{
  delete gRandom;
  gRandom = new TRandom(123456) ; // Setting the seed
  TH1F *gauss = new TH1F("gauss", "Gauss Distribution", 200, 0, 20);

  for(int i=0; i<100000; ++i) {
    double a=gRandom->Gaus(10, 2);
    gauss->Fill(a);
  }

  for(int i=0; i<100000; ++i) {
    double a=gRandom->Uniform(0,20);
    gauss->Fill(a);
  }

  TF1 *f1 = new TF1("f1", "gaus(0)+pol0(3)",0,20); // Orismos tis synartisis f1
  gStyle->SetOptFit(111);  // Ektypwsi toy apotelesmatos tis prosarmoghs
  c1=new TCanvas("c1", "Gauss", 700, 400);
  c1->cd();

  f1->SetParameter(0,1000); // amplitude
  f1->SetParameter(1,10);   // mean
  f1->SetParameter(2,1);    // sigma
  f1->SetParameter(3,1000); // const

  f1->SetParName(0,"amplitude");
  f1->SetParName(1,"mean");
  f1->SetParName(2,"sigma");
  f1->SetParName(3,"const");

  gauss->Fit(f1,"","",4,16); // Prosarmogh istogrammatos stin fl apo to 4 ews to 16
}