{

  TH1F * h = new TH1F( "myhist", "gaussian distribution" , 100 , 0 , 20 );

  for ( int i=0 ; i<10000 ; i++ ) {
    double x = gRandom->Gaus(10,2);
    h->Fill(x);
  }

  for ( int i=0 ; i<500 ; i++ ) {
    double x = gRandom->Gaus(14,0.5);
    h->Fill(x);
  }

  h->Draw();
  //h->Fit( "gaus" , "" , "" , 7 , 14 );
}