1 2 static char help[] = "Tests DMDAGlobalToNaturalAllCreate() using contour plotting for 2d DMDAs.\n\n"; 3 4 #include <petscdm.h> 5 #include <petscdmda.h> 6 #include <petscdraw.h> 7 8 int main(int argc, char **argv) 9 { 10 PetscInt i, j, M = 10, N = 8, m = PETSC_DECIDE, n = PETSC_DECIDE; 11 PetscMPIInt rank; 12 PetscBool flg = PETSC_FALSE; 13 DM da; 14 PetscViewer viewer; 15 Vec localall, global; 16 PetscScalar value, *vlocal; 17 DMBoundaryType bx = DM_BOUNDARY_NONE, by = DM_BOUNDARY_NONE; 18 DMDAStencilType stype = DMDA_STENCIL_BOX; 19 VecScatter tolocalall, fromlocalall; 20 PetscInt start, end; 21 22 PetscFunctionBeginUser; 23 PetscCall(PetscInitialize(&argc, &argv, (char *)0, help)); 24 PetscCall(PetscViewerDrawOpen(PETSC_COMM_WORLD, 0, "", 300, 0, 300, 300, &viewer)); 25 26 /* Read options */ 27 PetscCall(PetscOptionsGetInt(NULL, NULL, "-M", &M, NULL)); 28 PetscCall(PetscOptionsGetInt(NULL, NULL, "-N", &N, NULL)); 29 PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL)); 30 PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL)); 31 PetscCall(PetscOptionsGetBool(NULL, NULL, "-star_stencil", &flg, NULL)); 32 if (flg) stype = DMDA_STENCIL_STAR; 33 34 /* Create distributed array and get vectors */ 35 PetscCall(DMDACreate2d(PETSC_COMM_WORLD, bx, by, stype, M, N, m, n, 1, 1, NULL, NULL, &da)); 36 PetscCall(DMSetFromOptions(da)); 37 PetscCall(DMSetUp(da)); 38 39 PetscCall(DMCreateGlobalVector(da, &global)); 40 PetscCall(VecCreateSeq(PETSC_COMM_SELF, M * N, &localall)); 41 42 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank)); 43 PetscCall(VecGetOwnershipRange(global, &start, &end)); 44 for (i = start; i < end; i++) { 45 value = 5.0 * rank; 46 PetscCall(VecSetValues(global, 1, &i, &value, INSERT_VALUES)); 47 } 48 PetscCall(VecView(global, viewer)); 49 50 /* 51 Create Scatter from global DMDA parallel vector to local vector that 52 contains all entries 53 */ 54 PetscCall(DMDAGlobalToNaturalAllCreate(da, &tolocalall)); 55 PetscCall(DMDANaturalAllToGlobalCreate(da, &fromlocalall)); 56 57 PetscCall(VecScatterBegin(tolocalall, global, localall, INSERT_VALUES, SCATTER_FORWARD)); 58 PetscCall(VecScatterEnd(tolocalall, global, localall, INSERT_VALUES, SCATTER_FORWARD)); 59 60 PetscCall(VecGetArray(localall, &vlocal)); 61 for (j = 0; j < N; j++) { 62 for (i = 0; i < M; i++) *vlocal++ += i + j * M; 63 } 64 PetscCall(VecRestoreArray(localall, &vlocal)); 65 66 /* scatter back to global vector */ 67 PetscCall(VecScatterBegin(fromlocalall, localall, global, INSERT_VALUES, SCATTER_FORWARD)); 68 PetscCall(VecScatterEnd(fromlocalall, localall, global, INSERT_VALUES, SCATTER_FORWARD)); 69 70 PetscCall(VecView(global, viewer)); 71 72 /* Free memory */ 73 PetscCall(VecScatterDestroy(&tolocalall)); 74 PetscCall(VecScatterDestroy(&fromlocalall)); 75 PetscCall(PetscViewerDestroy(&viewer)); 76 PetscCall(VecDestroy(&localall)); 77 PetscCall(VecDestroy(&global)); 78 PetscCall(DMDestroy(&da)); 79 PetscCall(PetscFinalize()); 80 return 0; 81 } 82 83 /*TEST 84 85 build: 86 requires: !complex 87 88 test: 89 nsize: 3 90 91 TEST*/ 92