1c4762a1bSJed Brown 2c4762a1bSJed Brown static char help[] = "Tests MatCreateSubMatrices().\n\n"; 3c4762a1bSJed Brown 4c4762a1bSJed Brown #include <petscmat.h> 5c4762a1bSJed Brown 6*d71ae5a4SJacob Faibussowitsch int main(int argc, char **args) 7*d71ae5a4SJacob Faibussowitsch { 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 13327415f7SBarry 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++) { 189371c9d4SSatish Balay v = -1.0; 199371c9d4SSatish Balay Ii = j + n * i; 209371c9d4SSatish Balay if (i > 0) { 219371c9d4SSatish Balay J = Ii - n; 229371c9d4SSatish Balay PetscCall(MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES)); 239371c9d4SSatish Balay } 249371c9d4SSatish Balay if (i < m - 1) { 259371c9d4SSatish Balay J = Ii + n; 269371c9d4SSatish Balay PetscCall(MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES)); 279371c9d4SSatish Balay } 289371c9d4SSatish Balay if (j > 0) { 299371c9d4SSatish Balay J = Ii - 1; 309371c9d4SSatish Balay PetscCall(MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES)); 319371c9d4SSatish Balay } 329371c9d4SSatish Balay if (j < n - 1) { 339371c9d4SSatish Balay J = Ii + 1; 349371c9d4SSatish Balay PetscCall(MatSetValues(A, 1, &Ii, 1, &J, &v, INSERT_VALUES)); 359371c9d4SSatish Balay } 369371c9d4SSatish Balay v = 4.0; 379371c9d4SSatish Balay PetscCall(MatSetValues(A, 1, &Ii, 1, &Ii, &v, INSERT_VALUES)); 38c4762a1bSJed Brown } 39c4762a1bSJed Brown } 409566063dSJacob Faibussowitsch PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY)); 419566063dSJacob Faibussowitsch PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY)); 429566063dSJacob Faibussowitsch PetscCall(MatView(A, PETSC_VIEWER_STDOUT_SELF)); 43c4762a1bSJed Brown 44c4762a1bSJed Brown /* take the first diagonal block */ 459566063dSJacob Faibussowitsch PetscCall(ISCreateStride(PETSC_COMM_WORLD, m, 0, 1, &isrow)); 469566063dSJacob Faibussowitsch PetscCall(MatCreateSubMatrices(A, 1, &isrow, &isrow, MAT_INITIAL_MATRIX, &Bsub)); 47c4762a1bSJed Brown B = *Bsub; 489566063dSJacob Faibussowitsch PetscCall(ISDestroy(&isrow)); 499566063dSJacob Faibussowitsch PetscCall(MatView(B, PETSC_VIEWER_STDOUT_SELF)); 509566063dSJacob Faibussowitsch PetscCall(MatDestroySubMatrices(1, &Bsub)); 51c4762a1bSJed Brown 52c4762a1bSJed Brown /* take a strided block */ 539566063dSJacob Faibussowitsch PetscCall(ISCreateStride(PETSC_COMM_WORLD, m, 0, 2, &isrow)); 549566063dSJacob Faibussowitsch PetscCall(MatCreateSubMatrices(A, 1, &isrow, &isrow, MAT_INITIAL_MATRIX, &Bsub)); 55c4762a1bSJed Brown B = *Bsub; 569566063dSJacob Faibussowitsch PetscCall(ISDestroy(&isrow)); 579566063dSJacob Faibussowitsch PetscCall(MatView(B, PETSC_VIEWER_STDOUT_SELF)); 589566063dSJacob Faibussowitsch PetscCall(MatDestroySubMatrices(1, &Bsub)); 59c4762a1bSJed Brown 60c4762a1bSJed Brown /* take the last block */ 619566063dSJacob Faibussowitsch PetscCall(ISCreateStride(PETSC_COMM_WORLD, m, N - m - 1, 1, &isrow)); 629566063dSJacob Faibussowitsch PetscCall(MatCreateSubMatrices(A, 1, &isrow, &isrow, MAT_INITIAL_MATRIX, &Bsub)); 63c4762a1bSJed Brown B = *Bsub; 649566063dSJacob Faibussowitsch PetscCall(ISDestroy(&isrow)); 659566063dSJacob Faibussowitsch PetscCall(MatView(B, PETSC_VIEWER_STDOUT_SELF)); 66c4762a1bSJed Brown 679566063dSJacob Faibussowitsch PetscCall(MatDestroySubMatrices(1, &Bsub)); 689566063dSJacob Faibussowitsch PetscCall(MatDestroy(&A)); 69c4762a1bSJed Brown 709566063dSJacob Faibussowitsch PetscCall(PetscFinalize()); 71b122ec5aSJacob Faibussowitsch return 0; 72c4762a1bSJed Brown } 73c4762a1bSJed Brown 74c4762a1bSJed Brown /*TEST 75c4762a1bSJed Brown 76c4762a1bSJed Brown test: 77c4762a1bSJed Brown 78c4762a1bSJed Brown TEST*/ 79