1: static char help[] = "Test MatAXPY \n\n";

  3: #include <petscmat.h>
  4: int main(int argc, char **args)
  5: {
  6:   Mat            A = NULL, B = NULL;
  7:   const PetscInt M = 18, N = 18;
  8:   PetscMPIInt    rank;

 10:   /* A, B are 18 x 18 nonsymmetric matrices.  Initially, B's nonzero pattern is a subset of A.
 11:      Big enough to have complex communication patterns but still small enough for debugging.
 12:   */
 13:   PetscInt Ai[] = {0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 13, 14, 14, 15, 15, 16, 16, 17, 17};
 14:   PetscInt Aj[] = {0, 1, 2, 7, 3, 8, 4, 9, 5, 8, 2, 6, 11, 0, 7, 1, 6, 2, 4, 10, 16, 11, 15, 12, 17, 12, 13, 14, 15, 17, 11, 13, 3, 16, 9, 15, 11, 13};
 15:   PetscInt Bi[] = {0, 0, 1, 1, 2, 2, 4, 4, 5, 5, 5, 6, 7, 7, 8, 8, 9, 9, 10, 10, 12, 12, 13, 13, 14, 14, 15, 15, 16, 16, 17, 17};
 16:   PetscInt Bj[] = {0, 1, 2, 7, 3, 8, 5, 8, 2, 6, 11, 0, 1, 6, 2, 4, 10, 16, 11, 15, 12, 13, 14, 17, 11, 13, 3, 16, 9, 15, 11, 13};

 18:   PetscInt Annz = PETSC_STATIC_ARRAY_LENGTH(Ai);
 19:   PetscInt Bnnz = PETSC_STATIC_ARRAY_LENGTH(Bi);

 21:   PetscFunctionBeginUser;
 22:   PetscCall(PetscInitialize(&argc, &args, NULL, help));
 23:   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));

 25:   PetscCall(MatCreate(PETSC_COMM_WORLD, &A));
 26:   PetscCall(MatSetSizes(A, PETSC_DECIDE, PETSC_DECIDE, M, N));
 27:   PetscCall(MatSetFromOptions(A));
 28:   PetscCall(MatSeqAIJSetPreallocation(A, 2, NULL));
 29:   PetscCall(MatMPIAIJSetPreallocation(A, 2, NULL, 2, NULL));
 30:   PetscCall(MatSetOption(A, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));

 32:   if (rank == 0) {
 33:     for (PetscInt k = 0; k < Annz; k++) PetscCall(MatSetValue(A, Ai[k], Aj[k], Ai[k] + Aj[k] + 1.0, INSERT_VALUES));
 34:   }

 36:   PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
 37:   PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));

 39:   PetscCall(MatCreate(PETSC_COMM_WORLD, &B));
 40:   PetscCall(MatSetSizes(B, PETSC_DECIDE, PETSC_DECIDE, M, N));
 41:   PetscCall(MatSetFromOptions(B));
 42:   PetscCall(MatSeqAIJSetPreallocation(B, 2, NULL));
 43:   PetscCall(MatMPIAIJSetPreallocation(B, 2, NULL, 2, NULL));
 44:   PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));

 46:   if (rank == 0) {
 47:     for (PetscInt k = 0; k < Bnnz; k++) PetscCall(MatSetValue(B, Bi[k], Bj[k], Bi[k] + Bj[k] + 2.0, INSERT_VALUES));
 48:   }
 49:   PetscCall(MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY));
 50:   PetscCall(MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY));

 52:   PetscCall(MatAXPY(A, 1.0, B, SUBSET_NONZERO_PATTERN)); /* A += B */
 53:   PetscCall(MatView(A, PETSC_VIEWER_STDOUT_WORLD));

 55:   /* Blow up B so it will have the same nonzero pattern as A */
 56:   PetscCall(MatAXPY(B, 5, A, DIFFERENT_NONZERO_PATTERN)); /* B += 5A */
 57:   PetscCall(MatView(B, PETSC_VIEWER_STDOUT_WORLD));

 59:   PetscCall(MatAXPY(A, 3, B, SAME_NONZERO_PATTERN)); /* A += 7B */
 60:   PetscCall(MatView(A, PETSC_VIEWER_STDOUT_WORLD));

 62:   PetscCall(MatDestroy(&A));
 63:   PetscCall(MatDestroy(&B));

 65:   PetscCall(PetscFinalize());
 66:   return 0;
 67: }

 69: /*TEST
 70:   testset:
 71:     nsize: {{1 2}}
 72:     filter: grep -ve type -ve "Mat Object"
 73:     output_file: output/ex251_1.out

 75:     test:
 76:       suffix: 1
 77:       args: -mat_type aij

 79:     test:
 80:       suffix: cuda
 81:       requires: cuda
 82:       args: -mat_type aijcusparse

 84:     test:
 85:       suffix: kok
 86:       requires: kokkos_kernels
 87:       args: -mat_type aijkokkos

 89: TEST*/