BasicGenParticleValidation.cc

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/*class BasicGenParticleValidation
 *  
 *  Class to fill dqm monitor elements from existing EDM file
 *
 */

#include "Validation/EventGenerator/interface/BasicGenParticleValidation.h"

#include "CLHEP/Units/defs.h"
#include "CLHEP/Units/PhysicalConstants.h"
#include "Validation/EventGenerator/interface/DQMHelper.h"

using namespace edm;

BasicGenParticleValidation::BasicGenParticleValidation(const edm::ParameterSet& iPSet)
    : wmanager_(iPSet, consumesCollector()),
      hepmcCollection_(iPSet.getParameter<edm::InputTag>("hepmcCollection")),
      genparticleCollection_(iPSet.getParameter<edm::InputTag>("genparticleCollection")),
      genjetCollection_(iPSet.getParameter<edm::InputTag>("genjetsCollection")),
      matchPr_(iPSet.getParameter<double>("matchingPrecision")),
      verbosity_(iPSet.getUntrackedParameter<unsigned int>("verbosity", 0)) {
  hepmcCollectionToken_ = consumes<HepMCProduct>(hepmcCollection_);
  genparticleCollectionToken_ = consumes<reco::GenParticleCollection>(genparticleCollection_);
  genjetCollectionToken_ = consumes<reco::GenJetCollection>(genjetCollection_);
}

BasicGenParticleValidation::~BasicGenParticleValidation() {}

void BasicGenParticleValidation::bookHistograms(DQMStore::IBooker& i, edm::Run const&, edm::EventSetup const&) {
  DQMHelper dqm(&i);
  i.setCurrentFolder("Generator/GenParticles");

  // Number of analyzed events
  nEvt = dqm.book1dHisto("nEvt", "n analyzed Events", 1, 0., 1., "", "Number of Events");

  genPMultiplicity = dqm.book1dHisto("genPMultiplicty",
                                     "Log(No. all GenParticles)",
                                     50,
                                     -1,
                                     5,
                                     "log_{10}(N_{All GenParticles})",
                                     "Number of Events");  //Log
  //difference in HepMC and reco multiplicity
  genMatched = dqm.book1dHisto(
      "genMatched", "Difference reco - matched", 50, -25, 25, "N_{All GenParticles}-N_{Matched}", "Number of Events");
  //multiple matching
  multipleMatching = dqm.book1dHisto("multipleMatching",
                                     "multiple reco HepMC matching",
                                     50,
                                     0,
                                     50,
                                     "N_{multiple reco HepMC matching}",
                                     "Number of Events");
  //momentum difference of matched particles
  matchedResolution = dqm.book1dHisto("matchedResolution",
                                      "log10(momentum difference of matched particles)",
                                      70,
                                      -10.,
                                      -3.,
                                      "log_{10}(#DeltaP_{matched Particles})",
                                      "Number of Events");

  // GenJet general distributions
  genJetMult = dqm.book1dHisto("genJetMult", "GenJet multiplicity", 50, 0, 50, "N_{gen-jets}", "Number of Events");
  genJetEnergy = dqm.book1dHisto(
      "genJetEnergy", "Log10(GenJet energy)", 60, -1, 5, "log_{10}(E^{gen-jets}) (log_{10}(GeV))", "Number of Events");
  genJetPt = dqm.book1dHisto(
      "genJetPt", "Log10(GenJet pt)", 60, -1, 5, "log_{10}(P_{t}^{gen-jets}) (log_{10}(GeV))", "Number of Events");
  genJetEta = dqm.book1dHisto("genJetEta", "GenJet eta", 220, -11, 11, "#eta^{gen-jets}", "Number of Events");
  genJetPhi = dqm.book1dHisto("genJetPhi", "GenJet phi", 360, -180, 180, "#phi^{gen-jets} (rad)", "Number of Events");
  genJetDeltaEtaMin = dqm.book1dHisto(
      "genJetDeltaEtaMin", "GenJet minimum rapidity gap", 30, 0, 30, "#delta#eta_{min}^{gen-jets}", "Number of Events");

  genJetPto1 = dqm.book1dHisto(
      "genJetPto1", "GenJet multiplicity above 1 GeV", 50, 0, 50, "N_{gen-jets P_{t}>1GeV}", "Number of Events");
  genJetPto10 = dqm.book1dHisto(
      "genJetPto10", "GenJet multiplicity above 10 GeV", 50, 0, 50, "N_{gen-jets P_{t}>10GeV}", "Number of Events");
  genJetPto100 = dqm.book1dHisto(
      "genJetPto100", "GenJet multiplicity above 100 GeV", 50, 0, 50, "N_{gen-jets P_{t}>100GeV}", "Number of Events");
  genJetCentral = dqm.book1dHisto(
      "genJetCentral", "GenJet multiplicity |eta|.lt.2.5", 50, 0, 50, "N_{gen-jets |#eta|#leq2.5}", "Number of Events");

  genJetTotPt = dqm.book1dHisto("genJetTotPt",
                                "Log10(GenJet total pt)",
                                100,
                                -5,
                                5,
                                "log_{10}(#SigmaP_{t}^{gen-jets}) (log_{10}(GeV))",
                                "Number of Events");

  return;
}

void BasicGenParticleValidation::analyze(const edm::Event& iEvent, const edm::EventSetup& iSetup) {
  unsigned int initSize = 1000;

  edm::Handle<HepMCProduct> evt;
  iEvent.getByToken(hepmcCollectionToken_, evt);

  //Get HepMC EVENT
  HepMC::GenEvent* myGenEvent = new HepMC::GenEvent(*(evt->GetEvent()));

  double weight = wmanager_.weight(iEvent);

  nEvt->Fill(0.5, weight);

  std::vector<const HepMC::GenParticle*> hepmcGPCollection;
  std::vector<int> barcodeList;
  hepmcGPCollection.reserve(initSize);
  barcodeList.reserve(initSize);

  //Looping through HepMC::GenParticle collection to search for status 1 particles
  for (HepMC::GenEvent::particle_const_iterator iter = myGenEvent->particles_begin();
       iter != myGenEvent->particles_end();
       ++iter) {
    if ((*iter)->status() == 1) {
      hepmcGPCollection.push_back(*iter);
      barcodeList.push_back((*iter)->barcode());
      if (verbosity_ > 0) {
        std::cout << "HepMC " << std::setw(14) << std::fixed << (*iter)->pdg_id() << std::setw(14) << std::fixed
                  << (*iter)->momentum().px() << std::setw(14) << std::fixed << (*iter)->momentum().py()
                  << std::setw(14) << std::fixed << (*iter)->momentum().pz() << std::endl;
      }
    }
  }

  // Gather information on the reco::GenParticle collection
  edm::Handle<reco::GenParticleCollection> genParticles;
  iEvent.getByToken(genparticleCollectionToken_, genParticles);

  std::vector<const reco::GenParticle*> particles;
  particles.reserve(initSize);
  for (reco::GenParticleCollection::const_iterator iter = genParticles->begin(); iter != genParticles->end(); ++iter) {
    if ((*iter).status() == 1) {
      particles.push_back(&*iter);
      if (verbosity_ > 0) {
        std::cout << "reco  " << std::setw(14) << std::fixed << (*iter).pdgId() << std::setw(14) << std::fixed
                  << (*iter).px() << std::setw(14) << std::fixed << (*iter).py() << std::setw(14) << std::fixed
                  << (*iter).pz() << std::endl;
      }
    }
  }

  unsigned int nReco = particles.size();
  unsigned int nHepMC = hepmcGPCollection.size();

  genPMultiplicity->Fill(std::log10(nReco), weight);

  // Define vector containing index of hepmc corresponding to the reco::GenParticle
  std::vector<int> hepmcMatchIndex;
  hepmcMatchIndex.reserve(initSize);

  // Matching procedure

  // Check array size consistency

  if (nReco != nHepMC) {
    edm::LogWarning("CollectionSizeInconsistency")
        << "Collection size inconsistency: HepMC::GenParticle = " << nHepMC << " reco::GenParticle = " << nReco;
  }

  // Match each HepMC with a reco

  for (unsigned int i = 0; i < nReco; ++i) {
    for (unsigned int j = 0; j < nHepMC; ++j) {
      if (matchParticles(hepmcGPCollection[j], particles[i])) {
        hepmcMatchIndex.push_back((int)j);
        if (hepmcGPCollection[j]->momentum().rho() != 0.) {
          double reso = 1. - particles[i]->p() / hepmcGPCollection[j]->momentum().rho();
          if (verbosity_ > 0) {
            std::cout << "Matching momentum: reco = " << particles[i]->p()
                      << " HepMC = " << hepmcGPCollection[j]->momentum().rho() << " resoultion = " << reso << std::endl;
          }
          matchedResolution->Fill(std::log10(std::fabs(reso)), weight);
        }
        continue;
      }
    }
  }

  // Check unicity of matching

  unsigned int nMatched = hepmcMatchIndex.size();

  if (nMatched != nReco) {
    edm::LogWarning("IncorrectMatching") << "Incorrect number of matched indexes: GenParticle = " << nReco
                                         << " matched indexes = " << nMatched;
  }
  genMatched->Fill(int(nReco - nMatched), weight);

  unsigned int nWrMatch = 0;

  for (unsigned int i = 0; i < nMatched; ++i) {
    for (unsigned int j = i + 1; j < nMatched; ++j) {
      if (hepmcMatchIndex[i] == hepmcMatchIndex[j]) {
        int theIndex = hepmcMatchIndex[i];
        edm::LogWarning("DuplicatedMatching")
            << "Multiple matching occurencies for GenParticle barcode = " << barcodeList[theIndex];
        nWrMatch++;
      }
    }
  }
  multipleMatching->Fill(int(nWrMatch), weight);

  // Gather information in the GenJet collection
  edm::Handle<reco::GenJetCollection> genJets;
  iEvent.getByToken(genjetCollectionToken_, genJets);

  int nJets = 0;
  int nJetso1 = 0;
  int nJetso10 = 0;
  int nJetso100 = 0;
  int nJetsCentral = 0;
  double totPt = 0.;

  std::vector<double> jetEta;
  jetEta.reserve(initSize);

  for (reco::GenJetCollection::const_iterator iter = genJets->begin(); iter != genJets->end(); ++iter) {
    nJets++;
    double pt = (*iter).pt();
    totPt += pt;
    if (pt > 1.)
      nJetso1++;
    if (pt > 10.)
      nJetso10++;
    if (pt > 100.)
      nJetso100++;
    double eta = (*iter).eta();
    if (std::fabs(eta) < 2.5)
      nJetsCentral++;
    jetEta.push_back(eta);

    genJetEnergy->Fill(std::log10((*iter).energy()), weight);
    genJetPt->Fill(std::log10(pt), weight);
    genJetEta->Fill(eta, weight);
    genJetPhi->Fill((*iter).phi() / CLHEP::degree, weight);
  }

  genJetMult->Fill(nJets, weight);
  genJetPto1->Fill(nJetso1, weight);
  genJetPto10->Fill(nJetso10, weight);
  genJetPto100->Fill(nJetso100, weight);
  genJetCentral->Fill(nJetsCentral, weight);

  genJetTotPt->Fill(std::log10(totPt), weight);

  double deltaEta = 999.;
  if (jetEta.size() > 1) {
    for (unsigned int i = 0; i < jetEta.size(); i++) {
      for (unsigned int j = i + 1; j < jetEta.size(); j++) {
        deltaEta = std::min(deltaEta, std::fabs(jetEta[i] - jetEta[j]));
      }
    }
  }

  genJetDeltaEtaMin->Fill(deltaEta, weight);

  delete myGenEvent;
}  //analyze

bool BasicGenParticleValidation::matchParticles(const HepMC::GenParticle*& hepmcP, const reco::GenParticle*& recoP) {
  bool state = false;

  if (hepmcP->pdg_id() != recoP->pdgId())
    return state;
  if (std::fabs(hepmcP->momentum().px() - recoP->px()) < std::fabs(matchPr_ * hepmcP->momentum().px()) &&
      std::fabs(hepmcP->momentum().py() - recoP->py()) < std::fabs(matchPr_ * hepmcP->momentum().py()) &&
      std::fabs(hepmcP->momentum().pz() - recoP->pz()) < std::fabs(matchPr_ * hepmcP->momentum().pz())) {
    state = true;
  }

  return state;
}