/* $Id$ */
-////////////////////////////////////
-//
-// MUON track reconstructor in ALICE (class renamed from AliMUONEventReconstructor)
-//
-// This class contains as data:
-// * the parameters for the track reconstruction
-// * a pointer to the array of hits to be reconstructed (the event)
-// * a pointer to the array of segments made with these hits inside each station
-// * a pointer to the array of reconstructed tracks
-//
-// It contains as methods, among others:
-// * MakeEventToBeReconstructed to build the array of hits to be reconstructed
-// * MakeSegments to build the segments
-// * MakeTracks to build the tracks
-//
-////////////////////////////////////
-
-#include <stdlib.h>
-#include <Riostream.h>
-#include <TDirectory.h>
-#include <TFile.h>
-#include <TMatrixD.h>
+//-----------------------------------------------------------------------------
+/// \class AliMUONTrackReconstructor
+/// MUON track reconstructor using the original method
+///
+/// This class contains as data:
+/// - the parameters for the track reconstruction
+///
+/// It contains as methods, among others:
+/// - MakeTracks to build the tracks
+//-----------------------------------------------------------------------------
#include "AliMUONTrackReconstructor.h"
-#include "AliMUON.h"
+
#include "AliMUONConstants.h"
-#include "AliMUONHitForRec.h"
-#include "AliMUONTriggerTrack.h"
-#include "AliMUONTriggerCircuitNew.h"
-#include "AliMUONRawCluster.h"
-#include "AliMUONLocalTrigger.h"
-#include "AliMUONGlobalTrigger.h"
-#include "AliMUONSegment.h"
+#include "AliMUONVCluster.h"
+#include "AliMUONVClusterServer.h"
+#include "AliMUONVClusterStore.h"
#include "AliMUONTrack.h"
-#include "AliMUONTrackHit.h"
-#include "AliMagF.h"
-#include "AliRun.h" // for gAlice
-#include "AliRunLoader.h"
-#include "AliLoader.h"
-#include "AliMUONTrackK.h"
-#include "AliLog.h"
-#include "AliTracker.h"
-
-//************* Defaults parameters for reconstruction
-const Double_t AliMUONTrackReconstructor::fgkDefaultMinBendingMomentum = 3.0;
-const Double_t AliMUONTrackReconstructor::fgkDefaultMaxBendingMomentum = 3000.0;
-const Double_t AliMUONTrackReconstructor::fgkDefaultMaxChi2 = 100.0;
-const Double_t AliMUONTrackReconstructor::fgkDefaultMaxSigma2Distance = 16.0;
-const Double_t AliMUONTrackReconstructor::fgkDefaultBendingResolution = 0.01;
-const Double_t AliMUONTrackReconstructor::fgkDefaultNonBendingResolution = 0.144;
-const Double_t AliMUONTrackReconstructor::fgkDefaultChamberThicknessInX0 = 0.03;
-// Simple magnetic field:
-// Value taken from macro MUONtracking.C: 0.7 T, hence 7 kG
-// Length and Position from reco_muon.F, with opposite sign:
-// Length = ZMAGEND-ZCOIL
-// Position = (ZMAGEND+ZCOIL)/2
-// to be ajusted differently from real magnetic field ????
-const Double_t AliMUONTrackReconstructor::fgkDefaultSimpleBValue = 7.0;
-const Double_t AliMUONTrackReconstructor::fgkDefaultSimpleBLength = 428.0;
-const Double_t AliMUONTrackReconstructor::fgkDefaultSimpleBPosition = 1019.0;
-const Double_t AliMUONTrackReconstructor::fgkDefaultEfficiency = 0.95;
-
-ClassImp(AliMUONTrackReconstructor) // Class implementation in ROOT context
-
-//__________________________________________________________________________
-AliMUONTrackReconstructor::AliMUONTrackReconstructor(AliLoader* loader, AliMUONData* data)
- : TObject(),
- fTrackMethod(1), //AZ - tracking method (1-default, 2-Kalman)
- fMinBendingMomentum(fgkDefaultMinBendingMomentum),
- fMaxBendingMomentum(fgkDefaultMaxBendingMomentum),
- fMaxChi2(fgkDefaultMaxChi2),
- fMaxSigma2Distance(fgkDefaultMaxSigma2Distance),
- fBendingResolution(fgkDefaultBendingResolution),
- fNonBendingResolution(fgkDefaultNonBendingResolution),
- fChamberThicknessInX0(fgkDefaultChamberThicknessInX0),
- fSimpleBValue(fgkDefaultSimpleBValue),
- fSimpleBLength(fgkDefaultSimpleBLength),
- fSimpleBPosition(fgkDefaultSimpleBPosition),
- fEfficiency(fgkDefaultEfficiency),
- fHitsForRecPtr(0x0),
- fNHitsForRec(0),
- fRecTracksPtr(0x0),
- fNRecTracks(0),
- fRecTrackHitsPtr(0x0),
- fNRecTrackHits(0),
- fMUONData(data),
- fLoader(loader),
- fMuons(0),
- fTriggerTrack(new AliMUONTriggerTrack())
-{
- // Constructor for class AliMUONTrackReconstructor
- SetReconstructionParametersToDefaults();
-
- // Memory allocation for the TClonesArray of hits for reconstruction
- // Is 10000 the right size ????
- fHitsForRecPtr = new TClonesArray("AliMUONHitForRec", 10000);
+#include "AliMUONTrackParam.h"
+#include "AliMUONTrackExtrap.h"
+#include "AliMUONRecoParam.h"
+#include "AliMUONGeometryTransformer.h"
- // Memory allocation for the TClonesArray's of segments in stations
- // Is 2000 the right size ????
- for (Int_t st = 0; st < AliMUONConstants::NTrackingCh()/2; st++) {
- fSegmentsPtr[st] = new TClonesArray("AliMUONSegment", 2000);
- fNSegments[st] = 0; // really needed or GetEntriesFast sufficient ????
- }
- // Memory allocation for the TClonesArray of reconstructed tracks
- // Is 10 the right size ????
- fRecTracksPtr = new TClonesArray("AliMUONTrack", 10);
+#include "AliMpArea.h"
- // Memory allocation for the TClonesArray of hits on reconstructed tracks
- // Is 100 the right size ????
- fRecTrackHitsPtr = new TClonesArray("AliMUONTrackHit", 100);
-
- const AliMagF* kField = AliTracker::GetFieldMap();
- if (!kField) AliFatal("No field available");
- // Sign of fSimpleBValue according to sign of Bx value at (50,50,-950).
- Float_t b[3], x[3];
- x[0] = 50.; x[1] = 50.; x[2] = -950.;
- kField->Field(x,b);
+#include "AliLog.h"
- fSimpleBValue = TMath::Sign(fSimpleBValue,(Double_t) b[0]);
- fSimpleBPosition = TMath::Sign(fSimpleBPosition,(Double_t) x[2]);
- // See how to get fSimple(BValue, BLength, BPosition)
- // automatically calculated from the actual magnetic field ????
+#include <TMinuit.h>
+#include <Riostream.h>
+#include <TMath.h>
+#include <TMatrixD.h>
+#include <TClonesArray.h>
- return;
-}
+// Functions to be minimized with Minuit
+void TrackChi2(Int_t &nParam, Double_t *gradient, Double_t &chi2, Double_t *param, Int_t flag);
- //__________________________________________________________________________
-AliMUONTrackReconstructor::~AliMUONTrackReconstructor(void)
-{
- // Destructor for class AliMUONTrackReconstructor
- delete fHitsForRecPtr; // Correct destruction of everything ???? or delete [] ????
- for (Int_t st = 0; st < AliMUONConstants::NTrackingCh()/2; st++)
- delete fSegmentsPtr[st]; // Correct destruction of everything ????
+using std::endl;
+using std::cout;
+/// \cond CLASSIMP
+ClassImp(AliMUONTrackReconstructor) // Class implementation in ROOT context
+/// \endcond
- delete fTriggerTrack;
-}
//__________________________________________________________________________
-void AliMUONTrackReconstructor::SetReconstructionParametersToDefaults(void)
+AliMUONTrackReconstructor::AliMUONTrackReconstructor(const AliMUONRecoParam* recoParam, AliMUONVClusterServer* clusterServer,
+ const AliMUONGeometryTransformer* transformer)
+ : AliMUONVTrackReconstructor(recoParam, clusterServer, transformer)
{
- // Set reconstruction parameters to default values
- // Would be much more convenient with a structure (or class) ????
-
- // ******** Parameters for making HitsForRec
- // minimum radius,
- // like in TRACKF_STAT:
- // 2 degrees for stations 1 and 2, or ch(0...) from 0 to 3;
- // 30 cm for stations 3 to 5, or ch(0...) from 4 to 9
- for (Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) {
- if (ch < 4) fRMin[ch] = TMath::Abs(AliMUONConstants::DefaultChamberZ(ch)) *
- 2.0 * TMath::Pi() / 180.0;
- else fRMin[ch] = 30.0;
- // maximum radius at 10 degrees and Z of chamber
- fRMax[ch] = TMath::Abs(AliMUONConstants::DefaultChamberZ(ch)) *
- 10.0 * TMath::Pi() / 180.0;
- }
-
- // ******** Parameters for making segments
- // should be parametrized ????
- // according to interval between chambers in a station ????
- // Maximum distance in non bending plane
- // 5 * 0.22 just to remember the way it was made in TRACKF_STAT
- // SIGCUT*DYMAX(IZ)
- for (Int_t st = 0; st < AliMUONConstants::NTrackingCh()/2; st++)
- fSegmentMaxDistNonBending[st] = 5. * 0.22;
- // Maximum distance in bending plane:
- // values from TRACKF_STAT, corresponding to (J psi 20cm),
- // scaled to the real distance between chambers in a station
- fSegmentMaxDistBending[0] = TMath::Abs( 1.5 *
- (AliMUONConstants::DefaultChamberZ(1) - AliMUONConstants::DefaultChamberZ(0)) / 20.0);
- fSegmentMaxDistBending[1] = TMath::Abs( 1.5 *
- (AliMUONConstants::DefaultChamberZ(3) - AliMUONConstants::DefaultChamberZ(2)) / 20.0);
- fSegmentMaxDistBending[2] = TMath::Abs( 3.0 *
- (AliMUONConstants::DefaultChamberZ(5) - AliMUONConstants::DefaultChamberZ(4)) / 20.0);
- fSegmentMaxDistBending[3] = TMath::Abs( 6.0 *
- (AliMUONConstants::DefaultChamberZ(7) - AliMUONConstants::DefaultChamberZ(6)) / 20.0);
- fSegmentMaxDistBending[4] = TMath::Abs( 6.0 *
- (AliMUONConstants::DefaultChamberZ(9) - AliMUONConstants::DefaultChamberZ(8)) / 20.0);
-
- return;
+ /// Constructor
}
-//__________________________________________________________________________
-Double_t AliMUONTrackReconstructor::GetImpactParamFromBendingMomentum(Double_t BendingMomentum) const
+ //__________________________________________________________________________
+AliMUONTrackReconstructor::~AliMUONTrackReconstructor()
{
- // Returns impact parameter at vertex in bending plane (cm),
- // from the signed bending momentum "BendingMomentum" in bending plane (GeV/c),
- // using simple values for dipole magnetic field.
- // The sign of "BendingMomentum" is the sign of the charge.
- return (-0.0003 * fSimpleBValue * fSimpleBLength * fSimpleBPosition /
- BendingMomentum);
-}
+/// Destructor
+}
-//__________________________________________________________________________
-Double_t AliMUONTrackReconstructor::GetBendingMomentumFromImpactParam(Double_t ImpactParam) const
+ //__________________________________________________________________________
+Bool_t AliMUONTrackReconstructor::MakeTrackCandidates(AliMUONVClusterStore& clusterStore)
{
- // Returns signed bending momentum in bending plane (GeV/c),
- // the sign being the sign of the charge for particles moving forward in Z,
- // from the impact parameter "ImpactParam" at vertex in bending plane (cm),
- // using simple values for dipole magnetic field.
- return (-0.0003 * fSimpleBValue * fSimpleBLength * fSimpleBPosition /
- ImpactParam);
-}
+ /// To make track candidates (assuming linear propagation if the flag fgkMakeTrackCandidatesFast is set to 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.
+ /// Keep only best candidates or all of them according to the flag fgkTrackAllTracks.
+
+ TClonesArray *segments;
+ AliMUONTrack *track;
+ Int_t iCandidate = 0;
+ Bool_t clusterFound;
-//__________________________________________________________________________
-void AliMUONTrackReconstructor::EventReconstruct(void)
-{
- // To reconstruct one event
- AliDebug(1,"Enter EventReconstruct");
- ResetTracks(); //AZ
- ResetTrackHits(); //AZ
- ResetSegments(); //AZ
- ResetHitsForRec(); //AZ
- MakeEventToBeReconstructed();
- MakeSegments();
- MakeTracks();
- if (fMUONData->IsTriggerTrackBranchesInTree())
- ValidateTracksWithTrigger();
+ AliDebug(1,"Enter MakeTrackCandidates");
- // Add tracks to MUON data container
- for(Int_t i=0; i<GetNRecTracks(); i++) {
- AliMUONTrack * track = (AliMUONTrack*) GetRecTracksPtr()->At(i);
- fMUONData->AddRecTrack(*track);
+ // 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;
}
- return;
-}
-
-//__________________________________________________________________________
-void AliMUONTrackReconstructor::EventReconstructTrigger(void)
-{
- // To reconstruct one event
- AliDebug(1,"Enter EventReconstructTrigger");
- MakeTriggerTracks();
- return;
-}
-
- //__________________________________________________________________________
-void AliMUONTrackReconstructor::ResetHitsForRec(void)
-{
- // To reset the array and the number of HitsForRec,
- // and also the number of HitsForRec
- // and the index of the first HitForRec per chamber
- if (fHitsForRecPtr) fHitsForRecPtr->Delete();
- fNHitsForRec = 0;
- for (Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++)
- fNHitsForRecPerChamber[ch] = fIndexOfFirstHitForRecPerChamber[ch] = 0;
- return;
-}
-
- //__________________________________________________________________________
-void AliMUONTrackReconstructor::ResetSegments(void)
-{
- // To reset the TClonesArray of segments and the number of Segments
- // for all stations
- for (Int_t st = 0; st < AliMUONConstants::NTrackingCh()/2; st++) {
- if (fSegmentsPtr[st]) fSegmentsPtr[st]->Clear();
- fNSegments[st] = 0;
+ for (Int_t i = firstChamber; i <= lastChamber; ++i )
+ {
+ if (fClusterServer && GetRecoParam()->UseChamber(i)) fClusterServer->Clusterize(i, clusterStore, AliMpArea(), GetRecoParam());
}
- return;
-}
-
- //__________________________________________________________________________
-void AliMUONTrackReconstructor::ResetTracks(void)
-{
- // To reset the TClonesArray of reconstructed tracks
- if (fRecTracksPtr) fRecTracksPtr->Delete();
- // Delete in order that the Track destructors are called,
- // hence the space for the TClonesArray of pointers to TrackHit's is freed
- fNRecTracks = 0;
- return;
+
+ // 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 = MakeSegmentsBetweenChambers(clusterStore, 2*istat, 2*istat+1);
+
+ // Loop over segments
+ for (Int_t iseg=0; iseg<segments->GetEntriesFast(); iseg++)
+ {
+ AliDebug(1,Form("Making primary candidate(1..) %d",++iCandidate));
+
+ // Transform segments to tracks and put them at the end of fRecTracksPtr
+ track = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack((AliMUONObjectPair*)((*segments)[iseg]),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() - iseg - 1) > GetRecoParam()->GetMaxTrackCandidates()) {
+ AliError(Form("Too many track candidates (%d tracks). Stop tracking.", fNRecTracks + segments->GetEntriesFast() - iseg - 1));
+ return kFALSE;
+ }
+ }
+
+ }
+
+ }
+
+ // Keep all different tracks or only the best ones as required
+ if (GetRecoParam()->TrackAllTracks()) RemoveIdenticalTracks();
+ else RemoveDoubleTracks();
+
+ AliDebug(1,Form("Number of good candidates = %d",fNRecTracks));
+
+ return kTRUE;
+
}
-
//__________________________________________________________________________
-void AliMUONTrackReconstructor::ResetTrackHits(void)
+Bool_t AliMUONTrackReconstructor::MakeMoreTrackCandidates(AliMUONVClusterStore& clusterStore)
{
- // To reset the TClonesArray of hits on reconstructed tracks
- if (fRecTrackHitsPtr) fRecTrackHitsPtr->Clear();
- fNRecTrackHits = 0;
- return;
+ /// To make extra track candidates (assuming linear propagation if the flag fgkMakeTrackCandidatesFast is set to kTRUE):
+ /// 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 station 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;
+ 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 in the station
+ 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;
+ }
+
+ }
+
+ }
+ }
+
+ // 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 AliMUONTrackReconstructor::MakeEventToBeReconstructed(void)
+Bool_t AliMUONTrackReconstructor::FollowTracks(AliMUONVClusterStore& clusterStore)
{
- // To make the list of hits to be reconstructed,
- // either from the track ref. hits or from the raw clusters
- // according to the parameter set for the reconstructor
-
- AliRunLoader *runLoader = fLoader->GetRunLoader();
-
- AliDebug(1,"Enter MakeEventToBeReconstructed");
- //AZ ResetHitsForRec();
-
- // Reconstruction from raw clusters
- // AliMUON *MUON = (AliMUON*) gAlice->GetModule("MUON"); // necessary ????
- // Security on MUON ????
- // TreeR assumed to be be "prepared" in calling function
- // by "MUON->GetTreeR(nev)" ????
- TTree *treeR = fLoader->TreeR();
-
- //AZ? fMUONData->SetTreeAddress("RC");
- AddHitsForRecFromRawClusters(treeR);
- // No sorting: it is done automatically in the previous function
-
-
- AliDebug(1,"End of MakeEventToBeReconstructed");
- if (AliLog::GetGlobalDebugLevel() > 0) {
- AliDebug(1, Form("NHitsForRec: %d",fNHitsForRec));
- for (Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) {
- AliDebug(1, Form("Chamber(0...): %d",ch));
- AliDebug(1, Form("NHitsForRec: %d", fNHitsForRecPerChamber[ch]));
- AliDebug(1, Form("Index(first HitForRec): %d", fIndexOfFirstHitForRecPerChamber[ch]));
- for (Int_t hit = fIndexOfFirstHitForRecPerChamber[ch];
- hit < fIndexOfFirstHitForRecPerChamber[ch] + fNHitsForRecPerChamber[ch];
- hit++) {
- AliDebug(1, Form("HitForRec index(0...): %d",hit));
- ((*fHitsForRecPtr)[hit])->Dump();
+ /// Follow tracks in stations(1..) 3, 2 and 1
+ AliDebug(1,"Enter FollowTracks");
+
+ AliMUONTrack *track, *nextTrack;
+ AliMUONTrackParam *trackParam, *nextTrackParam;
+ Int_t currentNRecTracks;
+
+ Double_t sigmaCut2 = GetRecoParam()->GetSigmaCutForTracking() *
+ GetRecoParam()->GetSigmaCutForTracking();
+
+ 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);
+
+ // Fit the track:
+ // Do not take into account the multiple scattering to speed up the fit
+ // Calculate the track parameter covariance matrix
+ // If there is no cluster out of station 4 or 5 then use the vertex to better constrain the fit
+ if (((AliMUONTrackParam*) track->GetTrackParamAtCluster()->First())->GetClusterPtr()->GetChamberId() > 5)
+ Fit(*track, kFALSE, kTRUE, kTRUE);
+ else Fit(*track, kFALSE, kFALSE, kTRUE);
+
+ // remove tracks out of limits
+ if (!IsAcceptable(*((AliMUONTrackParam*)track->GetTrackParamAtCluster()->First()))) {
+ fRecTracksPtr->Remove(track);
+ fNRecTracks--;
+ continue;
+ }
+
+ // remove track if the normalized chi2 is too high
+ if (track->GetNormalizedChi2() > sigmaCut2) {
+ fRecTracksPtr->Remove(track);
+ fNRecTracks--;
+ continue;
+ }
+
+ // save parameters from fit into smoothed parameters to complete track afterward
+ if (GetRecoParam()->ComplementTracks()) {
+
+ if (station==2) { // save track parameters on stations 4 and 5
+
+ // extrapolate track parameters and covariances at each cluster
+ // remove the track in case of failure
+ if (!track->UpdateCovTrackParamAtCluster()) {
+ fRecTracksPtr->Remove(track);
+ fNRecTracks--;
+ continue;
+ }
+
+ // save them
+ trackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->First();
+ while (trackParam) {
+ trackParam->SetSmoothParameters(trackParam->GetParameters());
+ trackParam->SetSmoothCovariances(trackParam->GetCovariances());
+ trackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->After(trackParam);
+ }
+
+ } else { // or save track parameters on last station only
+
+ trackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->First();
+ if (trackParam->GetClusterPtr()->GetChamberId() < 2*(station+2)) {
+
+ // save parameters from fit
+ trackParam->SetSmoothParameters(trackParam->GetParameters());
+ trackParam->SetSmoothCovariances(trackParam->GetCovariances());
+
+ // save parameters extrapolated to the second chamber of the same station if it has been hit
+ nextTrackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->After(trackParam);
+ if (nextTrackParam->GetClusterPtr()->GetChamberId() < 2*(station+2)) {
+
+ // reset parameters and covariances
+ nextTrackParam->SetParameters(trackParam->GetParameters());
+ nextTrackParam->SetZ(trackParam->GetZ());
+ nextTrackParam->SetCovariances(trackParam->GetCovariances());
+
+ // extrapolate them to the z of the corresponding cluster
+ // remove the track in case of failure
+ if (!AliMUONTrackExtrap::ExtrapToZCov(nextTrackParam, nextTrackParam->GetClusterPtr()->GetZ())) {
+ fRecTracksPtr->Remove(track);
+ fNRecTracks--;
+ continue;
+ }
+
+ // save them
+ nextTrackParam->SetSmoothParameters(nextTrackParam->GetParameters());
+ nextTrackParam->SetSmoothCovariances(nextTrackParam->GetCovariances());
+
+ }
+
+ }
+
+ }
+
+ }
+
+ // 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--;
+ }
+
+ }
+
+ // abort tracking if there are too many candidates
+ if (fNRecTracks > GetRecoParam()->GetMaxTrackCandidates()) {
+ AliError(Form("Too many track candidates (%d tracks). Stop tracking.", fNRecTracks));
+ return kFALSE;
+ }
+
+ }
+
+ // Compress fRecTracksPtr for the next step
+ fRecTracksPtr->Compress();
+
+ // Keep only the best tracks if required
+ if (!GetRecoParam()->TrackAllTracks()) RemoveDoubleTracks();
+
+ }
+
+ // Last fit of track candidates with all stations
+ // Take into account the multiple scattering and remove bad tracks
+ Int_t trackIndex = -1;
+ track = (AliMUONTrack*) fRecTracksPtr->First();
+ while (track) {
+
+ trackIndex++;
+ nextTrack = (AliMUONTrack*) fRecTracksPtr->After(track); // prepare next track
+
+ Fit(*track, kTRUE, kFALSE, kTRUE);
+
+ // Printout for debuging
+ if (AliLog::GetGlobalDebugLevel() >= 3) {
+ cout << "FollowTracks: track candidate(0..) " << trackIndex << " after final fit" << endl;
+ track->RecursiveDump();
+ }
+
+ // Remove the track if the normalized chi2 is too high
+ if (track->GetNormalizedChi2() > sigmaCut2) {
+ fRecTracksPtr->Remove(track);
+ fNRecTracks--;
+ track = nextTrack;
+ continue;
+ }
+
+ // save parameters from fit into smoothed parameters to complete track afterward
+ if (GetRecoParam()->ComplementTracks()) {
+
+ trackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->First();
+ if (trackParam->GetClusterPtr()->GetChamberId() < 2) {
+
+ // save parameters from fit
+ trackParam->SetSmoothParameters(trackParam->GetParameters());
+ trackParam->SetSmoothCovariances(trackParam->GetCovariances());
+
+ // save parameters extrapolated to the second chamber of the same station if it has been hit
+ nextTrackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->After(trackParam);
+ if (nextTrackParam->GetClusterPtr()->GetChamberId() < 2) {
+
+ // reset parameters and covariances
+ nextTrackParam->SetParameters(trackParam->GetParameters());
+ nextTrackParam->SetZ(trackParam->GetZ());
+ nextTrackParam->SetCovariances(trackParam->GetCovariances());
+
+ // extrapolate them to the z of the corresponding cluster
+ // remove the track in case of failure
+ if (!AliMUONTrackExtrap::ExtrapToZCov(nextTrackParam, nextTrackParam->GetClusterPtr()->GetZ())) {
+ fRecTracksPtr->Remove(track);
+ fNRecTracks--;
+ track = nextTrack;
+ continue;
+ }
+
+ // save them
+ nextTrackParam->SetSmoothParameters(nextTrackParam->GetParameters());
+ nextTrackParam->SetSmoothCovariances(nextTrackParam->GetCovariances());
+
+ }
+
}
+
}
+
+ track = nextTrack;
+
}
- return;
+
+ fRecTracksPtr->Compress();
+
+ return kTRUE;
+
}
//__________________________________________________________________________
-void AliMUONTrackReconstructor::SortHitsForRecWithIncreasingChamber()
+Bool_t AliMUONTrackReconstructor::FollowTrackInChamber(AliMUONTrack &trackCandidate, AliMUONVClusterStore& clusterStore, Int_t nextChamber)
{
- // Sort HitsForRec's in increasing order with respect to chamber number.
- // Uses the function "Compare".
- // Update the information for HitsForRec per chamber too.
- Int_t ch, nhits, prevch;
- fHitsForRecPtr->Sort();
- for (ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) {
- fNHitsForRecPerChamber[ch] = 0;
- fIndexOfFirstHitForRecPerChamber[ch] = 0;
+ /// 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.
+ AliDebug(1,Form("Enter FollowTrackInChamber(1..) %d", nextChamber+1));
+
+ Double_t chi2WithOneCluster = AliMUONTrack::MaxChi2();
+ Double_t maxChi2WithOneCluster = 2. * GetRecoParam()->GetSigmaCutForTracking() *
+ GetRecoParam()->GetSigmaCutForTracking(); // 2 because 2 quantities in chi2
+ Double_t bestChi2WithOneCluster = maxChi2WithOneCluster;
+ Bool_t foundOneCluster = kFALSE;
+ AliMUONTrack *newTrack = 0x0;
+ AliMUONVCluster *cluster;
+ AliMUONTrackParam extrapTrackParam;
+ 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","AliMUONTrackReconstructor") >= 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.);
+
+ // 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))) return kFALSE;
+ // add MCS effect
+ AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(currentChamber),-1.);
+ }
+
+ //Extrapolate trackCandidate to chamber
+ if (!AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(nextChamber))) return kFALSE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 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","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: 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);
}
- prevch = 0; // previous chamber
- nhits = 0; // number of hits in current chamber
- // Loop over HitsForRec
- for (Int_t hit = 0; hit < fNHitsForRec; hit++) {
- // chamber number (0...)
- ch = ((AliMUONHitForRec*) ((*fHitsForRecPtr)[hit]))->GetChamberNumber();
- // increment number of hits in current chamber
- (fNHitsForRecPerChamber[ch])++;
- // update index of first HitForRec in current chamber
- // if chamber number different from previous one
- if (ch != prevch) {
- fIndexOfFirstHitForRecPerChamber[ch] = hit;
- prevch = ch;
+
+ // Create iterators to loop over clusters in both chambers
+ TIter next(clusterStore.CreateChamberIterator(nextChamber,nextChamber));
+
+ // look for cluster 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
+ chi2WithOneCluster = TryOneCluster(extrapTrackParamAtCh, cluster, extrapTrackParamAtCluster);
+
+ // if good chi2 then consider to add cluster
+ if (chi2WithOneCluster < maxChi2WithOneCluster) {
+ foundOneCluster = kTRUE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: found one cluster in chamber(1..): " << nextChamber+1
+ << " (Chi2 = " << chi2WithOneCluster << ")" << 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);
+ fNRecTracks++;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: added one cluster in chamber(1..): " << nextChamber+1 << endl;
+ if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
+ }
+
+ } else if (chi2WithOneCluster < bestChi2WithOneCluster) {
+ // keep track of the best single cluster except if a couple of clusters has already been found
+ bestChi2WithOneCluster = chi2WithOneCluster;
+ bestTrackParamAtCluster = extrapTrackParamAtCluster;
+ }
+
}
+
}
- return;
+
+ // fill out the best track if required else clean up the fRecTracksPtr array
+ if (!GetRecoParam()->TrackAllTracks()) {
+ if (foundOneCluster) {
+ UpdateTrack(trackCandidate,bestTrackParamAtCluster);
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: 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;
+
}
//__________________________________________________________________________
-void AliMUONTrackReconstructor::AddHitsForRecFromRawClusters(TTree* TR)
+Bool_t AliMUONTrackReconstructor::FollowTrackInStation(AliMUONTrack &trackCandidate, AliMUONVClusterStore& clusterStore, Int_t nextStation)
{
- // To add to the list of hits for reconstruction all the raw clusters
- // No condition added, like in Fortran TRACKF_STAT,
- // on the radius between RMin and RMax.
- AliMUONHitForRec *hitForRec;
- AliMUONRawCluster *clus;
- Int_t iclus, nclus, nTRentries;
- TClonesArray *rawclusters;
- AliDebug(1,"Enter AddHitsForRecFromRawClusters");
-
- if (fTrackMethod != 3) { //AZ
- fMUONData->SetTreeAddress("RC"); //AZ
- nTRentries = Int_t(TR->GetEntries());
- if (nTRentries != 1) {
- AliError(Form("nTRentries = %d not equal to 1 ",nTRentries));
- exit(0);
+ /// 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.
+ 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 chi2WithOneCluster = AliMUONTrack::MaxChi2();
+ Double_t chi2WithTwoClusters = AliMUONTrack::MaxChi2();
+ Double_t maxChi2WithOneCluster = 2. * GetRecoParam()->GetSigmaCutForTracking() *
+ GetRecoParam()->GetSigmaCutForTracking(); // 2 because 2 quantities in chi2
+ Double_t maxChi2WithTwoClusters = 4. * GetRecoParam()->GetSigmaCutForTracking() *
+ GetRecoParam()->GetSigmaCutForTracking(); // 4 because 4 quantities in chi2
+ Double_t bestChi2WithOneCluster = maxChi2WithOneCluster;
+ Double_t bestChi2WithTwoClusters = maxChi2WithTwoClusters;
+ 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","AliMUONTrackReconstructor") >= 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.);
+
+ // 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))) return kFALSE;
+ // add MCS effect
+ AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(currentChamber),-1.);
+ }
+
+ //Extrapolate trackCandidate to chamber "ch2"
+ if (!AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(ch2))) return kFALSE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 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","AliMUONTrackReconstructor") >= 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
+ chi2WithOneCluster = TryOneCluster(extrapTrackParamAtCh, clusterCh2, extrapTrackParamAtCluster2);
+
+ // if good chi2 then try to attach a cluster in the other chamber too
+ if (chi2WithOneCluster < maxChi2WithOneCluster) {
+ Bool_t foundSecondCluster = kFALSE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: found one cluster in chamber(1..): " << ch2+1
+ << " (Chi2 = " << chi2WithOneCluster << ")" << endl;
+ clusterCh2->Print();
+ cout << " look for second clusters in chamber(1..): " << ch1+1 << " ..." << endl;
+ }
+
+ // add MCS effect for next step
+ AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCluster2,AliMUONConstants::ChamberThicknessInX0(ch2),-1.);
+
+ // copy new track parameters for next step
+ extrapTrackParam = extrapTrackParamAtCluster2;
+
+ //Extrapolate track parameters to chamber "ch1"
+ Bool_t normalExtrap = AliMUONTrackExtrap::ExtrapToZ(&extrapTrackParam, AliMUONConstants::DefaultChamberZ(ch1));
+
+ // 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++;
+
+ // try to add the current cluster fast
+ if (!TryOneClusterFast(extrapTrackParam, clusterCh1)) continue;
+
+ // try to add the current cluster accurately
+ chi2WithTwoClusters = TryTwoClusters(extrapTrackParamAtCluster2, clusterCh1, extrapTrackParamAtCluster1);
+
+ // if good chi2 then create a new track by adding the 2 clusters to the "trackCandidate"
+ if (chi2WithTwoClusters < maxChi2WithTwoClusters) {
+ foundSecondCluster = kTRUE;
+ foundTwoClusters = kTRUE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: found second cluster in chamber(1..): " << ch1+1
+ << " (Global Chi2 = " << chi2WithTwoClusters << ")" << 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);
+ fNRecTracks++;
+
+ // Tag clusterCh1 as used
+ clusterCh1Used[iCluster1] = kTRUE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: added two clusters in station(1..): " << nextStation+1 << endl;
+ if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
+ }
+
+ } else if (chi2WithTwoClusters < bestChi2WithTwoClusters) {
+ // keep track of the best couple of clusters
+ bestChi2WithTwoClusters = chi2WithTwoClusters;
+ bestTrackParamAtCluster1 = extrapTrackParamAtCluster1;
+ bestTrackParamAtCluster2 = extrapTrackParamAtCluster2;
+ }
+
+ }
+
+ }
+
+ // if no clusterCh1 found then consider to add clusterCh2 only
+ if (!foundSecondCluster) {
+ 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);
+ fNRecTracks++;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: added one cluster in chamber(1..): " << ch2+1 << endl;
+ if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
+ }
+
+ } else if (!foundTwoClusters && chi2WithOneCluster < bestChi2WithOneCluster) {
+ // keep track of the best single cluster except if a couple of clusters has already been found
+ bestChi2WithOneCluster = chi2WithOneCluster;
+ bestTrackParamAtCluster1 = extrapTrackParamAtCluster2;
+ }
+
+ }
+
}
- fLoader->TreeR()->GetEvent(0); // only one entry
+
}
-
- // Loop over tracking chambers
- for (Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) {
- // number of HitsForRec to 0 for the chamber
- fNHitsForRecPerChamber[ch] = 0;
- // index of first HitForRec for the chamber
- if (ch == 0) fIndexOfFirstHitForRecPerChamber[ch] = 0;
- else fIndexOfFirstHitForRecPerChamber[ch] = fNHitsForRec;
- rawclusters =fMUONData->RawClusters(ch);
- nclus = (Int_t) (rawclusters->GetEntries());
- // Loop over (cathode correlated) raw clusters
- for (iclus = 0; iclus < nclus; iclus++) {
- clus = (AliMUONRawCluster*) rawclusters->UncheckedAt(iclus);
- // new AliMUONHitForRec from raw cluster
- // and increment number of AliMUONHitForRec's (total and in chamber)
- hitForRec = new ((*fHitsForRecPtr)[fNHitsForRec]) AliMUONHitForRec(clus);
- fNHitsForRec++;
- (fNHitsForRecPerChamber[ch])++;
- // more information into HitForRec
- // resolution: info should be already in raw cluster and taken from it ????
- //hitForRec->SetBendingReso2(fBendingResolution * fBendingResolution);
- //hitForRec->SetNonBendingReso2(fNonBendingResolution * fNonBendingResolution);
- hitForRec->SetBendingReso2(clus->GetErrY() * clus->GetErrY());
- hitForRec->SetNonBendingReso2(clus->GetErrX() * clus->GetErrX());
- // original raw cluster
- hitForRec->SetChamberNumber(ch);
- hitForRec->SetHitNumber(iclus);
- // Z coordinate of the raw cluster (cm)
- hitForRec->SetZ(clus->GetZ(0));
- if (AliLog::GetGlobalDebugLevel() > 1) {
- cout << "chamber (0...): " << ch <<
- " raw cluster (0...): " << iclus << endl;
- clus->Dump();
- cout << "AliMUONHitForRec number (1...): " << fNHitsForRec << endl;
- hitForRec->Dump();}
- } // end of cluster loop
- } // end of chamber loop
- SortHitsForRecWithIncreasingChamber();
- return;
+
+ // 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));
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 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();
+ }
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 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 cluster already used
+
+ // try to add the current cluster fast
+ if (!TryOneClusterFast(extrapTrackParamAtCh, clusterCh1)) continue;
+
+ // try to add the current cluster accuratly
+ chi2WithOneCluster = TryOneCluster(extrapTrackParamAtCh, clusterCh1, extrapTrackParamAtCluster1);
+
+ // 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 (chi2WithOneCluster < maxChi2WithOneCluster) {
+ foundOneCluster = kTRUE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: found one cluster in chamber(1..): " << ch1+1
+ << " (Chi2 = " << chi2WithOneCluster << ")" << 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);
+ fNRecTracks++;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: added one cluster in chamber(1..): " << ch1+1 << endl;
+ if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
+ }
+
+ } else if (chi2WithOneCluster < bestChi2WithOneCluster) {
+ // keep track of the best single cluster except if a couple of clusters has already been found
+ bestChi2WithOneCluster = chi2WithOneCluster;
+ bestTrackParamAtCluster1 = extrapTrackParamAtCluster1;
+ }
+
+ }
+
+ }
+
+ }
+
+ // fill out the best track if required else clean up the fRecTracksPtr array
+ if (!GetRecoParam()->TrackAllTracks()) {
+ if (foundTwoClusters) {
+ UpdateTrack(trackCandidate,bestTrackParamAtCluster1,bestTrackParamAtCluster2);
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 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);
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 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;
+ }
+
+ } else if (foundOneCluster || foundTwoClusters) {
+
+ // remove obsolete track
+ fRecTracksPtr->Remove(&trackCandidate);
+ fNRecTracks--;
+
+ } else {
+ delete [] clusterCh1Used;
+ return kFALSE;
+ }
+
+ delete [] clusterCh1Used;
+ return kTRUE;
+
}
//__________________________________________________________________________
-void AliMUONTrackReconstructor::MakeSegments(void)
+Double_t AliMUONTrackReconstructor::TryTwoClusters(const AliMUONTrackParam &trackParamAtCluster1, AliMUONVCluster* cluster2,
+ AliMUONTrackParam &trackParamAtCluster2)
{
- // To make the list of segments in all stations,
- // from the list of hits to be reconstructed
- AliDebug(1,"Enter MakeSegments");
- //AZ ResetSegments();
- // Loop over stations
- Int_t nb = (fTrackMethod != 1) ? 3 : 0; //AZ
- for (Int_t st = nb; st < AliMUONConstants::NTrackingCh()/2; st++)
- MakeSegmentsPerStation(st);
- if (AliLog::GetGlobalDebugLevel() > 1) {
- cout << "end of MakeSegments" << endl;
- for (Int_t st = 0; st < AliMUONConstants::NTrackingCh()/2; st++) {
- cout << "station(0...): " << st
- << " Segments: " << fNSegments[st]
- << endl;
- for (Int_t seg = 0;
- seg < fNSegments[st];
- seg++) {
- cout << "Segment index(0...): " << seg << endl;
- ((*fSegmentsPtr[st])[seg])->Dump();
+/// Test the compatibility between the track and the 2 clusters together (using trackParam's covariance matrix):
+/// return the corresponding Chi2 accounting for covariances between the 2 clusters
+/// return trackParamAtCluster1 & 2
+
+ // extrapolate track parameters at the z position of the second cluster (no need to extrapolate the covariances)
+ // and set pointer to cluster into trackParamAtCluster
+ trackParamAtCluster2.SetParameters(trackParamAtCluster1.GetParameters());
+ trackParamAtCluster2.SetZ(trackParamAtCluster1.GetZ());
+ trackParamAtCluster2.SetClusterPtr(cluster2);
+ if (!AliMUONTrackExtrap::ExtrapToZ(&trackParamAtCluster2, cluster2->GetZ())) return 2.*AliMUONTrack::MaxChi2();
+
+ // Set differences between track and the 2 clusters in the bending and non bending directions
+ AliMUONVCluster* cluster1 = trackParamAtCluster1.GetClusterPtr();
+ TMatrixD dPos(4,1);
+ dPos(0,0) = cluster1->GetX() - trackParamAtCluster1.GetNonBendingCoor();
+ dPos(1,0) = cluster1->GetY() - trackParamAtCluster1.GetBendingCoor();
+ dPos(2,0) = cluster2->GetX() - trackParamAtCluster2.GetNonBendingCoor();
+ dPos(3,0) = cluster2->GetY() - trackParamAtCluster2.GetBendingCoor();
+
+ // Calculate the error matrix from the track parameter covariances at first cluster
+ TMatrixD error(4,4);
+ error.Zero();
+ if (trackParamAtCluster1.CovariancesExist()) {
+ // Save track parameters at first cluster
+ TMatrixD paramAtCluster1Save(trackParamAtCluster1.GetParameters());
+
+ // Save track coordinates at second cluster
+ Double_t nonBendingCoor2 = trackParamAtCluster2.GetNonBendingCoor();
+ Double_t bendingCoor2 = trackParamAtCluster2.GetBendingCoor();
+
+ // copy track parameters at first cluster for jacobian calculation
+ AliMUONTrackParam trackParam(trackParamAtCluster1);
+
+ // Get the pointer to the parameter covariance matrix at first cluster
+ const TMatrixD& kParamCov = trackParam.GetCovariances();
+
+ // Calculate the jacobian related to the transformation between track parameters
+ // at first cluster and track coordinates at the 2 cluster z-positions
+ TMatrixD jacob(4,5);
+ jacob.Zero();
+ // first derivative at the first cluster:
+ jacob(0,0) = 1.; // dx1/dx
+ jacob(1,2) = 1.; // dy1/dy
+ // first derivative at the second cluster:
+ TMatrixD dParam(5,1);
+ Double_t direction[5] = {-1.,-1.,1.,1.,-1.};
+ for (Int_t i=0; i<5; i++) {
+ // Skip jacobian calculation for parameters with no associated error
+ if (kParamCov(i,i) == 0.) continue;
+ // Small variation of parameter i only
+ for (Int_t j=0; j<5; j++) {
+ if (j==i) {
+ dParam(j,0) = TMath::Sqrt(kParamCov(i,i));
+ dParam(j,0) *= TMath::Sign(1.,direction[j]*paramAtCluster1Save(j,0)); // variation always in the same direction
+ } else dParam(j,0) = 0.;
}
+
+ // Set new track parameters at first cluster
+ trackParam.SetParameters(paramAtCluster1Save);
+ trackParam.AddParameters(dParam);
+ trackParam.SetZ(cluster1->GetZ());
+
+ // Extrapolate new track parameters to the z position of the second cluster
+ if (!AliMUONTrackExtrap::ExtrapToZ(&trackParam,cluster2->GetZ())) return 2.*AliMUONTrack::MaxChi2();
+
+ // Calculate the jacobian
+ jacob(2,i) = (trackParam.GetNonBendingCoor() - nonBendingCoor2) / dParam(i,0); // dx2/dParami
+ jacob(3,i) = (trackParam.GetBendingCoor() - bendingCoor2 ) / dParam(i,0); // dy2/dParami
}
+
+ // Calculate the error matrix
+ TMatrixD tmp(jacob,TMatrixD::kMult,kParamCov);
+ error = TMatrixD(tmp,TMatrixD::kMultTranspose,jacob);
}
- return;
-}
-
- //__________________________________________________________________________
-void AliMUONTrackReconstructor::MakeSegmentsPerStation(Int_t Station)
-{
- // To make the list of segments in station number "Station" (0...)
- // from the list of hits to be reconstructed.
- // Updates "fNSegments"[Station].
- // Segments in stations 4 and 5 are sorted
- // according to increasing absolute value of "impact parameter"
- AliMUONHitForRec *hit1Ptr, *hit2Ptr;
- AliMUONSegment *segment;
- Bool_t last2st;
- Double_t bendingSlope, distBend, distNonBend, extBendCoor, extNonBendCoor,
- impactParam = 0., maxImpactParam = 0., minImpactParam = 0.; // =0 to avoid compilation warnings.
- AliDebug(1,Form("Enter MakeSegmentsPerStation (0...) %d",Station));
- // first and second chambers (0...) in the station
- Int_t ch1 = 2 * Station;
- Int_t ch2 = ch1 + 1;
- // variable true for stations downstream of the dipole:
- // Station(0..4) equal to 3 or 4
- if ((Station == 3) || (Station == 4)) {
- last2st = kTRUE;
- // maximum impact parameter (cm) according to fMinBendingMomentum...
- maxImpactParam =
- TMath::Abs(GetImpactParamFromBendingMomentum(fMinBendingMomentum));
- // minimum impact parameter (cm) according to fMaxBendingMomentum...
- minImpactParam =
- TMath::Abs(GetImpactParamFromBendingMomentum(fMaxBendingMomentum));
+
+ // Add cluster resolution to the error matrix
+ error(0,0) += cluster1->GetErrX2();
+ error(1,1) += cluster1->GetErrY2();
+ error(2,2) += cluster2->GetErrX2();
+ error(3,3) += cluster2->GetErrY2();
+
+ // invert the error matrix for Chi2 calculation
+ if (error.Determinant() != 0) {
+ error.Invert();
+ } else {
+ AliWarning(" Determinant error=0");
+ return 2.*AliMUONTrack::MaxChi2();
}
- else last2st = kFALSE;
- // extrapolation factor from Z of first chamber to Z of second chamber
- // dZ to be changed to take into account fine structure of chambers ????
- Double_t extrapFact;
- // index for current segment
- Int_t segmentIndex = 0;
- // Loop over HitsForRec in the first chamber of the station
- for (Int_t hit1 = fIndexOfFirstHitForRecPerChamber[ch1];
- hit1 < fIndexOfFirstHitForRecPerChamber[ch1] + fNHitsForRecPerChamber[ch1];
- hit1++) {
- // pointer to the HitForRec
- hit1Ptr = (AliMUONHitForRec*) ((*fHitsForRecPtr)[hit1]);
- // extrapolation,
- // on the straight line joining the HitForRec to the vertex (0,0,0),
- // to the Z of the second chamber of the station
- // Loop over HitsForRec in the second chamber of the station
- for (Int_t hit2 = fIndexOfFirstHitForRecPerChamber[ch2];
- hit2 < fIndexOfFirstHitForRecPerChamber[ch2] + fNHitsForRecPerChamber[ch2];
- hit2++) {
- // pointer to the HitForRec
- hit2Ptr = (AliMUONHitForRec*) ((*fHitsForRecPtr)[hit2]);
- // absolute values of distances, in bending and non bending planes,
- // between the HitForRec in the second chamber
- // and the previous extrapolation
- extrapFact = hit2Ptr->GetZ()/ hit1Ptr->GetZ();
- extBendCoor = extrapFact * hit1Ptr->GetBendingCoor();
- extNonBendCoor = extrapFact * hit1Ptr->GetNonBendingCoor();
- distBend = TMath::Abs(hit2Ptr->GetBendingCoor() - extBendCoor);
- distNonBend = TMath::Abs(hit2Ptr->GetNonBendingCoor() - extNonBendCoor);
- if (last2st) {
- // bending slope
- if ( hit1Ptr->GetZ() - hit2Ptr->GetZ() != 0.0 ) {
- bendingSlope = (hit1Ptr->GetBendingCoor() - hit2Ptr->GetBendingCoor()) /
- (hit1Ptr->GetZ() - hit2Ptr->GetZ());
- // absolute value of impact parameter
- impactParam =
- TMath::Abs(hit1Ptr->GetBendingCoor() - hit1Ptr->GetZ() * bendingSlope);
- }
- else {
- AliWarning("hit1Ptr->GetZ() = hit2Ptr->GetZ(): impactParam set to maxImpactParam");
- impactParam = maxImpactParam;
- }
- }
- // check for distances not too large,
- // and impact parameter not too big if stations downstream of the dipole.
- // Conditions "distBend" and "impactParam" correlated for these stations ????
- if ((distBend < fSegmentMaxDistBending[Station]) &&
- (distNonBend < fSegmentMaxDistNonBending[Station]) &&
- (!last2st || (impactParam < maxImpactParam)) &&
- (!last2st || (impactParam > minImpactParam))) {
- // make new segment
- segment = new ((*fSegmentsPtr[Station])[segmentIndex])
- AliMUONSegment(hit1Ptr, hit2Ptr);
- // update "link" to this segment from the hit in the first chamber
- if (hit1Ptr->GetNSegments() == 0)
- hit1Ptr->SetIndexOfFirstSegment(segmentIndex);
- hit1Ptr->SetNSegments(hit1Ptr->GetNSegments() + 1);
- if (AliLog::GetGlobalDebugLevel() > 1) {
- cout << "segmentIndex(0...): " << segmentIndex
- << " distBend: " << distBend
- << " distNonBend: " << distNonBend
- << endl;
- segment->Dump();
- cout << "HitForRec in first chamber" << endl;
- hit1Ptr->Dump();
- cout << "HitForRec in second chamber" << endl;
- hit2Ptr->Dump();
- };
- // increment index for current segment
- segmentIndex++;
- }
- } //for (Int_t hit2
- } // for (Int_t hit1...
- fNSegments[Station] = segmentIndex;
- // Sorting according to "impact parameter" if station(1..5) 4 or 5,
- // i.e. Station(0..4) 3 or 4, using the function "Compare".
- // After this sorting, it is impossible to use
- // the "fNSegments" and "fIndexOfFirstSegment"
- // of the HitForRec in the first chamber to explore all segments formed with it.
- // Is this sorting really needed ????
- if ((Station == 3) || (Station == 4)) (fSegmentsPtr[Station])->Sort();
- AliDebug(1,Form("Station: %d NSegments: %d ", Station, fNSegments[Station]));
- return;
+
+ // Compute the Chi2 value
+ TMatrixD tmp2(dPos,TMatrixD::kTransposeMult,error);
+ TMatrixD result(tmp2,TMatrixD::kMult,dPos);
+
+ return result(0,0);
+
}
//__________________________________________________________________________
-void AliMUONTrackReconstructor::MakeTracks(void)
+void AliMUONTrackReconstructor::UpdateTrack(AliMUONTrack &track, AliMUONTrackParam &trackParamAtCluster)
{
- // 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();
- //AZ ResetTrackHits();
- if (fTrackMethod != 1) { //AZ - Kalman filter
- MakeTrackCandidatesK();
- if (fRecTracksPtr->GetEntriesFast() == 0) return;
- // Follow tracks in stations(1..) 3, 2 and 1
- FollowTracksK();
- // Remove double tracks
- RemoveDoubleTracksK();
- // Propagate tracks to the vertex thru absorber
- GoToVertex();
- // Fill AliMUONTrack data members
- FillMUONTrack();
- } else {
- // Look for candidates from at least 3 aligned points in stations(1..) 4 and 5
- MakeTrackCandidates();
- // Follow tracks in stations(1..) 3, 2 and 1
- FollowTracks();
- // Remove double tracks
- RemoveDoubleTracks();
- UpdateTrackParamAtHit();
- UpdateHitForRecAtHit();
- }
- return;
+ /// Add 1 cluster to the track candidate
+ /// Update chi2 of the track
+
+ // Compute local chi2
+ AliMUONVCluster* cluster = trackParamAtCluster.GetClusterPtr();
+ Double_t deltaX = trackParamAtCluster.GetNonBendingCoor() - cluster->GetX();
+ Double_t deltaY = trackParamAtCluster.GetBendingCoor() - cluster->GetY();
+ Double_t localChi2 = deltaX*deltaX / cluster->GetErrX2() +
+ deltaY*deltaY / cluster->GetErrY2();
+
+ // Flag cluster as being not removable
+ if (GetRecoParam()->RequestStation(cluster->GetChamberId()/2))
+ trackParamAtCluster.SetRemovable(kFALSE);
+ else trackParamAtCluster.SetRemovable(kTRUE);
+ trackParamAtCluster.SetLocalChi2(0.); // --> Local chi2 not used
+
+ // Update the chi2 of the new track
+ track.SetGlobalChi2(track.GetGlobalChi2() + localChi2);
+
+ // Update TrackParamAtCluster
+ track.AddTrackParamAtCluster(trackParamAtCluster,*cluster);
+
}
//__________________________________________________________________________
-void AliMUONTrackReconstructor::ValidateTracksWithTrigger(void)
+void AliMUONTrackReconstructor::UpdateTrack(AliMUONTrack &track, AliMUONTrackParam &trackParamAtCluster1, AliMUONTrackParam &trackParamAtCluster2)
{
- // Try to match track from tracking system with trigger track
- AliMUONTrack *track;
- TClonesArray *recTriggerTracks;
+ /// Add 2 clusters to the track candidate
+ /// 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();
+ deltaX = trackParamAtCluster2.GetNonBendingCoor() - cluster2->GetX();
+ deltaY = trackParamAtCluster2.GetBendingCoor() - cluster2->GetY();
+ Double_t localChi2AtCluster2 = deltaX*deltaX / cluster2->GetErrX2() +
+ deltaY*deltaY / cluster2->GetErrY2();
+ trackParamAtCluster2.SetLocalChi2(localChi2AtCluster2);
+
+ // Flag first cluster as being removable
+ trackParamAtCluster2.SetRemovable(kTRUE);
+
+ // Update the chi2 of the new track
+ track.SetGlobalChi2(track.GetGlobalChi2() + localChi2AtCluster1 + localChi2AtCluster2);
+
+ // Update TrackParamAtCluster
+ track.AddTrackParamAtCluster(trackParamAtCluster1,*cluster1);
+ track.AddTrackParamAtCluster(trackParamAtCluster2,*cluster2);
- fMUONData->SetTreeAddress("RL");
- fMUONData->GetRecTriggerTracks();
- recTriggerTracks = fMUONData->RecTriggerTracks();
-
- track = (AliMUONTrack*) fRecTracksPtr->First();
- while (track) {
- track->MatchTriggerTrack(recTriggerTracks);
- track = (AliMUONTrack*) fRecTracksPtr->After(track);
- }
-
}
//__________________________________________________________________________
-Bool_t AliMUONTrackReconstructor::MakeTriggerTracks(void)
+Bool_t AliMUONTrackReconstructor::RecoverTrack(AliMUONTrack &trackCandidate, AliMUONVClusterStore& clusterStore, Int_t nextStation)
{
- // To make the trigger tracks from Local Trigger
- AliDebug(1, "Enter MakeTriggerTracks");
+ /// 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);
- Int_t nTRentries;
- Long_t gloTrigPat;
- TClonesArray *localTrigger;
- TClonesArray *globalTrigger;
- AliMUONLocalTrigger *locTrg;
- AliMUONGlobalTrigger *gloTrg;
-
- TTree* treeR = fLoader->TreeR();
+ // check if current cluster is in the previous station
+ if (trackParamAtCluster->GetClusterPtr()->GetChamberId()/2 != nextStation+1) break;
- // Loading MUON subsystem
- AliMUON * pMUON = (AliMUON *) gAlice->GetDetector("MUON");
-
- nTRentries = Int_t(treeR->GetEntries());
-
- treeR->GetEvent(0); // only one entry
-
- if (!(fMUONData->IsTriggerBranchesInTree())) {
- AliWarning(Form("Trigger information is not avalaible, nTRentries = %d not equal to 1",nTRentries));
- return kFALSE;
+ // check if current cluster is removable
+ if (!trackParamAtCluster->IsRemovable()) return kFALSE;
+
+ // reset the current cluster as beig 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;
}
-
- fMUONData->SetTreeAddress("TC");
- fMUONData->GetTrigger();
-
- // global trigger for trigger pattern
- gloTrigPat = 0;
- globalTrigger = fMUONData->GlobalTrigger();
- gloTrg = (AliMUONGlobalTrigger*)globalTrigger->UncheckedAt(0);
-
- if (gloTrg)
- gloTrigPat = gloTrg->GetGlobalPattern();
+
+ }
+
+ // check if worst cluster found
+ if (worstClusterNumber < 0) return kFALSE;
+
+ // Remove the worst cluster
+ trackCandidate.RemoveTrackParamAtCluster((AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->UncheckedAt(worstClusterNumber));
+
+ // Re-fit the track:
+ // Do not take into account the multiple scattering to speed up the fit
+ // Calculate the track parameter covariance matrix
+ Fit(trackCandidate, kFALSE, kFALSE, kTRUE);
+
+ // skip track if the normalized chi2 is too high
+ if (trackCandidate.GetNormalizedChi2() > GetRecoParam()->GetSigmaCutForTracking() * GetRecoParam()->GetSigmaCutForTracking()) 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);
-
- // local trigger for tracking
- localTrigger = fMUONData->LocalTrigger();
- Int_t nlocals = (Int_t) (localTrigger->GetEntries());
-
- Float_t z11 = AliMUONConstants::DefaultChamberZ(10);
- Float_t z21 = AliMUONConstants::DefaultChamberZ(12);
-
- Float_t y11 = 0.;
- Int_t stripX21 = 0;
- Float_t y21 = 0.;
- Float_t x11 = 0.;
-
- for (Int_t i=0; i<nlocals; i++) { // loop on Local Trigger
- locTrg = (AliMUONLocalTrigger*)localTrigger->UncheckedAt(i);
-
- AliDebug(1, "AliMUONTrackReconstructor::MakeTriggerTrack using NEW trigger \n");
- AliMUONTriggerCircuitNew * circuit =
- &(pMUON->TriggerCircuitNew(locTrg->LoCircuit()-1)); // -1 !!!
- y11 = circuit->GetY11Pos(locTrg->LoStripX());
- stripX21 = locTrg->LoStripX()+locTrg->LoDev()+1;
- y21 = circuit->GetY21Pos(stripX21);
- x11 = circuit->GetX11Pos(locTrg->LoStripY());
-
- AliDebug(1, Form(" MakeTriggerTrack %d %d %d %d %d %f %f %f \n",i,locTrg->LoCircuit(),
- locTrg->LoStripX(),locTrg->LoStripX()+locTrg->LoDev()+1,locTrg->LoStripY(),y11, y21, x11));
-
- Float_t thetax = TMath::ATan2( x11 , z11 );
- Float_t thetay = TMath::ATan2( (y21-y11) , (z21-z11) );
-
- fTriggerTrack->SetX11(x11);
- fTriggerTrack->SetY11(y11);
- fTriggerTrack->SetThetax(thetax);
- fTriggerTrack->SetThetay(thetay);
- fTriggerTrack->SetGTPattern(gloTrigPat);
-
- fMUONData->AddRecTriggerTrack(*fTriggerTrack);
- } // end of loop on Local Trigger
- return kTRUE;
}
//__________________________________________________________________________
-Int_t AliMUONTrackReconstructor::MakeTrackCandidatesWithTwoSegments(AliMUONSegment *BegSegment)
+void AliMUONTrackReconstructor::SetVertexErrXY2ForFit(AliMUONTrack &trackCandidate)
{
- // To make track candidates with two segments in stations(1..) 4 and 5,
- // the first segment being pointed to by "BegSegment".
- // Returns the number of such track candidates.
- Int_t endStation, iEndSegment, nbCan2Seg;
- AliMUONSegment *endSegment;
- AliMUONSegment *extrapSegment = NULL;
- AliMUONTrack *recTrack;
- Double_t mcsFactor;
- AliDebug(1,"Enter MakeTrackCandidatesWithTwoSegments");
- // Station for the end segment
- endStation = 7 - (BegSegment->GetHitForRec1())->GetChamberNumber() / 2;
- // multiple scattering factor corresponding to one chamber
- mcsFactor = 0.0136 /
- GetBendingMomentumFromImpactParam(BegSegment->GetBendingImpact());
- mcsFactor = fChamberThicknessInX0 * mcsFactor * mcsFactor;
- // linear extrapolation to end station
- // number of candidates with 2 segments to 0
- nbCan2Seg = 0;
- // Loop over segments in the end station
- for (iEndSegment = 0; iEndSegment < fNSegments[endStation]; iEndSegment++) {
- // pointer to segment
- endSegment = (AliMUONSegment*) ((*fSegmentsPtr[endStation])[iEndSegment]);
- // test compatibility between current segment and "extrapSegment"
- // 4 because 4 quantities in chi2
- extrapSegment =
- BegSegment->CreateSegmentFromLinearExtrapToStation(endSegment->GetZ(), mcsFactor);
- if ((endSegment->
- NormalizedChi2WithSegment(extrapSegment,
- fMaxSigma2Distance)) <= 4.0) {
- // both segments compatible:
- // make track candidate from "begSegment" and "endSegment"
- AliDebug(2,Form("TrackCandidate with Segment %d in Station(0..) %d", iEndSegment, endStation));
- // flag for both segments in one track:
- // to be done in track constructor ????
- BegSegment->SetInTrack(kTRUE);
- endSegment->SetInTrack(kTRUE);
- recTrack = new ((*fRecTracksPtr)[fNRecTracks])
- AliMUONTrack(BegSegment, endSegment, this);
- fNRecTracks++;
- if (AliLog::GetGlobalDebugLevel() > 1) recTrack->RecursiveDump();
- // increment number of track candidates with 2 segments
- nbCan2Seg++;
- }
- delete extrapSegment; // should not delete HitForRec's it points to !!!!
- } // for (iEndSegment = 0;...
- return nbCan2Seg;
+ /// Compute the vertex resolution square from natural vertex dispersion and
+ /// multiple scattering effets according to trackCandidate path in absorber
+ /// It is necessary to account for multiple scattering effects here instead of during the fit of
+ /// the "trackCandidate" to do not influence the result by changing track resolution at vertex
+ AliDebug(1,"Enter SetVertexForFit");
+
+ Double_t nonBendingReso2 = GetRecoParam()->GetNonBendingVertexDispersion() *
+ GetRecoParam()->GetNonBendingVertexDispersion();
+ Double_t bendingReso2 = GetRecoParam()->GetBendingVertexDispersion() *
+ GetRecoParam()->GetBendingVertexDispersion();
+
+ // add multiple scattering effets
+ AliMUONTrackParam paramAtVertex(*((AliMUONTrackParam*)(trackCandidate.GetTrackParamAtCluster()->First())));
+ paramAtVertex.DeleteCovariances(); // to be sure to account only for multiple scattering
+ if (!AliMUONTrackExtrap::ExtrapToZ(¶mAtVertex,AliMUONConstants::AbsZEnd())) {
+ nonBendingReso2 = 0.;
+ bendingReso2 = 0.;
+ } else {
+ AliMUONTrackExtrap::ExtrapToVertexUncorrected(¶mAtVertex,0.);
+ const TMatrixD& kParamCov = paramAtVertex.GetCovariances();
+ nonBendingReso2 += kParamCov(0,0);
+ bendingReso2 += kParamCov(2,2);
+ }
+
+ // Set the vertex resolution square
+ trackCandidate.SetVertexErrXY2(nonBendingReso2,bendingReso2);
}
//__________________________________________________________________________
-Int_t AliMUONTrackReconstructor::MakeTrackCandidatesWithOneSegmentAndOnePoint(AliMUONSegment *BegSegment)
+void AliMUONTrackReconstructor::Fit(AliMUONTrack &track, Bool_t includeMCS, Bool_t fitWithVertex, Bool_t calcCov)
{
- // To make track candidates with one segment and one point
- // in stations(1..) 4 and 5,
- // the segment being pointed to by "BegSegment".
- Int_t ch, ch1, ch2, endStation, iHit, iHitMax, iHitMin, nbCan1Seg1Hit;
- AliMUONHitForRec *extrapHitForRec= NULL;
- AliMUONHitForRec *hit;
- AliMUONTrack *recTrack;
- Double_t mcsFactor;
- AliDebug(1,"Enter MakeTrackCandidatesWithOneSegmentAndOnePoint");
- // station for the end point
- endStation = 7 - (BegSegment->GetHitForRec1())->GetChamberNumber() / 2;
- // multiple scattering factor corresponding to one chamber
- mcsFactor = 0.0136 /
- GetBendingMomentumFromImpactParam(BegSegment->GetBendingImpact());
- mcsFactor = fChamberThicknessInX0 * mcsFactor * mcsFactor;
- // first and second chambers(0..) in the end station
- ch1 = 2 * endStation;
- ch2 = ch1 + 1;
- // number of candidates to 0
- nbCan1Seg1Hit = 0;
- // Loop over chambers of the end station
- for (ch = ch2; ch >= ch1; ch--) {
- // limits for the hit index in the loop
- iHitMin = fIndexOfFirstHitForRecPerChamber[ch];
- iHitMax = iHitMin + fNHitsForRecPerChamber[ch];
- // Loop over HitForRec's in the chamber
- for (iHit = iHitMin; iHit < iHitMax; iHit++) {
- // pointer to HitForRec
- hit = (AliMUONHitForRec*) ((*fHitsForRecPtr)[iHit]);
- // test compatibility between current HitForRec and "extrapHitForRec"
- // 2 because 2 quantities in chi2
- // linear extrapolation to chamber
- extrapHitForRec =
- BegSegment->CreateHitForRecFromLinearExtrapToChamber( hit->GetZ(), mcsFactor);
- if ((hit->
- NormalizedChi2WithHitForRec(extrapHitForRec,
- fMaxSigma2Distance)) <= 2.0) {
- // both HitForRec's compatible:
- // make track candidate from begSegment and current HitForRec
- AliDebug(2, Form("TrackCandidate with HitForRec %d in Chamber(0..) %d", iHit, ch));
- // flag for beginning segments in one track:
- // to be done in track constructor ????
- BegSegment->SetInTrack(kTRUE);
- recTrack = new ((*fRecTracksPtr)[fNRecTracks])
- AliMUONTrack(BegSegment, hit, this);
- // the right place to eliminate "double counting" ???? how ????
- fNRecTracks++;
- if (AliLog::GetGlobalDebugLevel() > 1) recTrack->RecursiveDump();
- // increment number of track candidates
- nbCan1Seg1Hit++;
- }
- delete extrapHitForRec;
- } // for (iHit = iHitMin;...
- } // for (ch = ch2;...
- return nbCan1Seg1Hit;
+ /// Fit the track
+ /// w/wo multiple Coulomb scattering according to "includeMCS".
+ /// w/wo constraining the vertex according to "fitWithVertex".
+ /// calculating or not the covariance matrix according to "calcCov".
+ AliDebug(1,"Enter Fit");
+
+ Double_t benC, errorParam, invBenP, nonBenC, x, y;
+ AliMUONTrackParam *trackParam;
+ Double_t arg[1], fedm, errdef, globalChi2;
+ Int_t npari, nparx;
+ Int_t status, covStatus;
+
+ // Instantiate gMinuit if not already done
+ if (!gMinuit) gMinuit = new TMinuit(6);
+ // Clear MINUIT parameters
+ gMinuit->mncler();
+ // Give the fitted track to MINUIT
+ gMinuit->SetObjectFit(&track);
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) {
+ // Define print level
+ arg[0] = 1;
+ gMinuit->mnexcm("SET PRI", arg, 1, status);
+ // Print covariance matrix
+ gMinuit->mnexcm("SHO COV", arg, 0, status);
+ } else {
+ arg[0] = -1;
+ gMinuit->mnexcm("SET PRI", arg, 1, status);
+ }
+ // No warnings
+ gMinuit->mnexcm("SET NOW", arg, 0, status);
+ // Define strategy
+ //arg[0] = 2;
+ //gMinuit->mnexcm("SET STR", arg, 1, status);
+
+ // set flag w/wo multiple scattering according to "includeMCS"
+ track.FitWithMCS(includeMCS);
+ if (includeMCS) {
+ // compute cluster weights only once
+ if (!track.UpdateTrackParamAtCluster() || !track.ComputeClusterWeights()) {
+ AliWarning("cannot take into account the multiple scattering effects");
+ track.FitWithMCS(kFALSE);
+ }
+ }
+
+ track.FitWithVertex(fitWithVertex);
+ if (fitWithVertex) SetVertexErrXY2ForFit(track);
+
+ // Set fitting function
+ gMinuit->SetFCN(TrackChi2);
+
+ // Set fitted parameters (!! The order is very important for the covariance matrix !!)
+ // Mandatory limits to avoid NaN values of parameters
+ trackParam = (AliMUONTrackParam*) (track.GetTrackParamAtCluster()->First());
+ Double_t maxIBM = 1. / GetRecoParam()->GetMinBendingMomentum();
+ gMinuit->mnparm(0, "X", trackParam->GetNonBendingCoor(), 0.03, -500.0, 500.0, status);
+ gMinuit->mnparm(1, "NonBenS", trackParam->GetNonBendingSlope(), 0.001, -1., 1., status);
+ gMinuit->mnparm(2, "Y", trackParam->GetBendingCoor(), 0.10, -500.0, 500.0, status);
+ gMinuit->mnparm(3, "BenS", trackParam->GetBendingSlope(), 0.001, -1.5, 1.5, status);
+ gMinuit->mnparm(4, "InvBenP", trackParam->GetInverseBendingMomentum(), 0.003, -maxIBM, maxIBM, status);
+
+ // minimization
+ gMinuit->mnexcm("MIGRAD", arg, 0, status);
+
+ // Calculate the covariance matrix more accurately if required
+ if (calcCov) gMinuit->mnexcm("HESSE", arg, 0, status);
+
+ // get results into "invBenP", "benC", "nonBenC" ("x", "y")
+ gMinuit->GetParameter(0, x, errorParam);
+ trackParam->SetNonBendingCoor(x);
+ gMinuit->GetParameter(1, nonBenC, errorParam);
+ trackParam->SetNonBendingSlope(nonBenC);
+ gMinuit->GetParameter(2, y, errorParam);
+ trackParam->SetBendingCoor(y);
+ gMinuit->GetParameter(3, benC, errorParam);
+ trackParam->SetBendingSlope(benC);
+ gMinuit->GetParameter(4, invBenP, errorParam);
+ trackParam->SetInverseBendingMomentum(invBenP);
+
+ // global result of the fit
+ gMinuit->mnstat(globalChi2, fedm, errdef, npari, nparx, covStatus);
+ track.SetGlobalChi2(globalChi2);
+
+ // Get the covariance matrix if required
+ if (calcCov) {
+ // Covariance matrix according to HESSE status
+ // If problem then keep only the diagonal terms (variances)
+ Double_t matrix[5][5];
+ for (Int_t i=0; i<5; i++) for (Int_t j=0; j<5; j++) matrix[i][j] = 0.;
+ gMinuit->mnemat(&matrix[0][0],5);
+ if (covStatus == 3) trackParam->SetCovariances(matrix);
+ else trackParam->SetVariances(matrix);
+ } else trackParam->DeleteCovariances();
+
}
//__________________________________________________________________________
-void AliMUONTrackReconstructor::MakeTrackCandidates(void)
+void TrackChi2(Int_t & /*nParam*/, Double_t * /*gradient*/, Double_t &chi2, Double_t *param, Int_t /*flag*/)
{
- // To make track candidates
- // with at least 3 aligned points in stations(1..) 4 and 5
- // (two Segment's or one Segment and one HitForRec)
- Int_t begStation, iBegSegment, nbCan1Seg1Hit, nbCan2Seg;
- AliMUONSegment *begSegment;
- AliDebug(1,"Enter MakeTrackCandidates");
- // Loop over stations(1..) 5 and 4 for the beginning segment
- for (begStation = 4; begStation > 2; begStation--) {
- // Loop over segments in the beginning station
- for (iBegSegment = 0; iBegSegment < fNSegments[begStation]; iBegSegment++) {
- // pointer to segment
- begSegment = (AliMUONSegment*) ((*fSegmentsPtr[begStation])[iBegSegment]);
- AliDebug(2,Form("Look for TrackCandidate's with Segment %d in Station(0..) %d", iBegSegment, begStation));
- // Look for track candidates with two segments,
- // "begSegment" and all compatible segments in other station.
- // Only for beginning station(1..) 5
- // because candidates with 2 segments have to looked for only once.
- if (begStation == 4)
- nbCan2Seg = MakeTrackCandidatesWithTwoSegments(begSegment);
- // Look for track candidates with one segment and one point,
- // "begSegment" and all compatible HitForRec's in other station.
- // Only if "begSegment" does not belong already to a track candidate.
- // Is that a too strong condition ????
- if (!(begSegment->GetInTrack()))
- nbCan1Seg1Hit = MakeTrackCandidatesWithOneSegmentAndOnePoint(begSegment);
- } // for (iBegSegment = 0;...
- } // for (begStation = 4;...
- return;
+ /// Return the "Chi2" to be minimized with Minuit for track fitting.
+ /// Assumes that the trackParamAtCluster are sorted according to increasing Z.
+ /// Track parameters at each cluster are updated accordingly.
+ /// Vertex is used according to the flag "trackBeingFitted->GetFitWithVertex()".
+ /// Multiple Coulomb scattering is taken into account according to the flag "trackBeingFitted->GetFitWithMCS()".
+
+ AliMUONTrack *trackBeingFitted = (AliMUONTrack*) gMinuit->GetObjectFit();
+ AliMUONTrackParam* trackParamAtCluster = (AliMUONTrackParam*) trackBeingFitted->GetTrackParamAtCluster()->First();
+ Double_t dX, dY;
+ chi2 = 0.; // initialize chi2
+
+ // update track parameters
+ trackParamAtCluster->SetNonBendingCoor(param[0]);
+ trackParamAtCluster->SetNonBendingSlope(param[1]);
+ trackParamAtCluster->SetBendingCoor(param[2]);
+ trackParamAtCluster->SetBendingSlope(param[3]);
+ trackParamAtCluster->SetInverseBendingMomentum(param[4]);
+ if (!trackBeingFitted->UpdateTrackParamAtCluster()) {
+ chi2 = 2.*AliMUONTrack::MaxChi2();
+ return;
+ }
+
+ // Take the vertex into account in the fit if required
+ if (trackBeingFitted->FitWithVertex()) {
+ Double_t nonBendingReso2,bendingReso2;
+ trackBeingFitted->GetVertexErrXY2(nonBendingReso2,bendingReso2);
+ AliMUONTrackParam paramAtVertex(*trackParamAtCluster);
+ if (nonBendingReso2 != 0. && bendingReso2 != 0. && AliMUONTrackExtrap::ExtrapToZ(¶mAtVertex, 0.)) { // vextex position = (0,0,0)
+ dX = paramAtVertex.GetNonBendingCoor();
+ dY = paramAtVertex.GetBendingCoor();
+ chi2 += dX * dX / nonBendingReso2 + dY * dY / bendingReso2;
+ } else {
+ chi2 = 2.*AliMUONTrack::MaxChi2();
+ return;
+ }
+ }
+
+ // compute chi2 w/wo multiple scattering
+ chi2 += trackBeingFitted->ComputeGlobalChi2(trackBeingFitted->FitWithMCS());
+
}
//__________________________________________________________________________
-void AliMUONTrackReconstructor::FollowTracks(void)
+Bool_t AliMUONTrackReconstructor::ComplementTracks(const AliMUONVClusterStore& clusterStore)
{
- // Follow tracks in stations(1..) 3, 2 and 1
- // too long: should be made more modular !!!!
- AliMUONHitForRec *bestHit, *extrapHit, *hit;
- AliMUONSegment *bestSegment, *extrapSegment, *segment;
- AliMUONTrack *track, *nextTrack;
- AliMUONTrackParam *trackParam1, trackParam[2], trackParamVertex;
- // -1 to avoid compilation warnings
- Int_t ch = -1, chInStation, chBestHit = -1, iHit, iSegment, station, trackIndex;
- Double_t bestChi2, chi2, dZ1, dZ2, dZ3, maxSigma2Distance, mcsFactor;
- Double_t bendingMomentum, chi2Norm = 0.;
-
-
- // local maxSigma2Distance, for easy increase in testing
- maxSigma2Distance = fMaxSigma2Distance;
- AliDebug(2,"Enter FollowTracks");
- // Loop over track candidates
- track = (AliMUONTrack*) fRecTracksPtr->First();
- trackIndex = -1;
+ /// 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).
+ /// Re-fit track parameters and covariances.
+ /// Return kTRUE if one or more tracks have been complemented.
+ AliDebug(1,"Enter ComplementTracks");
+
+ Int_t chamberId, detElemId;
+ Double_t chi2OfCluster, bestChi2OfCluster;
+ Double_t sigmaCut2 = GetRecoParam()->GetSigmaCutForTracking() *
+ GetRecoParam()->GetSigmaCutForTracking();
+ Bool_t foundOneCluster, trackModified, hasChanged = kFALSE;
+ AliMUONVCluster* cluster;
+ AliMUONTrackParam *trackParam, *nextTrackParam, copyOfTrackParam, trackParamAtCluster, bestTrackParamAtCluster;
+
+ AliMUONTrack *track = (AliMUONTrack*) fRecTracksPtr->First();
while (track) {
- // Follow function for each track candidate ????
- trackIndex++;
- nextTrack = (AliMUONTrack*) fRecTracksPtr->After(track); // prepare next track
- AliDebug(2,Form("FollowTracks: track candidate(0..): %d", trackIndex));
- // Fit track candidate
- track->SetFitMCS(0); // without multiple Coulomb scattering
- track->SetFitNParam(3); // with 3 parameters (X = Y = 0)
- track->SetFitStart(0); // from parameters at vertex
- track->Fit();
- if (AliLog::GetGlobalDebugLevel()> 2) {
- cout << "FollowTracks: track candidate(0..): " << trackIndex
- << " after fit in stations(0..) 3 and 4" << endl;
- track->RecursiveDump();
- }
- // Loop over stations(1..) 3, 2 and 1
- // something SPECIAL for stations 2 and 1 for majority 3 coincidence ????
- // otherwise: majority coincidence 2 !!!!
- for (station = 2; station >= 0; station--) {
- // Track parameters at first track hit (smallest Z)
- trackParam1 = ((AliMUONTrackHit*)
- (track->GetTrackHitsPtr()->First()))->GetTrackParam();
- // extrapolation to station
- trackParam1->ExtrapToStation(station, trackParam);
- extrapSegment = new AliMUONSegment(); // empty segment
- // multiple scattering factor corresponding to one chamber
- // and momentum in bending plane (not total)
- mcsFactor = 0.0136 * trackParam1->GetInverseBendingMomentum();
- mcsFactor = fChamberThicknessInX0 * mcsFactor * mcsFactor;
- // Z difference from previous station
- dZ1 = AliMUONConstants::DefaultChamberZ(2 * station) -
- AliMUONConstants::DefaultChamberZ(2 * station + 2);
- // Z difference between the two previous stations
- dZ2 = AliMUONConstants::DefaultChamberZ(2 * station + 2) -
- AliMUONConstants::DefaultChamberZ(2 * station + 4);
- // Z difference between the two chambers in the previous station
- dZ3 = AliMUONConstants::DefaultChamberZ(2 * station) -
- AliMUONConstants::DefaultChamberZ(2 * station + 1);
- extrapSegment->SetBendingCoorReso2(fBendingResolution * fBendingResolution);
- extrapSegment->
- SetNonBendingCoorReso2(fNonBendingResolution * fNonBendingResolution);
- extrapSegment->UpdateFromStationTrackParam
- (trackParam, mcsFactor, dZ1, dZ2, dZ3, station,
- trackParam1->GetInverseBendingMomentum());
- bestChi2 = 5.0;
- bestSegment = NULL;
- if (AliLog::GetGlobalDebugLevel() > 2) {
- cout << "FollowTracks: track candidate(0..): " << trackIndex
- << " Look for segment in station(0..): " << station << endl;
- }
-
- // Loop over segments in station
- for (iSegment = 0; iSegment < fNSegments[station]; iSegment++) {
- // Look for best compatible Segment in station
- // should consider all possibilities ????
- // multiple scattering ????
- // separation in 2 functions: Segment and HitForRec ????
- segment = (AliMUONSegment*) ((*fSegmentsPtr[station])[iSegment]);
- // correction of corrected segment (fBendingCoor and fNonBendingCoor)
- // according to real Z value of "segment" and slopes of "extrapSegment"
- (&(trackParam[0]))->ExtrapToZ(segment->GetZ());
- (&(trackParam[1]))->ExtrapToZ(segment->GetZ());
- extrapSegment->SetBendingCoor((&(trackParam[0]))->GetBendingCoor());
- extrapSegment->SetNonBendingCoor((&(trackParam[0]))->GetNonBendingCoor());
- extrapSegment->SetBendingSlope((&(trackParam[0]))->GetBendingSlope());
- extrapSegment->SetNonBendingSlope((&(trackParam[0]))->GetNonBendingSlope());
- chi2 = segment->
- NormalizedChi2WithSegment(extrapSegment, maxSigma2Distance);
- if (chi2 < bestChi2) {
- // update best Chi2 and Segment if better found
- bestSegment = segment;
- bestChi2 = chi2;
- }
- }
- if (bestSegment) {
- // best segment found: add it to track candidate
- (&(trackParam[0]))->ExtrapToZ(bestSegment->GetZ());
- (&(trackParam[1]))->ExtrapToZ(bestSegment->GetZ());
- track->AddSegment(bestSegment);
- // set track parameters at these two TrakHit's
- track->SetTrackParamAtHit(track->GetNTrackHits() - 2, &(trackParam[0]));
- track->SetTrackParamAtHit(track->GetNTrackHits() - 1, &(trackParam[1]));
- AliDebug(3, Form("FollowTracks: track candidate(0..): %d Added segment in station(0..): %d", trackIndex, station));
- if (AliLog::GetGlobalDebugLevel()>2) track->RecursiveDump();
- }
- else {
- // No best segment found:
- // Look for best compatible HitForRec in station:
- // should consider all possibilities ????
- // multiple scattering ???? do about like for extrapSegment !!!!
- extrapHit = new AliMUONHitForRec(); // empty hit
- bestChi2 = 3.0;
- bestHit = NULL;
- AliDebug(3, Form("FollowTracks: track candidate(0..): %d Segment not found, look for hit in station(0..): %d ",
- trackIndex, station));
+ trackModified = kFALSE;
+
+ trackParam = (AliMUONTrackParam*)track->GetTrackParamAtCluster()->First();
+ while (trackParam) {
+ foundOneCluster = kFALSE;
+ bestChi2OfCluster = 2. * sigmaCut2; // 2 because 2 quantities in chi2
+ chamberId = trackParam->GetClusterPtr()->GetChamberId();
+ detElemId = trackParam->GetClusterPtr()->GetDetElemId();
+
+ // prepare nextTrackParam before adding new cluster because of the sorting
+ nextTrackParam = (AliMUONTrackParam*)track->GetTrackParamAtCluster()->After(trackParam);
+
+ // recover track parameters from local fit and put them into a copy of trackParam
+ copyOfTrackParam.SetZ(trackParam->GetZ());
+ copyOfTrackParam.SetParameters(trackParam->GetSmoothParameters());
+ copyOfTrackParam.SetCovariances(trackParam->GetSmoothCovariances());
+
+ // 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;
- // Loop over chambers of the station
- for (chInStation = 0; chInStation < 2; chInStation++) {
- ch = 2 * station + chInStation;
- for (iHit = fIndexOfFirstHitForRecPerChamber[ch];
- iHit < fIndexOfFirstHitForRecPerChamber[ch] +
- fNHitsForRecPerChamber[ch];
- iHit++) {
- hit = (AliMUONHitForRec*) ((*fHitsForRecPtr)[iHit]);
- // coordinates of extrapolated hit
- (&(trackParam[chInStation]))->ExtrapToZ(hit->GetZ());
- extrapHit->
- SetBendingCoor((&(trackParam[chInStation]))->GetBendingCoor());
- extrapHit->
- SetNonBendingCoor((&(trackParam[chInStation]))->GetNonBendingCoor());
- // resolutions from "extrapSegment"
- extrapHit->SetBendingReso2(extrapSegment->GetBendingCoorReso2());
- extrapHit->SetNonBendingReso2(extrapSegment->GetNonBendingCoorReso2());
- // Loop over hits in the chamber
- // condition for hit not already in segment ????
- chi2 = hit->NormalizedChi2WithHitForRec(extrapHit, maxSigma2Distance);
- if (chi2 < bestChi2) {
- // update best Chi2 and HitForRec if better found
- bestHit = hit;
- bestChi2 = chi2;
- chBestHit = chInStation;
- }
- }
- }
- if (bestHit) {
- // best hit found: add it to track candidate
- (&(trackParam[chBestHit]))->ExtrapToZ(bestHit->GetZ());
- track->AddHitForRec(bestHit);
- // set track parameters at this TrackHit
- track->SetTrackParamAtHit(track->GetNTrackHits() - 1,
- &(trackParam[chBestHit]));
- if (AliLog::GetGlobalDebugLevel() > 2) {
- cout << "FollowTracks: track candidate(0..): " << trackIndex
- << " Added hit in station(0..): " << station << endl;
- track->RecursiveDump();
- }
- }
- else {
- // Remove current track candidate
- // and corresponding TrackHit's, ...
- track->Remove();
- delete extrapSegment;
- delete extrapHit;
- break; // stop the search for this candidate:
- // exit from the loop over station
+ // try to add the current cluster fast
+ if (!TryOneClusterFast(copyOfTrackParam, cluster)) continue;
+
+ // try to add the current cluster accurately
+ chi2OfCluster = TryOneCluster(copyOfTrackParam, cluster, trackParamAtCluster);
+
+ // if better chi2 then prepare to add this cluster to the track
+ if (chi2OfCluster < bestChi2OfCluster) {
+ bestChi2OfCluster = chi2OfCluster;
+ bestTrackParamAtCluster = trackParamAtCluster;
+ foundOneCluster = kTRUE;
}
- delete extrapHit;
- }
- delete extrapSegment;
- // Sort track hits according to increasing Z
- track->GetTrackHitsPtr()->Sort();
- // Update track parameters at first track hit (smallest Z)
- trackParam1 = ((AliMUONTrackHit*)
- (track->GetTrackHitsPtr()->First()))->GetTrackParam();
- bendingMomentum = 0.;
- if (TMath::Abs(trackParam1->GetInverseBendingMomentum()) > 0.)
- bendingMomentum = TMath::Abs(1/(trackParam1->GetInverseBendingMomentum()));
- // Track removed if bendingMomentum not in window [min, max]
- if ((bendingMomentum < fMinBendingMomentum) || (bendingMomentum > fMaxBendingMomentum)) {
- track->Remove();
- break; // stop the search for this candidate:
- // exit from the loop over station
- }
- // Track fit
- // with multiple Coulomb scattering if all stations
- if (station == 0) track->SetFitMCS(1);
- // without multiple Coulomb scattering if not all stations
- else track->SetFitMCS(0);
- track->SetFitNParam(5); // with 5 parameters (momentum and position)
- track->SetFitStart(1); // from parameters at first hit
- track->Fit();
- Double_t numberOfDegFree = (2.0 * track->GetNTrackHits() - 5);
- if (numberOfDegFree > 0) {
- chi2Norm = track->GetFitFMin() / numberOfDegFree;
- } else {
- chi2Norm = 1.e10;
- }
- // Track removed if normalized chi2 too high
- if (chi2Norm > fMaxChi2) {
- track->Remove();
- break; // stop the search for this candidate:
- // exit from the loop over station
- }
- if (AliLog::GetGlobalDebugLevel() > 2) {
- cout << "FollowTracks: track candidate(0..): " << trackIndex
- << " after fit from station(0..): " << station << " to 4" << endl;
- track->RecursiveDump();
+
}
- // Track extrapolation to the vertex through the absorber (Branson)
- // after going through the first station
- if (station == 0) {
- trackParamVertex = *trackParam1;
- (&trackParamVertex)->ExtrapToVertex(0.,0.,0.);
- track->SetTrackParamAtVertex(&trackParamVertex);
- if (AliLog::GetGlobalDebugLevel() > 0) {
- cout << "FollowTracks: track candidate(0..): " << trackIndex
- << " after extrapolation to vertex" << endl;
- track->RecursiveDump();
+
+ // add new cluster if any
+ if (foundOneCluster) {
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "ComplementTracks: found one cluster in chamber(1..): " << chamberId+1 << endl;
+ bestTrackParamAtCluster.GetClusterPtr()->Print();
+ 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;
}
- } // for (station = 2;...
- // go really to next track
- track = nextTrack;
- } // while (track)
- // Compression of track array (necessary after Remove ????)
- fRecTracksPtr->Compress();
- return;
-}
-
- //__________________________________________________________________________
-void AliMUONTrackReconstructor::RemoveDoubleTracks(void)
-{
- // To remove double tracks.
- // Tracks are considered identical
- // if they have at least half of their hits in common.
- // Among two identical tracks, one keeps the track with the larger number of hits
- // or, if these numbers are equal, the track with the minimum Chi2.
- AliMUONTrack *track1, *track2, *trackToRemove;
- Bool_t identicalTracks;
- Int_t hitsInCommon, nHits1, nHits2;
- identicalTracks = kTRUE;
- while (identicalTracks) {
- identicalTracks = kFALSE;
- // Loop over first track of the pair
- track1 = (AliMUONTrack*) fRecTracksPtr->First();
- while (track1 && (!identicalTracks)) {
- nHits1 = track1->GetNTrackHits();
- // Loop over second track of the pair
- track2 = (AliMUONTrack*) fRecTracksPtr->After(track1);
- while (track2 && (!identicalTracks)) {
- nHits2 = track2->GetNTrackHits();
- // number of hits in common between two tracks
- hitsInCommon = track1->HitsInCommon(track2);
- // check for identical tracks
- if ((4 * hitsInCommon) >= (nHits1 + nHits2)) {
- identicalTracks = kTRUE;
- // decide which track to remove
- if (nHits1 > nHits2) trackToRemove = track2;
- else if (nHits1 < nHits2) trackToRemove = track1;
- else if ((track1->GetFitFMin()) < (track2->GetFitFMin()))
- trackToRemove = track2;
- else trackToRemove = track1;
- // remove it
- trackToRemove->Remove();
- }
- track2 = (AliMUONTrack*) fRecTracksPtr->After(track2);
- } // track2
- track1 = (AliMUONTrack*) fRecTracksPtr->After(track1);
- } // track1
- }
- return;
-}
-
- //__________________________________________________________________________
-void AliMUONTrackReconstructor::UpdateTrackParamAtHit()
-{
- // Set track parameters after track fitting. Fill fTrackParamAtHit of AliMUONTrack's
- AliMUONTrack *track;
- AliMUONTrackHit *trackHit;
- AliMUONTrackParam *trackParam;
- track = (AliMUONTrack*) fRecTracksPtr->First();
- while (track) {
- trackHit = (AliMUONTrackHit*) (track->GetTrackHitsPtr())->First();
- while (trackHit) {
- trackParam = trackHit->GetTrackParam();
- track->AddTrackParamAtHit(trackParam);
- trackHit = (AliMUONTrackHit*) (track->GetTrackHitsPtr())->After(trackHit);
- } // trackHit
- track = (AliMUONTrack*) fRecTracksPtr->After(track);
- } // track
- return;
-}
-
- //__________________________________________________________________________
-void AliMUONTrackReconstructor::UpdateHitForRecAtHit()
-{
- // Set cluster parameterss after track fitting. Fill fHitForRecAtHit of AliMUONTrack's
- AliMUONTrack *track;
- AliMUONTrackHit *trackHit;
- AliMUONHitForRec *hitForRec;
- track = (AliMUONTrack*) fRecTracksPtr->First();
- while (track) {
- trackHit = (AliMUONTrackHit*) (track->GetTrackHitsPtr())->First();
- while (trackHit) {
- hitForRec = trackHit->GetHitForRecPtr();
- track->AddHitForRecAtHit(hitForRec);
- trackHit = (AliMUONTrackHit*) (track->GetTrackHitsPtr())->After(trackHit);
- } // trackHit
+
+ trackParam = nextTrackParam;
+ }
+
+ // re-fit track parameters if needed
+ if (trackModified) Fit(*track, kTRUE, kFALSE, kTRUE);
+
track = (AliMUONTrack*) fRecTracksPtr->After(track);
- } // track
- return;
-}
-
- //__________________________________________________________________________
-void AliMUONTrackReconstructor::FillMUONTrack()
-{
- // Set track parameters at hits for Kalman track. Fill fTrackParamAtHit of AliMUONTrack's
- AliMUONTrackK *track;
- track = (AliMUONTrackK*) fRecTracksPtr->First();
- while (track) {
- track->FillMUONTrack();
- track = (AliMUONTrackK*) fRecTracksPtr->After(track);
- }
- return;
-}
-
- //__________________________________________________________________________
-void AliMUONTrackReconstructor::EventDump(void)
-{
- // Dump reconstructed event (track parameters at vertex and at first hit),
- // and the particle parameters
-
- AliMUONTrack *track;
- AliMUONTrackParam *trackParam, *trackParam1;
- Double_t bendingSlope, nonBendingSlope, pYZ;
- Double_t pX, pY, pZ, x, y, z, c;
- Int_t np, trackIndex, nTrackHits;
-
- AliDebug(1,"****** enter EventDump ******");
- AliDebug(1, Form("Number of Reconstructed tracks : %d", fNRecTracks));
-
- fRecTracksPtr->Compress(); // for simple loop without "Next" since no hole
- // Loop over reconstructed tracks
- for (trackIndex = 0; trackIndex < fNRecTracks; trackIndex++) {
- if (fTrackMethod != 1) continue; //AZ - skip the rest for now
- AliDebug(1, Form("track number: %d", trackIndex));
- // function for each track for modularity ????
- track = (AliMUONTrack*) ((*fRecTracksPtr)[trackIndex]);
- nTrackHits = track->GetNTrackHits();
- AliDebug(1, Form("Number of track hits: %d ", nTrackHits));
- // track parameters at Vertex
- trackParam = track->GetTrackParamAtVertex();
- x = trackParam->GetNonBendingCoor();
- y = trackParam->GetBendingCoor();
- z = trackParam->GetZ();
- bendingSlope = trackParam->GetBendingSlope();
- nonBendingSlope = trackParam->GetNonBendingSlope();
- pYZ = 1/TMath::Abs(trackParam->GetInverseBendingMomentum());
- pZ = pYZ/TMath::Sqrt(1+bendingSlope*bendingSlope);
- pX = pZ * nonBendingSlope;
- pY = pZ * bendingSlope;
- c = TMath::Sign(1.0, trackParam->GetInverseBendingMomentum());
- AliDebug(1, Form("Track parameters at Vertex z= %f: X= %f Y= %f pX= %f pY= %f pZ= %f c= %f\n",
- z, x, y, pX, pY, pZ, c));
-
- // track parameters at first hit
- trackParam1 = ((AliMUONTrackHit*)
- (track->GetTrackHitsPtr()->First()))->GetTrackParam();
- x = trackParam1->GetNonBendingCoor();
- y = trackParam1->GetBendingCoor();
- z = trackParam1->GetZ();
- bendingSlope = trackParam1->GetBendingSlope();
- nonBendingSlope = trackParam1->GetNonBendingSlope();
- pYZ = 1/TMath::Abs(trackParam1->GetInverseBendingMomentum());
- pZ = pYZ/TMath::Sqrt(1.0 + bendingSlope * bendingSlope);
- pX = pZ * nonBendingSlope;
- pY = pZ * bendingSlope;
- c = TMath::Sign(1.0, trackParam1->GetInverseBendingMomentum());
- AliDebug(1, Form("track parameters at z= %f: X= %f Y= %f pX= %f pY= %f pZ= %f c= %f\n",
- z, x, y, pX, pY, pZ, c));
}
- // informations about generated particles NO !!!!!!!!
-
-// for (Int_t iPart = 0; iPart < np; iPart++) {
-// p = gAlice->Particle(iPart);
-// printf(" particle %d: type= %d px= %f py= %f pz= %f pdg= %d\n",
-// iPart, p->GetPdgCode(), p->Px(), p->Py(), p->Pz(), p->GetPdgCode());
-// }
- return;
+
+ return hasChanged;
+
}
-
-//__________________________________________________________________________
-void AliMUONTrackReconstructor::EventDumpTrigger(void)
+ //__________________________________________________________________________
+void AliMUONTrackReconstructor::ImproveTrack(AliMUONTrack &track)
{
- // Dump reconstructed trigger event
- // and the particle parameters
+ /// Improve the given track by removing clusters with local chi2 highter than the defined cut
+ /// Recompute track parameters and covariances at the remaining clusters
+ AliDebug(1,"Enter ImproveTrack");
+
+ Double_t localChi2, worstLocalChi2;
+ AliMUONTrackParam *trackParamAtCluster, *worstTrackParamAtCluster;
+ Double_t sigmaCut2 = GetRecoParam()->GetSigmaCutForImprovement() *
+ GetRecoParam()->GetSigmaCutForImprovement();
+
+ while (!track.IsImproved()) {
- AliMUONTriggerTrack *triggertrack ;
- Int_t nTriggerTracks = fMUONData->RecTriggerTracks()->GetEntriesFast();
-
- AliDebug(1, "****** enter EventDumpTrigger ******");
- AliDebug(1, Form("Number of Reconstructed tracks : %d ", nTriggerTracks));
-
- // Loop over reconstructed tracks
- for (Int_t trackIndex = 0; trackIndex < nTriggerTracks; trackIndex++) {
- triggertrack = (AliMUONTriggerTrack*)fMUONData->RecTriggerTracks()->At(trackIndex);
- printf(" trigger track number %i x11=%f y11=%f thetax=%f thetay=%f \n",
- trackIndex,
- triggertrack->GetX11(),triggertrack->GetY11(),
- triggertrack->GetThetax(),triggertrack->GetThetay());
- }
-}
-
-//__________________________________________________________________________
-void AliMUONTrackReconstructor::MakeTrackCandidatesK(void)
-{
- // To make initial tracks for Kalman filter from the list of segments
- Int_t istat, iseg;
- AliMUONSegment *segment;
- AliMUONTrackK *trackK;
-
- AliDebug(1,"Enter MakeTrackCandidatesK");
-
- AliMUONTrackK a(this, fHitsForRecPtr);
- // Loop over stations(1...) 5 and 4
- for (istat=4; istat>=3; istat--) {
- // Loop over segments in the station
- for (iseg=0; iseg<fNSegments[istat]; iseg++) {
- // Transform segments to tracks and evaluate covariance matrix
- segment = (AliMUONSegment*) ((*fSegmentsPtr[istat])[iseg]);
- trackK = new ((*fRecTracksPtr)[fNRecTracks++]) AliMUONTrackK(segment);
- } // for (iseg=0;...)
- } // for (istat=4;...)
- return;
-}
-
-//__________________________________________________________________________
-void AliMUONTrackReconstructor::FollowTracksK(void)
-{
- // Follow tracks using Kalman filter
- Bool_t ok;
- Int_t icand, ichamBeg = 0, ichamEnd, chamBits;
- Double_t zDipole1, zDipole2;
- AliMUONTrackK *trackK;
- AliMUONHitForRec *hit;
- AliMUONRawCluster *clus;
- TClonesArray *rawclusters;
- clus = 0; rawclusters = 0;
-
- zDipole1 = GetSimpleBPosition() + GetSimpleBLength()/2;
- zDipole2 = zDipole1 - GetSimpleBLength();
-
- // Print hits
- trackK = (AliMUONTrackK*) ((*fRecTracksPtr)[0]);
-
- if (trackK->DebugLevel() > 0) {
- for (Int_t i1=0; i1<fNHitsForRec; i1++) {
- hit = (AliMUONHitForRec*) ((*fHitsForRecPtr)[i1]);
- printf(" Hit # %d %10.4f %10.4f %10.4f",
- hit->GetChamberNumber(), hit->GetBendingCoor(),
- hit->GetNonBendingCoor(), hit->GetZ());
-
- // from raw clusters
- rawclusters = fMUONData->RawClusters(hit->GetChamberNumber());
- clus = (AliMUONRawCluster*) rawclusters->UncheckedAt(hit->
- GetHitNumber());
- printf(" %d", clus->GetTrack(1));
- if (clus->GetTrack(2) != -1) printf(" %d \n", clus->GetTrack(2));
- else printf("\n");
-
- }
- } // if (trackK->DebugLevel() > 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 = CheckCandidateK(icand,nSeeds);
- if (!ok) {
- trackK->SetRecover(-1); // mark candidate to be removed
- continue;
- }
+ // identify removable clusters
+ track.TagRemovableClusters(GetRecoParam()->RequestedStationMask());
+
+ // Update track parameters and covariances
+ if (!track.UpdateCovTrackParamAtCluster()) {
+ AliWarning("unable to update track parameters and covariances --> stop improvement");
+ break;
}
- */
-
- ok = kTRUE;
- if (trackK->GetRecover() == 0)
- hit = (AliMUONHitForRec*) trackK->GetTrackHits()->Last(); // last hit
- else
- hit = trackK->GetHitLastOk(); // hit where track stopped
-
- if (hit) ichamBeg = hit->GetChamberNumber();
- 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;
- 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;
- }
- } else {
- if (trackK->GetBPFlag()) {
- // backpropagation
- ichamEnd = 6; // backward propagation
- // Change weight matrix and zero fChi2 for backpropagation
- trackK->StartBack();
- ok = trackK->KalmanFilter(ichamBeg,ichamEnd,kTRUE,zDipole1,zDipole2);
- ichamBeg = ichamEnd;
- ichamEnd = 0;
+
+ // Compute local chi2 of each clusters
+ track.ComputeLocalChi2(kTRUE);
+
+ // Look for the cluster to remove
+ worstTrackParamAtCluster = NULL;
+ worstLocalChi2 = 0.;
+ trackParamAtCluster = (AliMUONTrackParam*) track.GetTrackParamAtCluster()->First();
+ while (trackParamAtCluster) {
+
+ // Pick up cluster with the worst chi2
+ localChi2 = trackParamAtCluster->GetLocalChi2();
+ if (localChi2 > worstLocalChi2) {
+ worstLocalChi2 = localChi2;
+ worstTrackParamAtCluster = trackParamAtCluster;
}
+
+ trackParamAtCluster = (AliMUONTrackParam*) track.GetTrackParamAtCluster()->After(trackParamAtCluster);
}
-
- if (ok) {
- trackK->SetTrackDir(1);
- trackK->SetBPFlag(kFALSE);
- ok = trackK->KalmanFilter(ichamBeg,ichamEnd,kFALSE,zDipole1,zDipole2);
- }
- if (!ok) { trackK->SetRecover(-1); continue; } // mark candidate to be removed
-
- // Apply smoother
- if (trackK->GetRecover() >= 0) {
- ok = trackK->Smooth();
- if (!ok) trackK->SetRecover(-1); // mark candidate to be removed
+
+ // Check if worst cluster found
+ if (!worstTrackParamAtCluster) {
+ AliWarning("Bad local chi2 values?");
+ break;
}
-
- // 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);
+
+ // 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 (!((chamBits&3)==3 || (chamBits>>2&3)==3) && chi2max > 25) {
- //trackK->Recover();
- trackK->SetRecover(-1); //mark candidate to be removed
- continue;
+
+ // if the worst cluster is not removable then stop improvement
+ if (!worstTrackParamAtCluster->IsRemovable()) break;
+
+ // Remove the worst cluster
+ track.RemoveTrackParamAtCluster(worstTrackParamAtCluster);
+
+ // Re-fit the track:
+ // Take into account the multiple scattering
+ // Calculate the track parameter covariance matrix
+ Fit(track, kTRUE, kFALSE, kTRUE);
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "ImproveTracks: track " << fRecTracksPtr->IndexOf(&track)+1 << " improved " << endl;
}
- if (ok) trackK->SetTrackQuality(0); // compute "track quality"
- } // while
-
- for (Int_t i=0; i<fNRecTracks; i++) {
- trackK = (AliMUONTrackK*) ((*fRecTracksPtr)[i]);
- if (trackK->GetRecover() < 0) fRecTracksPtr->RemoveAt(i);
+
}
-
- // Compress TClonesArray
- fRecTracksPtr->Compress();
- fNRecTracks = fRecTracksPtr->GetEntriesFast();
- return;
+
}
-//__________________________________________________________________________
-Bool_t AliMUONTrackReconstructor::CheckCandidateK(Int_t icand, Int_t nSeeds) const
+ //__________________________________________________________________________
+Bool_t AliMUONTrackReconstructor::FinalizeTrack(AliMUONTrack &track)
{
- // 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;
-
- track1 = (AliMUONTrackK*) ((*fRecTracksPtr)[icand]);
- hit1 = (AliMUONHitForRec*) (*track1->GetTrackHits())[0]; // 1'st hit
- hit2 = (AliMUONHitForRec*) (*track1->GetTrackHits())[1]; // 2'nd hit
-
- for (Int_t i=0; i<icand; i++) {
- track2 = (AliMUONTrackK*) ((*fRecTracksPtr)[i]);
- //if (track2->GetRecover() < 0) continue;
- if (track2->GetRecover() < 0 && icand >= nSeeds) continue;
-
- if (track1->GetStartSegment() == track2->GetStartSegment()) {
- 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;
- }
- } // for (Int_t i=0;
+ /// Recompute track parameters and covariances at each attached cluster
+ /// from those at the first one, if not already done
+ AliDebug(1,"Enter FinalizeTrack");
+ if (!track.IsImproved() && !track.UpdateCovTrackParamAtCluster()) {
+ AliWarning("finalization failed due to extrapolation problem");
+ return kFALSE;
+ }
return kTRUE;
}
-//__________________________________________________________________________
-void AliMUONTrackReconstructor::RemoveDoubleTracksK(void)
-{
- // 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
-
- fNRecTracks = fRecTracksPtr->GetEntriesFast();
- if (debug >= 0) cout << " Number of Kalman tracks: " << fNRecTracks << endl;
-}
-
-//__________________________________________________________________________
-void AliMUONTrackReconstructor::GoToVertex(void)
+ //__________________________________________________________________________
+Bool_t AliMUONTrackReconstructor::RefitTrack(AliMUONTrack &track, Bool_t enableImprovement)
{
- // Propagates track to the vertex thru absorber
- // (using Branson correction for now)
-
- Double_t zVertex;
- zVertex = 0;
- for (Int_t i=0; i<fNRecTracks; i++) {
- //((AliMUONTrackK*)(*fRecTracksPtr)[i])->Branson();
- ((AliMUONTrackK*)(*fRecTracksPtr)[i])->SetTrackQuality(1); // compute Chi2
- //((AliMUONTrackK*)(*fRecTracksPtr)[i])->GoToZ(zVertex); // w/out absorber
- ((AliMUONTrackK*)(*fRecTracksPtr)[i])->GoToVertex(1); // with absorber
+ /// re-fit the given track
+
+ // check validity of the track
+ if (track.GetNClusters() < 3) {
+ AliWarning("the track does not contain enough clusters --> unable to refit");
+ return kFALSE;
+ }
+
+ // reset the seed (i.e. parameters at first cluster) before fitting
+ AliMUONTrackParam* firstTrackParam = (AliMUONTrackParam*) track.GetTrackParamAtCluster()->First();
+ if (firstTrackParam->GetInverseBendingMomentum() == 0.) {
+ AliWarning("track parameters at first chamber are not initialized --> unable to refit");
+ return kFALSE;
+ }
+
+ // compute track parameters at each cluster from parameters at the first one
+ // necessary to compute multiple scattering effect during refitting
+ if (!track.UpdateTrackParamAtCluster()) {
+ AliWarning("bad track refitting due to extrapolation failure");
+ return kFALSE;
}
+
+ // Re-fit the track:
+ // Take into account the multiple scattering
+ // Calculate the track parameter covariance matrix
+ Fit(track, kTRUE, kFALSE, kTRUE);
+
+ // 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;
+ }
+
}
-//__________________________________________________________________________
-void AliMUONTrackReconstructor::SetTrackMethod(Int_t iTrackMethod)
-{
- // Set track method and recreate track container if necessary
-
- fTrackMethod = TMath::Min (iTrackMethod, 3);
- fTrackMethod = TMath::Max (fTrackMethod, 1);
- if (fTrackMethod != 1) {
- if (fRecTracksPtr) delete fRecTracksPtr;
- fRecTracksPtr = new TClonesArray("AliMUONTrackK", 10);
- if (fTrackMethod == 2) cout << " *** Tracking with the Kalman filter *** " << endl;
- else cout << " *** Combined cluster / track finder ***" << endl;
- } else cout << " *** Original tracking *** " << endl;
-
-}