2: static char help[] = "Tests PetscRandom functions.\n\n";

  4: #include <petscsys.h>

  6: /* Usage:
  7:    mpiexec -n <np> ./ex1 -n <num_of_random_numbers> -random_type <type> -log_view
  8:                          -view_randomvalues <view_rank>
  9:                          -random_view ascii -random_view :filename
 10: */

 12: int main(int argc,char **argv)
 13: {
 14:   PetscInt       i,n = 1000,*values;
 15:   PetscRandom    rnd;
 16:   PetscScalar    value,avg = 0.0;
 17:   PetscMPIInt    rank;
 18:   PetscInt       view_rank=-1;
 19: #if defined(PETSC_USE_LOG)
 20:   PetscLogEvent  event;
 21: #endif

 23:   PetscInitialize(&argc,&argv,(char*)0,help);
 24:   MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
 25:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
 26:   PetscOptionsGetInt(NULL,NULL,"-view_randomvalues",&view_rank,NULL);

 28:   PetscRandomCreate(PETSC_COMM_WORLD,&rnd);
 29:   /* force imaginary part of random number to always be zero; thus obtain reproducible results with real and complex numbers */
 30:   PetscRandomSetInterval(rnd,0.0,1.0);
 31:   PetscRandomSetFromOptions(rnd);

 33:   PetscMalloc1(n,&values);
 34:   for (i=0; i<n; i++) {
 35:     PetscRandomGetValue(rnd,&value);
 36:     avg += value;
 37:     if (view_rank == (PetscInt)rank) {
 38:       PetscPrintf(PETSC_COMM_SELF,"[%d] value[%" PetscInt_FMT "] = %6.4e\n",rank,i,(double)PetscRealPart(value));
 39:     }
 40:     values[i] = (PetscInt)(n*PetscRealPart(value) + 2.0);
 41:   }
 42:   avg = avg/((PetscReal)n);
 43:   if (view_rank == (PetscInt)rank) {
 44:     PetscPrintf(PETSC_COMM_SELF,"[%d] Average value %6.4e\n",rank,(double)PetscRealPart(avg));
 45:   }

 47:   PetscSortInt(n,values);

 49:   PetscLogEventRegister("Sort",0,&event);
 50:   PetscLogEventBegin(event,0,0,0,0);

 52:   PetscRandomSeed(rnd);
 53:   for (i=0; i<n; i++) {
 54:     PetscRandomGetValue(rnd,&value);
 55:     values[i] = (PetscInt)(n*PetscRealPart(value) + 2.0);
 56:     /* printf("value[%d] = %g\n",i,value); */
 57:   }
 58:   PetscSortInt(n,values);
 59:   PetscLogEventEnd(event,0,0,0,0);

 61:   for (i=1; i<n; i++) {
 63:   }
 64:   PetscFree(values);
 65:   PetscRandomDestroy(&rnd);

 67:   PetscFinalize();
 68:   return 0;
 69: }

 71: /*TEST

 73:    test:

 75:    test:
 76:       suffix: 2
 77:       nsize: 2
 78:       output_file: output/ex1_1.out

 80:    test:
 81:       suffix: 3
 82:       args: -view_randomvalues 0

 84: TEST*/