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, (char *)0, 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*/