CaloClusterUpdate.cxx

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/*
  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
*/
 
/********************************************************************
 
NAME:     CaloClusterUpdate.cxx
PACKAGE:  offline/LArCalorimeter/LArClusterRec
 
AUTHORS:  H. Ma, S. Rajagopalan
CREATED:  Nov, 2000
 
PURPOSE:  Recalculate the total energy, eta,phi of a cluster.
      This should be called after all corrections to individual 
      samplings are done. 
 
      energy = Sum of energy in all sampling
      eta = average of eta1 and eta2, weighted by energy and
                relative resolution.  
        This needs to be tuned. 
      phi    = phi of second sampling. 
 
Base class: LArClusterCorrection (Algorithm)
 
Atrecon Orig: emreco/qetamod.F
 
Updated:  May 10, 2000    (SR, HM)
          Migrated to Athena Framework from PASO
 
Updated:  Jan 5, 2001    (HM)
          QA. 
 
Updated:  Feb 28, 2003, Mar 4, 2003    (MW)
          protect against unphysical clusters
 
Updated:  May 5, 2004    (Sven Menke)
      base class changed from algo to tool
 
********************************************************************/
// include header files
#include "CaloClusterUpdate.h"
 
#include "GaudiKernel/MsgStream.h"
#include "CaloGeoHelpers/proxim.h" 
#include "CaloGeoHelpers/CaloPhiRange.h"
 
using xAOD::CaloCluster;
void CaloClusterUpdate::makeCorrection (const Context& myctx,
                                        CaloCluster* cluster) const
{
  float energy=0; 
  float eta=0; 
  float weta=0;
 
  // set eta to be weighted average of eta1 and eta2
  ATH_MSG_DEBUG(" inBarrel "<<cluster->inBarrel()
        << " inEndcap "<<cluster->inEndcap()) ;
 
  for(int i=0; i<5; i=i+4 )
  { 
  
   if (i==0 && !cluster->inBarrel()) continue;
   if (i==4 && !cluster->inEndcap()) continue;
 
   CaloSampling::CaloSample sam0 = (CaloSampling::CaloSample)(CaloSampling::PreSamplerB+i);   
   CaloSampling::CaloSample sam1 = (CaloSampling::CaloSample)(CaloSampling::PreSamplerB+i+1);   
   CaloSampling::CaloSample sam2 = (CaloSampling::CaloSample)(CaloSampling::PreSamplerB+i+2);   
   CaloSampling::CaloSample sam3 = (CaloSampling::CaloSample)(CaloSampling::PreSamplerB+i+3);
   
   float e0 = cluster->eSample(sam0);
   float e1 = cluster->eSample(sam1);
   float e2 = cluster->eSample(sam2);
   float e3 = cluster->eSample(sam3);
 
   // total energy is the sum of each sampling, which had all corrections
   energy += (e0 + e1 + e2 + e3);
 
   // do not consider including in the average if both energies are negative
   if (e1 <= 0 && e2 <= 0) continue;
 
   // reject weird clusters. Not even sure it can ever happen
   float eta2 = cluster->etaSample(sam2);
   if (cluster->hasSampling(sam2) && eta2 == -999.) continue;
 
   float eta1 = cluster->etaSample(sam1);
   if (cluster->hasSampling(sam1) && eta1 == -999.) continue;
 
   // eta1 has better resolution, so weight it differently
   float w1 = e1*m_w1;
   float w2 = e2;
 
   // do not include layer if energy is negative
   if (e1 <= 0) {
     w1 = 0;
   }
   else if (e2 <= 0) {
     w2 = 0;
   }
 
   eta  += (eta1*w1+eta2*w2) ;
   weta += w1+w2; 
  }
 
  //
  // set them in the cluster. 
  //
  if (eta  != -999. && weta != 0)
    eta  = eta/weta; 
  else {
    ATH_MSG_DEBUG("Weird cluster "
          " EB1 = " << cluster->eSample(CaloSampling::EMB1)
          << " etaB1 = " << cluster->etaSample(CaloSampling::EMB1)
          << " EE1 = " << cluster->eSample(CaloSampling::EME1)
          << " etaE1 = " << cluster->etaSample(CaloSampling::EME1)
          << " EB2 = " << cluster->eSample(CaloSampling::EMB2)
          << " etaB2 = " << cluster->etaSample(CaloSampling::EMB2)
          << " EE2 = " << cluster->eSample(CaloSampling::EME2)
          << " etaE2 = " << cluster->etaSample(CaloSampling::EME2));
    if (cluster->inBarrel() && !cluster->inEndcap())
      eta = cluster->etaSample(CaloSampling::EMB2);
    else if (cluster->inEndcap() && !cluster->inBarrel())
      eta = cluster->etaSample(CaloSampling::EME2);
    else {
      if (cluster->eSample(CaloSampling::EMB2) >
      cluster->eSample(CaloSampling::EME2))
    eta = cluster->etaSample(CaloSampling::EMB2);
      else
    eta = cluster->etaSample(CaloSampling::EME2);
    }
  }
 
  cluster->setEta(eta);
  cluster->setPhi(cluster->phiBE(2));
 
  if (m_update_energy (myctx))
    cluster->setE(energy);
}