EMCAL/macros/trackMatching/SaveTrueMatchesSimple.C

   1 //
   2 // This macro generates a simple TTree containing
   3 // all true matches collected from one event.
   4 //
   5 // For each match it is stored:
   6 //  - label ID of the track
   7 //  - label ID of the EMCAL cluster
   8 //  - momentum (3D) of the track
   9 //  - vertex (3D) of the track
  10 //
  11 // All tracks which come from kinks are excluded
  12 // from this computation, and fake tracks are collected.
  13 // If desired, it is possible to change these settings
  14 // operating on the Bool_t variables listed below.
  15 //
  16
  17 Bool_t rejectKinks = kTRUE;     // switch to TRUE to include kinks in computation
  18 Bool_t rejectFakes = kFALSE;    // switch to TRUE to include fake tracks in computation
  19
  20 class match_t
  21 {
  22         public:
  23
  24         Int_t    label;       // GEANT label of particle
  25         Int_t    indexT;      // index of track in ESD collection
  26         Int_t    indexC;      // index of cluster in ESD collection
  27         Double_t p[3];        // track momentum
  28         Double_t v[3];        // track vertex
  29 };
  30
  31 //
  32 // Read AliESDs.root file and saves all true pairs of trak-cluster.
  33 //
  34 void SaveTrueMatchesSimple(const char *outFileName="true-matches.root")
  35 {
  36         //
  37         // open ESD file, retrieve tree and link to branch cursor
  38         //
  39         TFile *srcFile = TFile::Open("AliESDs.root");
  40         if (!srcFile) return;
  41         TTree *srcTree = (TTree*)srcFile->Get("esdTree");
  42         if (!srcTree) return;
  43
  44         AliESDEvent* esd = new AliESDEvent();
  45         esd->ReadFromTree(srcTree);
  46         Long64_t nEvents = srcTree->GetEntries();
  47
  48         //
  49         // Open output file and create output tree
  50         //
  51         TFile *outFile = new TFile(outFileName, "RECREATE");
  52         match_t match;
  53
  54         //
  55         // Loop on events and store true matches
  56         //
  57         Bool_t isKink;
  58         Int_t label, count, nTracks, firstCluster, lastCluster;
  59         for (Long64_t iev = 0; iev < nEvents; iev++) {
  60
  61                 srcTree->GetEntry(iev);
  62                 cout << "Event " << iev + 1 << " of " << nEvents << ": " << endl;
  63
  64                 nTracks = esd->GetNumberOfTracks();
  65                 firstCluster = 0;
  66                 lastCluster  = esd->GetNumberOfCaloClusters();
  67                 cout << "Tracks found      : " << nTracks << endl;
  68                 cout << "EMC clusters found: " << lastCluster - firstCluster << endl;
  69
  70                 // create new matches tree
  71                 TTree *outTree = new TTree(Form("tm_%d", iev), Form("True matches from event %d", iev));
  72                 outTree->Branch("matches", &match, "label/I:indexT/I:indexC/I:p[3]/D:v[3]/D");
  73
  74                 // external loop on tracks
  75                 for (Int_t it = 0; it < nTracks; it++) {
  76                         AliESDtrack *esdTrack = esd->GetTrack(it);
  77                         // start check to reject kinks
  78                         if (rejectKinks) {
  79                                 isKink = kFALSE;
  80                                 for (Int_t i = 0; i < 3; i++) {
  81                                         if (esdTrack->GetKinkIndex(i) > 0) isKink = kTRUE;
  82                                 }
  83                                 if (isKink) continue;
  84                         }
  85                         // get track GEANT label (to be checked for match)
  86                         label = esdTrack->GetLabel();
  87                         if (rejectFakes) {
  88                                 if (label < 0) continue;
  89                         }
  90                         else {
  91                                 label = TMath::Abs(label);
  92                         }
  93                         // store track data into candidate match variable
  94                         // anyway, it will be stored in the tree only
  95                         // if it matches a cluster
  96                         match.indexT = it;
  97                         esdTrack->GetPxPyPz(match.p);
  98                         esdTrack->GetXYZ(match.v);
  99                         // internal loop on clusters
 100                         // a counter counts how many true matches are
 101                         // generated for the same track
 102                         count = 0;
 103                         for (Int_t ic = firstCluster; ic < lastCluster; ic++) {
 104                                 AliESDCaloCluster *cl = esd->GetCaloCluster(ic);
 105                                 if (!cl->IsEMCAL()) continue;
 106                                 if (cl->GetLabel() != label) continue;
 107                                 // if the method reaches this point, we
 108                                 // have found a match to be stored
 109                                 match.label = label;
 110                                 match.indexC = ic;
 111                                 outTree->Fill();
 112                                 count++;
 113                         }
 114                         // alert for multiple matches
 115                         if (count > 0) {
 116                                 cout << "Found " << count << " clusters which match track " << it << " in ESD";
 117                                 if (count > 1) cout << " --> MULTIPLE MATCH";
 118                                 cout << endl;
 119                         }
 120                 } // end loop on tracks
 121
 122                 outFile->cd();
 123                 outTree->Write();
 124                 delete outTree;
 125         }
 126
 127         outFile->Close();
 128 }