// RooFit
#include "RooRealVar.h"
#include "RooDataSet.h"
using namespace RooFit;

// ROOT
#include "TTree.h"

// c/c++
#include <iostream>
using namespace std;

void fitw()
{
  const char* signal_name = "dstbg-e.d";
  
  /// === observables ================================================
  RooRealVar MW("MW", "M(W_{R})", 500, 3000, "GeV/c^{2}"); MW.setBins(25);
  RooRealVar MN("MN", "M(#nu_{R})", 0, 2500, "GeV/c^{2}"); MN.setBins(25);
  RooRealVar NoW("NoW", "M(#nu_{R})/M(W_{R})", 0, 1, "");  NoW.setBins(25);
  
  /// === Data definition ==============================================
  RooRealVar weight("weight", "weight", 1);
  
  // signal
  TTree stree(signal_name, signal_name);
  stree.ReadFile(signal_name, "MW/D:MN/D:NoW/D:weight/D");
  RooDataSet* sdata = new RooDataSet(signal_name, signal_name,
                                     RooArgSet(MW, MN, NoW, weight),
                                     Import(stree), WeightVar(weight));
  cout << "signal: " << sdata->GetTitle()
       << ", sumEntries = " << sdata->sumEntries()
       << ", numEntries = " << sdata->numEntries()
       << endl;
}