1 /* 2 Demonstrates using the HDF5 viewer with a DMDA Vec 3 - create a global vector containing a gauss profile (exp(-x^2-y^2)) 4 - write the global vector in a hdf5 file 5 6 The resulting file gauss.h5 can be viewed with Visit (an open-source visualization package) 7 Or with some versions of MATLAB with data=hdfread('gauss.h5','pressure'); mesh(data); 8 9 The file storage of the vector is independent of the number of processes used. 10 */ 11 12 #include <petscdm.h> 13 #include <petscdmda.h> 14 #include <petscsys.h> 15 #include <petscviewerhdf5.h> 16 17 static char help[] = "Test to write HDF5 file from PETSc DMDA Vec.\n\n"; 18 19 int main(int argc, char **argv) 20 { 21 DM da2D; 22 PetscInt i, j, ixs, ixm, iys, iym; 23 PetscViewer H5viewer; 24 PetscScalar xm = -1.0, xp = 1.0; 25 PetscScalar ym = -1.0, yp = 1.0; 26 PetscScalar value = 1.0, dx, dy; 27 PetscInt Nx = 40, Ny = 40; 28 Vec gauss, input; 29 PetscScalar **gauss_ptr; 30 PetscReal norm; 31 const char *vecname; 32 33 dx = (xp - xm) / (Nx - 1); 34 dy = (yp - ym) / (Ny - 1); 35 36 /* Initialize the Petsc context */ 37 PetscFunctionBeginUser; 38 PetscCall(PetscInitialize(&argc, &argv, (char *)0, help)); 39 PetscCall(DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DMDA_STENCIL_STAR, Nx, Ny, PETSC_DECIDE, PETSC_DECIDE, 1, 1, NULL, NULL, &da2D)); 40 PetscCall(DMSetFromOptions(da2D)); 41 PetscCall(DMSetUp(da2D)); 42 43 /* Set the coordinates */ 44 PetscCall(DMDASetUniformCoordinates(da2D, 0.0, 1.0, 0.0, 1.0, 0.0, 0.0)); 45 46 /* Declare gauss as a DMDA component */ 47 PetscCall(DMCreateGlobalVector(da2D, &gauss)); 48 PetscCall(PetscObjectSetName((PetscObject)gauss, "pressure")); 49 50 /* Initialize vector gauss with a constant value (=1) */ 51 PetscCall(VecSet(gauss, value)); 52 53 /* Get the coordinates of the corners for each process */ 54 PetscCall(DMDAGetCorners(da2D, &ixs, &iys, 0, &ixm, &iym, 0)); 55 56 /* Build the gaussian profile (exp(-x^2-y^2)) */ 57 PetscCall(DMDAVecGetArray(da2D, gauss, &gauss_ptr)); 58 for (j = iys; j < iys + iym; j++) { 59 for (i = ixs; i < ixs + ixm; i++) gauss_ptr[j][i] = PetscExpScalar(-(xm + i * dx) * (xm + i * dx) - (ym + j * dy) * (ym + j * dy)); 60 } 61 PetscCall(DMDAVecRestoreArray(da2D, gauss, &gauss_ptr)); 62 63 /* Create the HDF5 viewer */ 64 PetscCall(PetscViewerHDF5Open(PETSC_COMM_WORLD, "gauss.h5", FILE_MODE_WRITE, &H5viewer)); 65 PetscCall(PetscViewerSetFromOptions(H5viewer)); 66 67 /* Write the H5 file */ 68 PetscCall(VecView(gauss, H5viewer)); 69 70 /* Close the viewer */ 71 PetscCall(PetscViewerDestroy(&H5viewer)); 72 73 PetscCall(VecDuplicate(gauss, &input)); 74 PetscCall(PetscObjectGetName((PetscObject)gauss, &vecname)); 75 PetscCall(PetscObjectSetName((PetscObject)input, vecname)); 76 77 /* Create the HDF5 viewer for reading */ 78 PetscCall(PetscViewerHDF5Open(PETSC_COMM_WORLD, "gauss.h5", FILE_MODE_READ, &H5viewer)); 79 PetscCall(PetscViewerSetFromOptions(H5viewer)); 80 PetscCall(VecLoad(input, H5viewer)); 81 PetscCall(PetscViewerDestroy(&H5viewer)); 82 83 PetscCall(VecAXPY(input, -1.0, gauss)); 84 PetscCall(VecNorm(input, NORM_2, &norm)); 85 PetscCheck(norm <= 1.e-6, PETSC_COMM_WORLD, PETSC_ERR_PLIB, "Vec read in does not match vector written out"); 86 87 PetscCall(VecDestroy(&input)); 88 PetscCall(VecDestroy(&gauss)); 89 PetscCall(DMDestroy(&da2D)); 90 PetscCall(PetscFinalize()); 91 return 0; 92 } 93 94 /*TEST 95 96 build: 97 requires: hdf5 !defined(PETSC_USE_CXXCOMPLEX) 98 99 test: 100 nsize: 4 101 102 test: 103 nsize: 4 104 suffix: 2 105 args: -viewer_hdf5_base_dimension2 106 output_file: output/ex10_1.out 107 108 test: 109 nsize: 4 110 suffix: 3 111 args: -viewer_hdf5_sp_output 112 output_file: output/ex10_1.out 113 114 TEST*/ 115