#include <iostream>
#include <fstream>

using namespace std;

void writeReadData(int num=1000) {
  // write data to file
  //ofstream ofile("data",ios::binary);
  ofstream ofile("data");
  for (int i=0; i<num; ++i){
    float rnd = gRandom->Rndm();
    ofile << rnd << endl;
  }
  ofile.close();

  // now read data from file
  //ifstream ifile("data",ios::binary);
  ifstream ifile("data");
  TH1F* h = new TH1F("h","random",100,0.,1.);
  int nlines=0;
  while (ifile.good()) {
    float x;
    ifile >> x;
    if (ifile.eof()) break;
    //cout << "Entry:" << nlines << ": X " << x << " Y " << y << endl;
    h->Fill(x);
    nlines++;
    ifile.peek();
  };
  ifile.close();
  h->DrawCopy();
}