Date: 2021-03-03T22:25:48+00:00

Actual source code: ex5.c
petsc-3.14.5 2021-03-03
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      2: static char help[] = "Demonstrates using the PetscBag Object\n\n";

      4: /*T
      5:    Concepts: bags;
      6:    Processors: n
      7: T*/

     10: #include <petscsys.h>
     11: #include <petscbag.h>
     12: #include <petscviewer.h>

     14: /*
     15:   Enum variables can be stored in a bag but require a string array
     16:   to name their fields.  The fourth entry in this example is the name
     17:   of the enum, the fifth is the prefix (none in this case), and the last
     18:   entry is the null string.
     19: */
     20: typedef enum {
     21:   THIS = 0, THAT = 1, THE_OTHER = 2
     22: } YourChoice;
     23: const char *EnumeratedChoices[] = {"THIS","THAT","THE_OTHER","EnumeratedChoices","",0};

     25: /*
     26:   Data structures can be used in a bag as long as they
     27:   are declared in the bag with a variable, not with a pointer.
     28: */
     29: typedef struct {
     30:   PetscReal x1,x2;
     31: } TwoVec;

     33: /*
     34:   Define a C struct that will contain my program's parameters.

     36:   A PETSc bag is merely a representation of a C struct that can be printed, saved to a file and loaded from a file.
     37: */
     38: typedef struct {
     39:   PetscScalar   W;
     40:   PetscReal     rho;
     41:   TwoVec        pos;
     42:   PetscInt      Ii;
     43:   PetscInt      iarray[3];
     44:   PetscReal     rarray[2];
     45:   PetscBool     T;
     46:   PetscBool     Tarray[3];
     47:   PetscDataType dt;
     48:   char          filename[PETSC_MAX_PATH_LEN];
     49:   YourChoice    which;
     50: } Parameter;

     53: int main(int argc,char **argv)
     54: {
     56:   PetscBag       bag;
     57:   Parameter      *params;
     58:   PetscViewer    viewer;
     59:   PetscBool      flg;
     60:   char           filename[PETSC_MAX_PATH_LEN] = "binaryoutput";

     62:   /*
     63:     Every PETSc routine should begin with the PetscInitialize() routine.
     64:     argc, argv - These command line arguments are taken to extract the options
     65:                  supplied to PETSc and options supplied to MPI.
     66:     help       - When PETSc executable is invoked with the option -help,
     67:                  it prints the various options that can be applied at
     68:                  runtime.  The user can use the "help" variable place
     69:                  additional help messages in this printout.
     70:   */
     71:   PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;

     73:   /* Create an empty bag */
     74:   PetscBagCreate(PETSC_COMM_WORLD,sizeof(Parameter),&bag);
     75:   PetscBagGetData(bag,(void**)&params);

     77:   /* register variables, defaults, names, help strings */
     78:   PetscBagSetName(bag,"ParameterBag","contains parameters for simulations of top-secret, dangerous physics");
     79:   PetscBagSetOptionsPrefix(bag, "pbag_");
     80:   PetscBagRegisterString(bag,&params->filename,PETSC_MAX_PATH_LEN,"myfile","filename","Name of secret file");
     81:   PetscBagRegisterReal  (bag,&params->rho,3.0,"rho","Density, kg/m^3");
     82:   PetscBagRegisterScalar(bag,&params->W,  5.0,"W","Vertical velocity, m/sec");
     83:   PetscBagRegisterInt   (bag,&params->Ii, 2,"modes_x","Number of modes in x-direction");

     85:   params->iarray[0] = 1;
     86:   params->iarray[1] = 2;
     87:   params->iarray[2] = 3;

     89:   PetscBagRegisterIntArray(bag,&params->iarray, 3,"int_array","Int array with 3 locations");

     91:   params->rarray[0] = -1.0;
     92:   params->rarray[1] = -2.0;

     94:   PetscBagRegisterRealArray(bag,&params->rarray, 2,"real_array","Real array with 2 locations");
     95:   PetscBagRegisterBool (bag,&params->T,  PETSC_FALSE,"do_output","Write output file (yes/no)");
     96:   PetscBagRegisterBoolArray(bag,&params->Tarray, 3,"bool_array","Bool array with 3 locations");
     97:   PetscBagRegisterEnum  (bag,&params->dt, PetscDataTypes,(PetscEnum)PETSC_INT,"dt","meaningless datatype");
     98:   PetscBagRegisterReal  (bag,&params->pos.x1,1.0,"x1","x position");
     99:   PetscBagRegisterReal  (bag,&params->pos.x2,1.9,"x2","y position");
    100:   PetscBagRegisterEnum  (bag,&params->which, EnumeratedChoices, (PetscEnum)THAT, "choose","Express yourself by choosing among enumerated things");

    103:   /* This option allows loading user-provided PetscBag */
    104:   PetscOptionsGetString(NULL,NULL,"-f",filename,sizeof(filename),&flg);
    105:   if (!flg) {

    107:     /* write bag to stdio & binary file */
    108:     PetscBagView(bag,PETSC_VIEWER_STDOUT_WORLD);
    109:     PetscViewerBinaryOpen(PETSC_COMM_WORLD,filename,FILE_MODE_WRITE,&viewer);
    110:     PetscBagView(bag,viewer);
    111:     PetscViewerDestroy(&viewer);
    112:   }

    114:   PetscMemzero(params,sizeof(Parameter));

    116:   /* load bag from file & write to stdio */
    117:   PetscViewerBinaryOpen(PETSC_COMM_WORLD,filename,FILE_MODE_READ,&viewer);
    118:   PetscBagLoad(viewer,bag);
    119:   PetscViewerDestroy(&viewer);
    120:   PetscBagSetFromOptions(bag);
    121:   PetscBagView(bag,PETSC_VIEWER_STDOUT_WORLD);

    123:   /* reuse the parameter struct */
    124:   PetscBagGetData(bag,(void**)&params);
    125:   PetscPrintf(PETSC_COMM_WORLD,"The value of rho after loading is: %f\n",(double)params->rho);

    127:   /* clean up and exit */
    128:   PetscBagDestroy(&bag);
    129:   PetscFinalize();
    130:   return ierr;
    131: }

    134: /*TEST

    136:    test:
    137:       args: -pbag_rho 44 -pbag_do_output true
    138:       requires: !complex

    140:    test:
    141:       suffix: yaml
    142:       requires: yaml !complex
    143:       args: -options_file_yaml bag.yml -options_view
    144:       filter:  grep -v saws_port_auto_select |grep -v malloc_dump | grep -v display | grep -v check_pointer_intensity | grep -v error_output_stdout | grep -v nox | grep -v nox_warning
    145:       localrunfiles: bag.yml

    147: TEST*/