source: git/modules/EnergyScale.cc@ 6085382

/** \class EnergyScale
 *
 *  Performs transverse momentum resolution smearing.
 *
 *  $Date$
 *  $Revision$
 *
 *
 *  \author P. Demin - UCL, Louvain-la-Neuve
 *
 */

#include "modules/EnergyScale.h"

#include "classes/DelphesClasses.h"
#include "classes/DelphesFactory.h"
#include "classes/DelphesFormula.h"

#include "ExRootAnalysis/ExRootResult.h"
#include "ExRootAnalysis/ExRootFilter.h"
#include "ExRootAnalysis/ExRootClassifier.h"

#include "TMath.h"
#include "TString.h"
#include "TFormula.h"
#include "TRandom3.h"
#include "TObjArray.h"
#include "TDatabasePDG.h"
#include "TLorentzVector.h"

#include <algorithm> 
#include <stdexcept>
#include <iostream>
#include <sstream>

using namespace std;

//------------------------------------------------------------------------------

EnergyScale::EnergyScale() :
  fFormula(0), fItInputArray(0)
{
  fFormula = new DelphesFormula;
}

//------------------------------------------------------------------------------

EnergyScale::~EnergyScale()
{
  if(fFormula) delete fFormula;
}

//------------------------------------------------------------------------------

void EnergyScale::Init()
{
  // read resolution formula

  fFormula->Compile(GetString("ScaleFormula", "0.0"));

  // import input array

  fInputArray = ImportArray(GetString("InputArray", "ParticlePropagator/stableParticles"));
  fItInputArray = fInputArray->MakeIterator();

  // create output array

  fOutputArray = ExportArray(GetString("OutputArray", "stableParticles"));
}

//------------------------------------------------------------------------------

void EnergyScale::Finish()
{
  if(fItInputArray) delete fItInputArray;
}

//------------------------------------------------------------------------------

void EnergyScale::Process()
{
  Candidate *candidate;
  TLorentzVector momentum;
  Double_t scale;
  
  fItInputArray->Reset();
  while((candidate = static_cast<Candidate*>(fItInputArray->Next())))
  {
   momentum = candidate->Momentum;
   
   scale = fFormula->Eval(momentum.Pt(),momentum.Eta());
   
   if(scale>0)momentum *= scale;
   
   candidate = static_cast<Candidate*>(candidate->Clone());
   candidate->Momentum = momentum;

   fOutputArray->Add(candidate);

  }
}

//------------------------------------------------------------------------------