/* $Id$ */
+//-----------------------------------------------------------------------------
/// \class AliMUONTrackReconstructorK
-/////////////////////////////////////
///
/// MUON track reconstructor using the kalman method
///
/// It contains as methods, among others:
/// - MakeTracks to build the tracks
///
-////////////////////////////////////
+//-----------------------------------------------------------------------------
#include "AliMUONTrackReconstructorK.h"
+
#include "AliMUONConstants.h"
-#include "AliMUONHitForRec.h"
-#include "AliMUONObjectPair.h"
-#include "AliMUONRawCluster.h"
-#include "AliMUONTrackK.h"
+#include "AliMUONVCluster.h"
+#include "AliMUONVClusterServer.h"
+#include "AliMUONVClusterStore.h"
+#include "AliMUONTrack.h"
+#include "AliMUONTrackParam.h"
+#include "AliMUONTrackExtrap.h"
+#include "AliMUONRecoParam.h"
+
+#include "AliMpArea.h"
#include "AliLog.h"
#include <Riostream.h>
+#include <TMath.h>
+#include <TMatrixD.h>
+#include <TClonesArray.h>
+using std::endl;
+using std::cout;
/// \cond CLASSIMP
ClassImp(AliMUONTrackReconstructorK) // Class implementation in ROOT context
-ClassImp(AliMUONConstants)
/// \endcond
-//__________________________________________________________________________
-AliMUONTrackReconstructorK::AliMUONTrackReconstructorK(const Option_t* TrackMethod)
- : AliMUONVTrackReconstructor(),
- fTrackMethod(2) //tracking method (2-Kalman 3-Combination-Kalman/Clustering)
-{
- /// Constructor for class AliMUONTrackReconstructorK
-
- if (strstr(TrackMethod,"Kalman")) {
- AliInfo(" *** Tracking with the Kalman filter *** ");
- fTrackMethod = 2;
- } else if (strstr(TrackMethod,"Combi")) {
- AliInfo(" *** Combined cluster / track finder ***");
- fTrackMethod = 3;
- } else AliFatal(Form("Tracking method %s not available",TrackMethod));
-
- // Memory allocation for the TClonesArray of reconstructed tracks
- fRecTracksPtr = new TClonesArray("AliMUONTrackK", 10);
-}
-
-//__________________________________________________________________________
-AliMUONTrackReconstructorK::~AliMUONTrackReconstructorK(void)
+ //__________________________________________________________________________
+AliMUONTrackReconstructorK::AliMUONTrackReconstructorK(const AliMUONRecoParam* recoParam, AliMUONVClusterServer* clusterServer)
+ : AliMUONVTrackReconstructor(recoParam, clusterServer)
{
- /// Destructor for class AliMUONTrackReconstructorK
- delete fRecTracksPtr;
+ /// Constructor
}
-//__________________________________________________________________________
-void AliMUONTrackReconstructorK::MakeTracks(void)
+ //__________________________________________________________________________
+AliMUONTrackReconstructorK::~AliMUONTrackReconstructorK()
{
- /// To make the tracks from the list of segments and points in all stations
- AliDebug(1,"Enter MakeTracks");
- // The order may be important for the following Reset's
- //AZ ResetTracks();
- MakeTrackCandidates();
- if (fRecTracksPtr->GetEntriesFast() == 0) return;
- // Follow tracks in stations(1..) 3, 2 and 1
- FollowTracks();
- // Remove double tracks
- RemoveDoubleTracks();
- // Print out some track info (if necessary)
- EventDump();
- // Fill AliMUONTrack data members
- FillMUONTrack();
-}
+/// Destructor
+}
//__________________________________________________________________________
-void AliMUONTrackReconstructorK::MakeTrackCandidates(void)
+Bool_t AliMUONTrackReconstructorK::MakeTrackCandidates(AliMUONVClusterStore& clusterStore)
{
- /// To make initial tracks for Kalman filter from segments in stations(1..) 4 and 5
- Int_t istat, iseg;
+ /// To make track candidates (assuming linear propagation if AliMUONRecoParam::MakeTrackCandidatesFast() return kTRUE):
+ /// Start with segments station(1..) 4 or 5 then follow track in station 5 or 4.
+ /// Good candidates are made of at least three clusters if both stations are requested (two otherwise).
+ /// Keep only best candidates or all of them according to the flag AliMUONRecoParam::TrackAllTracks().
+
TClonesArray *segments;
AliMUONObjectPair *segment;
- AliMUONTrackK *trackK;
+ AliMUONTrack *track;
+ Int_t iCandidate = 0;
+ Bool_t clusterFound;
- AliDebug(1,"Enter MakeTrackCandidatesK");
+ AliDebug(1,"Enter MakeTrackCandidates");
- AliMUONTrackK a(this, fHitsForRecPtr);
- // Loop over stations(1...) 5 and 4
- for (istat=4; istat>=3; istat--)
+ // Unless we're doing combined tracking, we'll clusterize all stations at once
+ Int_t firstChamber(0);
+ Int_t lastChamber(9);
+
+ if (GetRecoParam()->CombineClusterTrackReco()) {
+ // ... Here's the exception : ask the clustering to reconstruct
+ // clusters *only* in station 4 and 5 for combined tracking
+ firstChamber = 6;
+ }
+
+ for (Int_t i = firstChamber; i <= lastChamber; ++i )
{
+ if (fClusterServer && GetRecoParam()->UseChamber(i)) fClusterServer->Clusterize(i, clusterStore, AliMpArea(), GetRecoParam());
+ }
+
+ // Loop over stations(1..) 5 and 4 and make track candidates
+ for (Int_t istat=4; istat>=3; istat--) {
+
// Make segments in the station
- segments = MakeSegmentsInStation(istat);
- // Loop over segments in the station
- for (iseg=0; iseg<segments->GetEntriesFast(); iseg++)
- {
- // Transform segments to tracks
- segment = (AliMUONObjectPair*) ((*segments)[iseg]);
- trackK = new ((*fRecTracksPtr)[fNRecTracks++]) AliMUONTrackK(*segment);
- } // for (iseg=0;...)
- delete segments;
- } // for (istat=4;...)
+ segments = MakeSegmentsBetweenChambers(clusterStore, 2*istat, 2*istat+1);
+
+ // Loop over segments
+ for (Int_t iSegment=0; iSegment<segments->GetEntriesFast(); iSegment++) {
+ AliDebug(1,Form("Making primary candidate(1..) %d",++iCandidate));
+ segment = (AliMUONObjectPair*) segments->UncheckedAt(iSegment);
+
+ // Transform segments to tracks and put them at the end of fRecTracksPtr
+ track = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(segment,GetRecoParam()->GetBendingVertexDispersion());
+ fNRecTracks++;
+
+ // Look for compatible cluster(s) in the other station
+ if (GetRecoParam()->MakeTrackCandidatesFast()) clusterFound = FollowLinearTrackInStation(*track, clusterStore, 7-istat);
+ else clusterFound = FollowTrackInStation(*track, clusterStore, 7-istat);
+
+ // Remove track if no cluster found on a requested station
+ // or abort tracking if there are too many candidates
+ if (GetRecoParam()->RequestStation(7-istat)) {
+ if (!clusterFound) {
+ fRecTracksPtr->Remove(track);
+ fNRecTracks--;
+ } else if (fNRecTracks > GetRecoParam()->GetMaxTrackCandidates()) {
+ AliError(Form("Too many track candidates (%d tracks). Stop tracking.", fNRecTracks));
+ return kFALSE;
+ }
+ } else {
+ if ((fNRecTracks + segments->GetEntriesFast() - iSegment - 1) > GetRecoParam()->GetMaxTrackCandidates()) {
+ AliError(Form("Too many track candidates (%d tracks). Stop tracking.", fNRecTracks + segments->GetEntriesFast() - iSegment - 1));
+ return kFALSE;
+ }
+ }
+
+ }
+
+ }
+
+ // Keep all different tracks if required
+ if (GetRecoParam()->TrackAllTracks()) RemoveIdenticalTracks();
+
+ // Retrace tracks using Kalman filter and select them if needed
+ Int_t nCurrentTracks = fRecTracksPtr->GetLast()+1;
+ for (Int_t iRecTrack = 0; iRecTrack < nCurrentTracks; iRecTrack++) {
+ track = (AliMUONTrack*) fRecTracksPtr->UncheckedAt(iRecTrack);
+
+ // skip empty slots
+ if(!track) continue;
+
+ // retrace tracks using Kalman filter and remove the ones for which extrap failed or that are out of limits
+ if (!RetraceTrack(*track,kTRUE) || !IsAcceptable(*((AliMUONTrackParam*)track->GetTrackParamAtCluster()->First()))) {
+ fRecTracksPtr->Remove(track);
+ fNRecTracks--;
+ }
+
+ }
+
+ // Keep only the best tracks if required
+ if (!GetRecoParam()->TrackAllTracks()) RemoveDoubleTracks();
+ else fRecTracksPtr->Compress();
+
+ AliDebug(1,Form("Number of good candidates = %d",fNRecTracks));
+
+ return kTRUE;
+
}
-//__________________________________________________________________________
-void AliMUONTrackReconstructorK::FollowTracks(void)
+ //__________________________________________________________________________
+Bool_t AliMUONTrackReconstructorK::MakeMoreTrackCandidates(AliMUONVClusterStore& clusterStore)
{
- /// Follow tracks using Kalman filter
- Bool_t ok;
- Int_t icand, ichamBeg = 0, ichamEnd, chamBits;
- AliMUONTrackK *trackK;
- AliMUONHitForRec *hit;
- AliMUONRawCluster *clus;
- TClonesArray *rawclusters;
- clus = 0; rawclusters = 0;
-
- Double_t simpleBPosition = 0.5 * (AliMUONConstants::CoilZ() + AliMUONConstants::YokeZ());
- Double_t simpleBLength = 0.5 * (AliMUONConstants::CoilL() + AliMUONConstants::YokeL());
- Double_t zDipole1 = simpleBPosition + 0.5 * simpleBLength;
- Double_t zDipole2 = zDipole1 - simpleBLength;
-
- // Print hits
- trackK = (AliMUONTrackK*) ((*fRecTracksPtr)[0]);
-
- icand = -1;
- Int_t nSeeds;
- nSeeds = fNRecTracks; // starting number of seeds
- // Loop over track candidates
- while (icand < fNRecTracks-1) {
- icand ++;
- if (trackK->DebugLevel()>0) cout << " *** Kalman track candidate No. " << icand << endl;
- trackK = (AliMUONTrackK*) ((*fRecTracksPtr)[icand]);
- if (trackK->GetRecover() < 0) continue; // failed track
-
- // Discard candidate which will produce the double track
- /*
- if (icand > 0) {
- ok = CheckCandidate(icand,nSeeds);
- if (!ok) {
- trackK->SetRecover(-1); // mark candidate to be removed
- continue;
+ /// To make extra track candidates assuming linear propagation:
+ /// clustering is supposed to be already done
+ /// Start with segments made of 1 cluster in each of the stations 4 and 5 then follow track in remaining chambers.
+ /// Good candidates are made of at least three clusters if both stations are requested (two otherwise).
+ /// Keep only best candidates or all of them according to the flag fgkTrackAllTracks.
+
+ TClonesArray *segments;
+ AliMUONObjectPair *segment;
+ AliMUONTrack *track;
+ Int_t iCandidate = 0, iCurrentTrack, nCurrentTracks;
+ Int_t initialNRecTracks = fNRecTracks;
+ Bool_t clusterFound;
+
+ AliDebug(1,"Enter MakeMoreTrackCandidates");
+
+ // Double loop over chambers in stations(1..) 4 and 5 to make track candidates
+ for (Int_t ich1 = 6; ich1 <= 7; ich1++) {
+ for (Int_t ich2 = 8; ich2 <= 9; ich2++) {
+
+ // Make segments between ch1 and ch2
+ segments = MakeSegmentsBetweenChambers(clusterStore, ich1, ich2);
+
+ /// Remove segments already attached to a track
+ RemoveUsedSegments(*segments);
+
+ // Loop over segments
+ for (Int_t iSegment=0; iSegment<segments->GetEntriesFast(); iSegment++) {
+ AliDebug(1,Form("Making primary candidate(1..) %d",++iCandidate));
+ segment = (AliMUONObjectPair*) segments->UncheckedAt(iSegment);
+
+ // Transform segments to tracks and put them at the end of fRecTracksPtr
+ iCurrentTrack = fRecTracksPtr->GetLast()+1;
+ track = new ((*fRecTracksPtr)[iCurrentTrack]) AliMUONTrack(segment,GetRecoParam()->GetBendingVertexDispersion());
+ fNRecTracks++;
+
+ // Look for compatible cluster(s) in the second chamber of station 5
+ clusterFound = FollowLinearTrackInChamber(*track, clusterStore, 17-ich2);
+
+ // skip the original track in case it has been removed
+ if (GetRecoParam()->TrackAllTracks() && clusterFound) iCurrentTrack++;
+
+ // loop over every new tracks
+ nCurrentTracks = fRecTracksPtr->GetLast()+1;
+ while (iCurrentTrack < nCurrentTracks) {
+ track = (AliMUONTrack*) fRecTracksPtr->UncheckedAt(iCurrentTrack);
+
+ // Look for compatible cluster(s) in the second chamber of station 4
+ FollowLinearTrackInChamber(*track, clusterStore, 13-ich1);
+
+ iCurrentTrack++;
+ }
+
+ // abort tracking if there are too many candidates
+ if ((fNRecTracks + segments->GetEntriesFast() - iSegment - 1) > GetRecoParam()->GetMaxTrackCandidates()) {
+ AliError(Form("Too many track candidates (%d tracks). Stop tracking.", fNRecTracks + segments->GetEntriesFast() - iSegment - 1));
+ return kFALSE;
+ }
+
}
+
}
- */
+ }
+
+ // Retrace tracks using Kalman filter (also compute track chi2) and select them
+ nCurrentTracks = fRecTracksPtr->GetLast()+1;
+ for (Int_t iRecTrack = initialNRecTracks; iRecTrack < nCurrentTracks; iRecTrack++) {
+ track = (AliMUONTrack*) fRecTracksPtr->UncheckedAt(iRecTrack);
+
+ // skip empty slots
+ if(!track) continue;
+
+ // retrace tracks using Kalman filter and remove the ones for which extrap failed or that are out of limits
+ if (!RetraceTrack(*track,kTRUE) || !IsAcceptable(*((AliMUONTrackParam*)track->GetTrackParamAtCluster()->First()))) {
+ fRecTracksPtr->Remove(track);
+ fNRecTracks--;
+ }
+
+ }
+
+ // Keep only the best tracks if required
+ if (!GetRecoParam()->TrackAllTracks()) RemoveDoubleTracks();
+ else fRecTracksPtr->Compress();
+
+ AliDebug(1,Form("Number of good candidates = %d",fNRecTracks));
+
+ return kTRUE;
+
+}
- ok = kTRUE;
- if (trackK->GetRecover() == 0)
- hit = (AliMUONHitForRec*) trackK->GetTrackHits()->Last(); // last hit
- else
- hit = trackK->GetHitLastOk(); // hit where track stopped
+ //__________________________________________________________________________
+Bool_t AliMUONTrackReconstructorK::RetraceTrack(AliMUONTrack &trackCandidate, Bool_t resetSeed)
+{
+ /// Re-run the kalman filter from the most downstream cluster to the most uptream one
+ /// Return kFALSE in case of failure (i.e. extrapolation problem)
+ AliDebug(1,"Enter RetraceTrack");
+
+ AliMUONTrackParam* lastTrackParam = (AliMUONTrackParam*) trackCandidate.GetTrackParamAtCluster()->Last();
+
+ // Reset the "seed" (= track parameters and their covariances at last cluster) if required
+ if (resetSeed) {
+
+ // parameters at last cluster
+ AliMUONVCluster* cluster2 = lastTrackParam->GetClusterPtr();
+ Double_t x2 = cluster2->GetX();
+ Double_t y2 = cluster2->GetY();
+ Double_t z2 = cluster2->GetZ();
+
+ // parameters at last but one cluster
+ AliMUONTrackParam* previousTrackParam = (AliMUONTrackParam*) trackCandidate.GetTrackParamAtCluster()->Before(lastTrackParam);
+ AliMUONVCluster* cluster1 = previousTrackParam->GetClusterPtr();
+ // make sure it is on the previous chamber (can have 2 clusters in the same chamber after "ComplementTrack")
+ if (cluster2->GetChamberId() == cluster1->GetChamberId()) {
+ previousTrackParam = (AliMUONTrackParam*) trackCandidate.GetTrackParamAtCluster()->Before(previousTrackParam);
+ cluster1 = previousTrackParam->GetClusterPtr();
+ }
+ Double_t x1 = cluster1->GetX();
+ Double_t y1 = cluster1->GetY();
+ Double_t z1 = cluster1->GetZ();
+
+ // reset track parameters
+ Double_t dZ = z1 - z2;
+ lastTrackParam->SetNonBendingCoor(x2);
+ lastTrackParam->SetBendingCoor(y2);
+ lastTrackParam->SetZ(z2);
+ lastTrackParam->SetNonBendingSlope((x1 - x2) / dZ);
+ lastTrackParam->SetBendingSlope((y1 - y2) / dZ);
+ Double_t bendingImpact = y2 - z2 * lastTrackParam->GetBendingSlope();
+ Double_t inverseBendingMomentum = 1. / AliMUONTrackExtrap::GetBendingMomentumFromImpactParam(bendingImpact);
+ lastTrackParam->SetInverseBendingMomentum(inverseBendingMomentum);
+
+ // => Reset track parameter covariances at last cluster (as if the other clusters did not exist)
+ TMatrixD lastParamCov(5,5);
+ lastParamCov.Zero();
+ // Non bending plane
+ lastParamCov(0,0) = cluster2->GetErrX2();
+ lastParamCov(0,1) = - cluster2->GetErrX2() / dZ;
+ lastParamCov(1,0) = lastParamCov(0,1);
+ lastParamCov(1,1) = ( 1000. * cluster1->GetErrX2() + cluster2->GetErrX2() ) / dZ / dZ;
+ // Bending plane
+ lastParamCov(2,2) = cluster2->GetErrY2();
+ lastParamCov(2,3) = - cluster2->GetErrY2() / dZ;
+ lastParamCov(3,2) = lastParamCov(2,3);
+ lastParamCov(3,3) = ( 1000. * cluster1->GetErrY2() + cluster2->GetErrY2() ) / dZ / dZ;
+ // Inverse bending momentum (vertex resolution + bending slope resolution + 10% error on dipole parameters+field)
+ if (AliMUONTrackExtrap::IsFieldON()) {
+ lastParamCov(4,4) = ((GetRecoParam()->GetBendingVertexDispersion() *
+ GetRecoParam()->GetBendingVertexDispersion() +
+ (z1 * z1 * cluster2->GetErrY2() + z2 * z2 * 1000. * cluster1->GetErrY2()) / dZ / dZ) /
+ bendingImpact / bendingImpact + 0.1 * 0.1) * inverseBendingMomentum * inverseBendingMomentum;
+ lastParamCov(2,4) = z1 * cluster2->GetErrY2() * inverseBendingMomentum / bendingImpact / dZ;
+ lastParamCov(4,2) = lastParamCov(2,4);
+ lastParamCov(3,4) = - (z1 * cluster2->GetErrY2() + z2 * 1000. * cluster1->GetErrY2()) *
+ inverseBendingMomentum / bendingImpact / dZ / dZ;
+ lastParamCov(4,3) = lastParamCov(3,4);
+ } else lastParamCov(4,4) = inverseBendingMomentum*inverseBendingMomentum;
+ lastTrackParam->SetCovariances(lastParamCov);
+
+ // Reset the track chi2
+ lastTrackParam->SetTrackChi2(0.);
+
+ }
+
+ // Redo the tracking
+ return RetracePartialTrack(trackCandidate, lastTrackParam);
+
+}
- if (hit) ichamBeg = hit->GetChamberNumber();
- if (ichamBeg == 8 && trackK->GetStation0() == 4) ichamBeg = 10;
+ //__________________________________________________________________________
+Bool_t AliMUONTrackReconstructorK::RetracePartialTrack(AliMUONTrack &trackCandidate, const AliMUONTrackParam* startingTrackParam)
+{
+ /// Re-run the kalman filter from the cluster attached to startingTrackParam to the most uptream cluster
+ /// Return kFALSE in case of failure (i.e. extrapolation problem)
+ AliDebug(1,"Enter RetracePartialTrack");
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "RetracePartialTrack: track chi2 before re-tracking: " << trackCandidate.GetGlobalChi2() << endl;
+ }
+
+ // Reset the track chi2
+ trackCandidate.SetGlobalChi2(startingTrackParam->GetTrackChi2());
+
+ // loop over attached clusters until the first one and recompute track parameters and covariances using kalman filter
+ Bool_t extrapStatus = kTRUE;
+ Int_t expectedChamber = startingTrackParam->GetClusterPtr()->GetChamberId() - 1;
+ Int_t currentChamber;
+ Double_t addChi2TrackAtCluster;
+ AliMUONTrackParam* trackParamAtCluster = (AliMUONTrackParam*) trackCandidate.GetTrackParamAtCluster()->Before(startingTrackParam);
+ while (trackParamAtCluster) {
+
+ // reset track parameters and their covariances
+ trackParamAtCluster->SetParameters(startingTrackParam->GetParameters());
+ trackParamAtCluster->SetZ(startingTrackParam->GetZ());
+ trackParamAtCluster->SetCovariances(startingTrackParam->GetCovariances());
+
+ // add MCS effect
+ AliMUONTrackExtrap::AddMCSEffect(trackParamAtCluster,AliMUONConstants::ChamberThicknessInX0(expectedChamber+1),-1.);
+
+ // reset propagator for smoother
+ if (GetRecoParam()->UseSmoother()) trackParamAtCluster->ResetPropagator();
+
+ // add MCS in missing chambers if any
+ currentChamber = trackParamAtCluster->GetClusterPtr()->GetChamberId();
+ while (currentChamber < expectedChamber) {
+ // extrapolation to the missing chamber (update the propagator)
+ if (!AliMUONTrackExtrap::ExtrapToZCov(trackParamAtCluster, AliMUONConstants::DefaultChamberZ(expectedChamber),
+ GetRecoParam()->UseSmoother())) extrapStatus = kFALSE;
+ // add MCS effect
+ AliMUONTrackExtrap::AddMCSEffect(trackParamAtCluster,AliMUONConstants::ChamberThicknessInX0(expectedChamber),-1.);
+ expectedChamber--;
+ }
+
+ // extrapolation to the plane of the cluster attached to the current trackParamAtCluster (update the propagator)
+ if (!AliMUONTrackExtrap::ExtrapToZCov(trackParamAtCluster, trackParamAtCluster->GetClusterPtr()->GetZ(),
+ GetRecoParam()->UseSmoother())) extrapStatus = kFALSE;
+
+ if (GetRecoParam()->UseSmoother()) {
+ // save extrapolated parameters for smoother
+ trackParamAtCluster->SetExtrapParameters(trackParamAtCluster->GetParameters());
+
+ // save extrapolated covariance matrix for smoother
+ trackParamAtCluster->SetExtrapCovariances(trackParamAtCluster->GetCovariances());
+ }
+
+ // Compute new track parameters using kalman filter
+ addChi2TrackAtCluster = RunKalmanFilter(*trackParamAtCluster);
+
+ // Update the track chi2
+ trackCandidate.SetGlobalChi2(trackCandidate.GetGlobalChi2() + addChi2TrackAtCluster);
+ trackParamAtCluster->SetTrackChi2(trackCandidate.GetGlobalChi2());
+
+ // prepare next step
+ expectedChamber = currentChamber - 1;
+ startingTrackParam = trackParamAtCluster;
+ trackParamAtCluster = (AliMUONTrackParam*) (trackCandidate.GetTrackParamAtCluster()->Before(startingTrackParam));
+ }
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "RetracePartialTrack: track chi2 after re-tracking: " << trackCandidate.GetGlobalChi2() << endl;
+ }
+
+ // set global chi2 to max value in case of problem during track extrapolation
+ if (!extrapStatus) trackCandidate.SetGlobalChi2(2.*AliMUONTrack::MaxChi2());
+ return extrapStatus;
+
+}
- ichamEnd = 0;
- // Check propagation direction
- if (!hit) { ichamBeg = ichamEnd; AliFatal(" ??? "); }
- else if (trackK->GetTrackDir() < 0) {
- ichamEnd = 9; // forward propagation
- ok = trackK->KalmanFilter(ichamBeg,ichamEnd,kFALSE,zDipole1,zDipole2);
- if (ok) {
- ichamBeg = ichamEnd + 1;
- ichamEnd = 6; // backward propagation
- // Change weight matrix and zero fChi2 for backpropagation
- trackK->StartBack();
- trackK->SetTrackDir(1);
- ok = trackK->KalmanFilter(ichamBeg,ichamEnd,kTRUE,zDipole1,zDipole2);
- ichamBeg = ichamEnd;
- ichamEnd = 0;
+ //__________________________________________________________________________
+Bool_t AliMUONTrackReconstructorK::FollowTracks(AliMUONVClusterStore& clusterStore)
+{
+ /// Follow tracks in stations(1..) 3, 2 and 1
+ AliDebug(1,"Enter FollowTracks");
+
+ AliMUONTrack *track;
+ Int_t currentNRecTracks;
+
+ for (Int_t station = 2; station >= 0; station--) {
+
+ // Save the actual number of reconstructed track in case of
+ // tracks are added or suppressed during the tracking procedure
+ // !! Do not compress fRecTracksPtr until the end of the loop over tracks !!
+ currentNRecTracks = fNRecTracks;
+
+ for (Int_t iRecTrack = 0; iRecTrack <currentNRecTracks; iRecTrack++) {
+ AliDebug(1,Form("FollowTracks: track candidate(1..) %d", iRecTrack+1));
+
+ track = (AliMUONTrack*) fRecTracksPtr->UncheckedAt(iRecTrack);
+
+ // Look for compatible cluster(s) in station(0..) "station"
+ if (!FollowTrackInStation(*track, clusterStore, station)) {
+
+ // Try to recover track if required
+ if (GetRecoParam()->RecoverTracks()) {
+
+ // work on a copy of the track if this station is not required
+ // to keep the case where no cluster is reconstructed as a possible candidate
+ if (!GetRecoParam()->RequestStation(station)) {
+ track = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(*track);
+ fNRecTracks++;
+ }
+
+ // try to recover
+ if (!RecoverTrack(*track, clusterStore, station)) {
+ // remove track if no cluster found
+ fRecTracksPtr->Remove(track);
+ fNRecTracks--;
+ }
+
+ } else if (GetRecoParam()->RequestStation(station)) {
+ // remove track if no cluster found
+ fRecTracksPtr->Remove(track);
+ fNRecTracks--;
+ }
+
}
- } else {
- if (trackK->GetBPFlag()) {
- // backpropagation
- if (ichamBeg == 10) ichamEnd = 8;
- else {
- if (ichamBeg == 9) ichamBeg++;
- ichamEnd = 6;
- // Change weight matrix and zero fChi2 for backpropagation
- trackK->StartBack();
+
+ // abort tracking if there are too many candidates
+ if (GetRecoParam()->RequestStation(station)) {
+ if (fNRecTracks > GetRecoParam()->GetMaxTrackCandidates()) {
+ AliError(Form("Too many track candidates (%d tracks). Stop tracking.", fNRecTracks));
+ return kFALSE;
+ }
+ } else {
+ if ((fNRecTracks + currentNRecTracks - iRecTrack - 1) > GetRecoParam()->GetMaxTrackCandidates()) {
+ AliError(Form("Too many track candidates (%d tracks). Stop tracking.", fNRecTracks + currentNRecTracks - iRecTrack - 1));
+ return kFALSE;
}
- ok = trackK->KalmanFilter(ichamBeg,ichamEnd,kTRUE,zDipole1,zDipole2);
- ichamBeg = ichamEnd;
- ichamEnd = 0;
}
+
}
+
+ fRecTracksPtr->Compress(); // this is essential before checking tracks
+
+ // Keep only the best tracks if required
+ if (!GetRecoParam()->TrackAllTracks()) RemoveDoubleTracks();
+
+ }
+
+ return kTRUE;
+
+}
- if (ok) {
- trackK->SetTrackDir(1);
- trackK->SetBPFlag(kFALSE);
- ok = trackK->KalmanFilter(ichamBeg,ichamEnd,kFALSE,zDipole1,zDipole2);
+ //__________________________________________________________________________
+Bool_t AliMUONTrackReconstructorK::FollowTrackInChamber(AliMUONTrack &trackCandidate, AliMUONVClusterStore& clusterStore, Int_t nextChamber)
+{
+ /// Follow trackCandidate in chamber(0..) nextChamber and search for compatible cluster(s)
+ /// Keep all possibilities or only the best one(s) according to the flag fgkTrackAllTracks:
+ /// kTRUE: duplicate "trackCandidate" if there are several possibilities and add the new tracks at the end of
+ /// fRecTracksPtr to avoid conficts with other track candidates at this current stage of the tracking procedure.
+ /// Remove the obsolete "trackCandidate" at the end.
+ /// kFALSE: add only the best cluster(s) to the "trackCandidate". Try to add a couple of clusters in priority.
+ /// return kTRUE if new cluster(s) have been found (otherwise return kFALSE)
+ AliDebug(1,Form("Enter FollowTrackInChamber(1..) %d", nextChamber+1));
+
+ Double_t chi2OfCluster;
+ Double_t maxChi2OfCluster = 2. * GetRecoParam()->GetSigmaCutForTracking() *
+ GetRecoParam()->GetSigmaCutForTracking(); // 2 because 2 quantities in chi2
+ Double_t addChi2TrackAtCluster;
+ Double_t bestAddChi2TrackAtCluster = AliMUONTrack::MaxChi2();
+ Bool_t foundOneCluster = kFALSE;
+ AliMUONTrack *newTrack = 0x0;
+ AliMUONVCluster *cluster;
+ AliMUONTrackParam extrapTrackParamAtCh;
+ AliMUONTrackParam extrapTrackParamAtCluster;
+ AliMUONTrackParam bestTrackParamAtCluster;
+
+ // Get track parameters according to the propagation direction
+ if (nextChamber > 7) extrapTrackParamAtCh = *(AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->Last();
+ else extrapTrackParamAtCh = *(AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->First();
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) {
+ cout<<endl<<"Track parameters and covariances at first cluster:"<<endl;
+ extrapTrackParamAtCh.GetParameters().Print();
+ extrapTrackParamAtCh.GetCovariances().Print();
+ }
+
+ // Add MCS effect
+ Int_t currentChamber = extrapTrackParamAtCh.GetClusterPtr()->GetChamberId();
+ AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(currentChamber),-1.);
+
+ // reset propagator for smoother
+ if (GetRecoParam()->UseSmoother()) extrapTrackParamAtCh.ResetPropagator();
+
+ // Add MCS in the missing chamber(s) if any
+ while (currentChamber > nextChamber + 1) {
+ // extrapolation to the missing chamber
+ currentChamber--;
+ if (!AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(currentChamber),
+ GetRecoParam()->UseSmoother())) return kFALSE;
+ // add MCS effect
+ AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(currentChamber),-1.);
+ }
+
+ //Extrapolate trackCandidate to chamber
+ if (!AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(nextChamber),
+ GetRecoParam()->UseSmoother())) return kFALSE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) {
+ cout<<endl<<"Track parameters and covariances at first cluster extrapolated to z = "<<AliMUONConstants::DefaultChamberZ(nextChamber)<<":"<<endl;
+ extrapTrackParamAtCh.GetParameters().Print();
+ extrapTrackParamAtCh.GetCovariances().Print();
+ }
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInChamber: look for clusters in chamber(1..): " << nextChamber+1 << endl;
+ }
+
+ // Ask the clustering to reconstruct new clusters around the track position in the current chamber
+ // except for station 4 and 5 that are already entirely clusterized
+ if (GetRecoParam()->CombineClusterTrackReco()) {
+ if (nextChamber < 6) AskForNewClustersInChamber(extrapTrackParamAtCh, clusterStore, nextChamber);
+ }
+
+ // Create iterators to loop over clusters in both chambers
+ TIter next(clusterStore.CreateChamberIterator(nextChamber,nextChamber));
+
+ // look for candidates in chamber
+ while ( ( cluster = static_cast<AliMUONVCluster*>(next()) ) ) {
+
+ // try to add the current cluster fast
+ if (!TryOneClusterFast(extrapTrackParamAtCh, cluster)) continue;
+
+ // try to add the current cluster accuratly
+ chi2OfCluster = TryOneCluster(extrapTrackParamAtCh, cluster, extrapTrackParamAtCluster,
+ GetRecoParam()->UseSmoother());
+
+ // if good chi2 then consider to add cluster
+ if (chi2OfCluster < maxChi2OfCluster) {
+
+ if (GetRecoParam()->UseSmoother()) {
+ // save extrapolated parameters for smoother
+ extrapTrackParamAtCluster.SetExtrapParameters(extrapTrackParamAtCluster.GetParameters());
+
+ // save extrapolated covariance matrix for smoother
+ extrapTrackParamAtCluster.SetExtrapCovariances(extrapTrackParamAtCluster.GetCovariances());
+ }
+
+ // Compute new track parameters including new cluster using kalman filter
+ addChi2TrackAtCluster = RunKalmanFilter(extrapTrackParamAtCluster);
+
+ // skip track out of limits
+ if (!IsAcceptable(extrapTrackParamAtCluster)) continue;
+
+ // remember a cluster was found
+ foundOneCluster = kTRUE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInChamber: found one cluster in chamber(1..): " << nextChamber+1
+ << " (Chi2 = " << chi2OfCluster << ")" << endl;
+ cluster->Print();
+ }
+
+ if (GetRecoParam()->TrackAllTracks()) {
+ // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new cluster
+ newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate);
+ UpdateTrack(*newTrack,extrapTrackParamAtCluster,addChi2TrackAtCluster);
+ fNRecTracks++;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInChamber: added one cluster in chamber(1..): " << nextChamber+1 << endl;
+ if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
+ }
+
+ } else if (addChi2TrackAtCluster < bestAddChi2TrackAtCluster) {
+ // keep track of the best cluster
+ bestAddChi2TrackAtCluster = addChi2TrackAtCluster;
+ bestTrackParamAtCluster = extrapTrackParamAtCluster;
+ }
+
}
- if (!ok) { trackK->SetRecover(-1); continue; } // mark candidate to be removed
+
+ }
+
+ // fill out the best track if required else clean up the fRecTracksPtr array
+ if (!GetRecoParam()->TrackAllTracks()) {
+ if (foundOneCluster) {
+ UpdateTrack(trackCandidate,bestTrackParamAtCluster,bestAddChi2TrackAtCluster);
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInChamber: added the best cluster in chamber(1..): " << bestTrackParamAtCluster.GetClusterPtr()->GetChamberId()+1 << endl;
+ if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
+ }
+
+ } else return kFALSE;
+
+ } else if (foundOneCluster) {
+
+ // remove obsolete track
+ fRecTracksPtr->Remove(&trackCandidate);
+ fNRecTracks--;
+
+ } else return kFALSE;
+
+ return kTRUE;
+
+}
- // Apply smoother
- if (trackK->GetRecover() >= 0) {
- ok = trackK->Smooth();
- if (!ok) trackK->SetRecover(-1); // mark candidate to be removed
+ //__________________________________________________________________________
+Bool_t AliMUONTrackReconstructorK::FollowTrackInStation(AliMUONTrack &trackCandidate, AliMUONVClusterStore& clusterStore, Int_t nextStation)
+{
+ /// Follow trackCandidate in station(0..) nextStation and search for compatible cluster(s)
+ /// Keep all possibilities or only the best one(s) according to the flag fgkTrackAllTracks:
+ /// kTRUE: duplicate "trackCandidate" if there are several possibilities and add the new tracks at the end of
+ /// fRecTracksPtr to avoid conficts with other track candidates at this current stage of the tracking procedure.
+ /// Remove the obsolete "trackCandidate" at the end.
+ /// kFALSE: add only the best cluster(s) to the "trackCandidate". Try to add a couple of clusters in priority.
+ /// return kTRUE if new cluster(s) have been found (otherwise return kFALSE)
+ AliDebug(1,Form("Enter FollowTrackInStation(1..) %d", nextStation+1));
+
+ // Order the chamber according to the propagation direction (tracking starts with chamber 2):
+ // - nextStation == station(1...) 5 => forward propagation
+ // - nextStation < station(1...) 5 => backward propagation
+ Int_t ch1, ch2;
+ if (nextStation==4) {
+ ch1 = 2*nextStation+1;
+ ch2 = 2*nextStation;
+ } else {
+ ch1 = 2*nextStation;
+ ch2 = 2*nextStation+1;
+ }
+
+ Double_t chi2OfCluster;
+ Double_t maxChi2OfCluster = 2. * GetRecoParam()->GetSigmaCutForTracking() *
+ GetRecoParam()->GetSigmaCutForTracking(); // 2 because 2 quantities in chi2
+ Double_t addChi2TrackAtCluster1;
+ Double_t addChi2TrackAtCluster2;
+ Double_t bestAddChi2TrackAtCluster1 = AliMUONTrack::MaxChi2();
+ Double_t bestAddChi2TrackAtCluster2 = AliMUONTrack::MaxChi2();
+ Bool_t foundOneCluster = kFALSE;
+ Bool_t foundTwoClusters = kFALSE;
+ AliMUONTrack *newTrack = 0x0;
+ AliMUONVCluster *clusterCh1, *clusterCh2;
+ AliMUONTrackParam extrapTrackParam;
+ AliMUONTrackParam extrapTrackParamAtCh;
+ AliMUONTrackParam extrapTrackParamAtCluster1;
+ AliMUONTrackParam extrapTrackParamAtCluster2;
+ AliMUONTrackParam bestTrackParamAtCluster1;
+ AliMUONTrackParam bestTrackParamAtCluster2;
+
+ // Get track parameters according to the propagation direction
+ if (nextStation==4) extrapTrackParamAtCh = *(AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->Last();
+ else extrapTrackParamAtCh = *(AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->First();
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) {
+ cout<<endl<<"Track parameters and covariances at first cluster:"<<endl;
+ extrapTrackParamAtCh.GetParameters().Print();
+ extrapTrackParamAtCh.GetCovariances().Print();
+ }
+
+ // Add MCS effect
+ Int_t currentChamber = extrapTrackParamAtCh.GetClusterPtr()->GetChamberId();
+ AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(currentChamber),-1.);
+
+ // reset propagator for smoother
+ if (GetRecoParam()->UseSmoother()) extrapTrackParamAtCh.ResetPropagator();
+
+ // Add MCS in the missing chamber(s) if any
+ while (ch1 < ch2 && currentChamber > ch2 + 1) {
+ // extrapolation to the missing chamber
+ currentChamber--;
+ if (!AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(currentChamber),
+ GetRecoParam()->UseSmoother())) return kFALSE;
+ // add MCS effect
+ AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(currentChamber),-1.);
+ }
+
+ //Extrapolate trackCandidate to chamber "ch2"
+ if (!AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(ch2),
+ GetRecoParam()->UseSmoother())) return kFALSE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) {
+ cout<<endl<<"Track parameters and covariances at first cluster extrapolated to z = "<<AliMUONConstants::DefaultChamberZ(ch2)<<":"<<endl;
+ extrapTrackParamAtCh.GetParameters().Print();
+ extrapTrackParamAtCh.GetCovariances().Print();
+ }
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: look for clusters in chamber(1..): " << ch2+1 << endl;
+ }
+
+ // Ask the clustering to reconstruct new clusters around the track position in the current station
+ // except for station 4 and 5 that are already entirely clusterized
+ if (GetRecoParam()->CombineClusterTrackReco()) {
+ if (nextStation < 3) AskForNewClustersInStation(extrapTrackParamAtCh, clusterStore, nextStation);
+ }
+
+ Int_t nClusters = clusterStore.GetSize();
+ Bool_t *clusterCh1Used = new Bool_t[nClusters];
+ for (Int_t i = 0; i < nClusters; i++) clusterCh1Used[i] = kFALSE;
+ Int_t iCluster1;
+
+ // Create iterators to loop over clusters in both chambers
+ TIter nextInCh1(clusterStore.CreateChamberIterator(ch1,ch1));
+ TIter nextInCh2(clusterStore.CreateChamberIterator(ch2,ch2));
+
+ // look for candidates in chamber 2
+ while ( ( clusterCh2 = static_cast<AliMUONVCluster*>(nextInCh2()) ) ) {
+
+ // try to add the current cluster fast
+ if (!TryOneClusterFast(extrapTrackParamAtCh, clusterCh2)) continue;
+
+ // try to add the current cluster accuratly
+ chi2OfCluster = TryOneCluster(extrapTrackParamAtCh, clusterCh2, extrapTrackParamAtCluster2,
+ GetRecoParam()->UseSmoother());
+
+ // if good chi2 then try to attach a cluster in the other chamber too
+ if (chi2OfCluster < maxChi2OfCluster) {
+
+ if (GetRecoParam()->UseSmoother()) {
+ // save extrapolated parameters for smoother
+ extrapTrackParamAtCluster2.SetExtrapParameters(extrapTrackParamAtCluster2.GetParameters());
+
+ // save extrapolated covariance matrix for smoother
+ extrapTrackParamAtCluster2.SetExtrapCovariances(extrapTrackParamAtCluster2.GetCovariances());
+ }
+
+ // Compute new track parameters including "clusterCh2" using kalman filter
+ addChi2TrackAtCluster2 = RunKalmanFilter(extrapTrackParamAtCluster2);
+
+ // skip track out of limits
+ if (!IsAcceptable(extrapTrackParamAtCluster2)) continue;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: found one cluster in chamber(1..): " << ch2+1
+ << " (Chi2 = " << chi2OfCluster << ")" << endl;
+ clusterCh2->Print();
+ cout << " look for second clusters in chamber(1..): " << ch1+1 << " ..." << endl;
+ }
+
+ // copy new track parameters for next step
+ extrapTrackParam = extrapTrackParamAtCluster2;
+
+ // add MCS effect
+ AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParam,AliMUONConstants::ChamberThicknessInX0(ch2),-1.);
+
+ // reset propagator for smoother
+ if (GetRecoParam()->UseSmoother()) extrapTrackParam.ResetPropagator();
+
+ //Extrapolate track parameters to chamber "ch1"
+ Bool_t normalExtrap = AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParam, AliMUONConstants::DefaultChamberZ(ch1),
+ GetRecoParam()->UseSmoother());
+
+ // reset cluster iterator of chamber 1
+ nextInCh1.Reset();
+ iCluster1 = -1;
+
+ // look for second candidates in chamber 1
+ Bool_t foundSecondCluster = kFALSE;
+ if (normalExtrap) while ( ( clusterCh1 = static_cast<AliMUONVCluster*>(nextInCh1()) ) ) {
+ iCluster1++;
+
+ // try to add the current cluster fast
+ if (!TryOneClusterFast(extrapTrackParam, clusterCh1)) continue;
+
+ // try to add the current cluster accuratly
+ chi2OfCluster = TryOneCluster(extrapTrackParam, clusterCh1, extrapTrackParamAtCluster1,
+ GetRecoParam()->UseSmoother());
+
+ // if good chi2 then consider to add the 2 clusters to the "trackCandidate"
+ if (chi2OfCluster < maxChi2OfCluster) {
+
+ if (GetRecoParam()->UseSmoother()) {
+ // save extrapolated parameters for smoother
+ extrapTrackParamAtCluster1.SetExtrapParameters(extrapTrackParamAtCluster1.GetParameters());
+
+ // save extrapolated covariance matrix for smoother
+ extrapTrackParamAtCluster1.SetExtrapCovariances(extrapTrackParamAtCluster1.GetCovariances());
+ }
+
+ // Compute new track parameters including "clusterCh1" using kalman filter
+ addChi2TrackAtCluster1 = RunKalmanFilter(extrapTrackParamAtCluster1);
+
+ // skip track out of limits
+ if (!IsAcceptable(extrapTrackParamAtCluster1)) continue;
+
+ // remember a second cluster was found
+ foundSecondCluster = kTRUE;
+ foundTwoClusters = kTRUE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: found one cluster in chamber(1..): " << ch1+1
+ << " (Chi2 = " << chi2OfCluster << ")" << endl;
+ clusterCh1->Print();
+ }
+
+ if (GetRecoParam()->TrackAllTracks()) {
+ // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new clusters
+ newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate);
+ UpdateTrack(*newTrack,extrapTrackParamAtCluster1,extrapTrackParamAtCluster2,addChi2TrackAtCluster1,addChi2TrackAtCluster2);
+ fNRecTracks++;
+
+ // Tag clusterCh1 as used
+ clusterCh1Used[iCluster1] = kTRUE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: added two clusters in station(1..): " << nextStation+1 << endl;
+ if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
+ }
+
+ } else if (addChi2TrackAtCluster1+addChi2TrackAtCluster2 < bestAddChi2TrackAtCluster1+bestAddChi2TrackAtCluster2) {
+ // keep track of the best couple of clusters
+ bestAddChi2TrackAtCluster1 = addChi2TrackAtCluster1;
+ bestAddChi2TrackAtCluster2 = addChi2TrackAtCluster2;
+ bestTrackParamAtCluster1 = extrapTrackParamAtCluster1;
+ bestTrackParamAtCluster2 = extrapTrackParamAtCluster2;
+ }
+
+ }
+
+ }
+
+ // if no clusterCh1 found then consider to add clusterCh2 only
+ if (!foundSecondCluster) {
+
+ // remember a cluster was found
+ foundOneCluster = kTRUE;
+
+ if (GetRecoParam()->TrackAllTracks()) {
+ // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new cluster
+ newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate);
+ UpdateTrack(*newTrack,extrapTrackParamAtCluster2,addChi2TrackAtCluster2);
+ fNRecTracks++;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: added one cluster in chamber(1..): " << ch2+1 << endl;
+ if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
+ }
+
+ } else if (!foundTwoClusters && addChi2TrackAtCluster2 < bestAddChi2TrackAtCluster1) {
+ // keep track of the best single cluster except if a couple of clusters has already been found
+ bestAddChi2TrackAtCluster1 = addChi2TrackAtCluster2;
+ bestTrackParamAtCluster1 = extrapTrackParamAtCluster2;
+ }
+
+ }
+
}
-
- // Majority 3 of 4 in first 2 stations
- if (!ok) continue;
- chamBits = 0;
- Double_t chi2max = 0;
- for (Int_t i=0; i<trackK->GetNTrackHits(); i++) {
- hit = (AliMUONHitForRec*) (*trackK->GetTrackHits())[i];
- chamBits |= BIT(hit->GetChamberNumber());
- if (trackK->GetChi2PerPoint(i) > chi2max) chi2max = trackK->GetChi2PerPoint(i);
+
+ }
+
+ // look for candidates in chamber 1 not already attached to a track
+ // if we want to keep all possible tracks or if no good couple of clusters has been found
+ if (GetRecoParam()->TrackAllTracks() || !foundTwoClusters) {
+
+ // add MCS effect for next step
+ AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(ch2),-1.);
+
+ //Extrapolate trackCandidate to chamber "ch1"
+ Bool_t normalExtrap = AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(ch1),
+ GetRecoParam()->UseSmoother());
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) {
+ cout<<endl<<"Track parameters and covariances at first cluster extrapolated to z = "<<AliMUONConstants::DefaultChamberZ(ch1)<<":"<<endl;
+ extrapTrackParamAtCh.GetParameters().Print();
+ extrapTrackParamAtCh.GetCovariances().Print();
}
- if (!((chamBits&3)==3 || (chamBits>>2&3)==3) && chi2max > 25) {
- //trackK->Recover();
- trackK->SetRecover(-1); //mark candidate to be removed
- continue;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: look for single clusters in chamber(1..): " << ch1+1 << endl;
+ }
+
+ // reset cluster iterator of chamber 1
+ nextInCh1.Reset();
+ iCluster1 = -1;
+
+ // look for second candidates in chamber 1
+ if (normalExtrap) while ( ( clusterCh1 = static_cast<AliMUONVCluster*>(nextInCh1()) ) ) {
+ iCluster1++;
+
+ if (clusterCh1Used[iCluster1]) continue; // Skip clusters already used
+
+ // try to add the current cluster fast
+ if (!TryOneClusterFast(extrapTrackParamAtCh, clusterCh1)) continue;
+
+ // try to add the current cluster accuratly
+ chi2OfCluster = TryOneCluster(extrapTrackParamAtCh, clusterCh1, extrapTrackParamAtCluster1,
+ GetRecoParam()->UseSmoother());
+
+ // if good chi2 then consider to add clusterCh1
+ // We do not try to attach a cluster in the other chamber too since it has already been done above
+ if (chi2OfCluster < maxChi2OfCluster) {
+
+ if (GetRecoParam()->UseSmoother()) {
+ // save extrapolated parameters for smoother
+ extrapTrackParamAtCluster1.SetExtrapParameters(extrapTrackParamAtCluster1.GetParameters());
+
+ // save extrapolated covariance matrix for smoother
+ extrapTrackParamAtCluster1.SetExtrapCovariances(extrapTrackParamAtCluster1.GetCovariances());
+ }
+
+ // Compute new track parameters including "clusterCh1" using kalman filter
+ addChi2TrackAtCluster1 = RunKalmanFilter(extrapTrackParamAtCluster1);
+
+ // skip track out of limits
+ if (!IsAcceptable(extrapTrackParamAtCluster1)) continue;
+
+ // remember a cluster was found
+ foundOneCluster = kTRUE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: found one cluster in chamber(1..): " << ch1+1
+ << " (Chi2 = " << chi2OfCluster << ")" << endl;
+ clusterCh1->Print();
+ }
+
+ if (GetRecoParam()->TrackAllTracks()) {
+ // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new cluster
+ newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate);
+ UpdateTrack(*newTrack,extrapTrackParamAtCluster1,addChi2TrackAtCluster1);
+ fNRecTracks++;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: added one cluster in chamber(1..): " << ch1+1 << endl;
+ if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
+ }
+
+ } else if (addChi2TrackAtCluster1 < bestAddChi2TrackAtCluster1) {
+ // keep track of the best single cluster except if a couple of clusters has already been found
+ bestAddChi2TrackAtCluster1 = addChi2TrackAtCluster1;
+ bestTrackParamAtCluster1 = extrapTrackParamAtCluster1;
+ }
+
+ }
+
+ }
+
+ }
+
+ // fill out the best track if required else clean up the fRecTracksPtr array
+ if (!GetRecoParam()->TrackAllTracks()) {
+ if (foundTwoClusters) {
+ UpdateTrack(trackCandidate,bestTrackParamAtCluster1,bestTrackParamAtCluster2,bestAddChi2TrackAtCluster1,bestAddChi2TrackAtCluster2);
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: added the two best clusters in station(1..): " << nextStation+1 << endl;
+ if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
+ }
+
+ } else if (foundOneCluster) {
+ UpdateTrack(trackCandidate,bestTrackParamAtCluster1,bestAddChi2TrackAtCluster1);
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: added the best cluster in chamber(1..): " << bestTrackParamAtCluster1.GetClusterPtr()->GetChamberId()+1 << endl;
+ if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
+ }
+
+ } else {
+ delete [] clusterCh1Used;
+ return kFALSE;
}
- if (ok) trackK->SetTrackQuality(0); // compute "track quality"
- } // while
+
+ } else if (foundOneCluster || foundTwoClusters) {
+
+ // remove obsolete track
+ fRecTracksPtr->Remove(&trackCandidate);
+ fNRecTracks--;
+
+ } else {
+ delete [] clusterCh1Used;
+ return kFALSE;
+ }
+
+ delete [] clusterCh1Used;
+ return kTRUE;
+
+}
- for (Int_t i=0; i<fNRecTracks; i++) {
- trackK = (AliMUONTrackK*) ((*fRecTracksPtr)[i]);
- if (trackK->GetRecover() < 0) fRecTracksPtr->RemoveAt(i);
+ //__________________________________________________________________________
+Double_t AliMUONTrackReconstructorK::RunKalmanFilter(AliMUONTrackParam &trackParamAtCluster)
+{
+ /// Compute new track parameters and their covariances including new cluster using kalman filter
+ /// return the additional track chi2
+ AliDebug(1,"Enter RunKalmanFilter");
+
+ // Get actual track parameters (p)
+ TMatrixD param(trackParamAtCluster.GetParameters());
+
+ // Get new cluster parameters (m)
+ AliMUONVCluster *cluster = trackParamAtCluster.GetClusterPtr();
+ TMatrixD clusterParam(5,1);
+ clusterParam.Zero();
+ clusterParam(0,0) = cluster->GetX();
+ clusterParam(2,0) = cluster->GetY();
+
+ // Compute the actual parameter weight (W)
+ TMatrixD paramWeight(trackParamAtCluster.GetCovariances());
+ if (paramWeight.Determinant() != 0) {
+ paramWeight.Invert();
+ } else {
+ AliWarning(" Determinant = 0");
+ return 2.*AliMUONTrack::MaxChi2();
}
+
+ // Compute the new cluster weight (U)
+ TMatrixD clusterWeight(5,5);
+ clusterWeight.Zero();
+ clusterWeight(0,0) = 1. / cluster->GetErrX2();
+ clusterWeight(2,2) = 1. / cluster->GetErrY2();
- // Compress TClonesArray
- fRecTracksPtr->Compress();
- fNRecTracks = fRecTracksPtr->GetEntriesFast();
- return;
+ // Compute the new parameters covariance matrix ( (W+U)^-1 )
+ TMatrixD newParamCov(paramWeight,TMatrixD::kPlus,clusterWeight);
+ if (newParamCov.Determinant() != 0) {
+ newParamCov.Invert();
+ } else {
+ AliWarning(" Determinant = 0");
+ return 2.*AliMUONTrack::MaxChi2();
+ }
+
+ // Save the new parameters covariance matrix
+ trackParamAtCluster.SetCovariances(newParamCov);
+
+ // Compute the new parameters (p' = ((W+U)^-1)U(m-p) + p)
+ TMatrixD tmp(clusterParam,TMatrixD::kMinus,param);
+ TMatrixD tmp2(clusterWeight,TMatrixD::kMult,tmp); // U(m-p)
+ TMatrixD newParam(newParamCov,TMatrixD::kMult,tmp2); // ((W+U)^-1)U(m-p)
+ newParam += param; // ((W+U)^-1)U(m-p) + p
+
+ // Save the new parameters
+ trackParamAtCluster.SetParameters(newParam);
+
+ // Compute the additional chi2 (= ((p'-p)^-1)W(p'-p) + ((p'-m)^-1)U(p'-m))
+ tmp = newParam; // p'
+ tmp -= param; // (p'-p)
+ TMatrixD tmp3(paramWeight,TMatrixD::kMult,tmp); // W(p'-p)
+ TMatrixD addChi2Track(tmp,TMatrixD::kTransposeMult,tmp3); // ((p'-p)^-1)W(p'-p)
+ tmp = newParam; // p'
+ tmp -= clusterParam; // (p'-m)
+ TMatrixD tmp4(clusterWeight,TMatrixD::kMult,tmp); // U(p'-m)
+ addChi2Track += TMatrixD(tmp,TMatrixD::kTransposeMult,tmp4); // ((p'-p)^-1)W(p'-p) + ((p'-m)^-1)U(p'-m)
+
+ return addChi2Track(0,0);
+
}
-//__________________________________________________________________________
-Bool_t AliMUONTrackReconstructorK::CheckCandidate(Int_t icand, Int_t nSeeds) const
+ //__________________________________________________________________________
+void AliMUONTrackReconstructorK::UpdateTrack(AliMUONTrack &track, AliMUONTrackParam &trackParamAtCluster, Double_t addChi2)
{
- /// Discards track candidate if it will produce the double track (having
- /// the same seed segment hits as hits of a good track found before)
- AliMUONTrackK *track1, *track2;
- AliMUONHitForRec *hit1, *hit2, *hit;
- AliMUONObjectPair *segment1, *segment2;
+ /// Add 1 cluster to the track candidate
+ /// Update chi2 of the track
+
+ // Flag cluster as being (not) removable
+ if (GetRecoParam()->RequestStation(trackParamAtCluster.GetClusterPtr()->GetChamberId()/2))
+ trackParamAtCluster.SetRemovable(kFALSE);
+ else trackParamAtCluster.SetRemovable(kTRUE);
+ trackParamAtCluster.SetLocalChi2(0.); // --> Local chi2 not used
+
+ // Update the track chi2 into trackParamAtCluster
+ trackParamAtCluster.SetTrackChi2(track.GetGlobalChi2() + addChi2);
+
+ // Update the chi2 of the new track
+ track.SetGlobalChi2(trackParamAtCluster.GetTrackChi2());
+
+ // Update array of TrackParamAtCluster
+ track.AddTrackParamAtCluster(trackParamAtCluster,*(trackParamAtCluster.GetClusterPtr()));
+
+}
- track1 = (AliMUONTrackK*) ((*fRecTracksPtr)[icand]);
- hit1 = (AliMUONHitForRec*) (*track1->GetTrackHits())[0]; // 1'st hit
- hit2 = (AliMUONHitForRec*) (*track1->GetTrackHits())[1]; // 2'nd hit
+ //__________________________________________________________________________
+void AliMUONTrackReconstructorK::UpdateTrack(AliMUONTrack &track, AliMUONTrackParam &trackParamAtCluster1, AliMUONTrackParam &trackParamAtCluster2,
+ Double_t addChi2AtCluster1, Double_t addChi2AtCluster2)
+{
+ /// Add 2 clusters to the track candidate (order is important)
+ /// Update track and local chi2
+
+ // Update local chi2 at first cluster
+ AliMUONVCluster* cluster1 = trackParamAtCluster1.GetClusterPtr();
+ Double_t deltaX = trackParamAtCluster1.GetNonBendingCoor() - cluster1->GetX();
+ Double_t deltaY = trackParamAtCluster1.GetBendingCoor() - cluster1->GetY();
+ Double_t localChi2AtCluster1 = deltaX*deltaX / cluster1->GetErrX2() +
+ deltaY*deltaY / cluster1->GetErrY2();
+ trackParamAtCluster1.SetLocalChi2(localChi2AtCluster1);
+
+ // Flag first cluster as being removable
+ trackParamAtCluster1.SetRemovable(kTRUE);
+
+ // Update local chi2 at second cluster
+ AliMUONVCluster* cluster2 = trackParamAtCluster2.GetClusterPtr();
+ AliMUONTrackParam extrapTrackParamAtCluster2(trackParamAtCluster1);
+ AliMUONTrackExtrap::ExtrapToZ(&extrapTrackParamAtCluster2, trackParamAtCluster2.GetZ());
+ deltaX = extrapTrackParamAtCluster2.GetNonBendingCoor() - cluster2->GetX();
+ deltaY = extrapTrackParamAtCluster2.GetBendingCoor() - cluster2->GetY();
+ Double_t localChi2AtCluster2 = deltaX*deltaX / cluster2->GetErrX2() +
+ deltaY*deltaY / cluster2->GetErrY2();
+ trackParamAtCluster2.SetLocalChi2(localChi2AtCluster2);
+
+ // Flag second cluster as being removable
+ trackParamAtCluster2.SetRemovable(kTRUE);
+
+ // Update the track chi2 into trackParamAtCluster2
+ trackParamAtCluster2.SetTrackChi2(track.GetGlobalChi2() + addChi2AtCluster2);
+
+ // Update the track chi2 into trackParamAtCluster1
+ trackParamAtCluster1.SetTrackChi2(trackParamAtCluster2.GetTrackChi2() + addChi2AtCluster1);
+
+ // Update the chi2 of the new track
+ track.SetGlobalChi2(trackParamAtCluster1.GetTrackChi2());
+
+ // Update array of trackParamAtCluster
+ track.AddTrackParamAtCluster(trackParamAtCluster1,*cluster1);
+ track.AddTrackParamAtCluster(trackParamAtCluster2,*cluster2);
+
+}
- for (Int_t i=0; i<icand; i++) {
- track2 = (AliMUONTrackK*) ((*fRecTracksPtr)[i]);
- //if (track2->GetRecover() < 0) continue;
- if (track2->GetRecover() < 0 && icand >= nSeeds) continue;
- segment1 = track1->GetStartSegment();
- segment2 = track2->GetStartSegment();
- if (segment1->First() == segment2->First() &&
- segment1->Second() == segment2->Second()) {
- return kFALSE;
- } else {
- Int_t nSame = 0;
- for (Int_t j=0; j<track2->GetNTrackHits(); j++) {
- hit = (AliMUONHitForRec*) (*track2->GetTrackHits())[j];
- if (hit == hit1 || hit == hit2) {
- nSame++;
- if (nSame == 2) return kFALSE;
- }
- } // for (Int_t j=0;
+ //__________________________________________________________________________
+Bool_t AliMUONTrackReconstructorK::RecoverTrack(AliMUONTrack &trackCandidate, AliMUONVClusterStore& clusterStore, Int_t nextStation)
+{
+ /// Try to recover the track candidate in the next station
+ /// by removing the worst of the two clusters attached in the current station
+ /// Return kTRUE if recovering succeeds
+ AliDebug(1,"Enter RecoverTrack");
+
+ // Do not try to recover track until we have attached cluster(s) on station(1..) 3
+ if (nextStation > 1) return kFALSE;
+
+ Int_t worstClusterNumber = -1;
+ Double_t localChi2, worstLocalChi2 = -1.;
+
+ // Look for the cluster to remove
+ for (Int_t clusterNumber = 0; clusterNumber < 2; clusterNumber++) {
+ AliMUONTrackParam *trackParamAtCluster = (AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->UncheckedAt(clusterNumber);
+
+ // check if current cluster is in the previous station
+ if (trackParamAtCluster->GetClusterPtr()->GetChamberId()/2 != nextStation+1) break;
+
+ // check if current cluster is removable
+ if (!trackParamAtCluster->IsRemovable()) return kFALSE;
+
+ // reset the current cluster as being not removable if it is on a required station
+ if (GetRecoParam()->RequestStation(nextStation+1)) trackParamAtCluster->SetRemovable(kFALSE);
+
+ // Pick up cluster with the worst chi2
+ localChi2 = trackParamAtCluster->GetLocalChi2();
+ if (localChi2 > worstLocalChi2) {
+ worstLocalChi2 = localChi2;
+ worstClusterNumber = clusterNumber;
}
- } // for (Int_t i=0;
- return kTRUE;
+ }
+
+ // check if worst cluster found
+ if (worstClusterNumber < 0) return kFALSE;
+
+ // Remove the worst cluster
+ trackCandidate.RemoveTrackParamAtCluster((AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->UncheckedAt(worstClusterNumber));
+
+ // Re-calculate track parameters at the (new) first cluster
+ if (!RetracePartialTrack(trackCandidate,(AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->UncheckedAt(1))) return kFALSE;
+
+ // skip track out of limits
+ if (!IsAcceptable(*((AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->First()))) return kFALSE;
+
+ // Look for new cluster(s) in next station
+ return FollowTrackInStation(trackCandidate, clusterStore, nextStation);
+
}
//__________________________________________________________________________
-void AliMUONTrackReconstructorK::RemoveDoubleTracks(void)
+Bool_t AliMUONTrackReconstructorK::RunSmoother(AliMUONTrack &track)
{
- /// Removes double tracks (sharing more than half of their hits).
- /// Keeps the track with higher quality
- AliMUONTrackK *track1, *track2, *trackToKill;
-
- // Sort tracks according to their quality
- fRecTracksPtr->Sort();
-
- // Loop over first track of the pair
- track1 = (AliMUONTrackK*) fRecTracksPtr->First();
- Int_t debug = track1->DebugLevel();
- while (track1) {
- // Loop over second track of the pair
- track2 = (AliMUONTrackK*) fRecTracksPtr->After(track1);
- while (track2) {
- // Check whether or not to keep track2
- if (!track2->KeepTrack(track1)) {
- if (debug >= 0) cout << " Killed track: " << 1/(*track2->GetTrackParameters())(4,0) <<
- " " << track2->GetTrackQuality() << endl;
- trackToKill = track2;
- track2 = (AliMUONTrackK*) fRecTracksPtr->After(track2);
- trackToKill->Kill();
- fRecTracksPtr->Compress();
- } else track2 = (AliMUONTrackK*) fRecTracksPtr->After(track2);
- } // track2
- track1 = (AliMUONTrackK*) fRecTracksPtr->After(track1);
- } // track1
+ /// Compute new track parameters and their covariances using smoother
+ AliDebug(1,"Enter UseSmoother");
+
+ AliMUONTrackParam *previousTrackParam = (AliMUONTrackParam*) track.GetTrackParamAtCluster()->First();
+
+ // Smoothed parameters and covariances at first cluster = filtered parameters and covariances
+ previousTrackParam->SetSmoothParameters(previousTrackParam->GetParameters());
+ previousTrackParam->SetSmoothCovariances(previousTrackParam->GetCovariances());
- fNRecTracks = fRecTracksPtr->GetEntriesFast();
- if (debug >= 0) cout << " Number of Kalman tracks: " << fNRecTracks << endl;
+ AliMUONTrackParam *currentTrackParam = (AliMUONTrackParam*) track.GetTrackParamAtCluster()->After(previousTrackParam);
+
+ // Save local chi2 at first cluster = last additional chi2 provided by Kalman
+ previousTrackParam->SetLocalChi2(previousTrackParam->GetTrackChi2() - currentTrackParam->GetTrackChi2());
+
+ // if the track contains only 2 clusters simply copy the filtered parameters
+ if (track.GetNClusters() == 2) {
+ currentTrackParam->SetSmoothParameters(currentTrackParam->GetParameters());
+ currentTrackParam->SetSmoothCovariances(currentTrackParam->GetCovariances());
+ currentTrackParam->SetLocalChi2(currentTrackParam->GetTrackChi2());
+ return kTRUE;
+ }
+
+ while (currentTrackParam) {
+
+ // Get variables
+ const TMatrixD &extrapParameters = previousTrackParam->GetExtrapParameters(); // X(k+1 k)
+ const TMatrixD &filteredParameters = currentTrackParam->GetParameters(); // X(k k)
+ const TMatrixD &previousSmoothParameters = previousTrackParam->GetSmoothParameters(); // X(k+1 n)
+ const TMatrixD &propagator = previousTrackParam->GetPropagator(); // F(k)
+ const TMatrixD &extrapCovariances = previousTrackParam->GetExtrapCovariances(); // C(k+1 k)
+ const TMatrixD &filteredCovariances = currentTrackParam->GetCovariances(); // C(k k)
+ const TMatrixD &previousSmoothCovariances = previousTrackParam->GetSmoothCovariances(); // C(k+1 n)
+
+ // Compute smoother gain: A(k) = C(kk) * F(k)^t * (C(k+1 k))^-1
+ TMatrixD extrapWeight(extrapCovariances);
+ if (extrapWeight.Determinant() != 0) {
+ extrapWeight.Invert(); // (C(k+1 k))^-1
+ } else {
+ AliWarning(" Determinant = 0");
+ return kFALSE;
+ }
+ TMatrixD smootherGain(filteredCovariances,TMatrixD::kMultTranspose,propagator); // C(kk) * F(k)^t
+ smootherGain *= extrapWeight; // C(kk) * F(k)^t * (C(k+1 k))^-1
+
+ // Compute smoothed parameters: X(k n) = X(k k) + A(k) * (X(k+1 n) - X(k+1 k))
+ TMatrixD tmpParam(previousSmoothParameters,TMatrixD::kMinus,extrapParameters); // X(k+1 n) - X(k+1 k)
+ TMatrixD smoothParameters(smootherGain,TMatrixD::kMult,tmpParam); // A(k) * (X(k+1 n) - X(k+1 k))
+ smoothParameters += filteredParameters; // X(k k) + A(k) * (X(k+1 n) - X(k+1 k))
+
+ // Save smoothed parameters
+ currentTrackParam->SetSmoothParameters(smoothParameters);
+
+ // Compute smoothed covariances: C(k n) = C(k k) + A(k) * (C(k+1 n) - C(k+1 k)) * (A(k))^t
+ TMatrixD tmpCov(previousSmoothCovariances,TMatrixD::kMinus,extrapCovariances); // C(k+1 n) - C(k+1 k)
+ TMatrixD tmpCov2(tmpCov,TMatrixD::kMultTranspose,smootherGain); // (C(k+1 n) - C(k+1 k)) * (A(k))^t
+ TMatrixD smoothCovariances(smootherGain,TMatrixD::kMult,tmpCov2); // A(k) * (C(k+1 n) - C(k+1 k)) * (A(k))^t
+ smoothCovariances += filteredCovariances; // C(k k) + A(k) * (C(k+1 n) - C(k+1 k)) * (A(k))^t
+
+ // Save smoothed covariances
+ currentTrackParam->SetSmoothCovariances(smoothCovariances);
+
+ // Compute smoothed residual: r(k n) = cluster - X(k n)
+ AliMUONVCluster* cluster = currentTrackParam->GetClusterPtr();
+ TMatrixD smoothResidual(2,1);
+ smoothResidual.Zero();
+ smoothResidual(0,0) = cluster->GetX() - smoothParameters(0,0);
+ smoothResidual(1,0) = cluster->GetY() - smoothParameters(2,0);
+
+ // Compute weight of smoothed residual: W(k n) = (clusterCov - C(k n))^-1
+ TMatrixD smoothResidualWeight(2,2);
+ smoothResidualWeight(0,0) = cluster->GetErrX2() - smoothCovariances(0,0);
+ smoothResidualWeight(0,1) = - smoothCovariances(0,2);
+ smoothResidualWeight(1,0) = - smoothCovariances(2,0);
+ smoothResidualWeight(1,1) = cluster->GetErrY2() - smoothCovariances(2,2);
+ if (smoothResidualWeight.Determinant() != 0) {
+ smoothResidualWeight.Invert();
+ } else {
+ AliWarning(" Determinant = 0");
+ return kFALSE;
+ }
+
+ // Compute local chi2 = (r(k n))^t * W(k n) * r(k n)
+ TMatrixD tmpChi2(smoothResidual,TMatrixD::kTransposeMult,smoothResidualWeight); // (r(k n))^t * W(k n)
+ TMatrixD localChi2(tmpChi2,TMatrixD::kMult,smoothResidual); // (r(k n))^t * W(k n) * r(k n)
+
+ // Save local chi2
+ currentTrackParam->SetLocalChi2(localChi2(0,0));
+
+ previousTrackParam = currentTrackParam;
+ currentTrackParam = (AliMUONTrackParam*) track.GetTrackParamAtCluster()->After(previousTrackParam);
+ }
+
+ return kTRUE;
+
}
//__________________________________________________________________________
-void AliMUONTrackReconstructorK::FillMUONTrack()
+Bool_t AliMUONTrackReconstructorK::ComplementTracks(const AliMUONVClusterStore& clusterStore)
{
- // Set track parameters at hits for Kalman track. Fill fTrackParamAtHit of AliMUONTrack's
- AliMUONTrackK *track;
- track = (AliMUONTrackK*) fRecTracksPtr->First();
+ /// Complete tracks by adding missing clusters (if there is an overlap between
+ /// two detection elements, the track may have two clusters in the same chamber).
+ /// Recompute track parameters and covariances at each clusters.
+ /// Remove tracks getting abnormal (i.e. extrapolation failed...) after being complemented.
+ /// Return kTRUE if one or more tracks have been complemented or removed.
+ AliDebug(1,"Enter ComplementTracks");
+
+ Int_t chamberId, detElemId;
+ Double_t chi2OfCluster, addChi2TrackAtCluster, bestAddChi2TrackAtCluster;
+ Double_t maxChi2OfCluster = 2. * GetRecoParam()->GetSigmaCutForTracking() *
+ GetRecoParam()->GetSigmaCutForTracking(); // 2 because 2 quantities in chi2
+ Bool_t foundOneCluster, trackModified, hasChanged = kFALSE;
+ AliMUONVCluster *cluster;
+ AliMUONTrackParam *trackParam, *previousTrackParam, *nextTrackParam, trackParamAtCluster, bestTrackParamAtCluster;
+ AliMUONTrack *nextTrack;
+
+ AliMUONTrack *track = (AliMUONTrack*) fRecTracksPtr->First();
while (track) {
- track->FillMUONTrack();
- track = (AliMUONTrackK*) fRecTracksPtr->After(track);
- }
- return;
+ trackModified = kFALSE;
+
+ trackParam = (AliMUONTrackParam*)track->GetTrackParamAtCluster()->First();
+ previousTrackParam = trackParam;
+ while (trackParam) {
+ foundOneCluster = kFALSE;
+ bestAddChi2TrackAtCluster = AliMUONTrack::MaxChi2();
+ chamberId = trackParam->GetClusterPtr()->GetChamberId();
+ detElemId = trackParam->GetClusterPtr()->GetDetElemId();
+
+ // prepare nextTrackParam before adding new cluster because of the sorting
+ nextTrackParam = (AliMUONTrackParam*)track->GetTrackParamAtCluster()->After(trackParam);
+
+ // Create iterators to loop over clusters in current chamber
+ TIter nextInCh(clusterStore.CreateChamberIterator(chamberId,chamberId));
+
+ // look for one second candidate in the same chamber
+ while ( ( cluster = static_cast<AliMUONVCluster*>(nextInCh()) ) ) {
+
+ // look for a cluster in another detection element
+ if (cluster->GetDetElemId() == detElemId) continue;
+
+ // try to add the current cluster fast
+ if (!TryOneClusterFast(*trackParam, cluster)) continue;
+
+ // try to add the current cluster accurately
+ // never use track parameters at last cluster because the covariance matrix is meaningless
+ if (nextTrackParam) chi2OfCluster = TryOneCluster(*trackParam, cluster, trackParamAtCluster);
+ else chi2OfCluster = TryOneCluster(*previousTrackParam, cluster, trackParamAtCluster);
+
+ // if good chi2 then consider to add this cluster to the track
+ if (chi2OfCluster < maxChi2OfCluster) {
+
+ // Compute local track parameters including current cluster using kalman filter
+ addChi2TrackAtCluster = RunKalmanFilter(trackParamAtCluster);
+
+ // keep track of the best cluster
+ if (addChi2TrackAtCluster < bestAddChi2TrackAtCluster) {
+ bestAddChi2TrackAtCluster = addChi2TrackAtCluster;
+ bestTrackParamAtCluster = trackParamAtCluster;
+ foundOneCluster = kTRUE;
+ }
+
+ }
+
+ }
+
+ // add new cluster if any
+ if (foundOneCluster) {
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "ComplementTracks: found one cluster in chamber(1..): " << chamberId+1 << endl;
+ bestTrackParamAtCluster.GetClusterPtr()->Print();
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) {
+ cout<<endl<<"Track parameters and covariances at cluster:"<<endl;
+ bestTrackParamAtCluster.GetParameters().Print();
+ bestTrackParamAtCluster.GetCovariances().Print();
+ }
+ }
+
+ trackParam->SetRemovable(kTRUE);
+ bestTrackParamAtCluster.SetRemovable(kTRUE);
+ track->AddTrackParamAtCluster(bestTrackParamAtCluster,*(bestTrackParamAtCluster.GetClusterPtr()));
+ trackModified = kTRUE;
+ hasChanged = kTRUE;
+ }
+
+ previousTrackParam = trackParam;
+ trackParam = nextTrackParam;
+ }
+
+ // prepare next track
+ nextTrack = (AliMUONTrack*) fRecTracksPtr->After(track);
+
+ // re-compute track parameters using kalman filter if needed
+ if (trackModified && !RetraceTrack(*track,kTRUE)) {
+ AliWarning("track modified but problem occur during refitting --> remove track");
+ fRecTracksPtr->Remove(track);
+ fNRecTracks--;
+ }
+
+ track = nextTrack;
+ }
+
+ return hasChanged;
+
}
+//__________________________________________________________________________
+void AliMUONTrackReconstructorK::ImproveTrack(AliMUONTrack &track)
+{
+ /// Improve the given track by removing removable clusters with local chi2 highter than the defined cut
+ /// Removable clusters are identified by the method AliMUONTrack::TagRemovableClusters()
+ /// Recompute track parameters and covariances at the remaining clusters
+ /// and if something goes wrong (i.e. extrapolation failed...) set track chi2 to max value
+ AliDebug(1,"Enter ImproveTrack");
+
+ Double_t localChi2, worstLocalChi2;
+ AliMUONTrackParam *trackParamAtCluster, *worstTrackParamAtCluster, *nextTrackParam, *next2nextTrackParam;
+ Int_t nextChamber, next2nextChamber;
+ Bool_t smoothed;
+ Double_t sigmaCut2 = GetRecoParam()->GetSigmaCutForImprovement() *
+ GetRecoParam()->GetSigmaCutForImprovement();
+
+ while (!track.IsImproved()) {
+
+ // identify removable clusters
+ track.TagRemovableClusters(GetRecoParam()->RequestedStationMask());
+
+ // Run smoother if required
+ smoothed = kFALSE;
+ if (GetRecoParam()->UseSmoother()) smoothed = RunSmoother(track);
+
+ // Use standard procedure to compute local chi2 if smoother not required or not working
+ if (!smoothed) {
+
+ // Update track parameters and covariances
+ if (!track.UpdateCovTrackParamAtCluster()) {
+ AliWarning("unable to update track parameters and covariances --> stop improvement");
+ // restore the kalman parameters
+ RetraceTrack(track,kTRUE);
+ break;
+ }
+
+ // Compute local chi2 of each clusters
+ track.ComputeLocalChi2(kTRUE);
+ }
+
+ // Look for the cluster to remove
+ worstTrackParamAtCluster = 0x0;
+ worstLocalChi2 = -1.;
+ trackParamAtCluster = (AliMUONTrackParam*)track.GetTrackParamAtCluster()->First();
+ while (trackParamAtCluster) {
+
+ // save parameters into smooth parameters in case of smoother did not work properly
+ if (GetRecoParam()->UseSmoother() && !smoothed) {
+ trackParamAtCluster->SetSmoothParameters(trackParamAtCluster->GetParameters());
+ trackParamAtCluster->SetSmoothCovariances(trackParamAtCluster->GetCovariances());
+ }
+
+ // Pick up cluster with the worst chi2
+ localChi2 = trackParamAtCluster->GetLocalChi2();
+ if (localChi2 > worstLocalChi2) {
+ worstLocalChi2 = localChi2;
+ worstTrackParamAtCluster = trackParamAtCluster;
+ }
+
+ trackParamAtCluster = (AliMUONTrackParam*)track.GetTrackParamAtCluster()->After(trackParamAtCluster);
+ }
+
+ // Check whether the worst chi2 is under requirement or not
+ if (worstLocalChi2 < 2. * sigmaCut2) { // 2 because 2 quantities in chi2
+ track.SetImproved(kTRUE);
+ break;
+ }
+
+ // if the worst cluster is not removable then stop improvement
+ if (!worstTrackParamAtCluster->IsRemovable()) {
+ // restore the kalman parameters in case they have been lost
+ if (!smoothed) RetraceTrack(track,kTRUE);
+ break;
+ }
+
+ // get track parameters at cluster next to the one to be removed
+ nextTrackParam = (AliMUONTrackParam*) track.GetTrackParamAtCluster()->After(worstTrackParamAtCluster);
+
+ // Remove the worst cluster
+ track.RemoveTrackParamAtCluster(worstTrackParamAtCluster);
+
+ // Re-calculate track parameters
+ // - from the cluster immediately downstream the one suppressed
+ // - or from the begining - if parameters have been re-computed using the standard method (kalman parameters have been lost)
+ // - or if the removed cluster was used to compute the tracking seed
+ Bool_t normalExtrap;
+ if (smoothed && nextTrackParam) {
+
+ nextChamber = nextTrackParam->GetClusterPtr()->GetChamberId();
+ next2nextTrackParam = nextTrackParam;
+ do {
+
+ next2nextChamber = next2nextTrackParam->GetClusterPtr()->GetChamberId();
+ next2nextTrackParam = (AliMUONTrackParam*) track.GetTrackParamAtCluster()->After(next2nextTrackParam);
+
+ } while (next2nextTrackParam && (next2nextChamber == nextChamber));
+
+ if (next2nextChamber == nextChamber) normalExtrap = RetraceTrack(track,kTRUE);
+ else normalExtrap = RetracePartialTrack(track,nextTrackParam);
+
+ } else normalExtrap = RetraceTrack(track,kTRUE);
+
+ // stop in case of extrapolation problem
+ if (!normalExtrap) {
+ AliWarning("track partially improved but problem occur during refitting --> stop improvement");
+ break;
+ }
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "ImproveTracks: track " << fRecTracksPtr->IndexOf(&track)+1 << " improved " << endl;
+ }
+
+ }
+
+}
+
+//__________________________________________________________________________
+Bool_t AliMUONTrackReconstructorK::FinalizeTrack(AliMUONTrack &track)
+{
+ /// Update track parameters and covariances at each attached cluster
+ /// using smoother if required, if not already done
+ /// return kFALSE if the track cannot be extrapolated uo to the last chamber
+
+ AliMUONTrackParam *trackParamAtCluster;
+ Bool_t smoothed = kFALSE;
+
+ // update track parameters (using smoother if required) if not already done
+ if (track.IsImproved()) smoothed = GetRecoParam()->UseSmoother();
+ else {
+ if (GetRecoParam()->UseSmoother()) smoothed = RunSmoother(track);
+ if (!smoothed) {
+ if (track.UpdateCovTrackParamAtCluster()) track.ComputeLocalChi2(kTRUE);
+ else {
+ AliWarning("finalization failed due to extrapolation problem");
+ return kFALSE;
+ }
+ }
+ }
+
+ // copy smoothed parameters and covariances if any
+ if (smoothed) {
+
+ trackParamAtCluster = (AliMUONTrackParam*) (track.GetTrackParamAtCluster()->First());
+ while (trackParamAtCluster) {
+
+ trackParamAtCluster->SetParameters(trackParamAtCluster->GetSmoothParameters());
+ trackParamAtCluster->SetCovariances(trackParamAtCluster->GetSmoothCovariances());
+
+ trackParamAtCluster = (AliMUONTrackParam*) (track.GetTrackParamAtCluster()->After(trackParamAtCluster));
+ }
+
+ }
+
+ return kTRUE;
+
+}
//__________________________________________________________________________
-void AliMUONTrackReconstructorK::EventDump(void)
+Bool_t AliMUONTrackReconstructorK::RefitTrack(AliMUONTrack &track, Bool_t enableImprovement)
{
- /// Dump reconstructed event (track parameters at vertex and at first hit),
- /// and the particle parameters
- AliDebug(1,"****** enter EventDump ******");
- AliDebug(1, Form("Number of Reconstructed tracks : %d", fNRecTracks));
-
- Int_t debug = ((AliMUONTrackK*) fRecTracksPtr->First())->DebugLevel();
- if (debug < 0) return;
-
- for (Int_t i = 0; i < fNRecTracks; ++i) {
- AliMUONTrackK *track = (AliMUONTrackK*) fRecTracksPtr->UncheckedAt(i);
- track->Print("");
+ /// re-fit the given track
+ AliDebug(1,"Enter RefitTrack");
+
+ // check validity of the track (i.e. at least 2 chambers hit on stations 4 and 5)
+ if (!track.IsValid(0)) {
+ AliWarning("the track is not valid --> unable to refit");
+ return kFALSE;
}
+
+ // re-compute track parameters and covariances using Kalman filter
+ if (!RetraceTrack(track,kTRUE)) {
+ AliWarning("bad track refitting due to extrapolation failure");
+ return kFALSE;
+ }
+
+ // Improve the reconstructed tracks if required
+ track.SetImproved(kFALSE);
+ if (enableImprovement && GetRecoParam()->ImproveTracks()) ImproveTrack(track);
+
+ // Fill AliMUONTrack data members
+ if (track.GetGlobalChi2() < AliMUONTrack::MaxChi2()) return FinalizeTrack(track);
+ else {
+ AliWarning("track not finalized due to extrapolation failure");
+ return kFALSE;
+ }
+
}
+
git://git.uio.no / u / mrichter / AliRoot.git / blobdiff