int main(int argc,char *argv[])
{
PetscErrorCode ierr;
Mat A,S = NULL,Sexplicit = NULL;
IS is0,is1;
ierr = PetscInitialize(&argc,&argv,0,help);if (ierr) return ierr;
/* Test the Schur complement one way */
ierr = Create(PETSC_COMM_WORLD,&A,&is0,&is1);CHKERRQ(ierr);
ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
ierr = ISView(is0,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
ierr = ISView(is1,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
ierr = MatGetSchurComplement(A,is0,is0,is1,is1,MAT_INITIAL_MATRIX,&S,MAT_SCHUR_COMPLEMENT_AINV_DIAG,MAT_IGNORE_MATRIX,NULL);CHKERRQ(ierr);
ierr = MatComputeExplicitOperator(S,&Sexplicit);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"\nExplicit Schur complement of (0,0) in (1,1)\n");CHKERRQ(ierr);
ierr = MatView(Sexplicit,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
ierr = Destroy(&A,&is0,&is1);CHKERRQ(ierr);
ierr = MatDestroy(&S);CHKERRQ(ierr);
ierr = MatDestroy(&Sexplicit);CHKERRQ(ierr);
/* And the other */
ierr = Create(PETSC_COMM_WORLD,&A,&is0,&is1);CHKERRQ(ierr);
ierr = MatGetSchurComplement(A,is1,is1,is0,is0,MAT_INITIAL_MATRIX,&S,MAT_SCHUR_COMPLEMENT_AINV_DIAG,MAT_IGNORE_MATRIX,NULL);CHKERRQ(ierr);
ierr = MatComputeExplicitOperator(S,&Sexplicit);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"\nExplicit Schur complement of (1,1) in (0,0)\n");CHKERRQ(ierr);
ierr = MatView(Sexplicit,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
ierr = Destroy(&A,&is0,&is1);CHKERRQ(ierr);
ierr = MatDestroy(&S);CHKERRQ(ierr);
ierr = MatDestroy(&Sexplicit);CHKERRQ(ierr);
/* This time just the preconditioning matrix. */
ierr = Create(PETSC_COMM_WORLD,&A,&is0,&is1);CHKERRQ(ierr);
ierr = MatGetSchurComplement(A,is0,is0,is1,is1,MAT_IGNORE_MATRIX,NULL,MAT_SCHUR_COMPLEMENT_AINV_DIAG,MAT_INITIAL_MATRIX,&S);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"\nPreconditioning Schur complement of (0,0) in (1,1)\n");CHKERRQ(ierr);
ierr = MatView(S,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
/* Modify and refresh */
ierr = MatShift(A,1.);CHKERRQ(ierr);
ierr = MatGetSchurComplement(A,is0,is0,is1,is1,MAT_IGNORE_MATRIX,NULL,MAT_SCHUR_COMPLEMENT_AINV_DIAG,MAT_REUSE_MATRIX,&S);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"\nAfter update\n");CHKERRQ(ierr);
ierr = MatView(S,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
ierr = Destroy(&A,&is0,&is1);CHKERRQ(ierr);
ierr = MatDestroy(&S);CHKERRQ(ierr);
ierr = PetscFinalize();
return ierr;
}
int main(int argc,char *argv[])
{
PetscErrorCode ierr;
Mat A,S,Sexplicit;
IS is0,is1;
ierr = PetscInitialize(&argc,&argv,0,help);CHKERRQ(ierr);
/* Test the Schur complement one way */
ierr = Create(PETSC_COMM_WORLD,&A,&is0,&is1);CHKERRQ(ierr);
ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
ierr = ISView(is0,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
ierr = ISView(is1,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
ierr = MatGetSchurComplement(A,is0,is0,is1,is1,MAT_INITIAL_MATRIX,&S,MAT_IGNORE_MATRIX,PETSC_NULL);CHKERRQ(ierr);
ierr = MatComputeExplicitOperator(S,&Sexplicit);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"\nExplicit Schur complement of (0,0) in (1,1)\n");CHKERRQ(ierr);
ierr = MatView(Sexplicit,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
ierr = Destroy(A,is0,is1);CHKERRQ(ierr);
ierr = MatDestroy(S);CHKERRQ(ierr);
ierr = MatDestroy(Sexplicit);CHKERRQ(ierr);
/* And the other */
ierr = Create(PETSC_COMM_WORLD,&A,&is0,&is1);CHKERRQ(ierr);
ierr = MatGetSchurComplement(A,is1,is1,is0,is0,MAT_INITIAL_MATRIX,&S,MAT_IGNORE_MATRIX,PETSC_NULL);CHKERRQ(ierr);
ierr = MatComputeExplicitOperator(S,&Sexplicit);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"\nExplicit Schur complement of (1,1) in (0,0)\n");CHKERRQ(ierr);
ierr = MatView(Sexplicit,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
ierr = Destroy(A,is0,is1);CHKERRQ(ierr);
ierr = MatDestroy(S);CHKERRQ(ierr);
ierr = MatDestroy(Sexplicit);CHKERRQ(ierr);
/* This time just the preconditioner */
ierr = Create(PETSC_COMM_WORLD,&A,&is0,&is1);CHKERRQ(ierr);
ierr = MatGetSchurComplement(A,is0,is0,is1,is1,MAT_IGNORE_MATRIX,PETSC_NULL,MAT_INITIAL_MATRIX,&S);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"\nPreconditioning Schur complement of (0,0) in (1,1)\n");CHKERRQ(ierr);
ierr = MatView(S,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
ierr = Destroy(A,is0,is1);CHKERRQ(ierr);
ierr = MatDestroy(S);CHKERRQ(ierr);
ierr = PetscFinalize();CHKERRQ(ierr);
return 0;
}
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);
}
int main(int argc,char **args)
{
Mat C,Caij;
PetscInt i,j,m = 5,n,nrows,ncols;
const PetscInt *rows,*cols;
IS isrows,iscols;
PetscErrorCode ierr;
PetscBool flg,Test_MatMatMult=PETSC_FALSE,mats_view=PETSC_FALSE;
PetscScalar *v;
PetscMPIInt rank,size;
PetscInitialize(&argc,&args,(char*)0,help);
ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
ierr = PetscOptionsHasName(NULL,"-mats_view",&mats_view);CHKERRQ(ierr);
/* Get local block or element size*/
ierr = PetscOptionsGetInt(NULL,"-m",&m,NULL);CHKERRQ(ierr);
n = m;
ierr = PetscOptionsGetInt(NULL,"-n",&n,NULL);CHKERRQ(ierr);
ierr = MatCreate(PETSC_COMM_WORLD,&C);CHKERRQ(ierr);
ierr = MatSetSizes(C,m,n,PETSC_DECIDE,PETSC_DECIDE);CHKERRQ(ierr);
ierr = MatSetType(C,MATELEMENTAL);CHKERRQ(ierr);
ierr = MatSetFromOptions(C);CHKERRQ(ierr);
ierr = MatSetUp(C);CHKERRQ(ierr);
ierr = PetscOptionsHasName(NULL,"-row_oriented",&flg);CHKERRQ(ierr);
if (flg) {ierr = MatSetOption(C,MAT_ROW_ORIENTED,PETSC_TRUE);CHKERRQ(ierr);}
ierr = MatGetOwnershipIS(C,&isrows,&iscols);CHKERRQ(ierr);
ierr = PetscOptionsHasName(NULL,"-Cexp_view_ownership",&flg);CHKERRQ(ierr);
if (flg) { /* View ownership of explicit C */
IS tmp;
ierr = PetscPrintf(PETSC_COMM_WORLD,"Ownership of explicit C:\n");CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Row index set:\n");CHKERRQ(ierr);
ierr = ISOnComm(isrows,PETSC_COMM_WORLD,PETSC_USE_POINTER,&tmp);CHKERRQ(ierr);
ierr = ISView(tmp,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
ierr = ISDestroy(&tmp);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,"Column index set:\n");CHKERRQ(ierr);
ierr = ISOnComm(iscols,PETSC_COMM_WORLD,PETSC_USE_POINTER,&tmp);CHKERRQ(ierr);
ierr = ISView(tmp,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
ierr = ISDestroy(&tmp);CHKERRQ(ierr);
}
/* Set local matrix entries */
ierr = ISGetLocalSize(isrows,&nrows);CHKERRQ(ierr);
ierr = ISGetIndices(isrows,&rows);CHKERRQ(ierr);
ierr = ISGetLocalSize(iscols,&ncols);CHKERRQ(ierr);
ierr = ISGetIndices(iscols,&cols);CHKERRQ(ierr);
ierr = PetscMalloc(nrows*ncols*sizeof(*v),&v);CHKERRQ(ierr);
for (i=0; i<nrows; i++) {
for (j=0; j<ncols; j++) {
/*v[i*ncols+j] = (PetscReal)(rank);*/
v[i*ncols+j] = (PetscReal)(rank*10000+100*rows[i]+cols[j]);
}
}
ierr = MatSetValues(C,nrows,rows,ncols,cols,v,INSERT_VALUES);CHKERRQ(ierr);
ierr = ISRestoreIndices(isrows,&rows);CHKERRQ(ierr);
ierr = ISRestoreIndices(iscols,&cols);CHKERRQ(ierr);
ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
/* Test MatView() */
if (mats_view) {
ierr = MatView(C,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
}
/* Set unowned matrix entries - add subdiagonals and diagonals from proc[0] */
if (!rank) {
PetscInt M,N,cols[2];
ierr = MatGetSize(C,&M,&N);CHKERRQ(ierr);
for (i=0; i<M; i++) {
cols[0] = i; v[0] = i + 0.5;
cols[1] = i-1; v[1] = 0.5;
if (i) {
ierr = MatSetValues(C,1,&i,2,cols,v,ADD_VALUES);CHKERRQ(ierr);
} else {
ierr = MatSetValues(C,1,&i,1,&i,v,ADD_VALUES);CHKERRQ(ierr);
}
}
}
ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
/* Test MatMult() */
ierr = MatComputeExplicitOperator(C,&Caij);CHKERRQ(ierr);
ierr = MatMultEqual(C,Caij,5,&flg);CHKERRQ(ierr);
if (!flg) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NOTSAMETYPE,"C != Caij. MatMultEqual() fails");
ierr = MatMultTransposeEqual(C,Caij,5,&flg);CHKERRQ(ierr);
if (!flg) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NOTSAMETYPE,"C != Caij. MatMultTransposeEqual() fails");
/* Test MatMultAdd() and MatMultTransposeAddEqual() */
ierr = MatMultAddEqual(C,Caij,5,&flg);CHKERRQ(ierr);
if (!flg) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NOTSAMETYPE,"C != Caij. MatMultAddEqual() fails");
ierr = MatMultTransposeAddEqual(C,Caij,5,&flg);CHKERRQ(ierr);
if (!flg) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NOTSAMETYPE,"C != Caij. MatMultTransposeAddEqual() fails");
/* Test MatMatMult() */
ierr = PetscOptionsHasName(NULL,"-test_matmatmult",&Test_MatMatMult);CHKERRQ(ierr);
if (Test_MatMatMult) {
Mat CCelem,CCaij;
ierr = MatMatMult(C,C,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&CCelem);CHKERRQ(ierr);
ierr = MatMatMult(Caij,Caij,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&CCaij);CHKERRQ(ierr);
ierr = MatMultEqual(CCelem,CCaij,5,&flg);CHKERRQ(ierr);
if (!flg) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_NOTSAMETYPE,"CCelem != CCaij. MatMatMult() fails");
ierr = MatDestroy(&CCaij);CHKERRQ(ierr);
ierr = MatDestroy(&CCelem);CHKERRQ(ierr);
}
ierr = PetscFree(v);CHKERRQ(ierr);
ierr = ISDestroy(&isrows);CHKERRQ(ierr);
ierr = ISDestroy(&iscols);CHKERRQ(ierr);
ierr = MatDestroy(&C);CHKERRQ(ierr);
ierr = MatDestroy(&Caij);CHKERRQ(ierr);
ierr = PetscFinalize();
return 0;
}
void PETSC_STDCALL matcomputeexplicitoperator_(Mat inmat,Mat *mat, int *__ierr ){
*__ierr = MatComputeExplicitOperator(
(Mat)PetscToPointer((inmat) ),mat);
}
Modified from the code contributed by Yaning Liu @lbl.gov \n\n";
/*
Example:
mpiexec -n <np> ./ex103
mpiexec -n <np> ./ex103 -mat_type elemental -mat_view
mpiexec -n <np> ./ex103 -mat_type aij
*/
#include <petscmat.h>
#undef __FUNCT__
#define __FUNCT__ "main"
int main(int argc, char** argv)
{
Mat A,A_elemental;
PetscInt i,j,M=10,N=5,nrows,ncols;
PetscErrorCode ierr;
PetscMPIInt rank,size;
IS isrows,iscols;
const PetscInt *rows,*cols;
PetscScalar *v;
MatType type;
PetscBool isDense,isAIJ,flg;
ierr = PetscInitialize(&argc, &argv, (char*)0, help);if (ierr) return ierr;
#if !defined(PETSC_HAVE_ELEMENTAL)
SETERRQ(PETSC_COMM_WORLD,1,"This example requires ELEMENTAL");
#endif
ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
/* Creat a matrix */
ierr = PetscOptionsGetInt(NULL,NULL,"-M",&M,NULL);CHKERRQ(ierr);
ierr = PetscOptionsGetInt(NULL,NULL,"-N",&N,NULL);CHKERRQ(ierr);
ierr = MatCreate(PETSC_COMM_WORLD, &A);CHKERRQ(ierr);
ierr = MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,M,N);CHKERRQ(ierr);
ierr = MatSetType(A,MATDENSE);CHKERRQ(ierr);
ierr = MatSetFromOptions(A);CHKERRQ(ierr);
ierr = MatSetUp(A);CHKERRQ(ierr);
/* Set local matrix entries */
ierr = MatGetOwnershipIS(A,&isrows,&iscols);CHKERRQ(ierr);
ierr = ISGetLocalSize(isrows,&nrows);CHKERRQ(ierr);
ierr = ISGetIndices(isrows,&rows);CHKERRQ(ierr);
ierr = ISGetLocalSize(iscols,&ncols);CHKERRQ(ierr);
ierr = ISGetIndices(iscols,&cols);CHKERRQ(ierr);
ierr = PetscMalloc1(nrows*ncols,&v);CHKERRQ(ierr);
for (i=0; i<nrows; i++) {
for (j=0; j<ncols; j++) {
if (size == 1) {
v[i*ncols+j] = (PetscScalar)(i+j);
} else {
v[i*ncols+j] = (PetscScalar)rank+j*0.1;
}
}
}
ierr = MatSetValues(A,nrows,rows,ncols,cols,v,INSERT_VALUES);CHKERRQ(ierr);
ierr = MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
ierr = MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
//ierr = PetscSynchronizedPrintf(PETSC_COMM_WORLD,"[%D] local nrows %D, ncols %D\n",rank,nrows,ncols);CHKERRQ(ierr);
//ierr = PetscSynchronizedFlush(PETSC_COMM_WORLD,PETSC_STDOUT);CHKERRQ(ierr);
/* Test MatSetValues() by converting A to A_elemental */
ierr = MatGetType(A,&type);CHKERRQ(ierr);
if (size == 1) {
ierr = PetscObjectTypeCompare((PetscObject)A,MATSEQDENSE,&isDense);CHKERRQ(ierr);
ierr = PetscObjectTypeCompare((PetscObject)A,MATSEQAIJ,&isAIJ);CHKERRQ(ierr);
} else {
ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIDENSE,&isDense);CHKERRQ(ierr);
ierr = PetscObjectTypeCompare((PetscObject)A,MATMPIAIJ,&isAIJ);CHKERRQ(ierr);
}
if (isDense || isAIJ) {
Mat Aexplicit;
ierr = MatConvert(A, MATELEMENTAL, MAT_INITIAL_MATRIX, &A_elemental);CHKERRQ(ierr);
ierr = MatComputeExplicitOperator(A_elemental,&Aexplicit);CHKERRQ(ierr);
ierr = MatMultEqual(Aexplicit,A_elemental,5,&flg);CHKERRQ(ierr);
if (!flg) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Aexplicit != A_elemental.");
ierr = MatDestroy(&Aexplicit);CHKERRQ(ierr);
/* Test MAT_REUSE_MATRIX which is only supported for inplace conversion */
ierr = MatConvert(A, MATELEMENTAL, MAT_INPLACE_MATRIX, &A);CHKERRQ(ierr);
ierr = MatMultEqual(A_elemental,A,5,&flg);CHKERRQ(ierr);
if (!flg) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"A_elemental != A.");
ierr = MatDestroy(&A_elemental);CHKERRQ(ierr);
}
ierr = ISRestoreIndices(isrows,&rows);CHKERRQ(ierr);
ierr = ISRestoreIndices(iscols,&cols);CHKERRQ(ierr);
ierr = ISDestroy(&isrows);CHKERRQ(ierr);
ierr = ISDestroy(&iscols);CHKERRQ(ierr);
ierr = PetscFree(v);CHKERRQ(ierr);
ierr = MatDestroy(&A);CHKERRQ(ierr);
ierr = PetscFinalize();
return ierr;
}
int main(int argc, char *argv[])
{
PetscErrorCode ierr;
IS is0a,is0b,is0,is1,isl0a,isl0b,isl0,isl1;
Mat A,Aexplicit;
PetscBool usenest;
PetscMPIInt rank,size;
PetscInt i,j;
PetscInitialize(&argc,&argv,PETSC_NULL,help);
ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
{
const PetscInt ix0a[] = {rank*2+0},ix0b[] = {rank*2+1},ix0[] = {rank*3+0,rank*3+1},ix1[] = {rank*3+2};
ierr = ISCreateGeneral(PETSC_COMM_WORLD,1,ix0a,PETSC_COPY_VALUES,&is0a);CHKERRQ(ierr);
ierr = ISCreateGeneral(PETSC_COMM_WORLD,1,ix0b,PETSC_COPY_VALUES,&is0b);CHKERRQ(ierr);
ierr = ISCreateGeneral(PETSC_COMM_WORLD,2,ix0,PETSC_COPY_VALUES,&is0);CHKERRQ(ierr);
ierr = ISCreateGeneral(PETSC_COMM_WORLD,1,ix1,PETSC_COPY_VALUES,&is1);CHKERRQ(ierr);
}
{
ierr = ISCreateStride(PETSC_COMM_SELF,6,0,1,&isl0);CHKERRQ(ierr);
ierr = ISCreateStride(PETSC_COMM_SELF,3,0,1,&isl0a);CHKERRQ(ierr);
ierr = ISCreateStride(PETSC_COMM_SELF,3,3,1,&isl0b);CHKERRQ(ierr);
ierr = ISCreateStride(PETSC_COMM_SELF,3,6,1,&isl1);CHKERRQ(ierr);
}
usenest = PETSC_FALSE;
ierr = PetscOptionsGetBool(PETSC_NULL,"-nest",&usenest,PETSC_NULL);CHKERRQ(ierr);
if (usenest) {
ISLocalToGlobalMapping l2g;
const PetscInt l2gind[3] = {(rank-1+size)%size,rank,(rank+1)%size};
Mat B[9];
ierr = ISLocalToGlobalMappingCreate(PETSC_COMM_WORLD,3,l2gind,PETSC_COPY_VALUES,&l2g);CHKERRQ(ierr);
for (i=0; i<9; i++) {
ierr = MatCreateAIJ(PETSC_COMM_WORLD,1,1,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,PETSC_NULL,PETSC_DECIDE,PETSC_NULL,&B[i]);CHKERRQ(ierr);
ierr = MatSetUp(B[i]);CHKERRQ(ierr);
ierr = MatSetLocalToGlobalMapping(B[i],l2g,l2g);CHKERRQ(ierr);
}
{
const IS isx[] = {is0a,is0b};
const Mat Bx00[] = {B[0],B[1],B[3],B[4]},Bx01[] = {B[2],B[5]},Bx10[] = {B[6],B[7]};
Mat B00,B01,B10;
ierr = MatCreateNest(PETSC_COMM_WORLD,2,isx,2,isx,Bx00,&B00);CHKERRQ(ierr);
ierr = MatSetUp(B00);CHKERRQ(ierr);
ierr = MatCreateNest(PETSC_COMM_WORLD,2,isx,1,PETSC_NULL,Bx01,&B01);CHKERRQ(ierr);
ierr = MatSetUp(B01);CHKERRQ(ierr);
ierr = MatCreateNest(PETSC_COMM_WORLD,1,PETSC_NULL,2,isx,Bx10,&B10);CHKERRQ(ierr);
ierr = MatSetUp(B10);CHKERRQ(ierr);
{
Mat By[] = {B00,B01,B10,B[8]};
IS isy[] = {is0,is1};
ierr = MatCreateNest(PETSC_COMM_WORLD,2,isy,2,isy,By,&A);CHKERRQ(ierr);
ierr = MatSetUp(A);CHKERRQ(ierr);
}
ierr = MatDestroy(&B00);CHKERRQ(ierr);
ierr = MatDestroy(&B01);CHKERRQ(ierr);
ierr = MatDestroy(&B10);CHKERRQ(ierr);
}
for (i=0; i<9; i++) {ierr = MatDestroy(&B[i]);CHKERRQ(ierr);}
ierr = ISLocalToGlobalMappingDestroy(&l2g);CHKERRQ(ierr);
} else {
ISLocalToGlobalMapping l2g;
PetscInt l2gind[9];
for (i=0; i<3; i++) for (j=0; j<3; j++) l2gind[3*i+j] = ((rank-1+j+size) % size)*3 + i;
ierr = ISLocalToGlobalMappingCreate(PETSC_COMM_WORLD,9,l2gind,PETSC_COPY_VALUES,&l2g);CHKERRQ(ierr);
ierr = MatCreateAIJ(PETSC_COMM_WORLD,3,3,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,PETSC_NULL,PETSC_DECIDE,PETSC_NULL,&A);CHKERRQ(ierr);
ierr = MatSetLocalToGlobalMapping(A,l2g,l2g);CHKERRQ(ierr);
ierr = ISLocalToGlobalMappingDestroy(&l2g);CHKERRQ(ierr);
}
{
Mat A00,A11,A0a0a,A0a0b;
ierr = MatGetLocalSubMatrix(A,isl0,isl0,&A00);CHKERRQ(ierr);
ierr = MatGetLocalSubMatrix(A,isl1,isl1,&A11);CHKERRQ(ierr);
ierr = MatGetLocalSubMatrix(A00,isl0a,isl0a,&A0a0a);CHKERRQ(ierr);
ierr = MatGetLocalSubMatrix(A00,isl0a,isl0b,&A0a0b);CHKERRQ(ierr);
ierr = MatSetValueLocal(A0a0a,0,0,100*rank+1,ADD_VALUES);CHKERRQ(ierr);
ierr = MatSetValueLocal(A0a0a,0,1,100*rank+2,ADD_VALUES);CHKERRQ(ierr);
ierr = MatSetValueLocal(A0a0a,2,2,100*rank+9,ADD_VALUES);CHKERRQ(ierr);
ierr = MatSetValueLocal(A0a0b,1,1,100*rank+50+5,ADD_VALUES);CHKERRQ(ierr);
ierr = MatSetValueLocal(A11,0,0,1000*(rank+1)+1,ADD_VALUES);CHKERRQ(ierr);
ierr = MatSetValueLocal(A11,1,2,1000*(rank+1)+6,ADD_VALUES);CHKERRQ(ierr);
ierr = MatRestoreLocalSubMatrix(A00,isl0a,isl0a,&A0a0a);CHKERRQ(ierr);
ierr = MatRestoreLocalSubMatrix(A00,isl0a,isl0b,&A0a0b);CHKERRQ(ierr);
ierr = MatRestoreLocalSubMatrix(A,isl0,isl0,&A00);CHKERRQ(ierr);
ierr = MatRestoreLocalSubMatrix(A,isl1,isl1,&A11);CHKERRQ(ierr);
}
ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
ierr = MatComputeExplicitOperator(A,&Aexplicit);CHKERRQ(ierr);
ierr = MatView(Aexplicit,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
ierr = MatDestroy(&A);CHKERRQ(ierr);
ierr = MatDestroy(&Aexplicit);CHKERRQ(ierr);
ierr = ISDestroy(&is0a);CHKERRQ(ierr);
ierr = ISDestroy(&is0b);CHKERRQ(ierr);
ierr = ISDestroy(&is0);CHKERRQ(ierr);
ierr = ISDestroy(&is1);CHKERRQ(ierr);
ierr = ISDestroy(&isl0a);CHKERRQ(ierr);
ierr = ISDestroy(&isl0b);CHKERRQ(ierr);
ierr = ISDestroy(&isl0);CHKERRQ(ierr);
ierr = ISDestroy(&isl1);CHKERRQ(ierr);
PetscFinalize();
return 0;
}
