CaloSwEtamod_v2.cxx

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/*
  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
*/
 
 
#include "CaloSwEtamod_v2.h"
#include "CaloClusterCorrection/interpolate.h"
#include "CaloDetDescr/CaloDetDescrManager.h"
#include <cmath>
 
 
using xAOD::CaloCluster;
using CaloClusterCorr::interpolate;
using std::abs;
 

void CaloSwEtamod_v2::makeTheCorrection (const Context& myctx,
                                         CaloCluster* cluster,
                                         const CaloDetDescrElement* elt,
                                         float eta,
                                         float adj_eta,
                                         float /*phi*/,
                                         float /*adj_phi*/,
                                         CaloSampling::CaloSample /*samp*/)
  const
{
  // Compute the eta offset within the cell.
  float etamod = eta - elt->eta() + elt->deta()/2;
  if (elt->eta_raw() < 0)
    etamod = elt->deta() - etamod;
 
  // These can happen due to DD bugs.
  if (etamod < 0)
    etamod = 0;
  else if (etamod > elt->deta())
    etamod = elt->deta();
 
  float adj_aeta = std::abs (adj_eta);
 
  // ??? In most of the calorimeter, the cells in sampling 2 have an eta
  //     width of 0.025.  This correction was derived with this assumption.
  //     However, it's not completely accurate: in the gap region, some
  //     cells have a different size.  For example, the last sampling 2
  //     cell in the barrel (starting at 1.4) has a width of 0.075.
  //     For this pass, fix up etamod to match what was used when
  //     the correction was derived.  This should be cleaned up in
  //     a subsequent version.
  if (adj_aeta >= 1.4 && adj_aeta <= 1.475)
    etamod = fmod (adj_aeta, 0.025);
 
  // Before doing the energy interpolation, make a crude total correction
  // of the energy.  This is needed since the corrections are tabulated
  // using the true cluster energies.
  float energy = cluster->e();
  float rfac = interpolate (m_rfac(myctx), adj_aeta, m_rfac_degree(myctx));
  energy /= rfac;
 
  // Calculate the correction.
  float corr = energy_interpolation (energy,
                                     Builder (m_correction(myctx), etamod),
                                     m_energies(myctx),
                                     m_energy_degree(myctx));
 
  // set energy, and rescale each sampling
  setenergy (cluster, cluster->e() / corr);
}
 

CaloSwEtamod_v2::Builder::Builder (const CxxUtils::Array<2>& correction,
                                   float etamod)
  : m_correction (correction),
    m_etamod (etamod)
{
}
 

float CaloSwEtamod_v2::Builder::calculate (int energy_ndx, bool& good) const
{
  good = true;
  return m_correction[energy_ndx][0] 
    + m_etamod*m_correction[energy_ndx][1]
    + m_etamod*m_etamod*m_correction[energy_ndx][2];
}