MuonTrackParticleThinning.cxx

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/*
  Copyright (C) 2002-2022 CERN for the benefit of the ATLAS collaboration
*/

// MuonTrackParticleThinning.cxx, (c) ATLAS Detector software
// Author: James Catmore (James.Catmore@cern.ch)
// This is a trivial example of an implementation of a thinning tool
// which removes all ID tracks which do not pass a user-defined cut
 
#include "DerivationFrameworkInDet/MuonTrackParticleThinning.h"
#include "ExpressionEvaluation/SGxAODProxyLoader.h"
#include "ExpressionEvaluation/SGNTUPProxyLoader.h"
#include "ExpressionEvaluation/MultipleProxyLoader.h"
#include "StoreGate/ThinningHandle.h"
#include "GaudiKernel/ThreadLocalContext.h"
#include <vector>
#include <string>
 
// Constructor
DerivationFramework::MuonTrackParticleThinning::MuonTrackParticleThinning(const std::string& t,
                                                                          const std::string& n,
                                                                          const IInterface* p ) :
base_class(t,n,p)
{
}
 
// Destructor
DerivationFramework::MuonTrackParticleThinning::~MuonTrackParticleThinning() = default;
 
// Athena initialize and finalize
StatusCode DerivationFramework::MuonTrackParticleThinning::initialize()
{
    // Decide which collections need to be checked for ID TrackParticles
    ATH_MSG_VERBOSE("initialize() ...");
    ATH_CHECK( m_inDetSGKey.initialize (m_streamName) );
    ATH_MSG_INFO("Using " << m_inDetSGKey.key() << "as the source collection for inner detector track particles");
    if (m_muonKey.key().empty()) {
        ATH_MSG_FATAL("No muon collection provided for thinning.");
        return StatusCode::FAILURE;
    } else { ATH_MSG_INFO("Inner detector track particles associated with objects in " << m_muonKey.key() << " will be retained in this format with the rest being thinned away");}
    ATH_CHECK(m_muonKey.initialize());
    // Set up the text-parsing machinery for selectiong the muon directly according to user cuts
    if (!m_selectionString.empty()) {
       ATH_CHECK(initializeParser(m_selectionString) );
    }
    return StatusCode::SUCCESS;
}
 
StatusCode DerivationFramework::MuonTrackParticleThinning::finalize()
{
    ATH_MSG_VERBOSE("finalize() ...");
    ATH_MSG_INFO("Processed "<< m_ntot <<" tracks, "<< m_npass<< " were retained ");
    ATH_CHECK( finalizeParser() );
    return StatusCode::SUCCESS;
}
 
// The thinning itself
StatusCode DerivationFramework::MuonTrackParticleThinning::doThinning() const
{
    const EventContext& ctx = Gaudi::Hive::currentContext();
 
    // Retrieve main TrackParticle collection
    SG::ThinningHandle<xAOD::TrackParticleContainer> importedTrackParticles
      (m_inDetSGKey, ctx);
    
    // Check the event contains tracks
    unsigned int nTracks = importedTrackParticles->size();
    if (nTracks==0) return StatusCode::SUCCESS;
    
    // Set up a mask with the same entries as the full TrackParticle collection
    std::vector<bool> mask;
    mask.assign(nTracks,false); // default: don't keep any tracks
    m_ntot += nTracks;
    
    // Retrieve containers
    // ... muons
    SG::ReadHandle<xAOD::MuonContainer> importedMuons( m_muonKey, ctx);
    if (!importedMuons.isValid()) {
        ATH_MSG_ERROR("No muon collection with name " << m_muonKey.key() << " found in StoreGate!");
        return StatusCode::FAILURE;
    }
    unsigned int nMuons(importedMuons->size());
    std::vector<const xAOD::Muon*> muToCheck; muToCheck.clear();
    // Execute the text parser if requested
    if (m_selectionString!="") {
        std::vector<int> entries =  m_parser->evaluateAsVector();
        unsigned int nEntries = entries.size();
        // check the sizes are compatible
        if (nMuons != nEntries ) {
            ATH_MSG_ERROR("Sizes incompatible! Are you sure your selection string used muons??");
            return StatusCode::FAILURE;
        } else {
            // identify which muons to keep for the thinning check
            for (unsigned int i=0; i<nMuons; ++i) if (entries[i]==1) muToCheck.push_back((*importedMuons)[i]);
        }
    }
 
    DerivationFramework::TracksInCone tInC;    
    if (m_selectionString=="") { // check all muons as user didn't provide a selection string
        for (const auto *muIt : *importedMuons) {
          if (muIt->inDetTrackParticleLink().isValid()) {
        //This line prevents SiliconAssociatedForwardMuon from being used unless we're skimming InDetForwardTrackParticles
        //since their track links point to this container while all others point to InDetTrackParticles
        if (muIt->muonType()==xAOD::Muon::SiliconAssociatedForwardMuon &&  m_inDetSGKey.key() != "InDetForwardTrackParticles")
          {
            ATH_MSG_DEBUG("Skipping Forward Muon since we are not skimming InDetForwardParticles");
          }
        else{
          ATH_MSG_DEBUG("Simming Muon tracks in " << m_inDetSGKey << " "<< muIt->muonType());
          int index = muIt->inDetTrackParticleLink().index();
          mask[index] = true;
        }
          }
            if (m_coneSize>0.0) tInC.select(muIt,m_coneSize,importedTrackParticles.cptr(),mask); // check tracks in a cone around the muon if req'd
          }
    } else { // check only muons passing user selection string
        for (auto & muIt : muToCheck) {
        if (muIt->inDetTrackParticleLink().isValid()) {
          
          if (muIt->muonType()==xAOD::Muon::SiliconAssociatedForwardMuon &&  m_inDetSGKey.key() != "InDetForwardTrackParticles")
        {
          ATH_MSG_DEBUG("Skipping Forward Muon since we are not skimming InDetForwardParticles");
        }
          else{
        ATH_MSG_DEBUG("Simming Muon tracks in " << m_inDetSGKey << " "<< muIt->muonType());
        int index = muIt->inDetTrackParticleLink().index();
        mask[index] = true;
          }
        }   
        if (m_coneSize>0.0) tInC.select(muIt,m_coneSize,importedTrackParticles.cptr(),mask); // check tracks in a cone around the muon if req'd   
        }
    }
 
    // Count up the mask contents
    unsigned int n_pass=0;
    for (unsigned int i=0; i<nTracks; ++i) {
        if (mask[i]) ++n_pass;
    }
    m_npass+=n_pass;
    // Execute the thinning service based on the mask. Finish.
    importedTrackParticles.keep (mask);
 
    return StatusCode::SUCCESS;
}