requires
application-specific information. The default for assembled matrices is to use the inverse of the diagonal of
the (0,0) block A00 in place of A00^{-1}. This rarely produce a scalable algorithm. Optionally, A00 can be lumped
before forming inv(diag(A00)).
Level: advanced
Concepts: matrices^submatrices
.seealso: MatSchurComplementAinvType, MatCreateSchurComplement(), MatGetSchurComplement(), MatSchurComplementGetPmat(), MatSchurComplementSetAinvType()
@*/
PetscErrorCode MatSchurComplementGetAinvType(Mat S,MatSchurComplementAinvType *ainvtype)
{
PetscErrorCode ierr;
const char* t;
PetscBool isschur;
Mat_SchurComplement *schur;
PetscFunctionBegin;
PetscValidHeaderSpecific(S,MAT_CLASSID,1);
ierr = PetscObjectGetType((PetscObject)S,&t);CHKERRQ(ierr);
ierr = PetscStrcmp(t,MATSCHURCOMPLEMENT,&isschur);CHKERRQ(ierr);
if (!isschur) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONG,"Expected Mat of type MATSCHURCOMPLEMENT, got %s instead",t);
schur = (Mat_SchurComplement*)S->data;
if (ainvtype) *ainvtype = schur->ainvtype;
PetscFunctionReturn(0);
}
