Date: 2021-03-03T22:25:38+00:00

Actual source code: ex1.c
petsc-3.14.5 2021-03-03
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      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;
     18:   PetscMPIInt    rank;
     19:   PetscInt       view_rank=-1;
     20: #if defined(PETSC_USE_LOG)
     21:   PetscLogEvent  event;
     22: #endif

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

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

     34:   PetscMalloc1(n,&values);
     35:   for (i=0; i<n; i++) {
     36:     PetscRandomGetValue(rnd,&value);
     37:     avg += value;
     38:     if (view_rank == (PetscInt)rank) {
     39:       PetscPrintf(PETSC_COMM_SELF,"[%d] value[%D] = %6.4e\n",rank,i,(double)PetscRealPart(value));
     40:     }
     41:     values[i] = (PetscInt)(n*PetscRealPart(value) + 2.0);
     42:   }
     43:   avg = avg/((PetscReal)n);
     44:   if (view_rank == (PetscInt)rank) {
     45:     PetscPrintf(PETSC_COMM_SELF,"[%d] Average value %6.4e\n",rank,(double)PetscRealPart(avg));
     46:   }

     48:   PetscSortInt(n,values);

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

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

     62:   for (i=1; i<n; i++) {
     63:     if (values[i] < values[i-1]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Values not sorted");
     64:   }
     65:   PetscFree(values);
     66:   PetscRandomDestroy(&rnd);

     68:   PetscFinalize();
     69:   return ierr;
     70: }

     74: /*TEST

     76:    test:

     78:    test:
     79:       suffix: 2
     80:       nsize: 2
     81:       output_file: output/ex1_1.out

     83:    test:
     84:       suffix: 3
     85:       args: -view_randomvalues 0

     87: TEST*/