]> git.uio.no Git - u/mrichter/AliRoot.git/blobdiff - TRD/AliTRDReconstructor.cxx
o small fix
[u/mrichter/AliRoot.git] / TRD / AliTRDReconstructor.cxx
index 9847b091e8ca418fade9623f25b2acfe2fe6beac..999fd3222ca7b61851af430624d4afa755eee47f 100644 (file)
 ///////////////////////////////////////////////////////////////////////////////
 //                                                                           //
 // Class for TRD reconstruction                                              //
+//                                                                           //   
+// For the special options which can be used during reconstruction and their //
+//  default values pls. see function SetOption().                            //
 //                                                                           //
 ///////////////////////////////////////////////////////////////////////////////
 
-#include <TFile.h>
 #include <TObjString.h>
 #include <TObjArray.h>
-#include <TClonesArray.h>
+#include <TTreeStream.h>
+#include <TDirectory.h>
+#include <TRef.h>
 
-#include "AliRunLoader.h"
 #include "AliRawReader.h"
 #include "AliLog.h"
-#include "AliESDTrdTrack.h"
-#include "AliESDEvent.h"
 
 #include "AliTRDReconstructor.h"
 #include "AliTRDclusterizer.h"
-#include "AliTRDtracker.h"
-#include "AliTRDpidESD.h"
-#include "AliTRDgtuTrack.h"
 #include "AliTRDrawData.h"
+#include "AliTRDrawStream.h"
 #include "AliTRDdigitsManager.h"
 #include "AliTRDtrackerV1.h"
-#include "AliTRDrecoParam.h"
+#include "AliESDEvent.h"
+#include "AliESDTrdTrack.h"
+#include "AliESDTrdTracklet.h"
+#include "AliESDTrdTrigger.h"
+#include "AliTRDtrackletWord.h"
+#include "AliTRDtrackletMCM.h"
+#include "AliTRDonlineTrackMatching.h"
 
 #define SETFLG(n,f) ((n) |= f)
 #define CLRFLG(n,f) ((n) &= ~f)
 
 ClassImp(AliTRDReconstructor)
 
-TClonesArray *AliTRDReconstructor::fgClusters = 0x0;
+AliESDTrdTrigger AliTRDReconstructor::fgTriggerFlags;
+AliTRDonlineTrackMatching AliTRDReconstructor::fgOnlineTrackMatcher;
+TClonesArray *AliTRDReconstructor::fgClusters = NULL;
+TClonesArray *AliTRDReconstructor::fgTracklets = NULL;
+TClonesArray *AliTRDReconstructor::fgTracks = NULL;
+Char_t const * AliTRDReconstructor::fgSteerNames[kNsteer] = {
+  "DigitsConversion       "
+ ,"Write Clusters         "
+ ,"Write Online Tracklets "
+ ,"Stand Alone Tracking   "
+ ,"HLT Mode              "
+ ,"Process Online Trklts  "
+ ,"Debug Streaming       "
+ ,"Cl. Radial Correction  "
+};
+Char_t const * AliTRDReconstructor::fgSteerFlags[kNsteer] = {
+  "dc"// digits conversion [false]
+ ,"cw"// write clusters [true]
+ ,"tw"// write online tracklets [false]
+ ,"sa"// track seeding (stand alone tracking) [true]
+ ,"hlt"// HLT reconstruction [false]
+ ,"tp"// also use online tracklets for reconstruction [false]
+ ,"deb"// Write debug stream [false]
+ ,"cc" // Cluster radial correction during reconstruction [false]
+};
+Char_t const * AliTRDReconstructor::fgTaskNames[AliTRDrecoParam::kTRDreconstructionTasks] = {
+  "Clusterizer"
+ ,"Tracker"
+ ,"PID"
+};
+Char_t const * AliTRDReconstructor::fgTaskFlags[AliTRDrecoParam::kTRDreconstructionTasks] = {
+  "cl"
+ ,"tr"
+ ,"pd"
+};
+Int_t AliTRDReconstructor::fgNTimeBins = -1;
+const  Float_t  AliTRDReconstructor::fgkMinClustersInTrack =  0.5;  //
+const  Float_t  AliTRDReconstructor::fgkLabelFraction      =  0.8;  //
+const  Double_t AliTRDReconstructor::fgkMaxChi2            = 12.0;  //
+const  Double_t AliTRDReconstructor::fgkMaxSnp             =  0.95; // Maximum local sine of the azimuthal angle
+const  Double_t AliTRDReconstructor::fgkMaxStep            =  2.0;  // Maximal step size in propagation
+const Double_t  AliTRDReconstructor::fgkEpsilon            = 1.e-5;                  // Precision of radial coordinate
+
 //_____________________________________________________________________________
 AliTRDReconstructor::AliTRDReconstructor()
   :AliReconstructor()
   ,fSteerParam(0)
+  ,fClusterizer(NULL)
 {
   // setting default "ON" steering parameters
+  // owner of debug streamers 
+  SETFLG(fSteerParam, kOwner);
   // write clusters [cw]
   SETFLG(fSteerParam, kWriteClusters);
   // track seeding (stand alone tracking) [sa]
-  SETFLG(fSteerParam, kSeeding);
-  // PID method in reconstruction (NN) [nn]
-  SETFLG(fSteerParam, kSteerPID);
-
-  memset(fStreamLevel, 0, 5*sizeof(UChar_t));
-  // Xe tail cancellation parameters
-  fTCParams[0] = 1.156; // r1
-  fTCParams[1] = 0.130; // r2
-  fTCParams[2] = 0.114; // c1
-  fTCParams[3] = 0.624; // c2
-  // Ar tail cancellation parameters
-  fTCParams[4] = 6.;    // r1
-  fTCParams[5] = 0.62;  // r2
-  fTCParams[6] = 0.0087;// c1
-  fTCParams[7] = 0.07;  // c2
-}
-
-//_____________________________________________________________________________
-AliTRDReconstructor::AliTRDReconstructor(const AliTRDReconstructor &r)
-  :AliReconstructor(r)
-  ,fSteerParam(r.fSteerParam)
-{
-  memcpy(fStreamLevel, r.fStreamLevel, 5*sizeof(UChar_t));
-  memcpy(fTCParams, r.fTCParams, 8*sizeof(Double_t));
+  //SETFLG(fSteerParam, kSeeding);
+  // Cluster radial correction during reconstruction [cc]
+  //SETFLG(fSteerParam, kClRadialCorr);
+  memset(fDebugStream, 0, sizeof(TTreeSRedirector *) * AliTRDrecoParam::kTRDreconstructionTasks);
 }
 
 //_____________________________________________________________________________
 AliTRDReconstructor::~AliTRDReconstructor()
 {
+  //
+  // Destructor
+  //
+
+  if(fClusterizer){
+    delete fClusterizer;
+    fClusterizer = NULL;
+  }
   if(fgClusters) {
-    fgClusters->Delete(); delete fgClusters;
+    fgClusters->Delete();
+    delete fgClusters;
+    fgClusters = NULL;
+  }
+  if(fgTracklets) {
+    fgTracklets->Delete();
+    delete fgTracklets;
+    fgTracklets = NULL;
+  }
+  if(fgTracks) {
+    fgTracks->Delete();
+    delete fgTracks;
+    fgTracks = NULL;
+  }
+  if(fSteerParam&kOwner){
+    for(Int_t itask = 0; itask < AliTRDrecoParam::kTRDreconstructionTasks; itask++)
+      if(fDebugStream[itask]) delete fDebugStream[itask];
   }
 }
 
@@ -98,17 +152,23 @@ void AliTRDReconstructor::Init(){
   // Init Options
   //
   SetOption(GetOption());
+  Options(fSteerParam);
 
-  AliInfo("TRD reconstruction will use the following settings:");
-  printf("\tDigitsConversion       [dc] : %s\n", fSteerParam&kDigitsConversion?"yes":"no");
-  printf("\tWrite Clusters         [cw] : %s\n", fSteerParam&kWriteClusters?"yes":"no");
-  printf("\tWrite Online Tracklets [tw] : %s\n", fSteerParam&kWriteTracklets?"yes":"no");
-  printf("\tDrift Gas Argon        [ar] : %s\n", fSteerParam&kDriftGas?"yes":"no");
-  printf("\tStand Alone Tracking   [sa] : %s\n", fSteerParam&kSeeding?"yes":"no");
-  printf("\tHLT         Tracking  [hlt] : %s\n", fSteerParam&kHLT?"yes":"no");
-  printf("\tCosmic Reconstruction [cos] : %s\n", fSteerParam&kCosmic?"yes":"no");
-  printf("\tNN PID                 [nn] : %s\n", fSteerParam&kSteerPID?"yes":"no");
-  printf("\tStreaming Levels            : Clusterizer[%d] Tracker[%d] PID[%d]\n", fStreamLevel[kClusterizer], fStreamLevel[kTracker], fStreamLevel[kPID]);
+  if(!fClusterizer){
+    fClusterizer = new AliTRDclusterizer(fgTaskNames[AliTRDrecoParam::kClusterizer], fgTaskNames[AliTRDrecoParam::kClusterizer]);
+    fClusterizer->SetReconstructor(this);
+    AliInfo(Form("Build TRD clusterizer[%p]", (void*)fClusterizer));
+  }
+  
+  // Make Debug Streams when Debug Streaming
+  if(IsDebugStreaming()){
+    for(Int_t task = 0; task < AliTRDrecoParam::kTRDreconstructionTasks; task++){
+      TDirectory *savedir = gDirectory;
+      fDebugStream[task] = new TTreeSRedirector(Form("TRD.Debug%s.root", fgTaskNames[task]));
+      savedir->cd();
+      SETFLG(fSteerParam, kOwner);
+    }
+  }
 }
 
 //_____________________________________________________________________________
@@ -119,16 +179,21 @@ void AliTRDReconstructor::ConvertDigits(AliRawReader *rawReader
   // Convert raw data digits into digit objects in a root tree
   //
 
-  AliInfo("Convert raw data digits into digit objects [RawReader -> Digit TTree]");
+  AliDebug(1, "Convert raw data digits into digit objects [RawReader -> Digit TTree]");
+  AliDebug(2, Form("clusters[%p] tracklets[%p] tracks[%p]", (void*)fgClusters, (void*)fgTracklets, (void*)fgTracks));
 
-  AliTRDrawData rawData;
   rawReader->Reset();
   rawReader->Select("TRD");
+  ResetContainers();
+
+  AliTRDrawData rawData;
+
   AliTRDdigitsManager *manager = rawData.Raw2Digits(rawReader);
   manager->MakeBranch(digitsTree);
   manager->WriteDigits();
   delete manager;
 
+  for (Int_t iSector = 0; iSector < 18; iSector++) fgTriggerFlags.SetFlags(iSector, rawData.GetTriggerFlags(iSector));
 }
 
 //_____________________________________________________________________________
@@ -139,24 +204,22 @@ void AliTRDReconstructor::Reconstruct(AliRawReader *rawReader
   // Reconstruct clusters
   //
 
-  //AliInfo("Reconstruct TRD clusters from RAW data [RawReader -> Cluster TTree]");
-
-
+  AliDebug(1, "Reconstruct TRD clusters from RAW data [RawReader -> Cluster TTree]");
+  AliDebug(2, Form("clusters[%p] tracklets[%p] tracks[%p]", (void*)fgClusters, (void*)fgTracklets, (void*)fgTracks));
+  if(!fClusterizer){
+    AliFatal("Clusterizer not available!");
+    return;
+  }
   rawReader->Reset();
   rawReader->Select("TRD");
-
-  // New (fast) cluster finder
-  AliTRDclusterizer clusterer("clusterer","TRD clusterizer");
-  clusterer.SetReconstructor(this);
-  clusterer.OpenOutput(clusterTree);
-  clusterer.SetAddLabels(kFALSE);
-  clusterer.Raw2ClustersChamber(rawReader);
-  
-  if(IsWritingClusters()) return;
-
-  // take over ownership of clusters
-  fgClusters = clusterer.RecPoints();
-  clusterer.SetClustersOwner(kFALSE);
+  ResetContainers();
+  fClusterizer->OpenOutput(clusterTree);
+  fClusterizer->SetUseLabels(kFALSE);
+  fClusterizer->SetStoreRawSignals(kTRUE);
+  fClusterizer->ResetRecPoints();
+  fClusterizer->Raw2ClustersChamber(rawReader);
+  fgNTimeBins = fClusterizer->GetNTimeBins();
+  for (Int_t iSector = 0; iSector < 18; iSector++) fgTriggerFlags.SetFlags(iSector, fClusterizer->GetTriggerFlags(iSector));
 }
 
 //_____________________________________________________________________________
@@ -167,19 +230,24 @@ void AliTRDReconstructor::Reconstruct(TTree *digitsTree
   // Reconstruct clusters
   //
 
-  //AliInfo("Reconstruct TRD clusters from Digits [Digit TTree -> Cluster TTree]");
-
-  AliTRDclusterizer clusterer("clusterer","TRD clusterizer");
-  clusterer.SetReconstructor(this);
-  clusterer.OpenOutput(clusterTree);
-  clusterer.ReadDigits(digitsTree);
-  clusterer.MakeClusters();
-
-  if(IsWritingClusters()) return;
+  AliDebug(1, "Reconstruct TRD clusters from Digits [Digit TTree -> Cluster TTree]");
+  AliDebug(2, Form("Start :: clusters[%p] tracklets[%p] tracks[%p]", (void*)fgClusters, (void*)fgTracklets, (void*)fgTracks));
+  if(!fClusterizer){
+    AliFatal("Clusterizer not available!");
+    return;
+  }
 
-  // take over ownership of clusters
-  fgClusters = clusterer.RecPoints();
-  clusterer.SetClustersOwner(kFALSE);
+  ResetContainers();
+  AliTRDclusterizer clusterizer(fgTaskNames[AliTRDrecoParam::kClusterizer], fgTaskNames[AliTRDrecoParam::kClusterizer]);
+  clusterizer.SetReconstructor(this);
+  clusterizer.SetUseLabels(kTRUE);
+  clusterizer.SetStoreRawSignals(kTRUE);
+  clusterizer.OpenOutput(clusterTree);
+  clusterizer.ReadDigits(digitsTree);
+  clusterizer.ReadTracklets();
+  clusterizer.ReadTracks();
+  clusterizer.MakeClusters();
+  fgNTimeBins = clusterizer.GetNTimeBins();
 }
 
 //_____________________________________________________________________________
@@ -192,6 +260,7 @@ AliTracker *AliTRDReconstructor::CreateTracker() const
   //return new AliTRDtracker(NULL);
   AliTRDtrackerV1 *tracker = new AliTRDtrackerV1();
   tracker->SetReconstructor(this);
+  AliInfo(Form("Build TRD tracker[%p]", (void*)tracker));
   return tracker;
 
 }
@@ -199,103 +268,172 @@ AliTracker *AliTRDReconstructor::CreateTracker() const
 //_____________________________________________________________________________
 void AliTRDReconstructor::FillESD(TTree* /*digitsTree*/
         , TTree* /*clusterTree*/
-        , AliESDEvent* /*esd*/) const
+        , AliESDEvent* esd) const
 {
   //
   // Fill ESD
   //
 
-}
+  // ----- filling tracklets -----
+  AliDebug(1, Form("Loading onl.tracklets(%i) to ESD", fgTracklets ? fgTracklets->GetEntriesFast() : 0));
+  Int_t trackletIndex[1080] = { 0 };
+  TList trklList;
+  AliTRDrawStream::SortTracklets(fgTracklets, trklList, trackletIndex);
+  TIter trackletIter(&trklList);
+  while (AliTRDtrackletBase* tracklet = (AliTRDtrackletBase*) trackletIter()) {
+    Int_t label = -2; // mark raw tracklets with label -2
+    if (AliTRDtrackletMCM *trklMCM = dynamic_cast<AliTRDtrackletMCM*> (tracklet)) label = trklMCM->GetLabel();
+    esd->AddTrdTracklet(tracklet->GetTrackletWord(), tracklet->GetHCId(), label);
+  }
+
+  // ----- filling GTU tracks -----
+  AliDebug(1, Form("Loading gtu.tracks(%i) to ESD", fgTracks ? fgTracks->GetEntriesFast() : 0));
+  if (fgTracks) {
+    for (Int_t iTrack = 0; iTrack < fgTracks->GetEntriesFast(); iTrack++) {
+      AliESDTrdTrack *trdTrack = (AliESDTrdTrack*) ((*fgTracks)[iTrack]);
+
+      UInt_t stack = trdTrack->GetStack();
+
+      Int_t refIndex[6];
+      AliTRDrawStream::AssignTracklets(trdTrack, trackletIndex, refIndex);
+
+      for (Int_t iLayer = 0; iLayer < 6; ++iLayer) {
+        Int_t det = trdTrack->GetSector()*30 + stack*6 + iLayer;
+        AliESDTrdTracklet *trkl = refIndex[iLayer] > -1 ? esd->GetTrdTracklet(refIndex[iLayer]) : 0x0;
+        if (trkl) {
+          AliDebug(5, Form("adding tracklet with index %i: 0x%08x",
+              refIndex[iLayer], trkl->GetTrackletWord()));
+          if (trkl->GetDetector() != det)
+            AliError(Form("inconsistent assignment of tracklet 0x%08x in det %i to track in %i",
+              trkl->GetTrackletWord(), trkl->GetDetector(), det));
+          trdTrack->AddTrackletReference(trkl, iLayer);
+        }
+      }
+      // only add the track when it's complete (including tracklet references)
+      esd->AddTrdTrack(trdTrack);
+    }
+  }
+  esd->SetTrdTrigger(&fgTriggerFlags);
 
+  // ----- matching GTU tracks to global tracks -----
+  AliDebug(1, Form("TRD track matching with %i ESD, %i TRD tracks",
+                  esd->GetNumberOfTracks(), esd->GetNumberOfTrdTracks()));
+  fgOnlineTrackMatcher.ProcessEvent(esd);
+}
 
 //_____________________________________________________________________________
 void AliTRDReconstructor::SetOption(Option_t *opt)
 {
-// Read option string into the steer param.
-//
-// Default steer param values
-//
-// digits conversion [dc] = false
-// write clusters [cw] = true
-// track seeding (stand alone tracking) [sa] = true
-// PID method in reconstruction (NN) [nn] = true
-// write online tracklets [tw] = false
-// drift gas [ar] = false
-// HLT tracking [hlt] = false
-// Cosmic Reconstruction [cos] = false
-//
+  //
+  // Read option string into the steer param.
+  //
+  // The following string options are available during reconstruction.
+  // In square brackets the default values are given.
+  //   "dc"  : digits conversion [false]
+  //   "cw"  : write clusters [true]
+  //   "tw"  : write online tracklets [false]
+  //   "sa"  : track seeding (stand alone tracking) [true]
+  //   "hlt" : HLT reconstruction [false]
+  //   "tp"  : also use online tracklets for reconstruction [false]
+  //   "deb" : Write debug stream [false]
+  //   "cc"  : Cluster radial correction during reconstruction [false]
+  //
+  // To check the actual options used during reconstruction include the following line in your rec.C script
+  // AliLog::SetClassDebugLevel("AliTRDReconstructor", 1);
 
   AliReconstructor::SetOption(opt);
 
   TString s(opt);
   TObjArray *opar = s.Tokenize(",");
   for(Int_t ipar=0; ipar<opar->GetEntriesFast(); ipar++){
+    Bool_t processed = kFALSE;
     TString sopt(((TObjString*)(*opar)[ipar])->String());
-    if(sopt.Contains("dc")){
-      SETFLG(fSteerParam, kDigitsConversion);
-      if(sopt.Contains("!")) CLRFLG(fSteerParam, kDigitsConversion);
-      continue;        
-    } else if(sopt.Contains("cw")){ 
-      SETFLG(fSteerParam, kWriteClusters);
-      if(sopt.Contains("!")) CLRFLG(fSteerParam, kWriteClusters);
-      continue;
-    } else if(sopt.Contains("sa")){
-      SETFLG(fSteerParam, kSeeding);
-      if(sopt.Contains("!")) CLRFLG(fSteerParam, kSeeding);
-      continue;
-    } else if(sopt.Contains("nn")){
-      SETFLG(fSteerParam, kSteerPID);
-      if(sopt.Contains("!")) CLRFLG(fSteerParam, kSteerPID);
-      continue;
-    } else if(sopt.Contains("tw")){
-      SETFLG(fSteerParam, kWriteTracklets);
-      if(sopt.Contains("!")) CLRFLG(fSteerParam, kWriteTracklets);
-      continue;        
-    } else if(sopt.Contains("ar")){
-      SETFLG(fSteerParam, kDriftGas);
-      if(sopt.Contains("!")) CLRFLG(fSteerParam, kDriftGas);
-      continue;        
-    } else if(sopt.Contains("hlt")){
-      SETFLG(fSteerParam, kHLT);
-      if(sopt.Contains("!")) CLRFLG(fSteerParam, kHLT);
-      continue;        
-    } else if(sopt.Contains("cos")){
-      SETFLG(fSteerParam, kCosmic);
-      if(sopt.Contains("!")) CLRFLG(fSteerParam, kCosmic);
-    } else if(sopt.Contains("sl")){
-      TObjArray *stl = sopt.Tokenize("_");
-      if(stl->GetEntriesFast() < 3) continue;
-      TString taskstr(((TObjString*)(*stl)[1])->String());
-      TString levelstring(((TObjString*)(*stl)[2])->String());
-      // Set the stream Level
-      Int_t level = levelstring.Atoi();
-      AliTRDReconstructorTask task = kTracker;
-      if(taskstr.CompareTo("cl") == 0) task = kClusterizer;    
-      else if(taskstr.CompareTo("tr") == 0) task = kTracker;
-      else if(taskstr.CompareTo("pi") == 0) task = kPID;
-      SetStreamLevel(level, task);
-      continue;
+    for(Int_t iopt=0; iopt<kNsteer; iopt++){
+      if(!sopt.Contains(fgSteerFlags[iopt])) continue;
+      SETFLG(fSteerParam, BIT(iopt));
+      if(sopt.Contains("!")) CLRFLG(fSteerParam, BIT(iopt));
+      processed = kTRUE;
+      break;   
     }
+    if(processed) continue;
+
+    AliWarning(Form("Unknown option flag %s.", sopt.Data()));
   }
+  opar->Delete();
+  delete opar;
 }
 
 //_____________________________________________________________________________
-void AliTRDReconstructor::SetStreamLevel(Int_t level, AliTRDReconstructorTask task){
+void AliTRDReconstructor::Options(UInt_t steer)
+{
   //
-  // Set the Stream Level for one of the tasks Clusterizer, Tracker or PID
+  // Print the options
   //
-  TString taskname;
-  switch(task){
-  case kClusterizer: 
-    taskname = "Clusterizer";
-    break;
-  case kTracker: 
-    taskname = "Tracker";
-    break;
-  case kPID: 
-    taskname = "PID";
-    break;
+
+  for(Int_t iopt=0; iopt<kNsteer; iopt++){
+    AliDebugGeneral("AliTRDReconstructor", 1, Form(" %s[%s]%s", fgSteerNames[iopt], fgSteerFlags[iopt], steer ?(((steer>>iopt)&1)?" : ON":" : OFF"):""));
+  }
+}
+
+
+//_____________________________________________________________________________
+TClonesArray* AliTRDReconstructor::GetClusters()
+{
+// Build/ Retrieve cluster array
+  if(!fgClusters){
+    fgClusters = new TClonesArray("AliTRDcluster", Int_t(GetRecoParam()->GetNClusters()));
+    fgClusters->SetOwner();
+    AliInfoGeneral("AliTRDReconstructor", Form("Allocate cluster array @ %p", (void*)fgClusters));
+  }
+  return fgClusters;
+}
+
+//_____________________________________________________________________________
+TClonesArray* AliTRDReconstructor::GetTracklets(const char *trkltype)
+{
+// Build/ Retrieve online tracklets array
+
+  if (trkltype && strlen(trkltype) > 0) {
+    if(fgTracklets && (TClass::GetClass(trkltype) != fgTracklets->GetClass())){
+      fgTracklets->Delete();
+      delete fgTracklets;
+    }
+    if (!fgTracklets) {
+      fgTracklets = new TClonesArray(trkltype, 200);
+      fgTracklets->SetOwner(kTRUE);
+      AliInfoGeneral("AliTRDReconstructor", Form("Allocate online tracklets[%s] array @ %p", trkltype, (void*)fgTracklets));
+    }
+  }
+  return fgTracklets;
+}
+
+//_____________________________________________________________________________
+TClonesArray* AliTRDReconstructor::GetTracks()
+{
+// Build/ Retrieve cluster array
+  if(!fgTracks){
+    fgTracks = new TClonesArray("AliESDTrdTrack", 100);
+    fgTracks->SetOwner();
+    AliInfoGeneral("AliTRDReconstructor", Form("Allocate online tracks array @ %p", (void*)fgTracks));
+  }
+  return fgTracks;
+}
+
+//_____________________________________________________________________________
+void AliTRDReconstructor::ResetContainers() const
+{
+// prepare data containers for a new event
+
+  if(fgClusters){
+    AliDebug(1, Form("Removing %5d clusters @ %p", fgClusters->GetEntriesFast(), (void*)fgClusters));
+    fgClusters->Clear();
+  }
+  if(fgTracklets){
+    AliDebug(1, Form("Removing %3d online tracklets @ %p", fgTracklets->GetEntriesFast(), (void*)fgTracklets));
+    fgTracklets->Clear();
+  }
+  if(fgTracks){
+    AliDebug(1, Form("Removing %3d online tracks @ %p", fgTracks->GetEntriesFast(), (void*)fgTracks));
+    fgTracks->Clear();
   }
-  //AliInfo(Form("Setting Stream Level for Task %s to %d", taskname.Data(),level));
-  fStreamLevel[(Int_t)task] = level;
 }