Actual source code: ex59.c

  1: static char help[] = "Tests MatCreateSubmatrix() in parallel.";

  3: #include <petscmat.h>

  5: int main(int argc, char **args)
  6: {
  7:   Mat         C, A;
  8:   PetscInt    i, j, m = 3, n = 2, rstart, rend;
  9:   PetscMPIInt size, rank;
 10:   PetscScalar v;
 11:   IS          isrow, iscol;
 12:   PetscBool   test_matmatmult = PETSC_FALSE;

 14:   PetscFunctionBeginUser;
 15:   PetscCall(PetscInitialize(&argc, &args, NULL, help));
 16:   PetscCall(PetscOptionsGetBool(NULL, NULL, "-test_matmatmult", &test_matmatmult, NULL));

 18:   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
 19:   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
 20:   n = 2 * size;

 22:   PetscCall(MatCreate(PETSC_COMM_WORLD, &C));
 23:   PetscCall(MatSetSizes(C, PETSC_DECIDE, PETSC_DECIDE, m * n, m * n));
 24:   PetscCall(MatSetFromOptions(C));
 25:   PetscCall(MatSetUp(C));

 27:   /*
 28:         This is JUST to generate a nice test matrix, all processors fill up
 29:     the entire matrix. This is not something one would ever do in practice.
 30:   */
 31:   PetscCall(MatGetOwnershipRange(C, &rstart, &rend));
 32:   for (i = rstart; i < rend; i++) {
 33:     for (j = 0; j < m * n; j++) {
 34:       v = i + j + 1;
 35:       PetscCall(MatSetValues(C, 1, &i, 1, &j, &v, INSERT_VALUES));
 36:     }
 37:   }

 39:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
 40:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
 41:   PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD, PETSC_VIEWER_ASCII_COMMON));
 42:   PetscCall(MatView(C, PETSC_VIEWER_STDOUT_WORLD));

 44:   /*
 45:      Generate a new matrix consisting of every second row and column of
 46:    the original matrix
 47:   */
 48:   PetscCall(MatGetOwnershipRange(C, &rstart, &rend));
 49:   /* Create parallel IS with the rows we want on THIS processor */
 50:   PetscCall(ISCreateStride(PETSC_COMM_WORLD, (rend - rstart) / 2, rstart, 2, &isrow));
 51:   /* Create parallel IS with the rows we want on THIS processor (same as rows for now) */
 52:   PetscCall(ISCreateStride(PETSC_COMM_WORLD, (rend - rstart) / 2, rstart, 2, &iscol));

 54:   PetscCall(MatCreateSubMatrix(C, isrow, iscol, MAT_INITIAL_MATRIX, &A));
 55:   PetscCall(MatCreateSubMatrix(C, isrow, iscol, MAT_REUSE_MATRIX, &A));
 56:   PetscCall(MatView(A, PETSC_VIEWER_STDOUT_WORLD));

 58:   if (test_matmatmult) {
 59:     PetscCall(MatDestroy(&C));
 60:     PetscCall(MatMatMult(A, A, MAT_INITIAL_MATRIX, PETSC_DETERMINE, &C));
 61:     PetscCall(MatView(C, PETSC_VIEWER_STDOUT_WORLD));
 62:   }

 64:   PetscCall(ISDestroy(&isrow));
 65:   PetscCall(ISDestroy(&iscol));
 66:   PetscCall(MatDestroy(&A));
 67:   PetscCall(MatDestroy(&C));
 68:   PetscCall(PetscFinalize());
 69:   return 0;
 70: }

 72: /*TEST

 74:    test:

 76:    test:
 77:       suffix: 2
 78:       nsize: 3

 80:    test:
 81:       suffix: 2_baij
 82:       nsize: 3
 83:       args: -mat_type baij

 85:    test:
 86:       suffix: 2_sbaij
 87:       nsize: 3
 88:       args: -mat_type sbaij

 90:    test:
 91:       suffix: baij
 92:       args: -mat_type baij
 93:       output_file: output/ex59_1_baij.out

 95:    test:
 96:       suffix: sbaij
 97:       args: -mat_type sbaij
 98:       output_file: output/ex59_1_sbaij.out

100:    test:
101:       suffix: kok
102:       nsize: 3
103:       requires: kokkos_kernels
104:       args: -mat_type aijkokkos -test_matmatmult
105:       filter: grep -v -i type
106:       output_file: output/ex59_kok.out

108: TEST*/