1 static char help[] = "Tests saving DMDA vectors to files.\n\n"; 2 3 /* 4 ex13.c reads in the DMDA and vector written by this program. 5 */ 6 7 #include <petscdm.h> 8 #include <petscdmda.h> 9 10 int main(int argc, char **argv) 11 { 12 PetscMPIInt rank; 13 PetscInt M = 10, N = 8, m = PETSC_DECIDE, n = PETSC_DECIDE, dof = 1; 14 DM da; 15 Vec local, global, natural; 16 PetscScalar value; 17 PetscViewer bviewer; 18 19 PetscFunctionBeginUser; 20 PetscCall(PetscInitialize(&argc, &argv, (char *)0, help)); 21 PetscCall(PetscOptionsGetInt(NULL, NULL, "-M", &M, NULL)); 22 PetscCall(PetscOptionsGetInt(NULL, NULL, "-N", &N, NULL)); 23 PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL)); 24 PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL)); 25 PetscCall(PetscOptionsGetInt(NULL, NULL, "-dof", &dof, NULL)); 26 27 /* Create distributed array and get vectors */ 28 PetscCall(DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DMDA_STENCIL_BOX, M, N, m, n, dof, 1, NULL, NULL, &da)); 29 PetscCall(DMSetFromOptions(da)); 30 PetscCall(DMSetUp(da)); 31 PetscCall(DMCreateGlobalVector(da, &global)); 32 PetscCall(DMCreateLocalVector(da, &local)); 33 34 value = -3.0; 35 PetscCall(VecSet(global, value)); 36 PetscCall(DMGlobalToLocalBegin(da, global, INSERT_VALUES, local)); 37 PetscCall(DMGlobalToLocalEnd(da, global, INSERT_VALUES, local)); 38 39 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank)); 40 value = rank + 1; 41 PetscCall(VecScale(local, value)); 42 PetscCall(DMLocalToGlobalBegin(da, local, ADD_VALUES, global)); 43 PetscCall(DMLocalToGlobalEnd(da, local, ADD_VALUES, global)); 44 45 PetscCall(DMDACreateNaturalVector(da, &natural)); 46 PetscCall(DMDAGlobalToNaturalBegin(da, global, INSERT_VALUES, natural)); 47 PetscCall(DMDAGlobalToNaturalEnd(da, global, INSERT_VALUES, natural)); 48 49 PetscCall(DMDASetFieldName(da, 0, "First field")); 50 /* PetscCall(VecView(global,PETSC_VIEWER_DRAW_WORLD)); */ 51 52 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "daoutput", FILE_MODE_WRITE, &bviewer)); 53 PetscCall(DMView(da, bviewer)); 54 PetscCall(VecView(global, bviewer)); 55 PetscCall(PetscViewerDestroy(&bviewer)); 56 57 /* Free memory */ 58 PetscCall(VecDestroy(&local)); 59 PetscCall(VecDestroy(&global)); 60 PetscCall(VecDestroy(&natural)); 61 PetscCall(DMDestroy(&da)); 62 PetscCall(PetscFinalize()); 63 return 0; 64 } 65