1c4762a1bSJed Brown static char help[] = "Tests MatCreateSubMatrices().\n\n"; 2c4762a1bSJed Brown 3c4762a1bSJed Brown #include <petscmat.h> 4c4762a1bSJed Brown 5d71ae5a4SJacob Faibussowitsch int main(int argc, char **args) 6d71ae5a4SJacob Faibussowitsch { 7c4762a1bSJed Brown Mat A, B, *Bsub; 8c4762a1bSJed Brown PetscInt i, j, m = 6, n = 6, N = 36, Ii, J; 9c4762a1bSJed Brown PetscScalar v; 10c4762a1bSJed Brown IS isrow; 11c4762a1bSJed Brown 12327415f7SBarry Smith PetscFunctionBeginUser; 13*c8025a54SPierre Jolivet PetscCall(PetscInitialize(&argc, &args, NULL, help)); 149566063dSJacob Faibussowitsch PetscCall(MatCreateSeqAIJ(PETSC_COMM_WORLD, N, N, 5, NULL, &A)); 15c4762a1bSJed Brown for (i = 0; i < m; i++) { 16c4762a1bSJed Brown for (j = 0; j < n; j++) { 179371c9d4SSatish Balay v = -1.0; 189371c9d4SSatish Balay Ii = j + n * i; 199371c9d4SSatish Balay if (i > 0) { 209371c9d4SSatish Balay J = Ii - n; 219371c9d4SSatish Balay PetscCall(MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES)); 229371c9d4SSatish Balay } 239371c9d4SSatish Balay if (i < m - 1) { 249371c9d4SSatish Balay J = Ii + n; 259371c9d4SSatish Balay PetscCall(MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES)); 269371c9d4SSatish Balay } 279371c9d4SSatish Balay if (j > 0) { 289371c9d4SSatish Balay J = Ii - 1; 299371c9d4SSatish Balay PetscCall(MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES)); 309371c9d4SSatish Balay } 319371c9d4SSatish Balay if (j < n - 1) { 329371c9d4SSatish Balay J = Ii + 1; 339371c9d4SSatish Balay PetscCall(MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES)); 349371c9d4SSatish Balay } 359371c9d4SSatish Balay v = 4.0; 369371c9d4SSatish Balay PetscCall(MatSetValues(A, 1, &Ii, 1, &Ii, &v, INSERT_VALUES)); 37c4762a1bSJed Brown } 38c4762a1bSJed Brown } 399566063dSJacob Faibussowitsch PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY)); 409566063dSJacob Faibussowitsch PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY)); 419566063dSJacob Faibussowitsch PetscCall(MatView(A, PETSC_VIEWER_STDOUT_SELF)); 42c4762a1bSJed Brown 43c4762a1bSJed Brown /* take the first diagonal block */ 449566063dSJacob Faibussowitsch PetscCall(ISCreateStride(PETSC_COMM_WORLD, m, 0, 1, &isrow)); 459566063dSJacob Faibussowitsch PetscCall(MatCreateSubMatrices(A, 1, &isrow, &isrow, MAT_INITIAL_MATRIX, &Bsub)); 46c4762a1bSJed Brown B = *Bsub; 479566063dSJacob Faibussowitsch PetscCall(ISDestroy(&isrow)); 489566063dSJacob Faibussowitsch PetscCall(MatView(B, PETSC_VIEWER_STDOUT_SELF)); 499566063dSJacob Faibussowitsch PetscCall(MatDestroySubMatrices(1, &Bsub)); 50c4762a1bSJed Brown 51c4762a1bSJed Brown /* take a strided block */ 529566063dSJacob Faibussowitsch PetscCall(ISCreateStride(PETSC_COMM_WORLD, m, 0, 2, &isrow)); 539566063dSJacob Faibussowitsch PetscCall(MatCreateSubMatrices(A, 1, &isrow, &isrow, MAT_INITIAL_MATRIX, &Bsub)); 54c4762a1bSJed Brown B = *Bsub; 559566063dSJacob Faibussowitsch PetscCall(ISDestroy(&isrow)); 569566063dSJacob Faibussowitsch PetscCall(MatView(B, PETSC_VIEWER_STDOUT_SELF)); 579566063dSJacob Faibussowitsch PetscCall(MatDestroySubMatrices(1, &Bsub)); 58c4762a1bSJed Brown 59c4762a1bSJed Brown /* take the last block */ 609566063dSJacob Faibussowitsch PetscCall(ISCreateStride(PETSC_COMM_WORLD, m, N - m - 1, 1, &isrow)); 619566063dSJacob Faibussowitsch PetscCall(MatCreateSubMatrices(A, 1, &isrow, &isrow, MAT_INITIAL_MATRIX, &Bsub)); 62c4762a1bSJed Brown B = *Bsub; 639566063dSJacob Faibussowitsch PetscCall(ISDestroy(&isrow)); 649566063dSJacob Faibussowitsch PetscCall(MatView(B, PETSC_VIEWER_STDOUT_SELF)); 65c4762a1bSJed Brown 669566063dSJacob Faibussowitsch PetscCall(MatDestroySubMatrices(1, &Bsub)); 679566063dSJacob Faibussowitsch PetscCall(MatDestroy(&A)); 68c4762a1bSJed Brown 699566063dSJacob Faibussowitsch PetscCall(PetscFinalize()); 70b122ec5aSJacob Faibussowitsch return 0; 71c4762a1bSJed Brown } 72c4762a1bSJed Brown 73c4762a1bSJed Brown /*TEST 74c4762a1bSJed Brown 75c4762a1bSJed Brown test: 76c4762a1bSJed Brown 77c4762a1bSJed Brown TEST*/ 78