X-Git-Url: http://git.uio.no/git/?a=blobdiff_plain;f=MUON%2FAliMUONTrackReconstructor.cxx;h=96aac39a8acce958887d0c73aa04124ef01f1c08;hb=b9560ae2d59030e59fe795ee8a6483127bc2a559;hp=449b3ba3d476b10b8ed543238f39b8d059b02697;hpb=80e33fc58d043effe6ef51e004359d818bf812bb;p=u%2Fmrichter%2FAliRoot.git diff --git a/MUON/AliMUONTrackReconstructor.cxx b/MUON/AliMUONTrackReconstructor.cxx index 449b3ba3d47..96aac39a8ac 100644 --- a/MUON/AliMUONTrackReconstructor.cxx +++ b/MUON/AliMUONTrackReconstructor.cxx @@ -15,1498 +15,1188 @@ /* $Id$ */ -//////////////////////////////////// -// -// 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 -#include -#include -#include -#include +//----------------------------------------------------------------------------- +/// \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 "AliMUONData.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 "AliMUONTrack.h" -#include "AliMUONTrackHit.h" -#include "AliMagF.h" -#include "AliMUONTrackK.h" +#include "AliMUONTrackParam.h" +#include "AliMUONTrackExtrap.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; +#include +#include +#include +#include + +// Functions to be minimized with Minuit +void TrackChi2(Int_t &nParam, Double_t *gradient, Double_t &chi2, Double_t *param, Int_t flag); +/// \cond CLASSIMP ClassImp(AliMUONTrackReconstructor) // Class implementation in ROOT context +/// \endcond -//__________________________________________________________________________ -AliMUONTrackReconstructor::AliMUONTrackReconstructor(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), - fMuons(0), - fTriggerTrack(new AliMUONTriggerTrack()), - fTriggerCircuit(0x0) + //__________________________________________________________________________ +AliMUONTrackReconstructor::AliMUONTrackReconstructor() + : AliMUONVTrackReconstructor() { - // Constructor for class AliMUONTrackReconstructor - SetReconstructionParametersToDefaults(); - - // Memory allocation for the TClonesArray of hits for reconstruction - // Is 10000 the right size ???? - fHitsForRecPtr = new TClonesArray("AliMUONHitForRec", 10000); - - // 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); - - // 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); - - 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 ???? - - return; + /// Constructor for class AliMUONTrackReconstructor + AliInfo("*** Original tracking ***"); } //__________________________________________________________________________ -AliMUONTrackReconstructor::~AliMUONTrackReconstructor(void) +AliMUONTrackReconstructor::~AliMUONTrackReconstructor() { - // 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 ???? +/// Destructor +} - delete fTriggerTrack; -} //__________________________________________________________________________ -void AliMUONTrackReconstructor::SetReconstructionParametersToDefaults(void) -{ - // 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; -} - -//__________________________________________________________________________ -Double_t AliMUONTrackReconstructor::GetImpactParamFromBendingMomentum(Double_t BendingMomentum) const +void AliMUONTrackReconstructor::MakeTrackCandidates() { - // 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); -} - -//__________________________________________________________________________ -Double_t AliMUONTrackReconstructor::GetBendingMomentumFromImpactParam(Double_t ImpactParam) const -{ - // 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 hitForRec's. + /// Keep only best candidates or all of them according to the flag fgkTrackAllTracks. + + TClonesArray *segments; + AliMUONTrack *track; + Int_t iCandidate = 0; + Bool_t hitFound; -//__________________________________________________________________________ -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; iAt(i); - fMUONData->AddRecTrack(*track); + // Loop over stations(1..) 5 and 4 and make track candidates + for (Int_t istat=4; istat>=3; istat--) { + + // Make segments in the station + segments = MakeSegmentsInStation(istat); + + // Loop over segments + for (Int_t iseg=0; isegGetEntriesFast(); 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])); + fNRecTracks++; + + // Printout for debuging + if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) + { + cout<GetTrackParamAtHit()->First())->GetCovariances().Print(); + } + + // Look for compatible hitForRec(s) in the other station + if (AliMUONReconstructor::GetRecoParam()->MakeTrackCandidatesFast()) hitFound = FollowLinearTrackInStation(*track,7-istat); + else hitFound = FollowTrackInStation(*track,7-istat); + + // Remove track if no hit found + if (!hitFound) { + fRecTracksPtr->Remove(track); + fNRecTracks--; + } + + } + + // delete the array of segments + delete segments; } -} - -//__________________________________________________________________________ -void AliMUONTrackReconstructor::EventReconstructTrigger(void) -{ - // To reconstruct one event - AliDebug(1,"Enter EventReconstructTrigger"); - MakeTriggerTracks(); -} - - //__________________________________________________________________________ -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; + + fRecTracksPtr->Compress(); // this is essential before checking tracks + + // Keep all different tracks or only the best ones as required + if (AliMUONReconstructor::GetRecoParam()->TrackAllTracks()) RemoveIdenticalTracks(); + else RemoveDoubleTracks(); + + AliDebug(1,Form("Number of good candidates = %d",fNRecTracks)); + } //__________________________________________________________________________ -void AliMUONTrackReconstructor::ResetSegments(void) +void AliMUONTrackReconstructor::FollowTracks() { - // 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; + /// Follow tracks in stations(1..) 3, 2 and 1 + AliDebug(1,"Enter FollowTracks"); + + AliMUONTrack *track, *nextTrack; + AliMUONTrackParam *trackParam, *nextTrackParam; + Int_t currentNRecTracks; + Bool_t hitFound; + + Double_t sigmaCut2 = AliMUONReconstructor::GetRecoParam()->GetSigmaCutForTracking() * + AliMUONReconstructor::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 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 "station" is station(1..) 3 then use the vertex to better constrain the fit + if (station==2) { + SetVertexForFit(*track); + track->SetFitWithVertex(kTRUE); + } else track->SetFitWithVertex(kFALSE); + Fit(*track, kFALSE, kTRUE); + + // Remove the 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 (AliMUONReconstructor::GetRecoParam()->ComplementTracks()) { + + if (station==2) { // save track parameters on stations 4 and 5 + + // extrapolate track parameters and covariances at each cluster + track->UpdateCovTrackParamAtHit(); + + // save them + trackParam = (AliMUONTrackParam*) track->GetTrackParamAtHit()->First(); + while (trackParam) { + trackParam->SetSmoothParameters(trackParam->GetParameters()); + trackParam->SetSmoothCovariances(trackParam->GetCovariances()); + trackParam = (AliMUONTrackParam*) track->GetTrackParamAtHit()->After(trackParam); + } + + } else { // or save track parameters on last station only + + // save parameters from fit + trackParam = (AliMUONTrackParam*) track->GetTrackParamAtHit()->First(); + 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->GetTrackParamAtHit()->After(trackParam); + if (nextTrackParam->GetHitForRecPtr()->GetChamberNumber() < 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 + AliMUONTrackExtrap::ExtrapToZCov(nextTrackParam, nextTrackParam->GetHitForRecPtr()->GetZ()); + + // save them + nextTrackParam->SetSmoothParameters(nextTrackParam->GetParameters()); + nextTrackParam->SetSmoothCovariances(nextTrackParam->GetCovariances()); + + } + + } + + } + + // Printout for debuging + if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) { + cout<GetTrackParamAtHit()->First())->GetCovariances().Print(); + } + + // Look for compatible hitForRec in station(0..) "station" + hitFound = FollowTrackInStation(*track,station); + + // Try to recover track if required + if (!hitFound && AliMUONReconstructor::GetRecoParam()->RecoverTracks()) hitFound = RecoverTrack(*track,station); + + // remove track if no hit found + if (!hitFound) { + fRecTracksPtr->Remove(track); + fNRecTracks--; + } + + } + + // Compress fRecTracksPtr for the next step + fRecTracksPtr->Compress(); + + // Keep only the best tracks if required + if (!AliMUONReconstructor::GetRecoParam()->TrackAllTracks()) RemoveDoubleTracks(); + } - 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; -} - - - //__________________________________________________________________________ -void AliMUONTrackReconstructor::ResetTrackHits(void) -{ - // To reset the TClonesArray of hits on reconstructed tracks - if (fRecTrackHitsPtr) fRecTrackHitsPtr->Clear(); - fNRecTrackHits = 0; - return; -} - - //__________________________________________________________________________ -void AliMUONTrackReconstructor::MakeEventToBeReconstructed(void) -{ - // 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 - - 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 = fMUONData->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(); + + // Last fit of track candidates with all station + // 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 + + track->SetFitWithVertex(kFALSE); // just to be sure + Fit(*track, kTRUE, 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--; + } + + // save parameters from fit into smoothed parameters to complete track afterward + if (AliMUONReconstructor::GetRecoParam()->ComplementTracks()) { + + // save parameters from fit + trackParam = (AliMUONTrackParam*) track->GetTrackParamAtHit()->First(); + 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->GetTrackParamAtHit()->After(trackParam); + if (nextTrackParam->GetHitForRecPtr()->GetChamberNumber() < 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 + AliMUONTrackExtrap::ExtrapToZCov(nextTrackParam, nextTrackParam->GetHitForRecPtr()->GetZ()); + + // save them + nextTrackParam->SetSmoothParameters(nextTrackParam->GetParameters()); + nextTrackParam->SetSmoothCovariances(nextTrackParam->GetCovariances()); + } + } + + track = nextTrack; + } - return; + + fRecTracksPtr->Compress(); + } //__________________________________________________________________________ -void AliMUONTrackReconstructor::SortHitsForRecWithIncreasingChamber() +Bool_t AliMUONTrackReconstructor::FollowTrackInStation(AliMUONTrack &trackCandidate, Int_t nextStation) { - // 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 station(0..) nextStation and search for compatible HitForRec(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 hit(s) to the "trackCandidate". Try to add a couple of hits 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; } - 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; + + Double_t chi2WithOneHitForRec = 1.e10; + Double_t chi2WithTwoHitForRec = 1.e10; + Double_t maxChi2WithOneHitForRec = 2. * AliMUONReconstructor::GetRecoParam()->GetSigmaCutForTracking() * + AliMUONReconstructor::GetRecoParam()->GetSigmaCutForTracking(); // 2 because 2 quantities in chi2 + Double_t maxChi2WithTwoHitForRec = 4. * AliMUONReconstructor::GetRecoParam()->GetSigmaCutForTracking() * + AliMUONReconstructor::GetRecoParam()->GetSigmaCutForTracking(); // 4 because 4 quantities in chi2 + Double_t bestChi2WithOneHitForRec = maxChi2WithOneHitForRec; + Double_t bestChi2WithTwoHitForRec = maxChi2WithTwoHitForRec; + Bool_t foundOneHit = kFALSE; + Bool_t foundTwoHits = kFALSE; + AliMUONTrack *newTrack = 0x0; + AliMUONHitForRec *hitForRecCh1, *hitForRecCh2; + AliMUONTrackParam extrapTrackParam; + AliMUONTrackParam extrapTrackParamAtHit1; + AliMUONTrackParam extrapTrackParamAtHit2; + AliMUONTrackParam bestTrackParamAtHit1; + AliMUONTrackParam bestTrackParamAtHit2; + Bool_t *hitForRecCh1Used = new Bool_t[fNHitsForRecPerChamber[ch1]]; + for (Int_t hit1 = 0; hit1 < fNHitsForRecPerChamber[ch1]; hit1++) hitForRecCh1Used[hit1] = kFALSE; + + // Get track parameters + AliMUONTrackParam extrapTrackParamAtCh(*(AliMUONTrackParam*)trackCandidate.GetTrackParamAtHit()->First()); + + // Add MCS effect + AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(),1.); + + // Add MCS in the missing chamber if any (only 1 chamber can be missing according to tracking criteria) + if (ch1 < ch2 && extrapTrackParamAtCh.GetHitForRecPtr()->GetChamberNumber() > ch2 + 1) { + // extrapolation to the missing chamber + AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(ch2 + 1)); + // add MCS effect + AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(),1.); + } + + //Extrapolate trackCandidate to chamber "ch2" + AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(ch2)); + + // Printout for debuging + if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) { + cout<= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { + cout << "FollowTrackInStation: look for hits in chamber(1..): " << ch2+1 << endl; + } + + // look for candidates in chamber 2 + for (Int_t hit2 = 0; hit2 < fNHitsForRecPerChamber[ch2]; hit2++) { + + hitForRecCh2 = (AliMUONHitForRec*) fHitsForRecPtr->UncheckedAt(fIndexOfFirstHitForRecPerChamber[ch2]+hit2); + + // try to add the current hit fast + if (!TryOneHitForRecFast(extrapTrackParamAtCh, hitForRecCh2)) continue; + + // try to add the current hit accuratly + chi2WithOneHitForRec = TryOneHitForRec(extrapTrackParamAtCh, hitForRecCh2, extrapTrackParamAtHit2); + + // if good chi2 then try to attach a hitForRec in the other chamber too + if (chi2WithOneHitForRec < maxChi2WithOneHitForRec) { + Bool_t foundSecondHit = kFALSE; + + // Printout for debuging + if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { + cout << "FollowTrackInStation: found one hit in chamber(1..): " << ch2+1 + << " (Chi2 = " << chi2WithOneHitForRec << ")" << endl; + cout << " look for second hits in chamber(1..): " << ch1+1 << " ..." << endl; + } + + // add MCS effect for next step + AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtHit2,AliMUONConstants::ChamberThicknessInX0(),1.); + + // copy new track parameters for next step + extrapTrackParam = extrapTrackParamAtHit2; + + //Extrapolate track parameters to chamber "ch1" + AliMUONTrackExtrap::ExtrapToZ(&extrapTrackParam, AliMUONConstants::DefaultChamberZ(ch1)); + + for (Int_t hit1 = 0; hit1 < fNHitsForRecPerChamber[ch1]; hit1++) { + + hitForRecCh1 = (AliMUONHitForRec*) fHitsForRecPtr->UncheckedAt(fIndexOfFirstHitForRecPerChamber[ch1]+hit1); + + // try to add the current hit fast + if (!TryOneHitForRecFast(extrapTrackParam, hitForRecCh1)) continue; + + // try to add the current hit accuratly + chi2WithTwoHitForRec = TryTwoHitForRec(extrapTrackParamAtHit2, hitForRecCh1, extrapTrackParamAtHit1); + + // if good chi2 then create a new track by adding the 2 hitForRec to the "trackCandidate" + if (chi2WithTwoHitForRec < maxChi2WithTwoHitForRec) { + foundSecondHit = kTRUE; + foundTwoHits = kTRUE; + + // Printout for debuging + if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { + cout << "FollowTrackInStation: found second hit in chamber(1..): " << ch1+1 + << " (Global Chi2 = " << chi2WithTwoHitForRec << ")" << endl; + } + + if (AliMUONReconstructor::GetRecoParam()->TrackAllTracks()) { + // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new hitForRec's + newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate); + UpdateTrack(*newTrack,extrapTrackParamAtHit1,extrapTrackParamAtHit2); + fNRecTracks++; + + // Tag hitForRecCh1 as used + hitForRecCh1Used[hit1] = kTRUE; + + // Printout for debuging + if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { + cout << "FollowTrackInStation: added two hits in station(1..): " << nextStation+1 << endl; + if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); + } + + } else if (chi2WithTwoHitForRec < bestChi2WithTwoHitForRec) { + // keep track of the best couple of hits + bestChi2WithTwoHitForRec = chi2WithTwoHitForRec; + bestTrackParamAtHit1 = extrapTrackParamAtHit1; + bestTrackParamAtHit2 = extrapTrackParamAtHit2; + } + + } + + } + + // if no hitForRecCh1 found then consider to add hitForRecCh2 only + if (!foundSecondHit) { + foundOneHit = kTRUE; + + if (AliMUONReconstructor::GetRecoParam()->TrackAllTracks()) { + // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new hitForRec's + newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate); + UpdateTrack(*newTrack,extrapTrackParamAtHit2); + fNRecTracks++; + + // Printout for debuging + if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { + cout << "FollowTrackInStation: added one hit in chamber(1..): " << ch2+1 << endl; + if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); + } + + } else if (!foundTwoHits && chi2WithOneHitForRec < bestChi2WithOneHitForRec) { + // keep track of the best single hitForRec except if a couple of hits has already been found + bestChi2WithOneHitForRec = chi2WithOneHitForRec; + bestTrackParamAtHit1 = extrapTrackParamAtHit2; + } + + } + } + } - return; -} - - //__________________________________________________________________________ -void AliMUONTrackReconstructor::AddHitsForRecFromRawClusters(TTree* TR) -{ - // 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); + + // 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 hitForRec has been found + if (AliMUONReconstructor::GetRecoParam()->TrackAllTracks() || !foundTwoHits) { + + // Printout for debuging + if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { + cout << "FollowTrackInStation: look for single hits in chamber(1..): " << ch1+1 << endl; + } + + // add MCS effect for next step + AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(),1.); + + //Extrapolate trackCandidate to chamber "ch1" + AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(ch1)); + + for (Int_t hit1 = 0; hit1 < fNHitsForRecPerChamber[ch1]; hit1++) { + + hitForRecCh1 = (AliMUONHitForRec*) fHitsForRecPtr->UncheckedAt(fIndexOfFirstHitForRecPerChamber[ch1]+hit1); + + if (hitForRecCh1Used[hit1]) continue; // Skip hitForRec already used + + // try to add the current hit fast + if (!TryOneHitForRecFast(extrapTrackParamAtCh, hitForRecCh1)) continue; + + // try to add the current hit accuratly + chi2WithOneHitForRec = TryOneHitForRec(extrapTrackParamAtCh, hitForRecCh1, extrapTrackParamAtHit1); + + // if good chi2 then consider to add hitForRecCh1 + // We do not try to attach a hitForRec in the other chamber too since it has already been done above + if (chi2WithOneHitForRec < maxChi2WithOneHitForRec) { + foundOneHit = kTRUE; + + // Printout for debuging + if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { + cout << "FollowTrackInStation: found one hit in chamber(1..): " << ch1+1 + << " (Chi2 = " << chi2WithOneHitForRec << ")" << endl; + } + + if (AliMUONReconstructor::GetRecoParam()->TrackAllTracks()) { + // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new hitForRec's + newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate); + UpdateTrack(*newTrack,extrapTrackParamAtHit1); + fNRecTracks++; + + // Printout for debuging + if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { + cout << "FollowTrackInStation: added one hit in chamber(1..): " << ch1+1 << endl; + if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); + } + + } else if (chi2WithOneHitForRec < bestChi2WithOneHitForRec) { + // keep track of the best single hitForRec except if a couple of hits has already been found + bestChi2WithOneHitForRec = chi2WithOneHitForRec; + bestTrackParamAtHit1 = extrapTrackParamAtHit1; + } + + } + } - fMUONData->GetRawClusters(); // 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)); + + // fill out the best track if required else clean up the fRecTracksPtr array + if (!AliMUONReconstructor::GetRecoParam()->TrackAllTracks()) { + if (foundTwoHits) { + UpdateTrack(trackCandidate,bestTrackParamAtHit1,bestTrackParamAtHit2); - StdoutToAliDebug(3, - cout << "Chamber " << ch << - " raw cluster " << iclus << " : " << endl; - clus->Print("full"); - cout << "AliMUONHitForRec number (1...): " << fNHitsForRec << endl; - hitForRec->Print("full"); - ); - } // end of cluster loop - } // end of chamber loop - SortHitsForRecWithIncreasingChamber(); - return; + // Printout for debuging + if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { + cout << "FollowTrackInStation: added the two best hits in station(1..): " << nextStation+1 << endl; + if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); + } + + } else if (foundOneHit) { + UpdateTrack(trackCandidate,bestTrackParamAtHit1); + + // Printout for debuging + if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { + cout << "FollowTrackInStation: added the best hit in chamber(1..): " << bestTrackParamAtHit1.GetHitForRecPtr()->GetChamberNumber()+1 << endl; + if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); + } + + } else { + delete [] hitForRecCh1Used; + return kFALSE; + } + + } else if (foundOneHit || foundTwoHits) { + + // remove obsolete track + fRecTracksPtr->Remove(&trackCandidate); + fNRecTracks--; + + } else { + delete [] hitForRecCh1Used; + return kFALSE; + } + + delete [] hitForRecCh1Used; + return kTRUE; + } //__________________________________________________________________________ -void AliMUONTrackReconstructor::MakeSegments(void) +Double_t AliMUONTrackReconstructor::TryTwoHitForRec(const AliMUONTrackParam &trackParamAtHit1, AliMUONHitForRec* hitForRec2, + AliMUONTrackParam &trackParamAtHit2) { - // 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); - } +/// Test the compatibility between the track and the 2 hitForRec together (using trackParam's covariance matrix): +/// return the corresponding Chi2 accounting for covariances between the 2 hitForRec +/// return trackParamAtHit1 & 2 - StdoutToAliDebug(3, - cout << "end of MakeSegments" << endl; - for (Int_t st = 0; st < AliMUONConstants::NTrackingCh()/2; st++) - { - cout << "station " << st - << " has " << fNSegments[st] << " segments:" - << endl; - for (Int_t seg = 0; seg < fNSegments[st]; seg++) - { - ((*fSegmentsPtr[st])[seg])->Print(); + // extrapolate track parameters at the z position of the second hit + trackParamAtHit2.SetParameters(trackParamAtHit1.GetParameters()); + trackParamAtHit2.SetZ(trackParamAtHit1.GetZ()); + AliMUONTrackExtrap::ExtrapToZ(&trackParamAtHit2, hitForRec2->GetZ()); + + // set pointer to hit2 into trackParamAtHit2 + trackParamAtHit2.SetHitForRecPtr(hitForRec2); + + // Set differences between track and the 2 hitForRec in the bending and non bending directions + AliMUONHitForRec* hitForRec1 = trackParamAtHit1.GetHitForRecPtr(); + TMatrixD dPos(4,1); + dPos(0,0) = hitForRec1->GetNonBendingCoor() - trackParamAtHit1.GetNonBendingCoor(); + dPos(1,0) = hitForRec1->GetBendingCoor() - trackParamAtHit1.GetBendingCoor(); + dPos(2,0) = hitForRec2->GetNonBendingCoor() - trackParamAtHit2.GetNonBendingCoor(); + dPos(3,0) = hitForRec2->GetBendingCoor() - trackParamAtHit2.GetBendingCoor(); + + // Calculate the error matrix from the track parameter covariances at first hitForRec + TMatrixD error(4,4); + error.Zero(); + if (trackParamAtHit1.CovariancesExist()) { + // Save track parameters at first hitForRec + AliMUONTrackParam trackParamAtHit1Save(trackParamAtHit1); + TMatrixD paramAtHit1Save(trackParamAtHit1Save.GetParameters()); + Double_t z1 = trackParamAtHit1Save.GetZ(); + + // Save track coordinates at second hitForRec + Double_t nonBendingCoor2 = trackParamAtHit2.GetNonBendingCoor(); + Double_t bendingCoor2 = trackParamAtHit2.GetBendingCoor(); + + // add MCS effect at first hitForRec + AliMUONTrackExtrap::AddMCSEffect(&trackParamAtHit1Save,AliMUONConstants::ChamberThicknessInX0(),1.); + + // Get the pointer to the parameter covariance matrix at first hitForRec + const TMatrixD& kParamCov = trackParamAtHit1Save.GetCovariances(); + + // Calculate the jacobian related to the transformation between track parameters + // at first hitForRec and track coordinates at the 2 hitForRec z-position + TMatrixD jacob(4,5); + jacob.Zero(); + // first derivative at the first hitForRec: + jacob(0,0) = 1.; // dx1/dx + jacob(1,2) = 1.; // dy1/dy + // first derivative at the second hitForRec: + TMatrixD dParam(5,1); + 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)); + if (j == 4) dParam(j,0) *= TMath::Sign(1.,-paramAtHit1Save(4,0)); // variation always in the same direction + } else dParam(j,0) = 0.; } + + // Set new track parameters at first hitForRec + trackParamAtHit1Save.SetParameters(paramAtHit1Save); + trackParamAtHit1Save.AddParameters(dParam); + trackParamAtHit1Save.SetZ(z1); + + // Extrapolate new track parameters to the z position of the second hitForRec + AliMUONTrackExtrap::ExtrapToZ(&trackParamAtHit1Save,hitForRec2->GetZ()); + + // Calculate the jacobian + jacob(2,i) = (trackParamAtHit1Save.GetNonBendingCoor() - nonBendingCoor2) / dParam(i,0); // dx2/dParami + jacob(3,i) = (trackParamAtHit1Save.GetBendingCoor() - bendingCoor2 ) / dParam(i,0); // dy2/dParami } - ); + + // Calculate the error matrix + TMatrixD tmp(jacob,TMatrixD::kMult,kParamCov); + error = TMatrixD(tmp,TMatrixD::kMultTranspose,jacob); + } + + // Add hitForRec resolution to the error matrix + error(0,0) += hitForRec1->GetNonBendingReso2(); + error(1,1) += hitForRec1->GetBendingReso2(); + error(2,2) += hitForRec2->GetNonBendingReso2(); + error(3,3) += hitForRec2->GetBendingReso2(); + + // invert the error matrix for Chi2 calculation + if (error.Determinant() != 0) { + error.Invert(); + } else { + AliWarning(" Determinant error=0"); + return 1.e10; + } + + // Compute the Chi2 value + TMatrixD tmp2(dPos,TMatrixD::kTransposeMult,error); + TMatrixD result(tmp2,TMatrixD::kMult,dPos); + + return result(0,0); + } //__________________________________________________________________________ -void AliMUONTrackReconstructor::MakeSegmentsPerStation(Int_t Station) +void AliMUONTrackReconstructor::UpdateTrack(AliMUONTrack &track, AliMUONTrackParam &trackParamAtHit) { - // 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)); - } - 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; + /// Add 1 hit to the track candidate + /// Update chi2 of the track + + // Compute local chi2 + AliMUONHitForRec* hit = trackParamAtHit.GetHitForRecPtr(); + Double_t deltaX = trackParamAtHit.GetNonBendingCoor() - hit->GetNonBendingCoor(); + Double_t deltaY = trackParamAtHit.GetBendingCoor() - hit->GetBendingCoor(); + Double_t localChi2 = deltaX*deltaX / hit->GetNonBendingReso2() + + deltaY*deltaY / hit->GetBendingReso2(); + + // Flag hit as being not removable + trackParamAtHit.SetRemovable(kFALSE); + trackParamAtHit.SetLocalChi2(0.); // --> Local chi2 not used + + // Update the chi2 of the new track + track.SetFitFMin(track.GetFitFMin() + localChi2); + + // Update TrackParamAtHit + track.AddTrackParamAtHit(&trackParamAtHit,trackParamAtHit.GetHitForRecPtr()); + track.GetTrackParamAtHit()->Sort(); + } //__________________________________________________________________________ -void AliMUONTrackReconstructor::MakeTracks(void) +void AliMUONTrackReconstructor::UpdateTrack(AliMUONTrack &track, AliMUONTrackParam &trackParamAtHit1, AliMUONTrackParam &trackParamAtHit2) { - // 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 2 hits to the track candidate + /// Update track and local chi2 + + // Update local chi2 at first hit + AliMUONHitForRec* hit1 = trackParamAtHit1.GetHitForRecPtr(); + Double_t deltaX = trackParamAtHit1.GetNonBendingCoor() - hit1->GetNonBendingCoor(); + Double_t deltaY = trackParamAtHit1.GetBendingCoor() - hit1->GetBendingCoor(); + Double_t localChi2AtHit1 = deltaX*deltaX / hit1->GetNonBendingReso2() + + deltaY*deltaY / hit1->GetBendingReso2(); + trackParamAtHit1.SetLocalChi2(localChi2AtHit1); + + // Flag first hit as being removable + trackParamAtHit1.SetRemovable(kTRUE); + + // Update local chi2 at second hit + AliMUONHitForRec* hit2 = trackParamAtHit2.GetHitForRecPtr(); + deltaX = trackParamAtHit2.GetNonBendingCoor() - hit2->GetNonBendingCoor(); + deltaY = trackParamAtHit2.GetBendingCoor() - hit2->GetBendingCoor(); + Double_t localChi2AtHit2 = deltaX*deltaX / hit2->GetNonBendingReso2() + + deltaY*deltaY / hit2->GetBendingReso2(); + trackParamAtHit2.SetLocalChi2(localChi2AtHit2); + + // Flag first hit as being removable + trackParamAtHit2.SetRemovable(kTRUE); + + // Update the chi2 of the new track + track.SetFitFMin(track.GetFitFMin() + localChi2AtHit1 + localChi2AtHit2); + + // Update TrackParamAtHit + track.AddTrackParamAtHit(&trackParamAtHit1,trackParamAtHit1.GetHitForRecPtr()); + track.AddTrackParamAtHit(&trackParamAtHit2,trackParamAtHit2.GetHitForRecPtr()); + track.GetTrackParamAtHit()->Sort(); + } //__________________________________________________________________________ -void AliMUONTrackReconstructor::ValidateTracksWithTrigger(void) +Bool_t AliMUONTrackReconstructor::RecoverTrack(AliMUONTrack &trackCandidate, Int_t nextStation) { - // Try to match track from tracking system with trigger track - AliMUONTrack *track; - TClonesArray *recTriggerTracks; + /// Try to recover the track candidate in the next station + /// by removing the worst of the two hits attached in the current station + /// Return kTRUE if recovering succeeds + AliDebug(1,"Enter RecoverTrack"); - fMUONData->SetTreeAddress("RL"); - fMUONData->GetRecTriggerTracks(); - recTriggerTracks = fMUONData->RecTriggerTracks(); - - track = (AliMUONTrack*) fRecTracksPtr->First(); - while (track) { - track->MatchTriggerTrack(recTriggerTracks); - track = (AliMUONTrack*) fRecTracksPtr->After(track); + // Do not try to recover track until we have attached hit(s) on station(1..) 3 + if (nextStation > 1) return kFALSE; + + Int_t worstHitNumber = -1; + Double_t localChi2, worstLocalChi2 = 0.; + + // Look for the hit to remove + for (Int_t hitNumber = 0; hitNumber < 2; hitNumber++) { + AliMUONTrackParam *trackParamAtHit = (AliMUONTrackParam*)trackCandidate.GetTrackParamAtHit()->UncheckedAt(hitNumber); + + // check if current hit is removable + if (!trackParamAtHit->IsRemovable()) return kFALSE; + + // Pick up hit with the worst chi2 + localChi2 = trackParamAtHit->GetLocalChi2(); + if (localChi2 > worstLocalChi2) { + worstLocalChi2 = localChi2; + worstHitNumber = hitNumber; + } } - + + // Reset best hit as being NOT removable + ((AliMUONTrackParam*)trackCandidate.GetTrackParamAtHit()->UncheckedAt((worstHitNumber+1)%2))->SetRemovable(kFALSE); + + // Remove the worst hit + trackCandidate.RemoveTrackParamAtHit((AliMUONTrackParam*)trackCandidate.GetTrackParamAtHit()->UncheckedAt(worstHitNumber)); + + // Re-fit the track: + // Do not take into account the multiple scattering to speed up the fit + // Calculate the track parameter covariance matrix + trackCandidate.SetFitWithVertex(kFALSE); // To be sure + Fit(trackCandidate, kFALSE, kTRUE); + + // Look for new hit(s) in next station + return FollowTrackInStation(trackCandidate,nextStation); + } //__________________________________________________________________________ -Bool_t AliMUONTrackReconstructor::MakeTriggerTracks(void) +void AliMUONTrackReconstructor::SetVertexForFit(AliMUONTrack &trackCandidate) { - // To make the trigger tracks from Local Trigger - AliDebug(1, "Enter MakeTriggerTracks"); - - Int_t nTRentries; - Long_t gloTrigPat; - TClonesArray *localTrigger; - TClonesArray *globalTrigger; - AliMUONLocalTrigger *locTrg; - AliMUONGlobalTrigger *gloTrg; - - TTree* treeR = fMUONData->TreeR(); - - 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; - } - - 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(); + /// Add the vertex as a measured hit to constrain the fit of the "trackCandidate" + /// Compute the vertex resolution 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"); - - // 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; iUncheckedAt(i); - - AliDebug(1, "AliMUONTrackReconstructor::MakeTriggerTrack using NEW trigger \n"); - AliMUONTriggerCircuitNew* circuit = - (AliMUONTriggerCircuitNew*)fTriggerCircuit->At(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; + Double_t nonBendingReso2 = AliMUONReconstructor::GetRecoParam()->GetNonBendingVertexDispersion() * + AliMUONReconstructor::GetRecoParam()->GetNonBendingVertexDispersion(); + Double_t bendingReso2 = AliMUONReconstructor::GetRecoParam()->GetBendingVertexDispersion() * + AliMUONReconstructor::GetRecoParam()->GetBendingVertexDispersion(); + // add multiple scattering effets + AliMUONTrackParam paramAtVertex(*((AliMUONTrackParam*)(trackCandidate.GetTrackParamAtHit()->First()))); + paramAtVertex.DeleteCovariances(); // to be sure to account only for multiple scattering + AliMUONTrackExtrap::ExtrapToVertexUncorrected(¶mAtVertex,0.); + const TMatrixD& kParamCov = paramAtVertex.GetCovariances(); + nonBendingReso2 += kParamCov(0,0); + bendingReso2 += kParamCov(2,2); + // Set the vertex + AliMUONHitForRec vertex; // Coordinates set to (0.,0.,0.) by default + vertex.SetNonBendingReso2(nonBendingReso2); + vertex.SetBendingReso2(bendingReso2); + trackCandidate.SetVertex(&vertex); } //__________________________________________________________________________ -Int_t AliMUONTrackReconstructor::MakeTrackCandidatesWithTwoSegments(AliMUONSegment *BegSegment) +void AliMUONTrackReconstructor::Fit(AliMUONTrack &track, Bool_t includeMCS, Bool_t calcCov) { - // 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++; + /// Fit the track "track" w/wo multiple Coulomb scattering according to "includeMCS". + + Double_t benC, errorParam, invBenP, nonBenC, x, y; + AliMUONTrackParam *trackParam; + Double_t arg[1], fedm, errdef, fitFMin; + 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.SetFitWithMCS(includeMCS); + if (includeMCS) { + // compute hit weights only once + if (!track.ComputeHitWeights()) { + AliWarning("cannot take into account the multiple scattering effects"); + track.SetFitWithMCS(kFALSE); } - delete extrapSegment; // should not delete HitForRec's it points to !!!! - } // for (iEndSegment = 0;... - return nbCan2Seg; + } + + // Set fitting function + gMinuit->SetFCN(TrackChi2); + + // Set fitted parameters (!! The order is very important for the covariance matrix !!) + trackParam = (AliMUONTrackParam*) (track.GetTrackParamAtHit()->First()); + // could be tried with no limits for the search (min=max=0) ???? + // mandatory limits in non Bending to avoid NaN values of parameters + gMinuit->mnparm(0, "X", trackParam->GetNonBendingCoor(), 0.03, -500.0, 500.0, status); + gMinuit->mnparm(1, "NonBenS", trackParam->GetNonBendingSlope(), 0.001, -0.5, 0.5, status); + // mandatory limits in Bending to avoid NaN values of parameters + gMinuit->mnparm(2, "Y", trackParam->GetBendingCoor(), 0.10, -500.0, 500.0, status); + gMinuit->mnparm(3, "BenS", trackParam->GetBendingSlope(), 0.001, -0.5, 0.5, status); + gMinuit->mnparm(4, "InvBenP", trackParam->GetInverseBendingMomentum(), 0.003, -0.4, 0.4, 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(fitFMin, fedm, errdef, npari, nparx, covStatus); + track.SetFitFMin(fitFMin); + + // 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]; + gMinuit->mnemat(&matrix[0][0],5); + if (covStatus == 3) trackParam->SetCovariances(matrix); + else trackParam->SetVariances(matrix); + } else trackParam->DeleteCovariances(); + } //__________________________________________________________________________ -Int_t AliMUONTrackReconstructor::MakeTrackCandidatesWithOneSegmentAndOnePoint(AliMUONSegment *BegSegment) +void TrackChi2(Int_t & /*nParam*/, Double_t * /*gradient*/, Double_t &chi2, Double_t *param, Int_t /*flag*/) { - // 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; + /// Return the "Chi2" to be minimized with Minuit for track fitting. + /// Assumes that the track hits are sorted according to increasing Z. + /// Track parameters at each TrackHit 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* trackParamAtHit = (AliMUONTrackParam*) trackBeingFitted->GetTrackParamAtHit()->First(); + Double_t dX, dY; + chi2 = 0.; // initialize chi2 + + // update track parameters + trackParamAtHit->SetNonBendingCoor(param[0]); + trackParamAtHit->SetNonBendingSlope(param[1]); + trackParamAtHit->SetBendingCoor(param[2]); + trackParamAtHit->SetBendingSlope(param[3]); + trackParamAtHit->SetInverseBendingMomentum(param[4]); + trackBeingFitted->UpdateTrackParamAtHit(); + + // Take the vertex into account in the fit if required + if (trackBeingFitted->GetFitWithVertex()) { + AliMUONTrackParam paramAtVertex(*trackParamAtHit); + AliMUONTrackExtrap::ExtrapToZ(¶mAtVertex, 0.); + AliMUONHitForRec *vertex = trackBeingFitted->GetVertex(); + if (!vertex) { + cout<<"Error in TrackChi2: Want to use the vertex in tracking but it has not been created!!"<GetNonBendingCoor() - paramAtVertex.GetNonBendingCoor(); + dY = vertex->GetBendingCoor() - paramAtVertex.GetBendingCoor(); + chi2 += dX * dX / vertex->GetNonBendingReso2() + dY * dY / vertex->GetBendingReso2(); + } + + // compute chi2 w/wo multiple scattering + chi2 += trackBeingFitted->ComputeGlobalChi2(trackBeingFitted->GetFitWithMCS()); + } //__________________________________________________________________________ -void AliMUONTrackReconstructor::MakeTrackCandidates(void) +void AliMUONTrackReconstructor::ComplementTracks() { - // 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; + /// 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 + AliDebug(1,"Enter ComplementTracks"); + + Int_t chamberId, detElemId; + Double_t chi2OfHitForRec, bestChi2OfHitForRec; + Bool_t foundOneHit, trackModified; + AliMUONHitForRec* hitForRec; + AliMUONTrackParam* trackParam, *nextTrackParam; + AliMUONTrackParam copyOfTrackParam; + AliMUONTrackParam trackParamAtHit; + AliMUONTrackParam bestTrackParamAtHit; + Double_t sigmaCut2 = AliMUONReconstructor::GetRecoParam()->GetSigmaCutForTracking() * + AliMUONReconstructor::GetRecoParam()->GetSigmaCutForTracking(); + + // Remove double track to complete only "good" tracks + RemoveDoubleTracks(); + + AliMUONTrack *track = (AliMUONTrack*) fRecTracksPtr->First(); + while (track) { + trackModified = kFALSE; + + trackParam = (AliMUONTrackParam*)track->GetTrackParamAtHit()->First(); + while (trackParam) { + foundOneHit = kFALSE; + bestChi2OfHitForRec = 2. * sigmaCut2; // 2 because 2 quantities in chi2 + + // prepare nextTrackParam before adding new cluster because of the sorting + nextTrackParam = (AliMUONTrackParam*)track->GetTrackParamAtHit()->After(trackParam); + + chamberId = trackParam->GetHitForRecPtr()->GetChamberNumber(); + detElemId = trackParam->GetHitForRecPtr()->GetDetElemId(); + + // 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()); + + // look for one second candidate in the same chamber + for (Int_t hit = 0; hit < fNHitsForRecPerChamber[chamberId]; hit++) { + + hitForRec = (AliMUONHitForRec*) fHitsForRecPtr->UncheckedAt(fIndexOfFirstHitForRecPerChamber[chamberId]+hit); + + // look for a cluster in another detection element + if (hitForRec->GetDetElemId() == detElemId) continue; + + // try to add the current hit fast + if (!TryOneHitForRecFast(copyOfTrackParam, hitForRec)) continue; + + // try to add the current hit accurately + chi2OfHitForRec = TryOneHitForRec(copyOfTrackParam, hitForRec, trackParamAtHit); + + // if better chi2 then prepare to add this cluster to the track + if (chi2OfHitForRec < bestChi2OfHitForRec) { + bestChi2OfHitForRec = chi2OfHitForRec; + bestTrackParamAtHit = trackParamAtHit; + foundOneHit = kTRUE; + } + + } + + // add new cluster if any + if (foundOneHit) { + UpdateTrack(*track,bestTrackParamAtHit); + bestTrackParamAtHit.SetAloneInChamber(kFALSE); + trackParam->SetAloneInChamber(kFALSE); + trackModified = kTRUE; + } + + trackParam = nextTrackParam; + } + + // re-fit track parameters if needed + if (trackModified) Fit(*track, kTRUE, kTRUE); + + track = (AliMUONTrack*) fRecTracksPtr->After(track); + } + } //__________________________________________________________________________ -void AliMUONTrackReconstructor::FollowTracks(void) +void AliMUONTrackReconstructor::ImproveTracks() { - // Follow tracks in stations(1..) 3, 2 and 1 - // too long: should be made more modular !!!! - AliMUONHitForRec *bestHit, *extrapHit, *hit; - AliMUONSegment *bestSegment, *extrapSegment, *segment; + /// Improve tracks by removing clusters with local chi2 highter than the defined cut + /// Recompute track parameters and covariances at the remaining clusters + AliDebug(1,"Enter ImproveTracks"); + + Double_t localChi2, worstLocalChi2; + Int_t worstChamber, previousChamber; 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 + AliMUONTrackParam *trackParamAtHit, *worstTrackParamAtHit, *previousTrackParam, *nextTrackParam; + Double_t sigmaCut2 = AliMUONReconstructor::GetRecoParam()->GetSigmaCutForImprovement() * + AliMUONReconstructor::GetRecoParam()->GetSigmaCutForImprovement(); + + // Remove double track to improve only "good" tracks + RemoveDoubleTracks(); + track = (AliMUONTrack*) fRecTracksPtr->First(); - trackIndex = -1; 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; + + // prepare next track in case the actual track is suppressed + nextTrack = (AliMUONTrack*) fRecTracksPtr->After(track); + + while (!track->IsImproved()) { + + // Update track parameters and covariances + track->UpdateCovTrackParamAtHit(); + + // Compute local chi2 of each hits + track->ComputeLocalChi2(kTRUE); + + // Look for the hit to remove + worstTrackParamAtHit = NULL; + worstLocalChi2 = 0.; + trackParamAtHit = (AliMUONTrackParam*) track->GetTrackParamAtHit()->First(); + while (trackParamAtHit) { + + // Pick up hit with the worst chi2 + localChi2 = trackParamAtHit->GetLocalChi2(); + if (localChi2 > worstLocalChi2) { + worstLocalChi2 = localChi2; + worstTrackParamAtHit = trackParamAtHit; + } + + trackParamAtHit = (AliMUONTrackParam*) track->GetTrackParamAtHit()->After(trackParamAtHit); } - - // 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; - } + + // Check if bad hit found + if (!worstTrackParamAtHit) { + track->SetImproved(kTRUE); + break; + } + + // 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 (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(); + + // if the worst hit is not removable then remove the entire track + if (!worstTrackParamAtHit->IsRemovable() && worstTrackParamAtHit->IsAloneInChamber()) { + fRecTracksPtr->Remove(track); + fNRecTracks--; + break; } - 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)); + + // Reset the second hit in the same station as being not removable + // or reset the second hit in the same chamber as being alone + worstChamber = worstTrackParamAtHit->GetHitForRecPtr()->GetChamberNumber(); + previousTrackParam = (AliMUONTrackParam*) track->GetTrackParamAtHit()->Before(worstTrackParamAtHit); + nextTrackParam = (AliMUONTrackParam*) track->GetTrackParamAtHit()->After(worstTrackParamAtHit); + if (worstTrackParamAtHit->IsAloneInChamber()) { // Worst hit removable and alone in chamber - // 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(); - } + if (worstChamber%2 == 0) { // Modify flags in next chamber + + nextTrackParam->SetRemovable(kFALSE); + if (!nextTrackParam->IsAloneInChamber()) // Make sure both hits in second chamber are not removable anymore + ((AliMUONTrackParam*) track->GetTrackParamAtHit()->After(nextTrackParam))->SetRemovable(kFALSE); + + } else { // Modify flags in previous chamber + + previousTrackParam->SetRemovable(kFALSE); + if (!previousTrackParam->IsAloneInChamber()) // Make sure both hits in second chamber are not removable anymore + ((AliMUONTrackParam*) track->GetTrackParamAtHit()->Before(previousTrackParam))->SetRemovable(kFALSE); + } - 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 + + } else { // Worst hit not alone in its chamber + + if (previousTrackParam) previousChamber = previousTrackParam->GetHitForRecPtr()->GetChamberNumber(); + else previousChamber = -1; + + if (previousChamber == worstChamber) { // the second hit on the same chamber is the previous one + + previousTrackParam->SetAloneInChamber(kTRUE); + // transfert the removability to the second hit + if (worstTrackParamAtHit->IsRemovable()) previousTrackParam->SetRemovable(kTRUE); + + } else { // the second hit on the same chamber is the next one + + nextTrackParam->SetAloneInChamber(kTRUE); + // transfert the removability to the second hit + if (worstTrackParamAtHit->IsRemovable()) nextTrackParam->SetRemovable(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(); - } + + // Remove the worst hit + track->RemoveTrackParamAtHit(worstTrackParamAtHit); + + // Re-fit the track: + // Take into account the multiple scattering + // Calculate the track parameter covariance matrix + Fit(*track, kTRUE, kTRUE); + + // Printout for debuging + if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { + cout << "ImproveTracks: track " << fRecTracksPtr->IndexOf(track)+1 << " improved " << endl; } - } // 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; + + // compress the array in case of some tracks have been removed + fRecTracksPtr->Compress(); + } //__________________________________________________________________________ -void AliMUONTrackReconstructor::UpdateHitForRecAtHit() +void AliMUONTrackReconstructor::Finalize() { - // Set cluster parameterss after track fitting. Fill fHitForRecAtHit of AliMUONTrack's + /// Fill AliMUONTrack's fHitForRecAtHit array + /// Recompute track parameters and covariances at each attached cluster from those at the first one + AliMUONTrack *track; - AliMUONTrackHit *trackHit; - AliMUONHitForRec *hitForRec; + AliMUONTrackParam *trackParamAtHit; + 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 - 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 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; -} - - -//__________________________________________________________________________ -void AliMUONTrackReconstructor::EventDumpTrigger(void) -{ - // Dump reconstructed trigger event - // and the particle parameters - 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; isegDebugLevel() > 0) { - for (Int_t i1=0; i1GetChamberNumber(), 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; - } - } - */ - - 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; - } - } - - 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 - } - - // Majority 3 of 4 in first 2 stations - if (!ok) continue; - chamBits = 0; - Double_t chi2max = 0; - for (Int_t i=0; iGetNTrackHits(); i++) { - hit = (AliMUONHitForRec*) (*trackK->GetTrackHits())[i]; - chamBits |= BIT(hit->GetChamberNumber()); - if (trackK->GetChi2PerPoint(i) > chi2max) chi2max = trackK->GetChi2PerPoint(i); - } - if (!((chamBits&3)==3 || (chamBits>>2&3)==3) && chi2max > 25) { - //trackK->Recover(); - trackK->SetRecover(-1); //mark candidate to be removed - continue; - } - if (ok) trackK->SetTrackQuality(0); // compute "track quality" - } // while - - for (Int_t i=0; iGetRecover() < 0) fRecTracksPtr->RemoveAt(i); - } - - // Compress TClonesArray - fRecTracksPtr->Compress(); - fNRecTracks = fRecTracksPtr->GetEntriesFast(); - return; -} - -//__________________________________________________________________________ -Bool_t AliMUONTrackReconstructor::CheckCandidateK(Int_t icand, Int_t nSeeds) const -{ - // 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; iGetRecover() < 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; jGetNTrackHits(); j++) { - hit = (AliMUONHitForRec*) (*track2->GetTrackHits())[j]; - if (hit == hit1 || hit == hit2) { - nSame++; - if (nSame == 2) return kFALSE; - } - } // for (Int_t j=0; + // update track parameters if not already done + if (!track->IsImproved()) track->UpdateCovTrackParamAtHit(); + + trackParamAtHit = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->First()); + while (trackParamAtHit) { + + // update array of track hit + track->AddHitForRecAtHit(trackParamAtHit->GetHitForRecPtr()); + + trackParamAtHit = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->After(trackParamAtHit)); } - } // for (Int_t i=0; - 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) -{ - // Propagates track to the vertex thru absorber - // (using Branson correction for now) - - Double_t zVertex; - zVertex = 0; - for (Int_t i=0; iBranson(); - ((AliMUONTrackK*)(*fRecTracksPtr)[i])->SetTrackQuality(1); // compute Chi2 - //((AliMUONTrackK*)(*fRecTracksPtr)[i])->GoToZ(zVertex); // w/out absorber - ((AliMUONTrackK*)(*fRecTracksPtr)[i])->GoToVertex(1); // with absorber + + track = (AliMUONTrack*) fRecTracksPtr->After(track); + } + } -//__________________________________________________________________________ -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; -}