RecoTau/plugins/RecoTauPiZeroStripPlugin3.cc

0001 /*
0002  * RecoTauPiZeroStripPlugin3
0003  *
0004  * Merges PFGammas in a PFJet into Candidate piZeros defined as
0005  * strips in eta-phi.
0006  *
0007  * Author: Michail Bachtis (University of Wisconsin)
0008  *
0009  * Code modifications: Evan Friis (UC Davis),
0010  *                     Christian Veelken (LLR)
0011  *
0012  */
0013
0014 #include <algorithm>
0015 #include <functional>
0016 #include <memory>
0017
0018 #include "RecoTauTag/RecoTau/interface/RecoTauPiZeroPlugins.h"
0019
0020 #include "DataFormats/ParticleFlowCandidate/interface/PFCandidateFwd.h"
0021 #include "DataFormats/ParticleFlowCandidate/interface/PFCandidate.h"
0022 #include "DataFormats/VertexReco/interface/Vertex.h"
0023 #include "DataFormats/VertexReco/interface/VertexFwd.h"
0024 #include "DataFormats/TauReco/interface/RecoTauPiZero.h"
0025 #include "DataFormats/JetReco/interface/PFJet.h"
0026 #include "CommonTools/CandUtils/interface/AddFourMomenta.h"
0027 #include "DataFormats/Math/interface/deltaPhi.h"
0028 #include "FWCore/MessageLogger/interface/MessageLogger.h"
0029
0030 #include "RecoTauTag/RecoTau/interface/RecoTauCommonUtilities.h"
0031 #include "RecoTauTag/RecoTau/interface/RecoTauQualityCuts.h"
0032 #include "RecoTauTag/RecoTau/interface/RecoTauVertexAssociator.h"
0033 #include "RecoTauTag/RecoTau/interface/CombinatoricGenerator.h"
0034
0035 //-------------------------------------------------------------------------------
0036 // CV: the following headers are needed only for debug print-out
0037 #include "DataFormats/GsfTrackReco/interface/GsfTrack.h"
0038 #include "DataFormats/TrackReco/interface/Track.h"
0039 //-------------------------------------------------------------------------------
0040
0041 #include "TString.h"
0042 #include "TFormula.h"
0043
0044 namespace reco {
0045   namespace tau {
0046
0047     namespace {
0048       // Apply a hypothesis on the mass of the strips.
0049       math::XYZTLorentzVector applyMassConstraint(const math::XYZTLorentzVector& vec, double mass) {
0050         double factor = sqrt(vec.energy() * vec.energy() - mass * mass) / vec.P();
0051         return math::XYZTLorentzVector(vec.px() * factor, vec.py() * factor, vec.pz() * factor, vec.energy());
0052       }
0053     }  // namespace
0054
0055     class RecoTauPiZeroStripPlugin3 : public RecoTauPiZeroBuilderPlugin {
0056     public:
0057       explicit RecoTauPiZeroStripPlugin3(const edm::ParameterSet&, edm::ConsumesCollector&& iC);
0058       ~RecoTauPiZeroStripPlugin3() override;
0059       // Return type is unique_ptr<PiZeroVector>
0060       return_type operator()(const reco::Jet&) const override;
0061       // Hook to update PV information
0062       void beginEvent() override;
0063
0064     private:
0065       typedef std::vector<reco::CandidatePtr> CandPtrs;
0066       void addCandsToStrip(RecoTauPiZero&, CandPtrs&, const std::vector<bool>&, std::set<size_t>&, bool&) const;
0067
0068       RecoTauVertexAssociator vertexAssociator_;
0069
0070       std::unique_ptr<RecoTauQualityCuts> qcuts_;
0071       bool applyElecTrackQcuts_;
0072       double minGammaEtStripSeed_;
0073       double minGammaEtStripAdd_;
0074
0075       double minStripEt_;
0076
0077       std::vector<int> inputParticleIds_;                       // type of candidates to clusterize
0078       std::unique_ptr<const TFormula> etaAssociationDistance_;  // size of strip clustering window in eta direction
0079       std::unique_ptr<const TFormula> phiAssociationDistance_;  // size of strip clustering window in phi direction
0080
0081       bool updateStripAfterEachDaughter_;
0082       int maxStripBuildIterations_;
0083
0084       // Parameters for build strip combinations
0085       bool combineStrips_;
0086       int maxStrips_;
0087       double combinatoricStripMassHypo_;
0088
0089       AddFourMomenta p4Builder_;
0090
0091       int verbosity_;
0092     };
0093
0094     namespace {
0095       std::unique_ptr<TFormula> makeFunction(const std::string& functionName, const edm::ParameterSet& pset) {
0096         TString formula = pset.getParameter<std::string>("function");
0097         formula = formula.ReplaceAll("pT", "x");
0098         auto function = std::make_unique<TFormula>(functionName.data(), formula.Data());
0099         int numParameter = function->GetNpar();
0100         for (int idxParameter = 0; idxParameter < numParameter; ++idxParameter) {
0101           std::string parameterName = Form("par%i", idxParameter);
0102           double parameter = pset.getParameter<double>(parameterName);
0103           function->SetParameter(idxParameter, parameter);
0104         }
0105         return function;
0106       }
0107     }  // namespace
0108
0109     RecoTauPiZeroStripPlugin3::RecoTauPiZeroStripPlugin3(const edm::ParameterSet& pset, edm::ConsumesCollector&& iC)
0110         : RecoTauPiZeroBuilderPlugin(pset, std::move(iC)),
0111           vertexAssociator_(pset.getParameter<edm::ParameterSet>("qualityCuts"), std::move(iC)),
0112           qcuts_(nullptr),
0113           etaAssociationDistance_(nullptr),
0114           phiAssociationDistance_(nullptr) {
0115       minGammaEtStripSeed_ = pset.getParameter<double>("minGammaEtStripSeed");
0116       minGammaEtStripAdd_ = pset.getParameter<double>("minGammaEtStripAdd");
0117
0118       minStripEt_ = pset.getParameter<double>("minStripEt");
0119
0120       edm::ParameterSet qcuts_pset = pset.getParameterSet("qualityCuts").getParameterSet("signalQualityCuts");
0121       //-------------------------------------------------------------------------------
0122       // CV: disable track quality cuts for PFElectronsPFElectron
0123       //       (treat PFElectrons like PFGammas for the purpose of building eta-phi strips)
0124       applyElecTrackQcuts_ = pset.getParameter<bool>("applyElecTrackQcuts");
0125       if (!applyElecTrackQcuts_) {
0126         qcuts_pset.addParameter<double>("minTrackPt", std::min(minGammaEtStripSeed_, minGammaEtStripAdd_));
0127         qcuts_pset.addParameter<double>("maxTrackChi2", 1.e+9);
0128         qcuts_pset.addParameter<double>("maxTransverseImpactParameter", 1.e+9);
0129         qcuts_pset.addParameter<double>("maxDeltaZ", 1.e+9);
0130         qcuts_pset.addParameter<double>("minTrackVertexWeight", -1.);
0131         qcuts_pset.addParameter<unsigned>("minTrackPixelHits", 0);
0132         qcuts_pset.addParameter<unsigned>("minTrackHits", 0);
0133       }
0134       //-------------------------------------------------------------------------------
0135       qcuts_pset.addParameter<double>("minGammaEt", std::min(minGammaEtStripSeed_, minGammaEtStripAdd_));
0136       qcuts_ = std::make_unique<RecoTauQualityCuts>(qcuts_pset);
0137
0138       inputParticleIds_ = pset.getParameter<std::vector<int> >("stripCandidatesParticleIds");
0139       const edm::ParameterSet& stripSize_eta_pset = pset.getParameterSet("stripEtaAssociationDistanceFunc");
0140       etaAssociationDistance_ = makeFunction("etaAssociationDistance", stripSize_eta_pset);
0141       const edm::ParameterSet& stripSize_phi_pset = pset.getParameterSet("stripPhiAssociationDistanceFunc");
0142       phiAssociationDistance_ = makeFunction("phiAssociationDistance", stripSize_phi_pset);
0143
0144       updateStripAfterEachDaughter_ = pset.getParameter<bool>("updateStripAfterEachDaughter");
0145       maxStripBuildIterations_ = pset.getParameter<int>("maxStripBuildIterations");
0146
0147       combineStrips_ = pset.getParameter<bool>("makeCombinatoricStrips");
0148       if (combineStrips_) {
0149         maxStrips_ = pset.getParameter<int>("maxInputStrips");
0150         combinatoricStripMassHypo_ = pset.getParameter<double>("stripMassWhenCombining");
0151       }
0152
0153       verbosity_ = pset.getParameter<int>("verbosity");
0154     }
0155     RecoTauPiZeroStripPlugin3::~RecoTauPiZeroStripPlugin3() {}
0156
0157     // Update the primary vertex
0158     void RecoTauPiZeroStripPlugin3::beginEvent() { vertexAssociator_.setEvent(*evt()); }
0159
0160     void RecoTauPiZeroStripPlugin3::addCandsToStrip(RecoTauPiZero& strip,
0161                                                     CandPtrs& cands,
0162                                                     const std::vector<bool>& candFlags,
0163                                                     std::set<size_t>& candIdsCurrentStrip,
0164                                                     bool& isCandAdded) const {
0165       if (verbosity_ >= 1) {
0166         edm::LogPrint("RecoTauPiZeroStripPlugin3") << "<RecoTauPiZeroStripPlugin3::addCandsToStrip>:";
0167       }
0168       size_t numCands = cands.size();
0169       for (size_t candId = 0; candId < numCands; ++candId) {
0170         if ((!candFlags[candId]) &&
0171             candIdsCurrentStrip.find(candId) == candIdsCurrentStrip.end()) {  // do not include same cand twice
0172           reco::CandidatePtr cand = cands[candId];
0173           double etaAssociationDistance_value =
0174               etaAssociationDistance_->Eval(strip.pt()) + etaAssociationDistance_->Eval(cand->pt());
0175           double phiAssociationDistance_value =
0176               phiAssociationDistance_->Eval(strip.pt()) + phiAssociationDistance_->Eval(cand->pt());
0177           if (fabs(strip.eta() - cand->eta()) <
0178                   etaAssociationDistance_value &&  // check if cand is within eta-phi window centered on strip
0179               reco::deltaPhi(strip.phi(), cand->phi()) < phiAssociationDistance_value) {
0180             if (verbosity_ >= 2) {
0181               edm::LogPrint("RecoTauPiZeroStripPlugin3")
0182                   << "--> adding PFCand #" << candId << " (" << cand.id() << ":" << cand.key()
0183                   << "): Et = " << cand->et() << ", eta = " << cand->eta() << ", phi = " << cand->phi();
0184             }
0185             strip.addDaughter(cand);
0186             if (updateStripAfterEachDaughter_)
0187               p4Builder_.set(strip);
0188             isCandAdded = true;
0189             candIdsCurrentStrip.insert(candId);
0190           }
0191         }
0192       }
0193     }
0194
0195     namespace {
0196       void markCandsInStrip(std::vector<bool>& candFlags, const std::set<size_t>& candIds) {
0197         for (std::set<size_t>::const_iterator candId = candIds.begin(); candId != candIds.end(); ++candId) {
0198           candFlags[*candId] = true;
0199         }
0200       }
0201
0202       // The following method has not been adapted to work with PackedCandidates,
0203       // however, it is only used for printing/debugging and can be adapted when
0204       // needed.
0205       inline const reco::TrackBaseRef getTrack(const Candidate& cand) {
0206         const PFCandidate* pfCandPtr = dynamic_cast<const PFCandidate*>(&cand);
0207         if (pfCandPtr) {
0208           if (pfCandPtr->trackRef().isNonnull())
0209             return reco::TrackBaseRef(pfCandPtr->trackRef());
0210           else if (pfCandPtr->gsfTrackRef().isNonnull())
0211             return reco::TrackBaseRef(pfCandPtr->gsfTrackRef());
0212           else
0213             return reco::TrackBaseRef();
0214         }
0215
0216         return reco::TrackBaseRef();
0217       }
0218     }  // namespace
0219
0220     RecoTauPiZeroStripPlugin3::return_type RecoTauPiZeroStripPlugin3::operator()(const reco::Jet& jet) const {
0221       if (verbosity_ >= 1) {
0222         edm::LogPrint("RecoTauPiZeroStripPlugin3") << "<RecoTauPiZeroStripPlugin3::operator()>:";
0223         edm::LogPrint("RecoTauPiZeroStripPlugin3") << " minGammaEtStripSeed = " << minGammaEtStripSeed_;
0224         edm::LogPrint("RecoTauPiZeroStripPlugin3") << " minGammaEtStripAdd = " << minGammaEtStripAdd_;
0225         edm::LogPrint("RecoTauPiZeroStripPlugin3") << " minStripEt = " << minStripEt_;
0226       }
0227
0228       PiZeroVector output;
0229
0230       // Get the candidates passing our quality cuts
0231       qcuts_->setPV(vertexAssociator_.associatedVertex(jet));
0232       CandPtrs candsVector = qcuts_->filterCandRefs(pfCandidates(jet, inputParticleIds_));
0233
0234       // Convert to stl::list to allow fast deletions
0235       CandPtrs seedCands;
0236       CandPtrs addCands;
0237       int idx = 0;
0238       for (CandPtrs::iterator cand = candsVector.begin(); cand != candsVector.end(); ++cand) {
0239         if (verbosity_ >= 1) {
0240           edm::LogPrint("RecoTauPiZeroStripPlugin3")
0241               << "PFGamma #" << idx << " (" << cand->id() << ":" << cand->key() << "): Et = " << (*cand)->et()
0242               << ", eta = " << (*cand)->eta() << ", phi = " << (*cand)->phi();
0243         }
0244         if ((*cand)->et() > minGammaEtStripSeed_) {
0245           if (verbosity_ >= 2) {
0246             edm::LogPrint("RecoTauPiZeroStripPlugin3") << "--> assigning seedCandId = " << seedCands.size();
0247             const reco::TrackBaseRef candTrack = getTrack(**cand);
0248             if (candTrack.isNonnull()) {
0249               edm::LogPrint("RecoTauPiZeroStripPlugin3")
0250                   << "track: Pt = " << candTrack->pt() << " eta = " << candTrack->eta()
0251                   << ", phi = " << candTrack->phi() << ", charge = " << candTrack->charge();
0252               edm::LogPrint("RecoTauPiZeroStripPlugin3")
0253                   << " (dZ = " << candTrack->dz(vertexAssociator_.associatedVertex(jet)->position())
0254                   << ", dXY = " << candTrack->dxy(vertexAssociator_.associatedVertex(jet)->position()) << ","
0255                   << " numHits = " << candTrack->hitPattern().numberOfValidTrackerHits()
0256                   << ", numPxlHits = " << candTrack->hitPattern().numberOfValidPixelHits() << ","
0257                   << " chi2 = " << candTrack->normalizedChi2()
0258                   << ", dPt/Pt = " << (candTrack->ptError() / candTrack->pt()) << ")";
0259             }
0260           }
0261           seedCands.push_back(*cand);
0262         } else if ((*cand)->et() > minGammaEtStripAdd_) {
0263           if (verbosity_ >= 2) {
0264             edm::LogPrint("RecoTauPiZeroStripPlugin3") << "--> assigning addCandId = " << addCands.size();
0265           }
0266           addCands.push_back(*cand);
0267         }
0268         ++idx;
0269       }
0270
0271       std::vector<bool> seedCandFlags(seedCands.size());  // true/false: seedCand is already/not yet included in strip
0272       std::vector<bool> addCandFlags(addCands.size());    // true/false: addCand  is already/not yet included in strip
0273
0274       std::set<size_t> seedCandIdsCurrentStrip;
0275       std::set<size_t> addCandIdsCurrentStrip;
0276
0277       size_t idxSeed = 0;
0278       while (idxSeed < seedCands.size()) {
0279         if (verbosity_ >= 2)
0280           edm::LogPrint("RecoTauPiZeroStripPlugin3") << "processing seed #" << idxSeed;
0281
0282         seedCandIdsCurrentStrip.clear();
0283         addCandIdsCurrentStrip.clear();
0284
0285         auto strip = std::make_unique<RecoTauPiZero>(*seedCands[idxSeed], RecoTauPiZero::kStrips);
0286         strip->addDaughter(seedCands[idxSeed]);
0287         seedCandIdsCurrentStrip.insert(idxSeed);
0288
0289         bool isCandAdded;
0290         int stripBuildIteration = 0;
0291         do {
0292           isCandAdded = false;
0293
0294           //if ( verbosity_ >= 2 ) edm::LogPrint("RecoTauPiZeroStripPlugin3") << " adding seedCands to strip..." ;
0295           addCandsToStrip(*strip, seedCands, seedCandFlags, seedCandIdsCurrentStrip, isCandAdded);
0296           //if ( verbosity_ >= 2 ) edm::LogPrint("RecoTauPiZeroStripPlugin3") << " adding addCands to strip..." ;
0297           addCandsToStrip(*strip, addCands, addCandFlags, addCandIdsCurrentStrip, isCandAdded);
0298
0299           if (!updateStripAfterEachDaughter_)
0300             p4Builder_.set(*strip);
0301
0302           ++stripBuildIteration;
0303         } while (isCandAdded && (stripBuildIteration < maxStripBuildIterations_ || maxStripBuildIterations_ == -1));
0304
0305         if (strip->et() > minStripEt_) {  // strip passed Et cuts, add it to the event
0306           if (verbosity_ >= 2)
0307             edm::LogPrint("RecoTauPiZeroStripPlugin3")
0308                 << "Building strip: Et = " << strip->et() << ", eta = " << strip->eta() << ", phi = " << strip->phi();
0309
0310           // Update the vertex
0311           if (strip->daughterPtr(0).isNonnull())
0312             strip->setVertex(strip->daughterPtr(0)->vertex());
0313           output.push_back(std::move(strip));
0314
0315           // Mark daughters as being part of this strip
0316           markCandsInStrip(seedCandFlags, seedCandIdsCurrentStrip);
0317           markCandsInStrip(addCandFlags, addCandIdsCurrentStrip);
0318         } else {  // strip failed Et cuts, just skip it
0319           if (verbosity_ >= 2)
0320             edm::LogPrint("RecoTauPiZeroStripPlugin3")
0321                 << "Discarding strip: Et = " << strip->et() << ", eta = " << strip->eta() << ", phi = " << strip->phi();
0322         }
0323
0324         ++idxSeed;
0325         while (idxSeed < seedCands.size() && seedCandFlags[idxSeed]) {
0326           ++idxSeed;  // fast-forward to next seed cand not yet included in any strip
0327         }
0328       }
0329
0330       // Check if we want to combine our strips
0331       if (combineStrips_ && output.size() > 1) {
0332         PiZeroVector stripCombinations;
0333         // Sort the output by descending pt
0334         std::sort(output.begin(), output.end(), [&](auto& arg1, auto& arg2) { return arg1->pt() > arg2->pt(); });
0335         // Get the end of interesting set of strips to try and combine
0336         PiZeroVector::const_iterator end_iter = takeNElements(output.begin(), output.end(), maxStrips_);
0337
0338         // Look at all the combinations
0339         for (PiZeroVector::const_iterator firstIter = output.begin(); firstIter != end_iter - 1; ++firstIter) {
0340           for (PiZeroVector::const_iterator secondIter = firstIter + 1; secondIter != end_iter; ++secondIter) {
0341             auto const& first = *firstIter;
0342             auto const& second = *secondIter;
0343             Candidate::LorentzVector firstP4 = first->p4();
0344             Candidate::LorentzVector secondP4 = second->p4();
0345             // If we assume a certain mass for each strip apply it here.
0346             firstP4 = applyMassConstraint(firstP4, combinatoricStripMassHypo_);
0347             secondP4 = applyMassConstraint(secondP4, combinatoricStripMassHypo_);
0348             Candidate::LorentzVector totalP4 = firstP4 + secondP4;
0349             // Make our new combined strip
0350             auto combinedStrips =
0351                 std::make_unique<RecoTauPiZero>(0,
0352                                                 totalP4,
0353                                                 Candidate::Point(0, 0, 0),
0354                                                 //111, 10001, true, RecoTauPiZero::kCombinatoricStrips));
0355                                                 111,
0356                                                 10001,
0357                                                 true,
0358                                                 RecoTauPiZero::kUndefined);
0359
0360             // Now loop over the strip members
0361             for (auto const& gamma : first->daughterPtrVector()) {
0362               combinedStrips->addDaughter(gamma);
0363             }
0364             for (auto const& gamma : second->daughterPtrVector()) {
0365               combinedStrips->addDaughter(gamma);
0366             }
0367             // Update the vertex
0368             if (combinedStrips->daughterPtr(0).isNonnull()) {
0369               combinedStrips->setVertex(combinedStrips->daughterPtr(0)->vertex());
0370             }
0371
0372             // Add to our collection of combined strips
0373             stripCombinations.push_back(std::move(combinedStrips));
0374           }
0375         }
0376         // When done doing all the combinations, add the combined strips to the
0377         // output.
0378         std::move(stripCombinations.begin(), stripCombinations.end(), std::back_inserter(output));
0379       }
0380
0381       // Compute correction to account for spread of photon energy in eta and phi
0382       // in case charged pions make nuclear interactions or photons convert within the tracking detector
0383       for (auto const& strip : output) {
0384         double bendCorrEta = 0.;
0385         double bendCorrPhi = 0.;
0386         double energySum = 0.;
0387         for (auto const& gamma : strip->daughterPtrVector()) {
0388           bendCorrEta += (gamma->energy() * etaAssociationDistance_->Eval(gamma->pt()));
0389           bendCorrPhi += (gamma->energy() * phiAssociationDistance_->Eval(gamma->pt()));
0390           energySum += gamma->energy();
0391         }
0392         if (energySum > 1.e-2) {
0393           bendCorrEta /= energySum;
0394           bendCorrPhi /= energySum;
0395         }
0396         //std::cout << "stripPt = " << strip->pt() << ": bendCorrEta = " << bendCorrEta << ", bendCorrPhi = " << bendCorrPhi << std::endl;
0397         strip->setBendCorrEta(bendCorrEta);
0398         strip->setBendCorrPhi(bendCorrPhi);
0399       }
0400
0401       return output;
0402     }
0403   }  // namespace tau
0404 }  // namespace reco
0405
0406 #include "FWCore/Framework/interface/MakerMacros.h"
0407 DEFINE_EDM_PLUGIN(RecoTauPiZeroBuilderPluginFactory, reco::tau::RecoTauPiZeroStripPlugin3, "RecoTauPiZeroStripPlugin3");