1 static char help[] = "Tests DMDAGlobalToNaturalAllCreate() using contour plotting for 2d DMDAs.\n\n"; 2 3 #include <petscdm.h> 4 #include <petscdmda.h> 5 #include <petscdraw.h> 6 7 int main(int argc, char **argv) 8 { 9 PetscInt i, j, M = 10, N = 8, m = PETSC_DECIDE, n = PETSC_DECIDE; 10 PetscMPIInt rank; 11 PetscBool flg = PETSC_FALSE; 12 DM da; 13 PetscViewer viewer; 14 Vec localall, global; 15 PetscScalar value, *vlocal; 16 DMBoundaryType bx = DM_BOUNDARY_NONE, by = DM_BOUNDARY_NONE; 17 DMDAStencilType stype = DMDA_STENCIL_BOX; 18 VecScatter tolocalall, fromlocalall; 19 PetscInt start, end; 20 21 PetscFunctionBeginUser; 22 PetscCall(PetscInitialize(&argc, &argv, (char *)0, help)); 23 PetscCall(PetscViewerDrawOpen(PETSC_COMM_WORLD, 0, "", 300, 0, 300, 300, &viewer)); 24 25 /* Read options */ 26 PetscCall(PetscOptionsGetInt(NULL, NULL, "-M", &M, NULL)); 27 PetscCall(PetscOptionsGetInt(NULL, NULL, "-N", &N, NULL)); 28 PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL)); 29 PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL)); 30 PetscCall(PetscOptionsGetBool(NULL, NULL, "-star_stencil", &flg, NULL)); 31 if (flg) stype = DMDA_STENCIL_STAR; 32 33 /* Create distributed array and get vectors */ 34 PetscCall(DMDACreate2d(PETSC_COMM_WORLD, bx, by, stype, M, N, m, n, 1, 1, NULL, NULL, &da)); 35 PetscCall(DMSetFromOptions(da)); 36 PetscCall(DMSetUp(da)); 37 38 PetscCall(DMCreateGlobalVector(da, &global)); 39 PetscCall(VecCreateSeq(PETSC_COMM_SELF, M * N, &localall)); 40 41 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank)); 42 PetscCall(VecGetOwnershipRange(global, &start, &end)); 43 for (i = start; i < end; i++) { 44 value = 5.0 * rank; 45 PetscCall(VecSetValues(global, 1, &i, &value, INSERT_VALUES)); 46 } 47 PetscCall(VecAssemblyBegin(global)); 48 PetscCall(VecAssemblyEnd(global)); 49 PetscCall(VecView(global, viewer)); 50 51 /* 52 Create Scatter from global DMDA parallel vector to local vector that 53 contains all entries 54 */ 55 PetscCall(DMDAGlobalToNaturalAllCreate(da, &tolocalall)); 56 PetscCall(DMDANaturalAllToGlobalCreate(da, &fromlocalall)); 57 58 PetscCall(VecScatterBegin(tolocalall, global, localall, INSERT_VALUES, SCATTER_FORWARD)); 59 PetscCall(VecScatterEnd(tolocalall, global, localall, INSERT_VALUES, SCATTER_FORWARD)); 60 61 PetscCall(VecGetArray(localall, &vlocal)); 62 for (j = 0; j < N; j++) { 63 for (i = 0; i < M; i++) *vlocal++ += i + j * M; 64 } 65 PetscCall(VecRestoreArray(localall, &vlocal)); 66 67 /* scatter back to global vector */ 68 PetscCall(VecScatterBegin(fromlocalall, localall, global, INSERT_VALUES, SCATTER_FORWARD)); 69 PetscCall(VecScatterEnd(fromlocalall, localall, global, INSERT_VALUES, SCATTER_FORWARD)); 70 71 PetscCall(VecView(global, viewer)); 72 73 /* Free memory */ 74 PetscCall(VecScatterDestroy(&tolocalall)); 75 PetscCall(VecScatterDestroy(&fromlocalall)); 76 PetscCall(PetscViewerDestroy(&viewer)); 77 PetscCall(VecDestroy(&localall)); 78 PetscCall(VecDestroy(&global)); 79 PetscCall(DMDestroy(&da)); 80 PetscCall(PetscFinalize()); 81 return 0; 82 } 83 84 /*TEST 85 86 build: 87 requires: !complex 88 89 test: 90 nsize: 3 91 92 TEST*/ 93