ExampleRandom.cpp

Example for random number generator

Author

MIP

/* 
This file is part of the BIAS library (Basic ImageAlgorithmS).

Copyright (C) 2003-2009    (see file CONTACT for details)
  Multimediale Systeme der Informationsverarbeitung
  Institut fuer Informatik
  Christian-Albrechts-Universitaet Kiel


BIAS is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

BIAS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License
along with BIAS; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

/**
   @example ExampleRandom.cpp   
   @relates Random
   @brief Example for random number generator
   @ingroup g_examples
   @author MIP 
*/
// must be first:
//#include <Base/Common/LeakChecking.h> 


#include <cmath>
#include <cstring>
#include <Base/Math/Random.hh>
#include <Base/Debug/TimeMeasure.hh>

using namespace BIAS;
using namespace std;

#define HIST_BIN_COUNT 64

int main()
{
  Random ran;
  double num;
  unsigned int hist[HIST_BIN_COUNT];
  //, histn[HIST_BIN_COUNT];
  //unsigned int histnum=0;
  double min=-100.0, max=100.0;
  //double mean=0.0, sigma=1.0;
  //long unsigned int outside=0;
  long unsigned int count=100000;
  long unsigned int sumuniform=0;
  //, sumnormal=0;
  //double sigma_int=2.576;
  //long int numint=0;

  memset((void *)hist, 0, HIST_BIN_COUNT*sizeof(unsigned int));

  TimeMeasure timer;
  double *uniform=new double[count];
  timer.Start();
  ran.GetUniformDistributed(min, max, count, uniform);
  timer.Stop();
  cerr << "getting "<<count<<" uniform distributed random vars took "
       << timer.GetRealTime() << " us"<< endl;
  for (register unsigned int i=0; i<count; i++){
    num = uniform[i];
    //    num = ran.GetUniformDistributed(min, max);
    //cerr << num << endl;
    hist[(unsigned int)floor((num-min)/(max-min)*HIST_BIN_COUNT)]++;
  }
  for (int i=0; i< HIST_BIN_COUNT; i++){
    cout << i << ":  \t" << hist[i] << endl;
    sumuniform+=hist[i];
  }
  cerr << "got "<<sumuniform<<" uniform distributed vars\n";
  sumuniform=0;

  delete[] uniform;

  return 0;


//
//  memset((void *)hist, 0, HIST_BIN_COUNT*sizeof(unsigned int));
//  memset((void *)histn, 0, HIST_BIN_COUNT*sizeof(unsigned int));
//
//  for (register unsigned int i=0; i<count; i++){
//    numint=ran.GetUniformDistributedInt(0, HIST_BIN_COUNT-1);
//    hist[numint]++;
//  }
//  cout << "uniform distributed integer between 0 and HIST_BIN_COUNT" << endl;
//  for (int i=0; i< HIST_BIN_COUNT; i++){
//    cout << i << ":  \t" << hist[i] << endl;
//    sumuniform+=hist[i];
//  }
//  cout << " got "<<sumuniform
//       << " uniform distributed integer random values between 0 "
//       << "and HIST_BIN_COUNT-1"<<endl;
//  sumuniform=0;
//  
//
//  memset((void *)hist, 0, HIST_BIN_COUNT*sizeof(unsigned int));
//
//  for (register unsigned int i=0; i<count; i++){
//    num = ran.GetUniformDistributed(min, max);
//    hist[(unsigned int)floor((num-min)/(max-min)*HIST_BIN_COUNT)]++;
//    num = ran.GetNormalDistributed(mean, sigma);
//    // 95.4% of all values lie within mean+-2*sigma
//    histnum = 
//      (unsigned int)floor((num - mean + sigma_int*sigma)/
//                          (2*sigma_int*sigma)*HIST_BIN_COUNT);
//    if ((histnum<0) || (histnum >=HIST_BIN_COUNT))
//      outside++;
//    else
//      histn[histnum]++;
//  }
//  cout << "bin\tuniform  \tnormal" << endl;
//  for (int i=0; i< HIST_BIN_COUNT; i++){
//    cout << i << ":  \t" << hist[i] << "   \t" << histn[i] << endl;
//    sumuniform+=hist[i];
//    sumnormal+=histn[i];
//  }
//  cout << "outside of choosen " << sigma_int 
//       << " sigma interval : #" << outside 
//       << " = " << (double)outside/(double)count*100.0 << "%" << endl;
////   cout << "normal distributed: " << endl;
////   for (int i=0; i< HIST_BIN_COUNT; i++){
////     cout << i << ":  \t" << histn[i] << endl;
////   }
//  cout << " got "<<sumuniform
//       << " uniform distributed double random values between 0 "
//       << "and HIST_BIN_COUNT-1"<<endl;
//
//  cout << " got "<<sumnormal<<" normal distributed random values"<<endl;
//
//  delete[] uniform;
//  return 0;
}