#include "TMinuit.h"
#include "TRandom.h"
#include "TH1F.h"
#include "TMath.h"
#include <iostream>
#include <stdlib.h>
#include "TGraphErrors.h"

const double TWOPI=TMath::TwoPi();
const double RANDM=RAND_MAX;

// Summary in a Histogram
TH1F *Average = new TH1F("Average","",100,0,1);

//----------------------------------------------------------------------
void CLT()
//----------------------------------------------------------------------
{
  // Illustration of the Central Limit Theorem (CLT)
  // Generate a number N of uniform distributions between 0 and 1
  // You can change the number of iterations here

  const int N = 2;
  double A;
  
  // Generate events    
  for (int ievt=0; ievt!=100000; ievt++)
    {
      A=0.;
      for (int i=0; i!=N; i++)
	{
	  A+=rand()/RANDM;
	}
      A=A/N;
      Average->Fill(A);
    }  

  // Usual Style options in root
  gROOT->SetStyle("Plain");
  gStyle->SetCanvasColor(0);
  gStyle->SetCanvasBorderMode(0);
  gStyle->SetPadBorderMode(0);
  gStyle->SetPadColor(0);
  gStyle->SetLineWidth(1.);
  gStyle->SetCanvasDefH(596);
  gStyle->SetCanvasDefW(596);
  gStyle->SetCanvasBorderMode(0);
  gStyle->SetPadBorderMode(0);
  gStyle->SetFrameBorderMode(0);
  gStyle->SetTitleBorderSize(0);
  gStyle->SetStatBorderSize(0);
  gStyle->SetPadTickX(1);
  gStyle->SetPadTickY(1);
  gStyle->SetPalette(1);
  gStyle->SetOptStat(0);
  
  c0 = new TCanvas("c0", "", 0, 0, 600, 450);
  c0->SetLeftMargin(0.12);
  c0->SetRightMargin(0.12);
  c0->SetBottomMargin(0.2);

  Average->SetMinimum(0.);
  Average->Draw();
  //Average->Fit("gaus");
  cout << "Mean " <<  Average->GetMean() << " RMS " << Average->GetRMS() << endl;

}