Date: 2013-07-02T14:38:34+00:00

Actual source code: ex1.c
petsc-3.4.2 2013-07-02

      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_summary
      8:                          -view_randomvalues <view_rank>
      9:                          -random_view ascii -random_view :filename
     10: */

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

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

     31:   PetscRandomCreate(PETSC_COMM_WORLD,&rnd);
     32: #if defined(PETSC_HAVE_DRAND48)
     33:   PetscRandomSetType(rnd,PETSCRAND48);
     34: #elif defined(PETSC_HAVE_RAND)
     35:   PetscRandomSetType(rnd,PETSCRAND);
     36: #endif
     37:   PetscRandomSetFromOptions(rnd);

     39:   PetscMalloc(n*sizeof(PetscInt),&values);
     40:   for (i=0; i<n; i++) {
     41:     PetscRandomGetValue(rnd,&value);
     42:     if (view_rank == (PetscInt)rank) {
     43:       PetscPrintf(PETSC_COMM_SELF,"[%D] value[%d] = %g\n",rank,i,PetscRealPart(value));
     44:     }
     45:     values[i] = (PetscInt)(n*PetscRealPart(value) + 2.0);
     46:   }
     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++) {
     62:     if (values[i] < values[i-1]) SETERRQ(PETSC_COMM_SELF,1,"Values not sorted");
     63:   }
     64:   PetscFree(values);
     65:   PetscRandomDestroy(&rnd);

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