#include "TCanvas.h"
#include "TH2F.h"
#include "TH1F.h"
#include "TFile.h"
#include "TLegend.h"
#include "TNtuple.h"



/*
This is an example of how to analyze an ntuple.
Carsten Rott (CCAPP) Jun 21, 2010

run it in the following way.
root -l
gSystem->CompileMacro("ntuple_analysis.C");
ntuple_analysis(4444); // run number as input
 */

void ntuple_analysis(int run_num = 123456)
{
 TFile *f_data   = new TFile("ntuple_file.root");

 TNtuple *chain_data = (TNtuple*) f_data->Get("ntuple");

 chain_data->SetBranchStatus("*",1);


 double date,run_number,subrun,rate,rate_error;

 //Data
 chain_data->SetBranchAddress("date",&date); // variable name in the ntuple, variable name in this macro ... can be identical
 chain_data->SetBranchAddress("run_number",&run_number);

  TH1F *h1_rate           = new TH1F("h1_rate","h1_rate",501,-0.5,500.5);


  // see how big the ntuple is ...
  const int size_data = chain_data->GetEntries();

  // now loop over the ntuple
  for(int i = 0;i<size_data;++i)
  {
    chain_data->GetEntry(i);
    if(run_number == run_num)
    {
     h1_rate->SetBinContent(subrun,rate);
     h1_rate->SetBinError(subrun,rate_error);
  }
 
  TCanvas *c4 = new TCanvas("c4","c4",450,550,500,600);
  h1_rate->Draw();

}