SimHitMatcher.cc

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#include "Validation/MuonGEMHits/interface/SimHitMatcher.h"
#include "FWCore/Framework/interface/ESHandle.h"
#include "DataFormats/MuonDetId/interface/GEMDetId.h"
#include "DataFormats/MuonDetId/interface/MuonSubdetId.h"
#include "Geometry/Records/interface/MuonGeometryRecord.h"
#include "Geometry/GEMGeometry/interface/GEMGeometry.h"
#include <algorithm>
#include <iomanip>
#include "FWCore/MessageLogger/interface/MessageLogger.h"

using namespace std;

namespace {

bool is_gem(unsigned int detid)
{
  DetId id(detid);
  if (id.subdetId() == MuonSubdetId::GEM) return true;
  return false;
}

}


SimHitMatcher::SimHitMatcher(const SimTrack& track, const edm::Event& e,  const GEMGeometry& geom, const edm::ParameterSet& cfg, edm::EDGetToken& simhitToken, edm::EDGetToken& simtrackToken, edm::EDGetToken& simvertexToken ):track_(track),gem_geo_(geom)
{
  simMuOnlyGEM_ = cfg.getUntrackedParameter<bool>("simMuOnlyGEM", true);
  discardEleHitsGEM_ = cfg.getUntrackedParameter<bool>("discardEleHitsGEM", true);
  simInputLabel_ = cfg.getUntrackedParameter<std::string>("simInputLabel");
  verbose_ = false;
  
  e.getByToken(simtrackToken, sim_tracks);
  e.getByToken(simvertexToken, sim_vertices);
  e.getByToken(simhitToken, gem_hits);
  init(e);
}


SimHitMatcher::~SimHitMatcher() {}


void SimHitMatcher::init(const edm::Event& e)
{


  // fill trkId2Index associoation:
  int no = 0;
  trkid_to_index_.clear();
  for (auto& t: *sim_tracks.product())
  {
    trkid_to_index_[t.trackId()] = no;
    no++;
  }
  vector<unsigned> track_ids = getIdsOfSimTrackShower(track_.trackId(), *sim_tracks.product(), *sim_vertices.product());

  matchSimHitsToSimTrack(track_ids, *gem_hits.product());

  if (verbose_)
  {
    auto gem_det_ids = detIdsGEM();
    for (auto id: gem_det_ids)
    {
      auto gem_simhits = hitsInDetId(id);
      auto gem_simhits_gp = simHitsMeanPosition(gem_simhits);
      auto strips = hitStripsInDetId(id);
      cout<<"detid "<<GEMDetId(id)<<": "<<gem_simhits.size()<<" "<<gem_simhits_gp.phi()<<" "<< gem_detid_to_hits_[id].size()<<endl;
      cout<<"nstrp "<<strips.size()<<endl;
      cout<<"strps : "; std::copy(strips.begin(), strips.end(), ostream_iterator<int>(cout, " ")); cout<<endl;
    }
    auto gem_ch_ids = chamberIdsGEM();
    for (auto id: gem_ch_ids)
    {
      auto& gem_simhits = hitsInChamber(id);
      auto gem_simhits_gp = simHitsMeanPosition(gem_simhits);
      cout<<"cchid "<<GEMDetId(id)<<": "<<gem_simhits.size()<<" "<<gem_simhits_gp.phi()<<" "<< gem_chamber_to_hits_[id].size()<<endl;
    }
    auto gem_sch_ids = superChamberIdsGEM();
    for (auto id: gem_sch_ids)
    {
      auto& gem_simhits = hitsInSuperChamber(id);
      auto gem_simhits_gp = simHitsMeanPosition(gem_simhits);
      cout<<"schid "<<GEMDetId(id)<<": "<<nCoincidencePadsWithHits() <<" | "<<gem_simhits.size()<<" "<<gem_simhits_gp.phi()<<" "<< gem_superchamber_to_hits_[id].size()<<endl;
    }
  }
}


std::vector<unsigned int>
SimHitMatcher::getIdsOfSimTrackShower(unsigned int initial_trk_id,
    const edm::SimTrackContainer & sim_tracks, const edm::SimVertexContainer & sim_vertices)
{
  vector<unsigned int> result;
  result.push_back(initial_trk_id);

  if (! (simMuOnlyGEM_ ) ) return result;
  for (auto& t: sim_tracks)
  {
    SimTrack last_trk = t;
    bool is_child = false;
    while (true)
    {
      if ( last_trk.noVertex() ) break;
      if ( sim_vertices[last_trk.vertIndex()].noParent() ) break;
      
      unsigned parentId = sim_vertices[last_trk.vertIndex()].parentIndex();
      if ( parentId == initial_trk_id )
      {
        is_child = true;
        break;
      }
      
      auto association = trkid_to_index_.find( parentId );
      if ( association == trkid_to_index_.end() ) break;

      last_trk = sim_tracks[ association->second ];
    }
    if (is_child)
    {
      result.push_back(t.trackId());
    }
  }
  return result;
}


void
SimHitMatcher::matchSimHitsToSimTrack(std::vector<unsigned int> track_ids,
    const edm::PSimHitContainer& gem_hits)
{
  for (auto& track_id: track_ids)
  {
    for (auto& h: gem_hits)
    {
      if (h.trackId() != track_id) continue;
      int pdgid = h.particleType();
      if (simMuOnlyGEM_ && std::abs(pdgid) != 13) continue;
      if (discardEleHitsGEM_ && std::abs(pdgid) == 11) continue;

      gem_detid_to_hits_[ h.detUnitId() ].push_back(h);
      gem_hits_.push_back(h);
      GEMDetId p_id( h.detUnitId() );
      gem_chamber_to_hits_[ p_id.chamberId().rawId() ].push_back(h);
      GEMDetId superch_id(p_id.region(), p_id.ring(), p_id.station(), 1, p_id.chamber(), 0);
      gem_superchamber_to_hits_[ superch_id() ].push_back(h);
    }
  }

  // find pads with hits
  auto detids = detIdsGEM();
  // find 2-layer coincidence pads with hits
  for (auto d: detids)
  {
    GEMDetId id(d);
    auto hits = hitsInDetId(d);
    auto roll = gem_geo_.etaPartition(id);
    //int max_npads = roll->npads();
    set<int> pads;
    for (auto& h: hits)
    {
      LocalPoint lp = h.entryPoint();
      pads.insert( 1 + static_cast<int>(roll->padTopology().channel(lp)) );
    }
    gem_detids_to_pads_[d] = pads;
  }

  // find 2-layer coincidence pads with hits
  for (auto d: detids)
  {
    GEMDetId id1(d);
    if (id1.layer() != 1) continue;
    GEMDetId id2(id1.region(), id1.ring(), id1.station(), 2, id1.chamber(), id1.roll());
    // does layer 2 has simhits?
    if (detids.find(id2()) == detids.end()) continue;

    // find pads with hits in layer1
    auto hits1 = hitsInDetId(d);
    auto roll1 = gem_geo_.etaPartition(id1);
    set<int> pads1;
    for (auto& h: hits1)
    {
      LocalPoint lp = h.entryPoint();
      pads1.insert( 1 + static_cast<int>(roll1->padTopology().channel(lp)) );
    }

    // find pads with hits in layer2
    auto hits2 = hitsInDetId(id2());
    auto roll2 = gem_geo_.etaPartition(id2);
    set<int> pads2;
    for (auto& h: hits2)
    {
      LocalPoint lp = h.entryPoint();
      pads2.insert( 1 + static_cast<int>(roll2->padTopology().channel(lp)) );
    }

    set<int> copads;
    std::set_intersection(pads1.begin(), pads1.end(), pads2.begin(), pads2.end(), std::inserter(copads, copads.begin()));
    if (copads.empty()) continue;
    gem_detids_to_copads_[d] = copads;
  }
}


std::set<unsigned int> SimHitMatcher::detIdsGEM() const
{
  std::set<unsigned int> result;
  for (auto& p: gem_detid_to_hits_) result.insert(p.first);
  return result;
}


std::set<unsigned int> SimHitMatcher::detIdsGEMCoincidences() const
{
  std::set<unsigned int> result;
  for (auto& p: gem_detids_to_copads_) result.insert(p.first);
  return result;
}


std::set<unsigned int> SimHitMatcher::chamberIdsGEM() const
{
  std::set<unsigned int> result;
  for (auto& p: gem_chamber_to_hits_) result.insert(p.first);
  return result;
}


std::set<unsigned int>
SimHitMatcher::superChamberIdsGEM() const
{
  std::set<unsigned int> result;
  for (auto& p: gem_superchamber_to_hits_) result.insert(p.first);
  return result;
}


std::set<unsigned int>
SimHitMatcher::superChamberIdsGEMCoincidences() const
{
  std::set<unsigned int> result;
  for (auto& p: gem_detids_to_copads_)
  {
    GEMDetId id(p.first);
    result.insert(id.chamberId().rawId());
  }
  return result;
}


const edm::PSimHitContainer&
SimHitMatcher::hitsInDetId(unsigned int detid) const
{
  if (is_gem(detid))
  {
    if (gem_detid_to_hits_.find(detid) == gem_detid_to_hits_.end()) return no_hits_;
    return gem_detid_to_hits_.at(detid);
  }
  return no_hits_;
}


const edm::PSimHitContainer&
SimHitMatcher::hitsInChamber(unsigned int detid) const
{
  if (is_gem(detid)) // make sure we use chamber id
  {
    GEMDetId id(detid);
    if (gem_chamber_to_hits_.find(id.chamberId().rawId()) == gem_chamber_to_hits_.end()) return no_hits_;
    return gem_chamber_to_hits_.at(id.chamberId().rawId());
  }
  return no_hits_;
}


const edm::PSimHitContainer&
SimHitMatcher::hitsInSuperChamber(unsigned int detid) const
{
  if (is_gem(detid))
  {
    GEMDetId id(detid);
    if (gem_superchamber_to_hits_.find(id.chamberId().rawId()) == gem_superchamber_to_hits_.end()) return no_hits_;
    return gem_superchamber_to_hits_.at(id.chamberId().rawId());
  }
  return no_hits_;
}


int
SimHitMatcher::nLayersWithHitsInSuperChamber(unsigned int detid) const
{
  set<int> layers_with_hits;
  auto hits = hitsInSuperChamber(detid);
  for (auto& h: hits)
  {
    if (is_gem(detid))
    {
      GEMDetId idd(h.detUnitId());
      layers_with_hits.insert(idd.layer());
    }
  }
  return layers_with_hits.size();
}


GlobalPoint
SimHitMatcher::simHitsMeanPosition(const edm::PSimHitContainer& sim_hits) const
{
  if (sim_hits.empty()) return GlobalPoint(); // point "zero"

  float sumx, sumy, sumz;
  sumx = sumy = sumz = 0.f;
  size_t n = 0;
  for (auto& h: sim_hits)
  {
    LocalPoint lp = h.entryPoint();
    GlobalPoint gp;
    if ( is_gem(h.detUnitId()) )
    {
      gp = gem_geo_.idToDet(h.detUnitId())->surface().toGlobal(lp);
    }
    else continue;
    sumx += gp.x();
    sumy += gp.y();
    sumz += gp.z();
    ++n;
  }
  if (n == 0) return GlobalPoint();
  return GlobalPoint(sumx/n, sumy/n, sumz/n);
}


float SimHitMatcher::simHitsMeanStrip(const edm::PSimHitContainer& sim_hits) const
{
  if (sim_hits.empty()) return -1.f;

  float sums = 0.f;
  size_t n = 0;
  for (auto& h: sim_hits)
  {
    LocalPoint lp = h.entryPoint();
    float s;
    auto d = h.detUnitId();
    if ( is_gem(d) )
    {
      s = gem_geo_.etaPartition(d)->strip(lp);
    }
    else continue;
    sums += s;
    ++n;
  }
  if (n == 0) return -1.f;
  return sums/n;
}


std::set<int> SimHitMatcher::hitStripsInDetId(unsigned int detid, int margin_n_strips) const
{
  set<int> result;
  auto simhits = hitsInDetId(detid);
  if ( is_gem(detid) )
  {
    GEMDetId id(detid);
    int max_nstrips = gem_geo_.etaPartition(id)->nstrips();
    for (auto& h: simhits)
    {
      LocalPoint lp = h.entryPoint();
      int central_strip = 1 + static_cast<int>(gem_geo_.etaPartition(id)->topology().channel(lp));
      int smin = central_strip - margin_n_strips;
      smin = (smin > 0) ? smin : 1;
      int smax = central_strip + margin_n_strips;
      smax = (smax <= max_nstrips) ? smax : max_nstrips;
      for (int ss = smin; ss <= smax; ++ss) result.insert(ss);
    }
  }
  return result;
}

std::set<int> SimHitMatcher::hitPadsInDetId(unsigned int detid) const
{
  set<int> none;
  if (gem_detids_to_pads_.find(detid) == gem_detids_to_pads_.end()) return none;
  return gem_detids_to_pads_.at(detid);
}

std::set<int>
SimHitMatcher::hitCoPadsInDetId(unsigned int detid) const
{
  set<int> none;
  if (gem_detids_to_copads_.find(detid) == gem_detids_to_copads_.end()) return none;
  return gem_detids_to_copads_.at(detid);
}


std::set<int> SimHitMatcher::hitPartitions() const
{
  std::set<int> result;

  auto detids = detIdsGEM();
  for (auto id: detids)
  {
    GEMDetId idd(id);
    result.insert( idd.roll() );
  }
  return result;
}


int
SimHitMatcher::nPadsWithHits() const
{
  int result = 0;
  auto pad_ids = detIdsGEM();
  for (auto id: pad_ids)
  {
    result += hitPadsInDetId(id).size();
  }
  return result;
}

int
SimHitMatcher::nCoincidencePadsWithHits() const
{
  int result = 0;
  auto copad_ids = detIdsGEMCoincidences();
  for (auto id: copad_ids)
  {
    result += hitCoPadsInDetId(id).size();
  }
  return result;
}