1: static char help[] = "A benchmark for testing PetscSortInt() and PetscSortIntWithArrayPair()\n\
  2:   The array is filled with random numbers, but one can control average duplicates for each unique integer with the -d option.\n\
  3:   Usage:\n\
  4:    mpirun -n 1 ./ex52 -n <length of the array to sort>, default=100 \n\
  5:                       -r <repeat times for each sort>, default=10 \n\
  6:                       -d <average duplicates for each unique integer>, default=1, i.e., no duplicates \n\n";

  8:  #include <petscsys.h>
  9:  #include <petsctime.h>
 10: int main(int argc,char **argv)
 11: {
 13:   PetscInt       i,l,n=100,r=10,d=1;
 14:   PetscInt       *X,*Y,*Z;
 15:   PetscReal      val;
 16:   PetscRandom    rdm;
 17:   PetscLogDouble time;
 18:   PetscMPIInt    size;

 20:   PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
 21:   MPI_Comm_size(PETSC_COMM_WORLD,&size);
 22:   if (size != 1) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_ARG_OUTOFRANGE,"This is a uniprocessor example only!");

 24:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
 25:   PetscOptionsGetInt(NULL,NULL,"-r",&r,NULL);
 26:   PetscOptionsGetInt(NULL,NULL,"-d",&d,NULL);
 27:   if (n<1 || r<1 || d<1 || d>n) SETERRQ3(PETSC_COMM_WORLD,PETSC_ERR_SUP,"Wrong input n=%D,r=%D,d=%d. They must be >=1 and n>=d\n",n,r,d);

 29:   PetscCalloc3(n,&X,n,&Y,n,&Z);
 30:   PetscRandomCreate(PETSC_COMM_SELF,&rdm);
 31:   PetscRandomSetFromOptions(rdm);

 33:   time = 0.0;
 34:   for (l=0; l<r; l++) { /* r loops */
 35:     for (i=0; i<n; i++) { /* Init X[] */
 36:       PetscRandomGetValueReal(rdm,&val);
 37:       X[i] = val*PETSC_MAX_INT;
 38:       if (d > 1) X[i] = X[i] % (n/d);
 39:     }

 41:     PetscTimeSubtract(&time);
 42:     PetscSortInt(n,X);
 43:     PetscTimeAdd(&time);

 45:     for (i=0; i<n-1; i++) {if (X[i] > X[i+1]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"PetscSortInt() produced wrong results!");}
 46:   }
 47:   PetscPrintf(PETSC_COMM_SELF,"PetscSortInt()              with %D integers, %D duplicate(s) per unique value took %g seconds\n",n,d,time/r);

 49:   time = 0.0;
 50:   for (l=0; l<r; l++) { /* r loops */
 51:     for (i=0; i<n; i++) { /* Init X[] */
 52:       PetscRandomGetValueReal(rdm,&val);
 53:       X[i] = val*PETSC_MAX_INT;
 54:       if (d > 1) X[i] = X[i] % (n/d);
 55:     }

 57:     PetscTimeSubtract(&time);
 58:     PetscSortIntWithArrayPair(n,X,Y,Z);
 59:     PetscTimeAdd(&time);

 61:     for (i=0; i<n-1; i++) {if (X[i] > X[i+1]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"PetscSortInt() produced wrong results!");}
 62:   }
 63:   PetscPrintf(PETSC_COMM_SELF,"PetscSortIntWithArrayPair() with %D integers, %D duplicate(s) per unique value took %g seconds\n",n,d,time/r);
 64:   PetscPrintf(PETSC_COMM_SELF,"SUCCEEDED\n");

 66:   PetscRandomDestroy(&rdm);
 67:   PetscFree3(X,Y,Z);
 68:   PetscFinalize();
 69:   return ierr;
 70: }

 72: /*TEST

 74:    test:
 75:       args: -n 1000 -r 1 -d 1
 76:       # Do not need to output timing results for test
 77:       filter: grep -v "per unique value took"

 79: TEST*/