1c4762a1bSJed Brown 2c4762a1bSJed Brown static char help[] = "Tests MatCreateSubmatrix() in parallel."; 3c4762a1bSJed Brown 4c4762a1bSJed Brown #include <petscmat.h> 5c4762a1bSJed Brown 6*d71ae5a4SJacob Faibussowitsch int main(int argc, char **args) 7*d71ae5a4SJacob Faibussowitsch { 8c4762a1bSJed Brown Mat C, A; 9c4762a1bSJed Brown PetscInt i, j, m = 3, n = 2, rstart, rend; 10c4762a1bSJed Brown PetscMPIInt size, rank; 11c4762a1bSJed Brown PetscScalar v; 12c4762a1bSJed Brown IS isrow, iscol; 13c4762a1bSJed Brown 14327415f7SBarry Smith PetscFunctionBeginUser; 159566063dSJacob Faibussowitsch PetscCall(PetscInitialize(&argc, &args, (char *)0, help)); 169566063dSJacob Faibussowitsch PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank)); 179566063dSJacob Faibussowitsch PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size)); 18c4762a1bSJed Brown n = 2 * size; 19c4762a1bSJed Brown 209566063dSJacob Faibussowitsch PetscCall(MatCreate(PETSC_COMM_WORLD, &C)); 219566063dSJacob Faibussowitsch PetscCall(MatSetSizes(C, PETSC_DECIDE, PETSC_DECIDE, m * n, m * n)); 229566063dSJacob Faibussowitsch PetscCall(MatSetFromOptions(C)); 239566063dSJacob Faibussowitsch PetscCall(MatSetUp(C)); 24c4762a1bSJed Brown 25c4762a1bSJed Brown /* 26c4762a1bSJed Brown This is JUST to generate a nice test matrix, all processors fill up 27c4762a1bSJed Brown the entire matrix. This is not something one would ever do in practice. 28c4762a1bSJed Brown */ 299566063dSJacob Faibussowitsch PetscCall(MatGetOwnershipRange(C, &rstart, &rend)); 30c4762a1bSJed Brown for (i = rstart; i < rend; i++) { 31c4762a1bSJed Brown for (j = 0; j < m * n; j++) { 32c4762a1bSJed Brown v = i + j + 1; 339566063dSJacob Faibussowitsch PetscCall(MatSetValues(C, 1, &i, 1, &j, &v, INSERT_VALUES)); 34c4762a1bSJed Brown } 35c4762a1bSJed Brown } 36c4762a1bSJed Brown 379566063dSJacob Faibussowitsch PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY)); 389566063dSJacob Faibussowitsch PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY)); 399566063dSJacob Faibussowitsch PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD, PETSC_VIEWER_ASCII_COMMON)); 409566063dSJacob Faibussowitsch PetscCall(MatView(C, PETSC_VIEWER_STDOUT_WORLD)); 41c4762a1bSJed Brown 42c4762a1bSJed Brown /* 43c4762a1bSJed Brown Generate a new matrix consisting of every second row and column of 44c4762a1bSJed Brown the original matrix 45c4762a1bSJed Brown */ 469566063dSJacob Faibussowitsch PetscCall(MatGetOwnershipRange(C, &rstart, &rend)); 47c4762a1bSJed Brown /* Create parallel IS with the rows we want on THIS processor */ 489566063dSJacob Faibussowitsch PetscCall(ISCreateStride(PETSC_COMM_WORLD, (rend - rstart) / 2, rstart, 2, &isrow)); 49c4762a1bSJed Brown /* Create parallel IS with the rows we want on THIS processor (same as rows for now) */ 509566063dSJacob Faibussowitsch PetscCall(ISCreateStride(PETSC_COMM_WORLD, (rend - rstart) / 2, rstart, 2, &iscol)); 51c4762a1bSJed Brown 529566063dSJacob Faibussowitsch PetscCall(MatCreateSubMatrix(C, isrow, iscol, MAT_INITIAL_MATRIX, &A)); 539566063dSJacob Faibussowitsch PetscCall(MatCreateSubMatrix(C, isrow, iscol, MAT_REUSE_MATRIX, &A)); 549566063dSJacob Faibussowitsch PetscCall(MatView(A, PETSC_VIEWER_STDOUT_WORLD)); 55c4762a1bSJed Brown 569566063dSJacob Faibussowitsch PetscCall(ISDestroy(&isrow)); 579566063dSJacob Faibussowitsch PetscCall(ISDestroy(&iscol)); 589566063dSJacob Faibussowitsch PetscCall(MatDestroy(&A)); 599566063dSJacob Faibussowitsch PetscCall(MatDestroy(&C)); 609566063dSJacob Faibussowitsch PetscCall(PetscFinalize()); 61b122ec5aSJacob Faibussowitsch return 0; 62c4762a1bSJed Brown } 63c4762a1bSJed Brown 64c4762a1bSJed Brown /*TEST 65c4762a1bSJed Brown 66c4762a1bSJed Brown test: 67c4762a1bSJed Brown 68c4762a1bSJed Brown test: 69c4762a1bSJed Brown suffix: 2 70c4762a1bSJed Brown nsize: 3 71c4762a1bSJed Brown 72c4762a1bSJed Brown test: 73c4762a1bSJed Brown suffix: 2_baij 74c4762a1bSJed Brown nsize: 3 75c4762a1bSJed Brown args: -mat_type baij 76c4762a1bSJed Brown 77c4762a1bSJed Brown test: 78c4762a1bSJed Brown suffix: 2_sbaij 79c4762a1bSJed Brown nsize: 3 80c4762a1bSJed Brown args: -mat_type sbaij 81c4762a1bSJed Brown 82c4762a1bSJed Brown test: 83c4762a1bSJed Brown suffix: baij 84c4762a1bSJed Brown args: -mat_type baij 85c4762a1bSJed Brown output_file: output/ex59_1_baij.out 86c4762a1bSJed Brown 87c4762a1bSJed Brown test: 88c4762a1bSJed Brown suffix: sbaij 89c4762a1bSJed Brown args: -mat_type sbaij 90c4762a1bSJed Brown output_file: output/ex59_1_sbaij.out 91c4762a1bSJed Brown 92c4762a1bSJed Brown TEST*/ 93