Actual source code: ex300.c

  1: static char help[] = "Show MatShift BUG happening after copying a matrix with no rows on a process";
  2: /*
  3:    Contributed by: Eric Chamberland
  4: */
  5: #include <petscmat.h>

  7: /* DEFINE this to turn on/off the bug: */
  8: #define SET_2nd_PROC_TO_HAVE_NO_LOCAL_LINES

 10: int main(int argc, char **args)
 11: {
 12:   Mat         C;
 13:   PetscInt    i, m = 3;
 14:   PetscMPIInt rank, size;
 15:   PetscScalar v;
 16:   Mat         lMatA;
 17:   PetscInt    locallines;
 18:   PetscInt    d_nnz[3] = {0, 0, 0};
 19:   PetscInt    o_nnz[3] = {0, 0, 0};

 21:   PetscFunctionBeginUser;
 22:   PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
 23:   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
 24:   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));

 26:   PetscCheck(2 == size, PETSC_COMM_WORLD, PETSC_ERR_ARG_INCOMP, "Relevant with 2 processes only");
 27:   PetscCall(MatCreate(PETSC_COMM_WORLD, &C));

 29: #ifdef SET_2nd_PROC_TO_HAVE_NO_LOCAL_LINES
 30:   if (0 == rank) {
 31:     locallines = m;
 32:     d_nnz[0]   = 1;
 33:     d_nnz[1]   = 1;
 34:     d_nnz[2]   = 1;
 35:   } else {
 36:     locallines = 0;
 37:   }
 38: #else
 39:   if (0 == rank) {
 40:     locallines = m - 1;
 41:     d_nnz[0]   = 1;
 42:     d_nnz[1]   = 1;
 43:   } else {
 44:     locallines = 1;
 45:     d_nnz[0]   = 1;
 46:   }
 47: #endif

 49:   PetscCall(MatSetSizes(C, locallines, locallines, m, m));
 50:   PetscCall(MatSetFromOptions(C));
 51:   PetscCall(MatXAIJSetPreallocation(C, 1, d_nnz, o_nnz, NULL, NULL));

 53:   v = 2;
 54:   /* Assembly on the diagonal: */
 55:   for (i = 0; i < m; i++) PetscCall(MatSetValues(C, 1, &i, 1, &i, &v, ADD_VALUES));
 56:   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
 57:   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
 58:   PetscCall(MatSetOption(C, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
 59:   PetscCall(MatSetOption(C, MAT_KEEP_NONZERO_PATTERN, PETSC_TRUE));
 60:   PetscCall(MatView(C, PETSC_VIEWER_STDOUT_WORLD));
 61:   PetscCall(MatConvert(C, MATSAME, MAT_INITIAL_MATRIX, &lMatA));
 62:   PetscCall(MatView(lMatA, PETSC_VIEWER_STDOUT_WORLD));

 64:   PetscCall(MatShift(lMatA, -1.0));

 66:   PetscCall(MatDestroy(&lMatA));
 67:   PetscCall(MatDestroy(&C));
 68:   PetscCall(PetscFinalize());
 69:   return 0;
 70: }

 72: /*TEST

 74:    test:
 75:       nsize: 2

 77: TEST*/