/* Developer Notes: This should be implemented with a MatCreate_SchurComplement() as that is the standard design for new Mat classes. */
PetscErrorCode MatGetSchurComplement_Basic(Mat mat,IS isrow0,IS iscol0,IS isrow1,IS iscol1,MatReuse mreuse,Mat *newmat,MatReuse preuse,Mat *newpmat)
{
PetscErrorCode ierr;
Mat A=0,Ap=0,B=0,C=0,D=0;
PetscFunctionBegin;
PetscValidHeaderSpecific(mat,MAT_CLASSID,1);
PetscValidHeaderSpecific(isrow0,IS_CLASSID,2);
PetscValidHeaderSpecific(iscol0,IS_CLASSID,3);
PetscValidHeaderSpecific(isrow1,IS_CLASSID,4);
PetscValidHeaderSpecific(iscol1,IS_CLASSID,5);
if (mreuse == MAT_REUSE_MATRIX) PetscValidHeaderSpecific(*newmat,MAT_CLASSID,7);
if (preuse == MAT_REUSE_MATRIX) PetscValidHeaderSpecific(*newpmat,MAT_CLASSID,9);
PetscValidType(mat,1);
if (mat->factortype) SETERRQ(((PetscObject)mat)->comm,PETSC_ERR_ARG_WRONGSTATE,"Not for factored matrix");
if (mreuse != MAT_IGNORE_MATRIX) {
/* Use MatSchurComplement */
if (mreuse == MAT_REUSE_MATRIX) {
ierr = MatSchurComplementGetSubmatrices(*newmat,&A,&Ap,&B,&C,&D);CHKERRQ(ierr);
if (!A || !Ap || !B || !C) SETERRQ(((PetscObject)mat)->comm,PETSC_ERR_ARG_WRONGSTATE,"Attempting to reuse matrix but Schur complement matrices unset");
if (A != Ap) SETERRQ(((PetscObject)mat)->comm,PETSC_ERR_ARG_WRONGSTATE,"Preconditioning matrix does not match operator");
ierr = MatDestroy(&Ap);CHKERRQ(ierr); /* get rid of extra reference */
}
ierr = MatGetSubMatrix(mat,isrow0,iscol0,mreuse,&A);CHKERRQ(ierr);
ierr = MatGetSubMatrix(mat,isrow0,iscol1,mreuse,&B);CHKERRQ(ierr);
ierr = MatGetSubMatrix(mat,isrow1,iscol0,mreuse,&C);CHKERRQ(ierr);
ierr = MatGetSubMatrix(mat,isrow1,iscol1,mreuse,&D);CHKERRQ(ierr);
switch (mreuse) {
case MAT_INITIAL_MATRIX:
ierr = MatCreateSchurComplement(A,A,B,C,D,newmat);CHKERRQ(ierr);
break;
case MAT_REUSE_MATRIX:
ierr = MatSchurComplementUpdate(*newmat,A,A,B,C,D,DIFFERENT_NONZERO_PATTERN);CHKERRQ(ierr);
break;
default:
SETERRQ(((PetscObject)mat)->comm,PETSC_ERR_SUP,"Unrecognized value of mreuse");
}
}
if (preuse != MAT_IGNORE_MATRIX) {
/* Use the diagonal part of A to form D - C inv(diag(A)) B */
Mat Ad,AdB,S;
Vec diag;
PetscInt i,m,n,mstart,mend;
PetscScalar *x;
/* We could compose these with newpmat so that the matrices can be reused. */
if (!A) {ierr = MatGetSubMatrix(mat,isrow0,iscol0,MAT_INITIAL_MATRIX,&A);CHKERRQ(ierr);}
if (!B) {ierr = MatGetSubMatrix(mat,isrow0,iscol1,MAT_INITIAL_MATRIX,&B);CHKERRQ(ierr);}
if (!C) {ierr = MatGetSubMatrix(mat,isrow1,iscol0,MAT_INITIAL_MATRIX,&C);CHKERRQ(ierr);}
if (!D) {ierr = MatGetSubMatrix(mat,isrow1,iscol1,MAT_INITIAL_MATRIX,&D);CHKERRQ(ierr);}
ierr = MatGetVecs(A,&diag,PETSC_NULL);CHKERRQ(ierr);
ierr = MatGetDiagonal(A,diag);CHKERRQ(ierr);
ierr = VecReciprocal(diag);CHKERRQ(ierr);
ierr = MatGetLocalSize(A,&m,&n);CHKERRQ(ierr);
/* We need to compute S = D - C inv(diag(A)) B. For row-oriented formats, it is easy to scale the rows of B and
* for column-oriented formats the columns of C can be scaled. Would skip creating a silly diagonal matrix. */
ierr = MatCreate(((PetscObject)A)->comm,&Ad);CHKERRQ(ierr);
ierr = MatSetSizes(Ad,m,n,PETSC_DETERMINE,PETSC_DETERMINE);CHKERRQ(ierr);
ierr = MatSetOptionsPrefix(Ad,((PetscObject)mat)->prefix);CHKERRQ(ierr);
ierr = MatAppendOptionsPrefix(Ad,"diag_");CHKERRQ(ierr);
ierr = MatSetFromOptions(Ad);CHKERRQ(ierr);
ierr = MatSeqAIJSetPreallocation(Ad,1,PETSC_NULL);CHKERRQ(ierr);
ierr = MatMPIAIJSetPreallocation(Ad,1,PETSC_NULL,0,PETSC_NULL);CHKERRQ(ierr);
ierr = MatGetOwnershipRange(Ad,&mstart,&mend);CHKERRQ(ierr);
ierr = VecGetArray(diag,&x);CHKERRQ(ierr);
for (i=mstart; i<mend; i++) {
ierr = MatSetValue(Ad,i,i,x[i-mstart],INSERT_VALUES);CHKERRQ(ierr);
}
ierr = VecRestoreArray(diag,&x);CHKERRQ(ierr);
ierr = MatAssemblyBegin(Ad,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
ierr = MatAssemblyEnd(Ad,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
ierr = VecDestroy(&diag);CHKERRQ(ierr);
ierr = MatMatMult(Ad,B,MAT_INITIAL_MATRIX,1,&AdB);CHKERRQ(ierr);
S = (preuse == MAT_REUSE_MATRIX) ? *newpmat : (Mat)0;
ierr = MatMatMult(C,AdB,preuse,PETSC_DEFAULT,&S);CHKERRQ(ierr);
ierr = MatAYPX(S,-1,D,DIFFERENT_NONZERO_PATTERN);CHKERRQ(ierr);
*newpmat = S;
ierr = MatDestroy(&Ad);CHKERRQ(ierr);
ierr = MatDestroy(&AdB);CHKERRQ(ierr);
}
ierr = MatDestroy(&A);CHKERRQ(ierr);
ierr = MatDestroy(&B);CHKERRQ(ierr);
ierr = MatDestroy(&C);CHKERRQ(ierr);
ierr = MatDestroy(&D);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
static PetscErrorCode PCSetUp_PCD_Feelpp(PC pc)
{
PetscErrorCode ierr;
PC_PCD_Feelpp *pcpcd = (PC_PCD_Feelpp*)pc->data;
if ( !pcpcd->allocated )
{
ierr = KSPCreate(PetscObjectComm((PetscObject)pc),&pcpcd->kspAp);CHKERRQ(ierr);
ierr = PetscObjectIncrementTabLevel((PetscObject)pcpcd->kspAp,(PetscObject)pc,1);CHKERRQ(ierr);
ierr = KSPSetType(pcpcd->kspAp,KSPPREONLY);CHKERRQ(ierr);
ierr = KSPSetOptionsPrefix(pcpcd->kspAp,((PetscObject)pc)->prefix);CHKERRQ(ierr);
ierr = KSPAppendOptionsPrefix(pcpcd->kspAp,"pcd_Ap");CHKERRQ(ierr);
ierr = KSPSetFromOptions(pcpcd->kspAp);CHKERRQ(ierr);
ierr = KSPCreate(PetscObjectComm((PetscObject)pc),&pcpcd->kspMp);CHKERRQ(ierr);
ierr = PetscObjectIncrementTabLevel((PetscObject)pcpcd->kspMp,(PetscObject)pc,1);CHKERRQ(ierr);
ierr = KSPSetType(pcpcd->kspMp,KSPPREONLY);CHKERRQ(ierr);
ierr = KSPSetOptionsPrefix(pcpcd->kspMp,((PetscObject)pc)->prefix);CHKERRQ(ierr);
ierr = KSPAppendOptionsPrefix(pcpcd->kspMp,"pcd_Mp");CHKERRQ(ierr);
ierr = KSPSetFromOptions(pcpcd->kspMp);CHKERRQ(ierr);
#if PETSC_VERSION_LESS_THAN(3,6,0)
ierr = MatGetVecs(pcpcd->matFp,&pcpcd->x2,&pcpcd->x1);CHKERRQ(ierr);
#else
ierr = MatCreateVecs(pcpcd->matFp,&pcpcd->x2,&pcpcd->x1);CHKERRQ(ierr);
#endif
pcpcd->allocated = PETSC_TRUE;
}
PetscBool isBTBt;
PetscStrcmp(pcpcd->pcdApType,"BTBt",&isBTBt);
if ( isBTBt )
{
if (!pcpcd->MvDiag )
{
#if PETSC_VERSION_LESS_THAN(3,6,0)
ierr = MatGetVecs(pcpcd->matMv,&pcpcd->MvDiag,NULL);CHKERRQ(ierr);
#else
ierr = MatCreateVecs(pcpcd->matMv,&pcpcd->MvDiag,NULL);CHKERRQ(ierr);
#endif
}
Mat B, C;
#if PETSC_VERSION_GREATER_OR_EQUAL_THAN( 3,5,0 )
ierr = MatSchurComplementGetSubMatrices(pc->mat,NULL,NULL,&B,&C,NULL);CHKERRQ(ierr);
#else
ierr = MatSchurComplementGetSubmatrices(pc->mat,NULL,NULL,&B,&C,NULL);CHKERRQ(ierr);
#endif
ierr = MatGetDiagonal(pcpcd->matMv,pcpcd->MvDiag);CHKERRQ(ierr);
ierr = VecReciprocal(pcpcd->MvDiag);CHKERRQ(ierr);
// diag(F)^-1 * B
ierr = MatDiagonalScale( B, pcpcd->MvDiag ,NULL);CHKERRQ(ierr);
// C* diag(F)^-1 * B
if ( !pcpcd->matApBTBt )
ierr = MatMatMult(C,B,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&pcpcd->matApBTBt);
else
ierr = MatMatMult(C,B,MAT_REUSE_MATRIX,PETSC_DEFAULT,&pcpcd->matApBTBt);
CHKERRQ(ierr);
ierr = VecReciprocal(pcpcd->MvDiag);CHKERRQ(ierr);
ierr = MatDiagonalScale( B, pcpcd->MvDiag ,NULL);CHKERRQ(ierr);
pcpcd->matAp = pcpcd->matApBTBt;
}
else
pcpcd->matAp = pcpcd->matApLaplacian;
#if PETSC_VERSION_GREATER_OR_EQUAL_THAN( 3,5,0 )
ierr = KSPSetOperators(pcpcd->kspAp,pcpcd->matAp,pcpcd->matAp);CHKERRQ(ierr);
ierr = KSPSetOperators(pcpcd->kspMp,pcpcd->matMp,pcpcd->matMp);CHKERRQ(ierr);
#else
ierr = KSPSetOperators(pcpcd->kspAp,pcpcd->matAp,pcpcd->matAp,SAME_PRECONDITIONER);CHKERRQ(ierr);
ierr = KSPSetOperators(pcpcd->kspMp,pcpcd->matMp,pcpcd->matMp,SAME_PRECONDITIONER);CHKERRQ(ierr);
#endif
PetscFunctionReturn(0);
}
