CaloSwEta2b_g3.cxx

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/*
  Copyright (C) 2002-2024 CERN for the benefit of the ATLAS collaboration
*/
 
/********************************************************************
 
NAME:     CaloSwEta2b_g3.cxx
PACKAGE:  offline/Calorimeter/CaloClusterCorrection
 
AUTHORS:  H. Ma, S. Rajagopalan
CREATED:  Dec. 15, 1999
 
PURPOSE:  S-shape corrections in sampling 2 as a function of eta
      for barrel EM calorimeter. 
          (Tuned using 50 GeV Et photons)  
          base class: CaloClusterCorrection
          Correction tuned on G3 samples.
 
Atrecon Orig: emreco/qeta2b.age          
 
Updated:  May 10, 2000    (SR, HM)
          Migrated to Athena Framework from PASO
 
Updated:  Jan 5, 2001    (HM)
          QA. 
 
Updated:  Feb 28, 2003    (MW)
          barrel goes only up to eta=1.475, not 1.5
 
Updated:  May 5, 2004    (Sven Menke)
      base class changed from algo to tool
 
Updated:  June, 2004    (sss)
          Use ToolWithConstants to get correction constants.
********************************************************************/
 
#include "CaloSwEta2b_g3.h"
#include "CaloClusterCorrection/interpolate.h"
#include <cmath>
 
using xAOD::CaloCluster;
using CaloClusterCorr::interpolate;
 
// granularity of middle EM barrel layer
 
const float CaloSwEta2b_g3::s_middle_layer_granularity = 0.025;
 
 
void CaloSwEta2b_g3::makeCorrection (const Context& myctx,
                                     CaloCluster* cluster) const
{
  // Only for barrel
  if (!cluster->inBarrel())
    return;
 
  const CxxUtils::Array<2> correction = m_correction (myctx);
  const CxxUtils::Array<2> residuals = m_residuals (myctx);
  const CxxUtils::Array<1> residual_bins = m_residual_bins (myctx);
  const int correction_degree = m_correction_degree(myctx);
  const int residual_eval_degree = m_residual_eval_degree(myctx);
  const int residual_degree = m_residual_degree(myctx);
  const float correction_coef = m_correction_coef(myctx);
  const float residual_coef = m_residual_coef(myctx);
 
  assert (residuals.size(1)-1 == residual_bins.size());
 
  // eta of second sampling
  float eta = cluster->etaSample(CaloSampling::EMB2); 
  if (eta == -999.) return;
  float aeta = fabs(eta);
 
  //   u2 is the distance to the inner edge of the cell (granularity 0.025)
  float u2 = fmod(aeta,s_middle_layer_granularity) ;
 
  //   First order (average) S-shape correction
  float deta = correction_coef * interpolate (correction,
                                              u2,
                                              correction_degree);
 
  //    Residual S-shape correction: six ranges in eta from 0 to 1.2
  //    Evaluated by 2nd order interpolation between 10 tabulated values
 
  // first we evaluate our residual in each eta range, given u2
 
  unsigned int shape[] = {residual_bins.size(), 2};
  CaloRec::WritableArrayData<2> w (shape);
  
  for (unsigned int i=0; i < residual_bins.size(); i++) {
    w[i][0] = residual_bins[i];
    w[i][1] = interpolate (residuals,
               u2, 
               residual_eval_degree,
               i+1);
  }
 
  // finally we interpolate (2nd order) for the actual eta
 
  deta += residual_coef * interpolate (w,
                                       aeta,
                                       residual_degree);
  if (eta < 0)
    deta = -deta;
 
  // make correction to second sampling
  cluster->setEta(CaloSampling::EMB2, eta - deta);
}
 
 
const std::string& CaloSwEta2b_g3::toolType() const
{
  static const std::string typeName = "CaloSwEta_g3";
  return typeName;
}