Adding cluster size to track extra (AliceO2Group#12044)

* Add ITS cluster size to the AO2D * Add TracksExtra_001 * Update readerhelper * Add cluster sizes to AB * Remove its cluster map * Please consider the following formatting changes * Add table versioning * Fix comments Co-authored-by: Jan Fiete <[email protected]> * Fix comments (2) Co-authored-by: Jan Fiete <[email protected]> * Set old TrackExtra as default * Fix data descriptor for trackextra * Please consider the following formatting changes * Fix test * Clean commented code * Fix comment (3) Co-authored-by: Jan Fiete <[email protected]> * Move dyn columns to versioning namespace * Update Framework/Core/include/Framework/AnalysisDataModel.h * Add braces + unsigned shorts * Move cluster sizes to uint8_t * Swap pattern and clsizes order --------- Co-authored-by: Maximiliano Puccio <[email protected]> Co-authored-by: ALICE Action Bot <[email protected]> Co-authored-by: Jan Fiete <[email protected]>
bblidaru · Oct 19, 2023 · 997cb57 · 997cb57
1 parent b7107e6
commit 997cb57
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Showing 12 changed files with 224 additions and 56 deletions.
diff --git a/DataFormats/Detectors/ITSMFT/ITS/include/DataFormatsITS/TrackITS.h b/DataFormats/Detectors/ITSMFT/ITS/include/DataFormatsITS/TrackITS.h
@@ -122,13 +122,39 @@ class TrackITS : public o2::track::TrackParCov
   void setNextROFbit(bool toggle = true) { setUserField((getUserField() & ~kNextROF) | (-toggle & kNextROF)); }
   bool hasHitInNextROF() const { return getUserField() & kNextROF; }
 
+  void setClusterSize(int l, int size)
+  {
+    if (l >= 8) {
+      return;
+    }
+    if (size > 15) {
+      size = 15;
+    }
+    mClusterSizes &= ~(0xf << (l * 4));
+    mClusterSizes |= (size << (l * 4));
+  }
+
+  int getClusterSize(int l)
+  {
+    if (l >= 8) {
+      return 0;
+    }
+    return (mClusterSizes >> (l * 4)) & 0xf;
+  }
+
+  int getClusterSizes() const
+  {
+    return mClusterSizes;
+  }
+
  private:
   o2::track::TrackParCov mParamOut; ///< parameter at largest radius
   ClusRefs mClusRef;                ///< references on clusters
   float mChi2 = 0.;                 ///< Chi2 for this track
   uint32_t mPattern = 0;            ///< layers pattern
+  unsigned int mClusterSizes = 0u;
 
-  ClassDefNV(TrackITS, 5);
+  ClassDefNV(TrackITS, 6);
 };
 
 class TrackITSExt : public TrackITS

diff --git a/DataFormats/Detectors/ITSMFT/common/include/DataFormatsITSMFT/TrkClusRef.h b/DataFormats/Detectors/ITSMFT/common/include/DataFormatsITSMFT/TrkClusRef.h
@@ -25,12 +25,35 @@ namespace itsmft
 // can refer to max 15 indices in the vector of total length <268435456, i.e. 17895697 tracks in worst case
 struct TrkClusRef : public o2::dataformats::RangeRefComp<4> {
   using o2::dataformats::RangeRefComp<4>::RangeRefComp;
+  uint32_t clsizes = 0; ///< cluster sizes for each layer
   uint16_t pattern = 0; ///< layers pattern
 
   GPUd() int getNClusters() const { return getEntries(); }
   bool hasHitOnLayer(int i) { return pattern & (0x1 << i); }
 
-  ClassDefNV(TrkClusRef, 1);
+  void setClusterSize(int l, int size)
+  {
+    if (l >= 8)
+      return;
+    if (size > 15)
+      size = 15;
+    clsizes &= ~(0xf << (l * 4));
+    clsizes |= (size << (l * 4));
+  }
+
+  int getClusterSize(int l)
+  {
+    if (l >= 8)
+      return 0;
+    return (clsizes >> (l * 4)) & 0xf;
+  }
+
+  int getClusterSizes() const
+  {
+    return clsizes;
+  }
+
+  ClassDefNV(TrkClusRef, 2);
 };
 
 } // namespace itsmft

diff --git a/Detectors/AOD/include/AODProducerWorkflow/AODProducerWorkflowSpec.h b/Detectors/AOD/include/AODProducerWorkflow/AODProducerWorkflowSpec.h
@@ -356,6 +356,7 @@ class AODProducerWorkflowDPL : public Task
   struct TrackExtraInfo {
     float tpcInnerParam = 0.f;
     uint32_t flags = 0;
+    uint32_t itsClusterSizes = 0u;
     uint8_t itsClusterMap = 0;
     uint8_t tpcNClsFindable = 0;
     int8_t tpcNClsFindableMinusFound = 0;

diff --git a/Detectors/AOD/src/AODProducerWorkflowSpec.cxx b/Detectors/AOD/src/AODProducerWorkflowSpec.cxx
@@ -2729,6 +2729,9 @@ DataProcessorSpec getAODProducerWorkflowSpec(GID::mask_t src, bool enableSV, boo
     dataRequest->requestStrangeTracks(useMC);
     LOGF(info, "requestStrangeTracks Finish");
   }
+  if (src[GID::ITS]) {
+    dataRequest->requestClusters(GIndex::getSourcesMask("ITS"), false);
+  }
   if (src[GID::TPC]) {
     dataRequest->requestClusters(GIndex::getSourcesMask("TPC"), false); // no need to ask for TOF clusters as they are requested with TOF tracks
   }

diff --git a/Detectors/GlobalTracking/include/GlobalTracking/MatchTPCITS.h b/Detectors/GlobalTracking/include/GlobalTracking/MatchTPCITS.h
@@ -89,7 +89,7 @@ namespace tpc
 {
 class TrackTPC;
 class VDriftCorrFact;
-}
+} // namespace tpc
 
 namespace gpu
 {
@@ -127,7 +127,7 @@ struct TrackLocTPC : public o2::track::TrackParCov {
   float timeErr = 0.f;                  ///< time sigma (makes sense for constrained tracks only)
   int sourceID = 0;                     ///< TPC track origin in
   o2::dataformats::GlobalTrackID gid{}; // global track source ID (TPC track may be part of it)
-  int matchID = MinusOne;              ///< entry (non if MinusOne) of its matchTPC struct in the mMatchesTPC
+  int matchID = MinusOne;               ///< entry (non if MinusOne) of its matchTPC struct in the mMatchesTPC
   Constraint_t constraint{Constrained};
 
   float getCorrectedTime(float dt) const // return time0 corrected for extra drift (to match certain Z)
@@ -148,9 +148,9 @@ struct TrackLocITS : public o2::track::TrackParCov {
   enum : uint16_t { CloneBefore = 0x1,
                     CloneAfter = 0x2 };
   o2::math_utils::Bracketf_t tBracket; ///< bracketing time in \mus
-  int sourceID = 0;       ///< track origin id
-  int roFrame = MinusOne; ///< ITS readout frame assigned to this track
-  int matchID = MinusOne; ///< entry (non if MinusOne) of its matchCand struct in the mMatchesITS
+  int sourceID = 0;                    ///< track origin id
+  int roFrame = MinusOne;              ///< ITS readout frame assigned to this track
+  int matchID = MinusOne;              ///< entry (non if MinusOne) of its matchCand struct in the mMatchesITS
   bool hasCloneBefore() const { return getUserField() & CloneBefore; }
   bool hasCloneAfter() const { return getUserField() & CloneAfter; }
   int getCloneShift() const { return hasCloneBefore() ? -1 : (hasCloneAfter() ? 1 : 0); }
@@ -536,13 +536,13 @@ class MatchTPCITS
   float correctTPCTrack(o2::track::TrackParCov& trc, const TrackLocTPC& tTPC, const InteractionCandidate& cand) const; // RS FIXME will be needed for refit
   //================================================================
 
-  bool mInitDone = false;  ///< flag init already done
-  bool mFieldON = true;    ///< flag for field ON/OFF
-  bool mCosmics = false;   ///< flag cosmics mode
-  bool mMCTruthON = false; ///< flag availability of MC truth
-  float mBz = 0;           ///< nominal Bz
-  int mTFCount = 0;        ///< internal TF counter for debugger
-  int mNThreads = 1;       ///< number of OMP threads
+  bool mInitDone = false;               ///< flag init already done
+  bool mFieldON = true;                 ///< flag for field ON/OFF
+  bool mCosmics = false;                ///< flag cosmics mode
+  bool mMCTruthON = false;              ///< flag availability of MC truth
+  float mBz = 0;                        ///< nominal Bz
+  int mTFCount = 0;                     ///< internal TF counter for debugger
+  int mNThreads = 1;                    ///< number of OMP threads
   o2::InteractionRecord mStartIR{0, 0}; ///< IR corresponding to the start of the TF
 
   ///========== Parameters to be set externally, e.g. from CCDB ====================
@@ -566,27 +566,27 @@ class MatchTPCITS
   ///< assigned time0 and its track Z position (converted from mTPCTimeEdgeZSafeMargin)
   float mTPCTimeEdgeTSafeMargin = 0.f;
   float mTPCExtConstrainedNSigmaInv = 0.f; // inverse for NSigmas for TPC time-interval from external constraint time sigma
-  int mITSROFrameLengthInBC = 0;    ///< ITS RO frame in BC (for ITS cont. mode only)
-  float mITSROFrameLengthMUS = -1.; ///< ITS RO frame in \mus
-  float mITSTimeResMUS = -1.;       ///< nominal ITS time resolution derived from ROF
-  float mITSROFrameLengthMUSInv = -1.; ///< ITS RO frame in \mus inverse
-  int mITSTimeBiasInBC = 0;            ///< ITS RO frame shift in BCs, i.e. t_i = (I_ROF*mITSROFrameLengthInBC + mITSTimeBiasInBC)*BCLength_MUS
-  float mITSTimeBiasMUS = 0.;          ///< ITS RO frame shift in \mus, i.e. t_i = (I_ROF*mITSROFrameLengthInBC)*BCLength_MUS + mITSTimeBiasMUS
-  float mTPCVDrift = -1.;              ///< TPC drift speed in cm/microseconds
-  float mTPCVDriftInv = -1.;           ///< inverse TPC nominal drift speed in cm/microseconds
-  float mTPCDriftTimeOffset = 0;       ///< drift time offset in mus
-  float mTPCTBinMUS = 0.;           ///< TPC time bin duration in microseconds
-  float mTPCTBinNS = 0.;            ///< TPC time bin duration in ns
-  float mTPCTBinMUSInv = 0.;        ///< inverse TPC time bin duration in microseconds
-  float mZ2TPCBin = 0.;             ///< conversion coeff from Z to TPC time-bin
-  float mTPCBin2Z = 0.;             ///< conversion coeff from TPC time-bin to Z
-  float mNTPCBinsFullDrift = 0.;    ///< max time bin for full drift
-  float mTPCZMax = 0.;              ///< max drift length
-  float mTPCmeanX0Inv = 1. / 31850.; ///< TPC gas 1/X0
+  int mITSROFrameLengthInBC = 0;           ///< ITS RO frame in BC (for ITS cont. mode only)
+  float mITSROFrameLengthMUS = -1.;        ///< ITS RO frame in \mus
+  float mITSTimeResMUS = -1.;              ///< nominal ITS time resolution derived from ROF
+  float mITSROFrameLengthMUSInv = -1.;     ///< ITS RO frame in \mus inverse
+  int mITSTimeBiasInBC = 0;                ///< ITS RO frame shift in BCs, i.e. t_i = (I_ROF*mITSROFrameLengthInBC + mITSTimeBiasInBC)*BCLength_MUS
+  float mITSTimeBiasMUS = 0.;              ///< ITS RO frame shift in \mus, i.e. t_i = (I_ROF*mITSROFrameLengthInBC)*BCLength_MUS + mITSTimeBiasMUS
+  float mTPCVDrift = -1.;                  ///< TPC drift speed in cm/microseconds
+  float mTPCVDriftInv = -1.;               ///< inverse TPC nominal drift speed in cm/microseconds
+  float mTPCDriftTimeOffset = 0;           ///< drift time offset in mus
+  float mTPCTBinMUS = 0.;                  ///< TPC time bin duration in microseconds
+  float mTPCTBinNS = 0.;                   ///< TPC time bin duration in ns
+  float mTPCTBinMUSInv = 0.;               ///< inverse TPC time bin duration in microseconds
+  float mZ2TPCBin = 0.;                    ///< conversion coeff from Z to TPC time-bin
+  float mTPCBin2Z = 0.;                    ///< conversion coeff from TPC time-bin to Z
+  float mNTPCBinsFullDrift = 0.;           ///< max time bin for full drift
+  float mTPCZMax = 0.;                     ///< max drift length
+  float mTPCmeanX0Inv = 1. / 31850.;       ///< TPC gas 1/X0
 
   float mMinTPCTrackPtInv = 999.; ///< cutoff on TPC track inverse pT
   float mMinITSTrackPtInv = 999.; ///< cutoff on ITS track inverse pT
-  bool mVDriftCalibOn = false;                                ///< flag to produce VDrift calibration data
+  bool mVDriftCalibOn = false;    ///< flag to produce VDrift calibration data
   o2::tpc::VDriftCorrFact mTPCDrift{};
   o2::gpu::CorrectionMapsHelper* mTPCCorrMapsHelper = nullptr;
 
@@ -601,12 +601,14 @@ class MatchTPCITS
   const o2::globaltracking::RecoContainer* mRecoCont = nullptr;
   ///>>>------ these are input arrays which should not be modified by the matching code
   //           since this info is provided by external device
-  gsl::span<const o2::tpc::TrackTPC> mTPCTracksArray;       ///< input TPC tracks span
-  gsl::span<const o2::tpc::TPCClRefElem> mTPCTrackClusIdx;  ///< input TPC track cluster indices span
-  gsl::span<const o2::itsmft::ROFRecord> mITSTrackROFRec;   ///< input ITS tracks ROFRecord span
-  gsl::span<const o2::its::TrackITS> mITSTracksArray;       ///< input ITS tracks span
-  gsl::span<const int> mITSTrackClusIdx;                    ///< input ITS track cluster indices span
-  std::vector<ITSCluster> mITSClustersArray;                ///< ITS clusters created in loadInput
+  gsl::span<const o2::tpc::TrackTPC> mTPCTracksArray;      ///< input TPC tracks span
+  gsl::span<const o2::tpc::TPCClRefElem> mTPCTrackClusIdx; ///< input TPC track cluster indices span
+  gsl::span<const o2::itsmft::ROFRecord> mITSTrackROFRec;  ///< input ITS tracks ROFRecord span
+  gsl::span<const o2::its::TrackITS> mITSTracksArray;      ///< input ITS tracks span
+  gsl::span<const int> mITSTrackClusIdx;                   ///< input ITS track cluster indices span
+  std::vector<ITSCluster> mITSClustersArray;               ///< ITS clusters created in loadInput
+  std::vector<uint8_t> mITSClusterSizes;                   ///< ITS cluster sizes created in loadInput
+
   gsl::span<const o2::itsmft::ROFRecord> mITSClusterROFRec; ///< input ITS clusters ROFRecord span
   gsl::span<const o2::ft0::RecPoints> mFITInfo;             ///< optional input FIT info span
 
@@ -624,6 +626,7 @@ class MatchTPCITS
   size_t mNMatches = 0;
   size_t mNCalibPrelim = 0;
   size_t mNMatchesControl = 0;
+
   size_t mNABRefsClus = 0;
   float mAB2MatchGuess = 0.2;                                          // heuristic guess about fraction of AB matches in total matches
   std::vector<InteractionCandidate> mInteractions;                     ///< possible interaction times
@@ -693,7 +696,6 @@ class MatchTPCITS
   static constexpr std::string_view TimerName[] = {"Total", "PrepareITS", "PrepareTPC", "DoMatching", "SelectBest", "Refit",
                                                    "ABSeeds", "ABMatching", "ABWinners", "ABRefit", "IO", "Debug"};
   TStopwatch mTimer[NStopWatches];
-
 };
 
 //______________________________________________
@@ -714,7 +716,6 @@ inline bool MatchTPCITS::isDisabledITS(const TrackLocITS& t) const { return t.ma
 //______________________________________________
 inline bool MatchTPCITS::isDisabledTPC(const TrackLocTPC& t) const { return t.matchID < 0; }
 
-
 } // namespace globaltracking
 } // namespace o2
 

diff --git a/Detectors/GlobalTracking/src/MatchTPCITS.cxx b/Detectors/GlobalTracking/src/MatchTPCITS.cxx
@@ -155,6 +155,7 @@ void MatchTPCITS::clear()
   mITSROFTimes.clear();
   mITSTrackROFContMapping.clear();
   mITSClustersArray.clear();
+  mITSClusterSizes.clear();
   mTPCABSeeds.clear();
   mTPCABIndexCache.clear();
   mABWinnersIDs.clear();
@@ -309,7 +310,7 @@ bool MatchTPCITS::validateTPCMatch(int iTPC)
   if (rcITS.nextRecID == Validated) {
     return false;
   }
-  if (rcITS.partnerID == iTPC) { // is best matching TPC track for this ITS track actually iTPC?
+  if (rcITS.partnerID == iTPC) {        // is best matching TPC track for this ITS track actually iTPC?
     int cloneID = tITS.getCloneShift(); // check if there is a clone of tITS
     while (cloneID) {
       cloneID += rcTPC.partnerID;
@@ -580,6 +581,27 @@ bool MatchTPCITS::prepareITSData()
   auto pattIt = patterns.begin();
   mITSClustersArray.reserve(clusITS.size());
   o2::its::ioutils::convertCompactClusters(clusITS, pattIt, mITSClustersArray, mITSDict);
+
+  // ITS clusters sizes
+  mITSClusterSizes.reserve(clusITS.size());
+  auto pattIt2 = patterns.begin();
+  for (auto& clus : clusITS) {
+    auto pattID = clus.getPatternID();
+    unsigned int npix;
+    if (pattID == o2::itsmft::CompCluster::InvalidPatternID || mITSDict->isGroup(pattID)) {
+      o2::itsmft::ClusterPattern patt;
+      patt.acquirePattern(pattIt2);
+      npix = patt.getNPixels();
+    } else {
+      npix = mITSDict->getNpixels(pattID);
+    }
+    if (npix < 255) {
+      mITSClusterSizes.push_back(npix);
+    } else {
+      mITSClusterSizes.push_back(255);
+    }
+  }
+
   if (mMCTruthON) {
     mITSClsLabels = inp.mcITSClusters.get();
   }
@@ -1295,21 +1317,21 @@ bool MatchTPCITS::refitTrackTPCITS(int iTPC, int& iITS, pmr::vector<o2::dataform
   const auto& itsTrOrig = mITSTracksArray[tITS.sourceID];
 
   auto& trfit = matchedTracks.emplace_back(tTPC, tITS); // create a copy of TPC track at xRef
-  trfit.getParamOut().setUserField(0); // reset eventual clones flag
+  trfit.getParamOut().setUserField(0);                  // reset eventual clones flag
   // in continuos mode the Z of TPC track is meaningless, unless it is CE crossing
   // track (currently absent, TODO)
   if (!mCompareTracksDZ) {
     trfit.setZ(tITS.getZ()); // fix the seed Z
   }
-  float deltaT = (trfit.getZ() - tTPC.getZ()) * mTPCVDriftInv;                                                                                    // time correction in \mus
-  float timeErr = tTPC.constraint == TrackLocTPC::Constrained ? tTPC.timeErr : std::sqrt(tITS.getSigmaZ2() + tTPC.getSigmaZ2()) * mTPCVDriftInv;  // estimate the error on time
+  float deltaT = (trfit.getZ() - tTPC.getZ()) * mTPCVDriftInv;                                                                                   // time correction in \mus
+  float timeErr = tTPC.constraint == TrackLocTPC::Constrained ? tTPC.timeErr : std::sqrt(tITS.getSigmaZ2() + tTPC.getSigmaZ2()) * mTPCVDriftInv; // estimate the error on time
   if (timeErr > mITSTimeResMUS && tTPC.constraint != TrackLocTPC::Constrained) {
     timeErr = mITSTimeResMUS; // chose smallest error
     deltaT = tTPC.constraint == TrackLocTPC::ASide ? tITS.tBracket.mean() - tTPC.time0 : tTPC.time0 - tITS.tBracket.mean();
   }
   timeErr += mParams->globalTimeExtraErrorMUS;
-  float timeC = tTPC.getCorrectedTime(deltaT) + mParams->globalTimeBiasMUS;                                                                       /// precise time estimate, optionally corrected for bias
-  if (timeC < 0) {                                                                                                                                // RS TODO similar check is needed for other edge of TF
+  float timeC = tTPC.getCorrectedTime(deltaT) + mParams->globalTimeBiasMUS; /// precise time estimate, optionally corrected for bias
+  if (timeC < 0) {                                                          // RS TODO similar check is needed for other edge of TF
     if (timeC + std::min(timeErr, mParams->tfEdgeTimeToleranceMUS * mTPCTBinMUSInv) < 0) {
       matchedTracks.pop_back(); // destroy failed track
       return false;
@@ -1845,6 +1867,7 @@ void MatchTPCITS::refitABWinners(pmr::vector<o2::dataformats::TrackTPCITS>& matc
         ABTrackletClusterIDs.push_back(winL.clID);
         ncl++;
         clref.pattern |= 0x1 << winL.layerID;
+        clref.setClusterSize(winL.layerID, mITSClusterSizes[winL.clID]);
         if (mMCTruthON) {
           accountClusterLabel(winL.clID);
         }

diff --git a/Detectors/ITSMFT/ITS/tracking/include/ITStracking/TimeFrame.h b/Detectors/ITSMFT/ITS/tracking/include/ITStracking/TimeFrame.h
@@ -129,6 +129,7 @@ class TimeFrame
   const gsl::span<const MCCompLabel> getClusterLabels(int layerId, const Cluster& cl) const;
   const gsl::span<const MCCompLabel> getClusterLabels(int layerId, const int clId) const;
   int getClusterExternalIndex(int layerId, const int clId) const;
+  int getClusterSize(int clusterId);
 
   std::vector<MCCompLabel>& getTrackletsLabel(int layer) { return mTrackletLabels[layer]; }
   std::vector<MCCompLabel>& getCellsLabel(int layer) { return mCellLabels[layer]; }
@@ -244,6 +245,7 @@ class TimeFrame
   std::vector<float> mMSangles;
   std::vector<float> mPhiCuts;
   std::vector<float> mPositionResolution;
+  std::vector<uint8_t> mClusterSize;
   std::vector<bool> mMultiplicityCutMask;
   std::vector<std::array<float, 2>> mPValphaX; /// PV x and alpha for track propagation
   std::vector<std::vector<Cluster>> mUnsortedClusters;
@@ -424,6 +426,11 @@ inline const gsl::span<const MCCompLabel> TimeFrame::getClusterLabels(int layerI
   return mClusterLabels->getLabels(mClusterExternalIndices[layerId][clId]);
 }
 
+inline int TimeFrame::getClusterSize(int clusterId)
+{
+  return mClusterSize[clusterId];
+}
+
 inline int TimeFrame::getClusterExternalIndex(int layerId, const int clId) const
 {
   return mClusterExternalIndices[layerId][clId];

diff --git a/Detectors/ITSMFT/ITS/tracking/src/TimeFrame.cxx b/Detectors/ITSMFT/ITS/tracking/src/TimeFrame.cxx
@@ -175,6 +175,8 @@ int TimeFrame::loadROFrameData(gsl::span<o2::itsmft::ROFRecord> rofs,
   geom->fillMatrixCache(o2::math_utils::bit2Mask(o2::math_utils::TransformType::T2L, o2::math_utils::TransformType::L2G));
 
   mNrof = 0;
+  mClusterSize.clear();
+  mClusterSize.reserve(clusters.size());
   for (auto& rof : rofs) {
     for (int clusterId{rof.getFirstEntry()}; clusterId < rof.getFirstEntry() + rof.getNEntries(); ++clusterId) {
       auto& c = clusters[clusterId];
@@ -184,18 +186,27 @@ int TimeFrame::loadROFrameData(gsl::span<o2::itsmft::ROFRecord> rofs,
       auto pattID = c.getPatternID();
       o2::math_utils::Point3D<float> locXYZ;
       float sigmaY2 = DefClusError2Row, sigmaZ2 = DefClusError2Col, sigmaYZ = 0; // Dummy COG errors (about half pixel size)
+      unsigned int clusterSize{0};
       if (pattID != itsmft::CompCluster::InvalidPatternID) {
         sigmaY2 = dict->getErr2X(pattID);
         sigmaZ2 = dict->getErr2Z(pattID);
         if (!dict->isGroup(pattID)) {
           locXYZ = dict->getClusterCoordinates(c);
+          clusterSize = dict->getNpixels(pattID);
         } else {
           o2::itsmft::ClusterPattern patt(pattIt);
           locXYZ = dict->getClusterCoordinates(c, patt);
+          clusterSize = patt.getNPixels();
         }
       } else {
         o2::itsmft::ClusterPattern patt(pattIt);
         locXYZ = dict->getClusterCoordinates(c, patt, false);
+        clusterSize = patt.getNPixels();
+      }
+      if (clusterSize < 255) {
+        mClusterSize.push_back(clusterSize);
+      } else {
+        mClusterSize.push_back(255);
       }
       auto sensorID = c.getSensorID();
       // Inverse transformation to the local --> tracking

diff --git a/Detectors/ITSMFT/ITS/workflow/src/TrackerSpec.cxx b/Detectors/ITSMFT/ITS/workflow/src/TrackerSpec.cxx
@@ -296,6 +296,7 @@ void TrackerDPL::run(ProcessingContext& pc)
         for (int ic = TrackITSExt::MaxClusters; ic--;) { // track internally keeps in->out cluster indices, but we want to store the references as out->in!!!
           auto clid = trc.getClusterIndex(ic);
           if (clid >= 0) {
+            trc.setClusterSize(ic, mTimeFrame->getClusterSize(clid));
             allClusIdx.push_back(clid);
             nclf++;
           }