Merge pull request #40 from peruzzim/FSRphotons_110X_arizzi_noNano

As #39 without NANOAOD code

MuonAnalysis/MuonAssociators/plugins/MuonFSRAssociator.cc

@@ -0,0 +1,89 @@
+// system include files
+#include <memory>
+
+// user include files
+#include "FWCore/Framework/interface/Frameworkfwd.h"
+#include "FWCore/Framework/interface/global/EDProducer.h"
+
+#include "FWCore/Framework/interface/Event.h"
+#include "FWCore/Framework/interface/MakerMacros.h"
+
+#include "FWCore/ParameterSet/interface/ParameterSet.h"
+#include "FWCore/Utilities/interface/StreamID.h"
+
+#include "DataFormats/Candidate/interface/Candidate.h"
+#include "DataFormats/PatCandidates/interface/GenericParticle.h"
+#include "DataFormats/Math/interface/LorentzVector.h"
+
+#include "DataFormats/PatCandidates/interface/Muon.h"
+#include "DataFormats/Common/interface/ValueMap.h"
+
+#include "DataFormats/Common/interface/Association.h"
+
+//
+// class declaration
+//
+
+class MuonFSRAssociator : public edm::global::EDProducer<> {
+public:
+  explicit MuonFSRAssociator(const edm::ParameterSet& iConfig)
+      :
+
+        photons_{consumes<pat::GenericParticleCollection>(iConfig.getParameter<edm::InputTag>("photons"))},
+        muons_{consumes<edm::View<reco::Muon>>(iConfig.getParameter<edm::InputTag>("muons"))}
+
+  {
+    produces<edm::Association<std::vector<pat::GenericParticle>>>();
+    produces<edm::ValueMap<int>>("fsrIndex");
+  }
+
+  static void fillDescriptions(edm::ConfigurationDescriptions& descriptions) {
+    edm::ParameterSetDescription desc;
+    desc.add<edm::InputTag>("photons")->setComment("FSR photon collection to associate with muons");
+    desc.add<edm::InputTag>("muons")->setComment("collection of muons to associate with FSR photons");
+
+    descriptions.add("MuonFSRAssociator", desc);
+  }
+  ~MuonFSRAssociator() override {}
+
+private:
+  void produce(edm::StreamID, edm::Event&, const edm::EventSetup&) const override;
+
+  // ----------member data ---------------------------
+  const edm::EDGetTokenT<pat::GenericParticleCollection> photons_;
+  const edm::EDGetTokenT<edm::View<reco::Muon>> muons_;
+};
+
+void MuonFSRAssociator::produce(edm::StreamID streamID, edm::Event& iEvent, const edm::EventSetup& iSetup) const {
+  using namespace std;
+
+  edm::Handle<pat::GenericParticleCollection> photons;
+  iEvent.getByToken(photons_, photons);
+  edm::Handle<edm::View<reco::Muon>> muons;
+  iEvent.getByToken(muons_, muons);
+
+  std::vector<int> muonMapping(muons->size(), -1);
+  // loop over all muons
+  for (auto muon = muons->begin(); muon != muons->end(); ++muon) {
+    for (auto iter_pho = photons->begin(); iter_pho != photons->end(); iter_pho++) {
+      if (iter_pho->hasUserCand("associatedMuon") and
+          iter_pho->userCand("associatedMuon") == reco::CandidatePtr(muons, muon - muons->begin()))
+        muonMapping[muon - muons->begin()] = (iter_pho - photons->begin());
+    }
+  }
+
+  auto muon2photon = std::make_unique<edm::Association<std::vector<pat::GenericParticle>>>(photons);
+  edm::Association<std::vector<pat::GenericParticle>>::Filler muon2photonFiller(*muon2photon);
+  muon2photonFiller.insert(muons, muonMapping.begin(), muonMapping.end());
+  muon2photonFiller.fill();
+  iEvent.put(std::move(muon2photon));
+
+  std::unique_ptr<edm::ValueMap<int>> bareIdx(new edm::ValueMap<int>());
+  edm::ValueMap<int>::Filler fillerBareIdx(*bareIdx);
+  fillerBareIdx.insert(muons, muonMapping.begin(), muonMapping.end());
+  fillerBareIdx.fill();
+  iEvent.put(std::move(bareIdx), "fsrIndex");
+}
+
+//define this as a plug-in
+DEFINE_FWK_MODULE(MuonFSRAssociator);