Actual source code: ex7.c

      1: static char help[] = "Demonstrates using PetscViewerPushFormat(viewer,PETSC_VIEWER_BINARY_MATLAB)\n\n";

      3: #include <petscsys.h>
      4: #include <petscdm.h>
      5: #include <petscdmda.h>
      6: #include <petscbag.h>

      8: typedef struct {
      9:   char      filename[PETSC_MAX_PATH_LEN];
     10:   PetscReal ra;
     11:   PetscInt  ia;
     12:   PetscBool ta;
     13: } Parameter;

     15: int main(int argc, char **argv)
     16: {
     17:   PetscBag    bag;
     18:   Parameter  *params;
     19:   PetscViewer viewer;
     20:   DM          da;
     21:   Vec         global, local;
     22:   PetscMPIInt rank;

     24:   /*
     25:     Every PETSc routine should begin with the PetscInitialize() routine.
     26:     argc, argv - These command line arguments are taken to extract the options
     27:                  supplied to PETSc and options supplied to MPI.
     28:     help       - When PETSc executable is invoked with the option -help,
     29:                  it prints the various options that can be applied at
     30:                  runtime.  The user can use the "help" variable place
     31:                  additional help messages in this printout.
     32:   */
     33:   PetscFunctionBeginUser;
     34:   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
     35:   /* Create a DMDA and an associated vector */
     36:   PetscCall(DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DMDA_STENCIL_BOX, 10, 10, PETSC_DECIDE, PETSC_DECIDE, 2, 1, NULL, NULL, &da));
     37:   PetscCall(DMSetFromOptions(da));
     38:   PetscCall(DMSetUp(da));
     39:   PetscCall(DMCreateGlobalVector(da, &global));
     40:   PetscCall(DMCreateLocalVector(da, &local));
     41:   PetscCall(VecSet(global, -1.0));
     42:   PetscCall(DMGlobalToLocalBegin(da, global, INSERT_VALUES, local));
     43:   PetscCall(DMGlobalToLocalEnd(da, global, INSERT_VALUES, local));
     44:   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
     45:   PetscCall(VecScale(local, rank + 1));
     46:   PetscCall(DMLocalToGlobalBegin(da, local, ADD_VALUES, global));
     47:   PetscCall(DMLocalToGlobalEnd(da, local, ADD_VALUES, global));

     49:   /* Create an empty bag */
     50:   PetscCall(PetscBagCreate(PETSC_COMM_WORLD, sizeof(Parameter), &bag));
     51:   PetscCall(PetscBagGetData(bag, (void **)&params));

     53:   /* fill bag: register variables, defaults, names, help strings */
     54:   PetscCall(PetscBagSetName(bag, "ParameterBag", "contains problem parameters"));
     55:   PetscCall(PetscBagRegisterString(bag, &params->filename, PETSC_MAX_PATH_LEN, "output_file", "filename", "Name of secret file"));
     56:   PetscCall(PetscBagRegisterReal(bag, &params->ra, 1.0, "param_1", "The first parameter"));
     57:   PetscCall(PetscBagRegisterInt(bag, &params->ia, 5, "param_2", "The second parameter"));
     58:   PetscCall(PetscBagRegisterBool(bag, &params->ta, PETSC_TRUE, "do_output", "Write output file (true/false)"));

     60:   /*
     61:      Write output file with PETSC_VIEWER_BINARY_MATLAB format
     62:      NOTE: the output generated with this viewer can be loaded into
     63:      MATLAB using $PETSC_DIR/share/petsc/matlab/PetscReadBinaryMatlab.m
     64:   */
     65:   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, params->filename, FILE_MODE_WRITE, &viewer));
     66:   PetscCall(PetscViewerPushFormat(viewer, PETSC_VIEWER_BINARY_MATLAB));
     67:   PetscCall(PetscBagView(bag, viewer));
     68:   PetscCall(DMDASetFieldName(da, 0, "field1"));
     69:   PetscCall(DMDASetFieldName(da, 1, "field2"));
     70:   PetscCall(PetscObjectSetName((PetscObject)global, "da1"));
     71:   PetscCall(VecView(global, viewer));
     72:   PetscCall(PetscViewerPopFormat(viewer));
     73:   PetscCall(PetscViewerDestroy(&viewer));

     75:   /* clean up and exit */
     76:   PetscCall(PetscBagDestroy(&bag));
     77:   PetscCall(DMDestroy(&da));
     78:   PetscCall(VecDestroy(&local));
     79:   PetscCall(VecDestroy(&global));
     80:   PetscCall(PetscFinalize());
     81:   return 0;
     82: }

     84: /*TEST

     86:    test:

     88: TEST*/