1c4762a1bSJed Brown 2c4762a1bSJed Brown static char help[] = "Tests MatCreateSubMatrices().\n\n"; 3c4762a1bSJed Brown 4c4762a1bSJed Brown #include <petscmat.h> 5c4762a1bSJed Brown 6c4762a1bSJed Brown int main(int argc,char **args) 7c4762a1bSJed Brown { 8c4762a1bSJed Brown Mat A,B,*Bsub; 9c4762a1bSJed Brown PetscInt i,j,m = 6,n = 6,N = 36,Ii,J; 10c4762a1bSJed Brown PetscScalar v; 11c4762a1bSJed Brown IS isrow; 12c4762a1bSJed Brown 13*327415f7SBarry Smith PetscFunctionBeginUser; 149566063dSJacob Faibussowitsch PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 159566063dSJacob Faibussowitsch PetscCall(MatCreateSeqAIJ(PETSC_COMM_WORLD,N,N,5,NULL,&A)); 16c4762a1bSJed Brown for (i=0; i<m; i++) { 17c4762a1bSJed Brown for (j=0; j<n; j++) { 18c4762a1bSJed Brown v = -1.0; Ii = j + n*i; 199566063dSJacob Faibussowitsch if (i>0) {J = Ii - n; PetscCall(MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES));} 209566063dSJacob Faibussowitsch if (i<m-1) {J = Ii + n; PetscCall(MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES));} 219566063dSJacob Faibussowitsch if (j>0) {J = Ii - 1; PetscCall(MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES));} 229566063dSJacob Faibussowitsch if (j<n-1) {J = Ii + 1; PetscCall(MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES));} 239566063dSJacob Faibussowitsch v = 4.0; PetscCall(MatSetValues(A,1,&Ii,1,&Ii,&v,INSERT_VALUES)); 24c4762a1bSJed Brown } 25c4762a1bSJed Brown } 269566063dSJacob Faibussowitsch PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY)); 279566063dSJacob Faibussowitsch PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY)); 289566063dSJacob Faibussowitsch PetscCall(MatView(A,PETSC_VIEWER_STDOUT_SELF)); 29c4762a1bSJed Brown 30c4762a1bSJed Brown /* take the first diagonal block */ 319566063dSJacob Faibussowitsch PetscCall(ISCreateStride(PETSC_COMM_WORLD,m,0,1,&isrow)); 329566063dSJacob Faibussowitsch PetscCall(MatCreateSubMatrices(A,1,&isrow,&isrow,MAT_INITIAL_MATRIX,&Bsub)); 33c4762a1bSJed Brown B = *Bsub; 349566063dSJacob Faibussowitsch PetscCall(ISDestroy(&isrow)); 359566063dSJacob Faibussowitsch PetscCall(MatView(B,PETSC_VIEWER_STDOUT_SELF)); 369566063dSJacob Faibussowitsch PetscCall(MatDestroySubMatrices(1,&Bsub)); 37c4762a1bSJed Brown 38c4762a1bSJed Brown /* take a strided block */ 399566063dSJacob Faibussowitsch PetscCall(ISCreateStride(PETSC_COMM_WORLD,m,0,2,&isrow)); 409566063dSJacob Faibussowitsch PetscCall(MatCreateSubMatrices(A,1,&isrow,&isrow,MAT_INITIAL_MATRIX,&Bsub)); 41c4762a1bSJed Brown B = *Bsub; 429566063dSJacob Faibussowitsch PetscCall(ISDestroy(&isrow)); 439566063dSJacob Faibussowitsch PetscCall(MatView(B,PETSC_VIEWER_STDOUT_SELF)); 449566063dSJacob Faibussowitsch PetscCall(MatDestroySubMatrices(1,&Bsub)); 45c4762a1bSJed Brown 46c4762a1bSJed Brown /* take the last block */ 479566063dSJacob Faibussowitsch PetscCall(ISCreateStride(PETSC_COMM_WORLD,m,N-m-1,1,&isrow)); 489566063dSJacob Faibussowitsch PetscCall(MatCreateSubMatrices(A,1,&isrow,&isrow,MAT_INITIAL_MATRIX,&Bsub)); 49c4762a1bSJed Brown B = *Bsub; 509566063dSJacob Faibussowitsch PetscCall(ISDestroy(&isrow)); 519566063dSJacob Faibussowitsch PetscCall(MatView(B,PETSC_VIEWER_STDOUT_SELF)); 52c4762a1bSJed Brown 539566063dSJacob Faibussowitsch PetscCall(MatDestroySubMatrices(1,&Bsub)); 549566063dSJacob Faibussowitsch PetscCall(MatDestroy(&A)); 55c4762a1bSJed Brown 569566063dSJacob Faibussowitsch PetscCall(PetscFinalize()); 57b122ec5aSJacob Faibussowitsch return 0; 58c4762a1bSJed Brown } 59c4762a1bSJed Brown 60c4762a1bSJed Brown /*TEST 61c4762a1bSJed Brown 62c4762a1bSJed Brown test: 63c4762a1bSJed Brown 64c4762a1bSJed Brown TEST*/ 65