code/test/Util/t.rng.c

   1 #include "lut.h"
   2 #include "Util/rng.h"
   3 #include <stdlib.h>
   4 #include <cds/Vector.h>
   5 #include <math.h>
   6
   7 // Auxiliary to perform K-S test for a given flag, sample size and bins count
   8 void aux_ks_test(int flag, uint32_t N, uint32_t nBins)
   9 {
  10     init_rng(flag);
  11
  12     // Fill the bins
  13     uint32_t bins[nBins];
  14     for (uint32_t i=0; i<nBins; i++)
  15         bins[i] = 0;
  16     for (uint32_t i=0; i<N; i++)
  17     {
  18         Real rf = get_rand_real();
  19         uint32_t index = floor(rf*nBins);
  20         if (index >= nBins) index = nBins - 1; //in case of...
  21         bins[index]++;
  22     }
  23
  24     // Test the bins
  25     double ksThreshold = 1.358 / sqrt((double)N);
  26     double countPerBin = (double)N / nBins;
  27     uint32_t cumulativeSum = 0;
  28     for (uint32_t i=0; i<nBins; i++)
  29     {
  30         cumulativeSum += bins[i];
  31         LUT_ASSERT((double)cumulativeSum / N - (i+1)*countPerBin/N < ksThreshold);
  32     }
  33 }
  34
  35 // Kolmogorov-Smirnov test on random real numbers (flag==0)
  36 void t_rng1()
  37 {
  38     aux_ks_test(0, 1000000, 1000);
  39     aux_ks_test(0, 100000, 1000);
  40     aux_ks_test(0, 10000, 100);
  41 }
  42
  43 // Kolmogorov-Smirnov test on random real numbers (flag==1)
  44 void t_rng2()
  45 {
  46     aux_ks_test(1, 1000000, 1000);
  47     aux_ks_test(1, 100000, 1000);
  48     aux_ks_test(1, 10000, 100);
  49 }