/* $Id$ */
+//-----------------------------------------------------------------------------
/// \class AliMUONTrackReconstructor
/// MUON track reconstructor using the original method
///
///
/// It contains as methods, among others:
/// - MakeTracks to build the tracks
-///
-
-#include <stdlib.h>
-#include <Riostream.h>
-#include <TMatrixD.h>
+//-----------------------------------------------------------------------------
-#include "AliMUONVTrackReconstructor.h"
#include "AliMUONTrackReconstructor.h"
-#include "AliMUONData.h"
+
#include "AliMUONConstants.h"
-#include "AliMUONRawCluster.h"
-#include "AliMUONHitForRec.h"
-#include "AliMUONSegment.h"
+#include "AliMUONVCluster.h"
+#include "AliMUONVClusterStore.h"
#include "AliMUONTrack.h"
#include "AliMUONTrackParam.h"
#include "AliMUONTrackExtrap.h"
-#include "AliLog.h"
-#include <TVirtualFitter.h>
-// Functions to be minimized with Minuit
-void TrackChi2(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag);
-void TrackChi2MCS(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag);
+#include "AliLog.h"
-void mnvertLocal(Double_t* a, Int_t l, Int_t m, Int_t n, Int_t& ifail);
+#include <TMinuit.h>
+#include <Riostream.h>
+#include <TMath.h>
+#include <TMatrixD.h>
-Double_t MultipleScatteringAngle2(AliMUONTrackParam *param);
+// 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
-//************* Defaults parameters for reconstruction
-const Double_t AliMUONTrackReconstructor::fgkDefaultMaxChi2 = 100.0;
-
-TVirtualFitter* AliMUONTrackReconstructor::fgFitter = 0x0;
-
-//__________________________________________________________________________
-AliMUONTrackReconstructor::AliMUONTrackReconstructor(AliMUONData* data)
- : AliMUONVTrackReconstructor(data),
- fMaxChi2(fgkDefaultMaxChi2)
+ //__________________________________________________________________________
+AliMUONTrackReconstructor::AliMUONTrackReconstructor()
+ : AliMUONVTrackReconstructor()
{
- /// Constructor for class AliMUONTrackReconstructor
-
- // Memory allocation for the TClonesArray of reconstructed tracks
- fRecTracksPtr = new TClonesArray("AliMUONTrack", 10);
+ /// Constructor
}
//__________________________________________________________________________
-AliMUONTrackReconstructor::~AliMUONTrackReconstructor(void)
+AliMUONTrackReconstructor::~AliMUONTrackReconstructor()
{
- /// Destructor for class AliMUONTrackReconstructor
- delete fRecTracksPtr;
-}
+/// Destructor
+}
//__________________________________________________________________________
-void AliMUONTrackReconstructor::AddHitsForRecFromRawClusters()
+void AliMUONTrackReconstructor::MakeTrackCandidates(const AliMUONVClusterStore& clusterStore)
{
- /// To add to the list of hits for reconstruction all the raw clusters
- TTree *treeR;
- AliMUONHitForRec *hitForRec;
- AliMUONRawCluster *clus;
- Int_t iclus, nclus, nTRentries;
- TClonesArray *rawclusters;
- AliDebug(1,"Enter AddHitsForRecFromRawClusters");
-
- treeR = fMUONData->TreeR();
- if (!treeR) {
- AliError("TreeR must be loaded");
- exit(0);
- }
-
- nTRentries = Int_t(treeR->GetEntries());
+ /// To make track candidates (assuming linear propagation if the flag fgkMakeTrackCandidatesFast is set to kTRUE):
+ /// Start with segments station(1..) 4 or 5 then follow track in station 5 or 4.
+ /// Good candidates are made of at least three clusters.
+ /// Keep only best candidates or all of them according to the flag fgkTrackAllTracks.
- if (!(fMUONData->IsRawClusterBranchesInTree())) {
- AliError(Form("RawCluster information is not avalaible, nTRentries = %d not equal to 1",nTRentries));
- exit(0);
- }
+ TClonesArray *segments;
+ AliMUONTrack *track;
+ Int_t iCandidate = 0;
+ Bool_t clusterFound;
+
+ AliDebug(1,"Enter MakeTrackCandidates");
- fMUONData->SetTreeAddress("RC");
- 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
- 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));
+ // 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(clusterStore,istat);
+
+ // Loop over segments
+ for (Int_t iseg=0; iseg<segments->GetEntriesFast(); iseg++)
+ {
+ AliDebug(1,Form("Making primary candidate(1..) %d",++iCandidate));
- 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();
-
- AliDebug(1,"End of AddHitsForRecFromRawClusters");
- 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();
+ // 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<<endl<<"Track parameter covariances at first cluster:"<<endl;
+ ((AliMUONTrackParam*) track->GetTrackParamAtCluster()->First())->GetCovariances().Print();
+ }
+
+ // Look for compatible cluster(s) in the other station
+ if (AliMUONReconstructor::GetRecoParam()->MakeTrackCandidatesFast())
+ clusterFound = FollowLinearTrackInStation(*track, clusterStore, 7-istat);
+ else clusterFound = FollowTrackInStation(*track, clusterStore, 7-istat);
+
+ // Remove track if no cluster found
+ if (!clusterFound) {
+ fRecTracksPtr->Remove(track);
+ fNRecTracks--;
}
+
}
+
+ // delete the array of segments
+ delete segments;
}
- 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::MakeSegments(void)
+void AliMUONTrackReconstructor::FollowTracks(const AliMUONVClusterStore& clusterStore)
{
- /// To make the list of segments in all stations,
- /// from the list of hits to be reconstructed
- AliDebug(1,"Enter MakeSegments");
- // Loop over stations
- for (Int_t st = 0; st < AliMUONConstants::NTrackingCh()/2; st++) MakeSegmentsPerStation(st);
-
- 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();
+ /// Follow tracks in stations(1..) 3, 2 and 1
+ AliDebug(1,"Enter FollowTracks");
+
+ AliMUONTrack *track, *nextTrack;
+ AliMUONTrackParam *trackParam, *nextTrackParam;
+ Int_t currentNRecTracks;
+ Bool_t clusterFound;
+
+ 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 <currentNRecTracks; iRecTrack++) {
+ AliDebug(1,Form("FollowTracks: track candidate(1..) %d", iRecTrack+1));
+
+ track = (AliMUONTrack*) fRecTracksPtr->UncheckedAt(iRecTrack);
+
+ // Fit the track:
+ // Do not take into account the multiple scattering to speed up the fit
+ // Calculate the track parameter covariance matrix
+ // If "station" is station(1..) 3 then use the vertex to better constrain the fit
+ if (station==2) Fit(*track, kFALSE, kTRUE, kTRUE);
+ else Fit(*track, kFALSE, 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->UpdateCovTrackParamAtCluster();
+
+ // save them
+ trackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->First();
+ while (trackParam) {
+ trackParam->SetSmoothParameters(trackParam->GetParameters());
+ trackParam->SetSmoothCovariances(trackParam->GetCovariances());
+ trackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->After(trackParam);
+ }
+
+ } else { // or save track parameters on last station only
+
+ // save parameters from fit
+ trackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->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->GetTrackParamAtCluster()->After(trackParam);
+ if (nextTrackParam->GetClusterPtr()->GetChamberId() < 2*(station+2)) {
+
+ // reset parameters and covariances
+ nextTrackParam->SetParameters(trackParam->GetParameters());
+ nextTrackParam->SetZ(trackParam->GetZ());
+ nextTrackParam->SetCovariances(trackParam->GetCovariances());
+
+ // extrapolate them to the z of the corresponding cluster
+ AliMUONTrackExtrap::ExtrapToZCov(nextTrackParam, nextTrackParam->GetClusterPtr()->GetZ());
+
+ // save them
+ nextTrackParam->SetSmoothParameters(nextTrackParam->GetParameters());
+ nextTrackParam->SetSmoothCovariances(nextTrackParam->GetCovariances());
+
+ }
+
+ }
+
+ }
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) {
+ cout<<endl<<"Track parameter covariances at first cluster:"<<endl;
+ ((AliMUONTrackParam*) track->GetTrackParamAtCluster()->First())->GetCovariances().Print();
+ }
+
+ // Look for compatible cluster(s) in station(0..) "station"
+ clusterFound = FollowTrackInStation(*track, clusterStore, station);
+
+ // Try to recover track if required
+ if (!clusterFound && AliMUONReconstructor::GetRecoParam()->RecoverTracks())
+ clusterFound = RecoverTrack(*track, clusterStore, station);
+
+ // remove track if no cluster found
+ if (!clusterFound) {
+ fRecTracksPtr->Remove(track);
+ fNRecTracks--;
+ }
+
+ }
+
+ // Compress fRecTracksPtr for the next step
+ fRecTracksPtr->Compress();
+
+ // Keep only the best tracks if required
+ if (!AliMUONReconstructor::GetRecoParam()->TrackAllTracks()) RemoveDoubleTracks();
+
+ }
+
+ // Last fit of track candidates with all stations
+ // Take into account the multiple scattering and remove bad tracks
+ Int_t trackIndex = -1;
+ track = (AliMUONTrack*) fRecTracksPtr->First();
+ while (track) {
+
+ trackIndex++;
+ nextTrack = (AliMUONTrack*) fRecTracksPtr->After(track); // prepare next track
+
+ Fit(*track, kTRUE, kFALSE, kTRUE);
+
+ // Printout for debuging
+ if (AliLog::GetGlobalDebugLevel() >= 3) {
+ cout << "FollowTracks: track candidate(0..) " << trackIndex << " after final fit" << endl;
+ track->RecursiveDump();
+ }
+
+ // Remove the track if the normalized chi2 is too high
+ if (track->GetNormalizedChi2() > sigmaCut2) {
+ fRecTracksPtr->Remove(track);
+ fNRecTracks--;
+ }
+
+ // save parameters from fit into smoothed parameters to complete track afterward
+ if (AliMUONReconstructor::GetRecoParam()->ComplementTracks()) {
+
+ // save parameters from fit
+ trackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->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->GetTrackParamAtCluster()->After(trackParam);
+ if (nextTrackParam->GetClusterPtr()->GetChamberId() < 2) {
+
+ // reset parameters and covariances
+ nextTrackParam->SetParameters(trackParam->GetParameters());
+ nextTrackParam->SetZ(trackParam->GetZ());
+ nextTrackParam->SetCovariances(trackParam->GetCovariances());
+
+ // extrapolate them to the z of the corresponding cluster
+ AliMUONTrackExtrap::ExtrapToZCov(nextTrackParam, nextTrackParam->GetClusterPtr()->GetZ());
+
+ // save them
+ nextTrackParam->SetSmoothParameters(nextTrackParam->GetParameters());
+ nextTrackParam->SetSmoothCovariances(nextTrackParam->GetCovariances());
+
+ }
+
}
- );
- return;
+
+ track = nextTrack;
+
+ }
+
+ fRecTracksPtr->Compress();
+
}
//__________________________________________________________________________
-void AliMUONTrackReconstructor::MakeTracks(void)
+Bool_t AliMUONTrackReconstructor::FollowTrackInStation(AliMUONTrack &trackCandidate, const AliMUONVClusterStore& clusterStore, Int_t nextStation)
{
- /// To make the tracks from the list of segments and points in all stations
- AliDebug(1,"Enter MakeTracks");
- // 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();
- UpdateHitForRecAtHit();
+ /// Follow trackCandidate in station(0..) nextStation and search for compatible cluster(s)
+ /// Keep all possibilities or only the best one(s) according to the flag fgkTrackAllTracks:
+ /// kTRUE: duplicate "trackCandidate" if there are several possibilities and add the new tracks at the end of
+ /// fRecTracksPtr to avoid conficts with other track candidates at this current stage of the tracking procedure.
+ /// Remove the obsolete "trackCandidate" at the end.
+ /// kFALSE: add only the best cluster(s) to the "trackCandidate". Try to add a couple of clusters in priority.
+ AliDebug(1,Form("Enter FollowTrackInStation(1..) %d", nextStation+1));
+
+ // Order the chamber according to the propagation direction (tracking starts with chamber 2):
+ // - nextStation == station(1...) 5 => forward propagation
+ // - nextStation < station(1...) 5 => backward propagation
+ Int_t ch1, ch2;
+ if (nextStation==4) {
+ ch1 = 2*nextStation+1;
+ ch2 = 2*nextStation;
+ } else {
+ ch1 = 2*nextStation;
+ ch2 = 2*nextStation+1;
+ }
+
+ Double_t chi2WithOneCluster = 1.e10;
+ Double_t chi2WithTwoClusters = 1.e10;
+ Double_t maxChi2WithOneCluster = 2. * AliMUONReconstructor::GetRecoParam()->GetSigmaCutForTracking() *
+ AliMUONReconstructor::GetRecoParam()->GetSigmaCutForTracking(); // 2 because 2 quantities in chi2
+ Double_t maxChi2WithTwoClusters = 4. * AliMUONReconstructor::GetRecoParam()->GetSigmaCutForTracking() *
+ AliMUONReconstructor::GetRecoParam()->GetSigmaCutForTracking(); // 4 because 4 quantities in chi2
+ Double_t bestChi2WithOneCluster = maxChi2WithOneCluster;
+ Double_t bestChi2WithTwoClusters = maxChi2WithTwoClusters;
+ Bool_t foundOneCluster = kFALSE;
+ Bool_t foundTwoClusters = kFALSE;
+ AliMUONTrack *newTrack = 0x0;
+ AliMUONVCluster *clusterCh1, *clusterCh2;
+ AliMUONTrackParam extrapTrackParam;
+ AliMUONTrackParam extrapTrackParamAtCluster1;
+ AliMUONTrackParam extrapTrackParamAtCluster2;
+ AliMUONTrackParam bestTrackParamAtCluster1;
+ AliMUONTrackParam bestTrackParamAtCluster2;
+
+ Int_t nClusters = clusterStore.GetSize();
+ Bool_t *clusterCh1Used = new Bool_t[nClusters];
+ for (Int_t i = 0; i < nClusters; i++) clusterCh1Used[i] = kFALSE;
+ Int_t iCluster1;
+
+ // Get track parameters
+ AliMUONTrackParam extrapTrackParamAtCh(*(AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->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.GetClusterPtr()->GetChamberId() > 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<<endl<<"Track parameter covariances at first cluster extrapolated to z = "<<AliMUONConstants::DefaultChamberZ(ch2)<<":"<<endl;
+ extrapTrackParamAtCh.GetCovariances().Print();
+ }
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: look for clusters in chamber(1..): " << ch2+1 << endl;
+ }
+
+ // Create iterators to loop over clusters in both chambers
+ TIter nextInCh1(clusterStore.CreateChamberIterator(ch1,ch1));
+ TIter nextInCh2(clusterStore.CreateChamberIterator(ch2,ch2));
+
+ // look for candidates in chamber 2
+ while ( ( clusterCh2 = static_cast<AliMUONVCluster*>(nextInCh2()) ) ) {
+
+ // try to add the current cluster fast
+ if (!TryOneClusterFast(extrapTrackParamAtCh, clusterCh2)) continue;
+
+ // try to add the current cluster accuratly
+ chi2WithOneCluster = TryOneCluster(extrapTrackParamAtCh, clusterCh2, extrapTrackParamAtCluster2);
+
+ // if good chi2 then try to attach a cluster in the other chamber too
+ if (chi2WithOneCluster < maxChi2WithOneCluster) {
+ Bool_t foundSecondCluster = kFALSE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: found one cluster in chamber(1..): " << ch2+1
+ << " (Chi2 = " << chi2WithOneCluster << ")" << endl;
+ cout << " look for second clusters in chamber(1..): " << ch1+1 << " ..." << endl;
+ }
+
+ // add MCS effect for next step
+ AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCluster2,AliMUONConstants::ChamberThicknessInX0(),1.);
+
+ // copy new track parameters for next step
+ extrapTrackParam = extrapTrackParamAtCluster2;
+
+ //Extrapolate track parameters to chamber "ch1"
+ AliMUONTrackExtrap::ExtrapToZ(&extrapTrackParam, AliMUONConstants::DefaultChamberZ(ch1));
+
+ // reset cluster iterator of chamber 1
+ nextInCh1.Reset();
+ iCluster1 = -1;
+
+ // look for second candidates in chamber 1
+ while ( ( clusterCh1 = static_cast<AliMUONVCluster*>(nextInCh1()) ) ) {
+ iCluster1++;
+
+ // try to add the current cluster fast
+ if (!TryOneClusterFast(extrapTrackParam, clusterCh1)) continue;
+
+ // try to add the current cluster accuratly
+ chi2WithTwoClusters = TryTwoClusters(extrapTrackParamAtCluster2, clusterCh1, extrapTrackParamAtCluster1);
+
+ // if good chi2 then create a new track by adding the 2 clusters to the "trackCandidate"
+ if (chi2WithTwoClusters < maxChi2WithTwoClusters) {
+ foundSecondCluster = kTRUE;
+ foundTwoClusters = kTRUE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: found second cluster in chamber(1..): " << ch1+1
+ << " (Global Chi2 = " << chi2WithTwoClusters << ")" << endl;
+ }
+
+ if (AliMUONReconstructor::GetRecoParam()->TrackAllTracks()) {
+ // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new clusters
+ newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate);
+ UpdateTrack(*newTrack,extrapTrackParamAtCluster1,extrapTrackParamAtCluster2);
+ fNRecTracks++;
+
+ // Tag clusterCh1 as used
+ clusterCh1Used[iCluster1] = kTRUE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: added two clusters in station(1..): " << nextStation+1 << endl;
+ if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
+ }
+
+ } else if (chi2WithTwoClusters < bestChi2WithTwoClusters) {
+ // keep track of the best couple of clusters
+ bestChi2WithTwoClusters = chi2WithTwoClusters;
+ bestTrackParamAtCluster1 = extrapTrackParamAtCluster1;
+ bestTrackParamAtCluster2 = extrapTrackParamAtCluster2;
+ }
+
+ }
+
+ }
+
+ // if no clusterCh1 found then consider to add clusterCh2 only
+ if (!foundSecondCluster) {
+ foundOneCluster = kTRUE;
+
+ if (AliMUONReconstructor::GetRecoParam()->TrackAllTracks()) {
+ // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new cluster
+ newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate);
+ UpdateTrack(*newTrack,extrapTrackParamAtCluster2);
+ fNRecTracks++;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: added one cluster in chamber(1..): " << ch2+1 << endl;
+ if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
+ }
+
+ } else if (!foundTwoClusters && chi2WithOneCluster < bestChi2WithOneCluster) {
+ // keep track of the best single cluster except if a couple of clusters has already been found
+ bestChi2WithOneCluster = chi2WithOneCluster;
+ bestTrackParamAtCluster1 = extrapTrackParamAtCluster2;
+ }
+
+ }
+
+ }
+
+ }
+
+ // look for candidates in chamber 1 not already attached to a track
+ // if we want to keep all possible tracks or if no good couple of clusters has been found
+ if (AliMUONReconstructor::GetRecoParam()->TrackAllTracks() || !foundTwoClusters) {
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: look for single clusters 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));
+
+ // reset cluster iterator of chamber 1
+ nextInCh1.Reset();
+ iCluster1 = -1;
+
+ // look for second candidates in chamber 1
+ while ( ( clusterCh1 = static_cast<AliMUONVCluster*>(nextInCh1()) ) ) {
+ iCluster1++;
+
+ if (clusterCh1Used[iCluster1]) continue; // Skip cluster already used
+
+ // try to add the current cluster fast
+ if (!TryOneClusterFast(extrapTrackParamAtCh, clusterCh1)) continue;
+
+ // try to add the current cluster accuratly
+ chi2WithOneCluster = TryOneCluster(extrapTrackParamAtCh, clusterCh1, extrapTrackParamAtCluster1);
+
+ // if good chi2 then consider to add clusterCh1
+ // We do not try to attach a cluster in the other chamber too since it has already been done above
+ if (chi2WithOneCluster < maxChi2WithOneCluster) {
+ foundOneCluster = kTRUE;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: found one cluster in chamber(1..): " << ch1+1
+ << " (Chi2 = " << chi2WithOneCluster << ")" << endl;
+ }
+
+ if (AliMUONReconstructor::GetRecoParam()->TrackAllTracks()) {
+ // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new cluster
+ newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate);
+ UpdateTrack(*newTrack,extrapTrackParamAtCluster1);
+ fNRecTracks++;
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: added one cluster in chamber(1..): " << ch1+1 << endl;
+ if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
+ }
+
+ } else if (chi2WithOneCluster < bestChi2WithOneCluster) {
+ // keep track of the best single cluster except if a couple of clusters has already been found
+ bestChi2WithOneCluster = chi2WithOneCluster;
+ bestTrackParamAtCluster1 = extrapTrackParamAtCluster1;
+ }
+
+ }
+
+ }
+
+ }
+
+ // fill out the best track if required else clean up the fRecTracksPtr array
+ if (!AliMUONReconstructor::GetRecoParam()->TrackAllTracks()) {
+ if (foundTwoClusters) {
+ UpdateTrack(trackCandidate,bestTrackParamAtCluster1,bestTrackParamAtCluster2);
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: added the two best clusters in station(1..): " << nextStation+1 << endl;
+ if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
+ }
+
+ } else if (foundOneCluster) {
+ UpdateTrack(trackCandidate,bestTrackParamAtCluster1);
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "FollowTrackInStation: added the best cluster in chamber(1..): " << bestTrackParamAtCluster1.GetClusterPtr()->GetChamberId()+1 << endl;
+ if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
+ }
+
+ } else {
+ delete [] clusterCh1Used;
+ return kFALSE;
+ }
+
+ } else if (foundOneCluster || foundTwoClusters) {
+
+ // remove obsolete track
+ fRecTracksPtr->Remove(&trackCandidate);
+ fNRecTracks--;
+
+ } else {
+ delete [] clusterCh1Used;
+ return kFALSE;
+ }
+
+ delete [] clusterCh1Used;
+ return kTRUE;
+
}
//__________________________________________________________________________
-void AliMUONTrackReconstructor::MakeTrackCandidates(void)
+Double_t AliMUONTrackReconstructor::TryTwoClusters(const AliMUONTrackParam &trackParamAtCluster1, AliMUONVCluster* cluster2,
+ AliMUONTrackParam &trackParamAtCluster2)
{
- /// 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;
+/// Test the compatibility between the track and the 2 clusters together (using trackParam's covariance matrix):
+/// return the corresponding Chi2 accounting for covariances between the 2 clusters
+/// return trackParamAtCluster1 & 2
+
+ // extrapolate track parameters at the z position of the second cluster (no need to extrapolate the covariances)
+ trackParamAtCluster2.SetParameters(trackParamAtCluster1.GetParameters());
+ trackParamAtCluster2.SetZ(trackParamAtCluster1.GetZ());
+ AliMUONTrackExtrap::ExtrapToZ(&trackParamAtCluster2, cluster2->GetZ());
+
+ // set pointer to cluster2 into trackParamAtCluster2
+ trackParamAtCluster2.SetClusterPtr(cluster2);
+
+ // Set differences between track and the 2 clusters in the bending and non bending directions
+ AliMUONVCluster* cluster1 = trackParamAtCluster1.GetClusterPtr();
+ TMatrixD dPos(4,1);
+ dPos(0,0) = cluster1->GetX() - trackParamAtCluster1.GetNonBendingCoor();
+ dPos(1,0) = cluster1->GetY() - trackParamAtCluster1.GetBendingCoor();
+ dPos(2,0) = cluster2->GetX() - trackParamAtCluster2.GetNonBendingCoor();
+ dPos(3,0) = cluster2->GetY() - trackParamAtCluster2.GetBendingCoor();
+
+ // Calculate the error matrix from the track parameter covariances at first cluster
+ TMatrixD error(4,4);
+ error.Zero();
+ if (trackParamAtCluster1.CovariancesExist()) {
+ // Save track parameters at first cluster
+ TMatrixD paramAtCluster1Save(trackParamAtCluster1.GetParameters());
+
+ // Save track coordinates at second cluster
+ Double_t nonBendingCoor2 = trackParamAtCluster2.GetNonBendingCoor();
+ Double_t bendingCoor2 = trackParamAtCluster2.GetBendingCoor();
+
+ // copy track parameters at first cluster for jacobian calculation
+ AliMUONTrackParam trackParam(trackParamAtCluster1);
+
+ // add MCS effect to the covariance matrix at first cluster
+ AliMUONTrackExtrap::AddMCSEffect(&trackParam,AliMUONConstants::ChamberThicknessInX0(),1.);
+
+ // Get the pointer to the parameter covariance matrix at first cluster
+ const TMatrixD& kParamCov = trackParam.GetCovariances();
+
+ // Calculate the jacobian related to the transformation between track parameters
+ // at first cluster and track coordinates at the 2 cluster z-positions
+ TMatrixD jacob(4,5);
+ jacob.Zero();
+ // first derivative at the first cluster:
+ jacob(0,0) = 1.; // dx1/dx
+ jacob(1,2) = 1.; // dy1/dy
+ // first derivative at the second cluster:
+ TMatrixD dParam(5,1);
+ 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.,-paramAtCluster1Save(4,0)); // variation always in the same direction
+ } else dParam(j,0) = 0.;
+ }
+
+ // Set new track parameters at first cluster
+ trackParam.SetParameters(paramAtCluster1Save);
+ trackParam.AddParameters(dParam);
+ trackParam.SetZ(cluster1->GetZ());
+
+ // Extrapolate new track parameters to the z position of the second cluster
+ AliMUONTrackExtrap::ExtrapToZ(&trackParam,cluster2->GetZ());
+
+ // Calculate the jacobian
+ jacob(2,i) = (trackParam.GetNonBendingCoor() - nonBendingCoor2) / dParam(i,0); // dx2/dParami
+ jacob(3,i) = (trackParam.GetBendingCoor() - bendingCoor2 ) / dParam(i,0); // dy2/dParami
+ }
+
+ // Calculate the error matrix
+ TMatrixD tmp(jacob,TMatrixD::kMult,kParamCov);
+ error = TMatrixD(tmp,TMatrixD::kMultTranspose,jacob);
+ }
+
+ // Add cluster resolution to the error matrix
+ error(0,0) += cluster1->GetErrX2();
+ error(1,1) += cluster1->GetErrY2();
+ error(2,2) += cluster2->GetErrX2();
+ error(3,3) += cluster2->GetErrY2();
+
+ // invert the error matrix for Chi2 calculation
+ if (error.Determinant() != 0) {
+ error.Invert();
+ } else {
+ AliWarning(" Determinant error=0");
+ return 1.e10;
+ }
+
+ // Compute the Chi2 value
+ TMatrixD tmp2(dPos,TMatrixD::kTransposeMult,error);
+ TMatrixD result(tmp2,TMatrixD::kMult,dPos);
+
+ return result(0,0);
+
}
//__________________________________________________________________________
-Int_t AliMUONTrackReconstructor::MakeTrackCandidatesWithTwoSegments(AliMUONSegment *BegSegment)
+void AliMUONTrackReconstructor::UpdateTrack(AliMUONTrack &track, AliMUONTrackParam &trackParamAtCluster)
{
- /// 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);
- // Set track parameters at vertex from last stations 4 & 5
- CalcTrackParamAtVertex(recTrack);
- fNRecTracks++;
- if (AliLog::GetGlobalDebugLevel() > 1) recTrack->RecursiveDump();
- // increment number of track candidates with 2 segments
- nbCan2Seg++;
- }
- delete extrapSegment; // should not delete HitForRec's it points to !!!!
- } // for (iEndSegment = 0;...
- return nbCan2Seg;
+ /// Add 1 cluster to the track candidate
+ /// Update chi2 of the track
+
+ // Compute local chi2
+ AliMUONVCluster* cluster = trackParamAtCluster.GetClusterPtr();
+ Double_t deltaX = trackParamAtCluster.GetNonBendingCoor() - cluster->GetX();
+ Double_t deltaY = trackParamAtCluster.GetBendingCoor() - cluster->GetY();
+ Double_t localChi2 = deltaX*deltaX / cluster->GetErrX2() +
+ deltaY*deltaY / cluster->GetErrY2();
+
+ // Flag cluster as being not removable
+ trackParamAtCluster.SetRemovable(kFALSE);
+ trackParamAtCluster.SetLocalChi2(0.); // --> Local chi2 not used
+
+ // Update the chi2 of the new track
+ track.SetGlobalChi2(track.GetGlobalChi2() + localChi2);
+
+ // Update TrackParamAtCluster
+ track.AddTrackParamAtCluster(trackParamAtCluster,*cluster);
+ track.GetTrackParamAtCluster()->Sort();
+
}
//__________________________________________________________________________
-Int_t AliMUONTrackReconstructor::MakeTrackCandidatesWithOneSegmentAndOnePoint(AliMUONSegment *BegSegment)
+void AliMUONTrackReconstructor::UpdateTrack(AliMUONTrack &track, AliMUONTrackParam &trackParamAtCluster1, AliMUONTrackParam &trackParamAtCluster2)
{
- /// 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);
- // Set track parameters at vertex from last stations 4 & 5
- CalcTrackParamAtVertex(recTrack);
- // 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;
+ /// Add 2 clusters to the track candidate
+ /// Update track and local chi2
+
+ // Update local chi2 at first cluster
+ AliMUONVCluster* cluster1 = trackParamAtCluster1.GetClusterPtr();
+ Double_t deltaX = trackParamAtCluster1.GetNonBendingCoor() - cluster1->GetX();
+ Double_t deltaY = trackParamAtCluster1.GetBendingCoor() - cluster1->GetY();
+ Double_t localChi2AtCluster1 = deltaX*deltaX / cluster1->GetErrX2() +
+ deltaY*deltaY / cluster1->GetErrY2();
+ trackParamAtCluster1.SetLocalChi2(localChi2AtCluster1);
+
+ // Flag first cluster as being removable
+ trackParamAtCluster1.SetRemovable(kTRUE);
+
+ // Update local chi2 at second cluster
+ AliMUONVCluster* cluster2 = trackParamAtCluster2.GetClusterPtr();
+ deltaX = trackParamAtCluster2.GetNonBendingCoor() - cluster2->GetX();
+ deltaY = trackParamAtCluster2.GetBendingCoor() - cluster2->GetY();
+ Double_t localChi2AtCluster2 = deltaX*deltaX / cluster2->GetErrX2() +
+ deltaY*deltaY / cluster2->GetErrY2();
+ trackParamAtCluster2.SetLocalChi2(localChi2AtCluster2);
+
+ // Flag first cluster as being removable
+ trackParamAtCluster2.SetRemovable(kTRUE);
+
+ // Update the chi2 of the new track
+ track.SetGlobalChi2(track.GetGlobalChi2() + localChi2AtCluster1 + localChi2AtCluster2);
+
+ // Update TrackParamAtCluster
+ track.AddTrackParamAtCluster(trackParamAtCluster1,*cluster1);
+ track.AddTrackParamAtCluster(trackParamAtCluster2,*cluster2);
+ track.GetTrackParamAtCluster()->Sort();
+
}
//__________________________________________________________________________
-void AliMUONTrackReconstructor::CalcTrackParamAtVertex(AliMUONTrack *Track) const
+Bool_t AliMUONTrackReconstructor::RecoverTrack(AliMUONTrack &trackCandidate, const AliMUONVClusterStore& clusterStore, Int_t nextStation)
{
- /// Set track parameters at vertex.
- /// TrackHit's are assumed to be only in stations(1..) 4 and 5,
- /// and sorted according to increasing Z.
- /// Parameters are calculated from information in HitForRec's
- /// of first and last TrackHit's.
- AliMUONTrackParam *trackParamVertex = Track->GetTrackParamAtVertex(); // pointer to track parameters at vertex
- // Pointer to HitForRec attached to first TrackParamAtHit
- AliMUONHitForRec *firstHit = ((AliMUONTrackParam*) (Track->GetTrackParamAtHit()->First()))->GetHitForRecPtr();
- // Pointer to HitForRec attached to last TrackParamAtHit
- AliMUONHitForRec *lastHit = ((AliMUONTrackParam*) (Track->GetTrackParamAtHit()->Last()))->GetHitForRecPtr();
- // Z difference between first and last hits
- Double_t deltaZ = firstHit->GetZ() - lastHit->GetZ();
- // bending slope in stations(1..) 4 and 5
- Double_t bendingSlope = (firstHit->GetBendingCoor() - lastHit->GetBendingCoor()) / deltaZ;
- trackParamVertex->SetBendingSlope(bendingSlope);
- // impact parameter
- Double_t impactParam = firstHit->GetBendingCoor() - bendingSlope * firstHit->GetZ();
- // signed bending momentum
- trackParamVertex->SetInverseBendingMomentum(1.0 / GetBendingMomentumFromImpactParam(impactParam));
- // bending slope at vertex
- trackParamVertex->SetBendingSlope(bendingSlope + impactParam / fSimpleBPosition);
- // non bending slope
- trackParamVertex->SetNonBendingSlope((firstHit->GetNonBendingCoor() - lastHit->GetNonBendingCoor()) / deltaZ);
- // vertex coordinates at (0,0,0)
- trackParamVertex->SetZ(0.0);
- trackParamVertex->SetBendingCoor(0.0);
- trackParamVertex->SetNonBendingCoor(0.0);
+ /// Try to recover the track candidate in the next station
+ /// by removing the worst of the two clusters attached in the current station
+ /// Return kTRUE if recovering succeeds
+ AliDebug(1,"Enter RecoverTrack");
+
+ // Do not try to recover track until we have attached cluster(s) on station(1..) 3
+ if (nextStation > 1) return kFALSE;
+
+ Int_t worstClusterNumber = -1;
+ Double_t localChi2, worstLocalChi2 = 0.;
+
+ // Look for the cluster to remove
+ for (Int_t clusterNumber = 0; clusterNumber < 2; clusterNumber++) {
+ AliMUONTrackParam *trackParamAtCluster = (AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->UncheckedAt(clusterNumber);
+
+ // check if current cluster is removable
+ if (!trackParamAtCluster->IsRemovable()) return kFALSE;
+
+ // Pick up cluster with the worst chi2
+ localChi2 = trackParamAtCluster->GetLocalChi2();
+ if (localChi2 > worstLocalChi2) {
+ worstLocalChi2 = localChi2;
+ worstClusterNumber = clusterNumber;
+ }
+ }
+
+ // Reset best cluster as being NOT removable
+ ((AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->UncheckedAt((worstClusterNumber+1)%2))->SetRemovable(kFALSE);
+
+ // Remove the worst cluster
+ trackCandidate.RemoveTrackParamAtCluster((AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->UncheckedAt(worstClusterNumber));
+
+ // Re-fit the track:
+ // Do not take into account the multiple scattering to speed up the fit
+ // Calculate the track parameter covariance matrix
+ Fit(trackCandidate, kFALSE, kFALSE, kTRUE);
+
+ // Look for new cluster(s) in next station
+ return FollowTrackInStation(trackCandidate,clusterStore,nextStation);
+
}
//__________________________________________________________________________
-void AliMUONTrackReconstructor::FollowTracks(void)
+void AliMUONTrackReconstructor::SetVertexErrXY2ForFit(AliMUONTrack &trackCandidate)
{
- /// Follow tracks in stations(1..) 3, 2 and 1
- // too long: should be made more modular !!!!
- AliMUONHitForRec *bestHit, *extrapHit, *hit;
- AliMUONSegment *bestSegment, *extrapSegment, *segment;
- AliMUONTrack *track, *nextTrack;
- AliMUONTrackParam *trackParam1, trackParam[2], trackParamVertex;
- // -1 to avoid compilation warnings
- Int_t ch = -1, chInStation, chBestHit = -1, iHit, iSegment, station, trackIndex;
- Double_t bestChi2, chi2, dZ1, dZ2, dZ3, maxSigma2Distance, mcsFactor;
- Double_t bendingMomentum, chi2Norm = 0.;
-
-
- // local maxSigma2Distance, for easy increase in testing
- maxSigma2Distance = fMaxSigma2Distance;
- AliDebug(2,"Enter FollowTracks");
- // Loop over track candidates
- track = (AliMUONTrack*) fRecTracksPtr->First();
- trackIndex = -1;
- while (track) {
- trackIndex++;
- nextTrack = (AliMUONTrack*) fRecTracksPtr->After(track); // prepare next track
- AliDebug(2,Form("FollowTracks: track candidate(0..): %d", trackIndex));
- // Fit track candidate from parameters at vertex
- // -> with 3 parameters (X_vertex and Y_vertex are fixed)
- // without multiple Coulomb scattering
- Fit(track,0,0);
- 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 = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->First());
- // extrapolation to station
- AliMUONTrackExtrap::ExtrapToStation(trackParam1, station, trackParam);
- extrapSegment = new AliMUONSegment(); // empty segment
- // multiple scattering factor corresponding to one chamber
- // and momentum in bending plane (not total)
- mcsFactor = 0.0136 * trackParam1->GetInverseBendingMomentum();
- mcsFactor = fChamberThicknessInX0 * mcsFactor * mcsFactor;
- // Z difference from previous station
- dZ1 = AliMUONConstants::DefaultChamberZ(2 * station) -
- AliMUONConstants::DefaultChamberZ(2 * station + 2);
- // Z difference between the two previous stations
- dZ2 = AliMUONConstants::DefaultChamberZ(2 * station + 2) -
- AliMUONConstants::DefaultChamberZ(2 * station + 4);
- // Z difference between the two chambers in the previous station
- dZ3 = AliMUONConstants::DefaultChamberZ(2 * station) -
- AliMUONConstants::DefaultChamberZ(2 * station + 1);
- extrapSegment->SetBendingCoorReso2(fBendingResolution * fBendingResolution);
- extrapSegment->SetNonBendingCoorReso2(fNonBendingResolution * fNonBendingResolution);
- extrapSegment->UpdateFromStationTrackParam(trackParam, mcsFactor, dZ1, dZ2, dZ3, station,
- trackParam1->GetInverseBendingMomentum());
- bestChi2 = 5.0;
- bestSegment = NULL;
- if (AliLog::GetGlobalDebugLevel() > 2) {
- cout << "FollowTracks: track candidate(0..): " << trackIndex
- << " Look for segment in station(0..): " << station << endl;
- }
-
- // Loop over segments in station
- for (iSegment = 0; iSegment < fNSegments[station]; iSegment++) {
- // Look for best compatible Segment in station
- // should consider all possibilities ????
- // multiple scattering ????
- // separation in 2 functions: Segment and HitForRec ????
- segment = (AliMUONSegment*) ((*fSegmentsPtr[station])[iSegment]);
- // correction of corrected segment (fBendingCoor and fNonBendingCoor)
- // according to real Z value of "segment" and slopes of "extrapSegment"
- AliMUONTrackExtrap::ExtrapToZ(&(trackParam[0]), segment->GetZ());
- AliMUONTrackExtrap::ExtrapToZ(&(trackParam[1]), segment->GetZ()); // now same as trackParam[0] !?!?!?!?!?!
- extrapSegment->SetBendingCoor((&(trackParam[0]))->GetBendingCoor());
- extrapSegment->SetNonBendingCoor((&(trackParam[0]))->GetNonBendingCoor());
- extrapSegment->SetBendingSlope((&(trackParam[0]))->GetBendingSlope());
- extrapSegment->SetNonBendingSlope((&(trackParam[0]))->GetNonBendingSlope());
- chi2 = segment->NormalizedChi2WithSegment(extrapSegment, maxSigma2Distance);
- if (chi2 < bestChi2) {
- // update best Chi2 and Segment if better found
- bestSegment = segment;
- bestChi2 = chi2;
- }
- }
- if (bestSegment) {
- // best segment found: add it to track candidate
- AliMUONTrackExtrap::ExtrapToZ(&(trackParam[0]), bestSegment->GetZ());
- track->AddTrackParamAtHit(&(trackParam[0]),bestSegment->GetHitForRec1());
- AliMUONTrackExtrap::ExtrapToZ(&(trackParam[1]), bestSegment->GetZ()); // now same as trackParam[0] !?!?!?!?!?!
- track->AddTrackParamAtHit(&(trackParam[1]),bestSegment->GetHitForRec2());
- AliDebug(3, Form("FollowTracks: track candidate(0..): %d Added segment in station(0..): %d", trackIndex, station));
- if (AliLog::GetGlobalDebugLevel()>2) track->RecursiveDump();
- } else {
- // No best segment found:
- // Look for best compatible HitForRec in station:
- // should consider all possibilities ????
- // multiple scattering ???? do about like for extrapSegment !!!!
- extrapHit = new AliMUONHitForRec(); // empty hit
- bestChi2 = 3.0;
- bestHit = NULL;
- AliDebug(3, Form("FollowTracks: track candidate(0..): %d Segment not found, look for hit in station(0..): %d ",
- trackIndex, station));
-
- // 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
- AliMUONTrackExtrap::ExtrapToZ(&(trackParam[chInStation]), 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
- AliMUONTrackExtrap::ExtrapToZ(&(trackParam[chBestHit]), bestHit->GetZ());
- track->AddTrackParamAtHit(&(trackParam[chBestHit]),bestHit);
- if (AliLog::GetGlobalDebugLevel() > 2) {
- cout << "FollowTracks: track candidate(0..): " << trackIndex
- << " Added hit in station(0..): " << station << endl;
- track->RecursiveDump();
- }
- } else {
- // Remove current track candidate
- // and corresponding TrackHit's, ...
- fRecTracksPtr->Remove(track);
- fNRecTracks--;
- delete extrapSegment;
- delete extrapHit;
- break; // stop the search for this candidate:
- // exit from the loop over station
- }
- delete extrapHit;
- }
- delete extrapSegment;
- // Sort TrackParamAtHit according to increasing Z
- track->GetTrackParamAtHit()->Sort();
- // Update track parameters at first track hit (smallest Z)
- trackParam1 = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->First());
- 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)) {
- fRecTracksPtr->Remove(track);
- fNRecTracks--;
- break; // stop the search for this candidate:
- // exit from the loop over station
- }
- // Track fit from parameters at first hit
- // -> with 5 parameters (momentum and position)
- // with multiple Coulomb scattering if all stations
- if (station == 0) Fit(track,1,1);
- // without multiple Coulomb scattering if not all stations
- else Fit(track,1,0);
- 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) {
- fRecTracksPtr->Remove(track);
- fNRecTracks--;
- 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 = *((AliMUONTrackParam*) (track->GetTrackParamAtHit()->First()));
- AliMUONTrackExtrap::ExtrapToVertex(&trackParamVertex, 0., 0., 0.);
- track->SetTrackParamAtVertex(&trackParamVertex);
- if (AliLog::GetGlobalDebugLevel() > 0) {
- cout << "FollowTracks: track candidate(0..): " << trackIndex
- << " after extrapolation to vertex" << endl;
- track->RecursiveDump();
- }
- }
- } // for (station = 2;...
- // go really to next track
- track = nextTrack;
- } // while (track)
- // Compression of track array (necessary after Remove)
- fRecTracksPtr->Compress();
- return;
+ /// Compute the vertex resolution square from natural vertex dispersion and
+ /// multiple scattering effets according to trackCandidate path in absorber
+ /// It is necessary to account for multiple scattering effects here instead of during the fit of
+ /// the "trackCandidate" to do not influence the result by changing track resolution at vertex
+ AliDebug(1,"Enter SetVertexForFit");
+
+ Double_t nonBendingReso2 = AliMUONReconstructor::GetRecoParam()->GetNonBendingVertexDispersion() *
+ AliMUONReconstructor::GetRecoParam()->GetNonBendingVertexDispersion();
+ Double_t bendingReso2 = AliMUONReconstructor::GetRecoParam()->GetBendingVertexDispersion() *
+ AliMUONReconstructor::GetRecoParam()->GetBendingVertexDispersion();
+
+ // add multiple scattering effets
+ AliMUONTrackParam paramAtVertex(*((AliMUONTrackParam*)(trackCandidate.GetTrackParamAtCluster()->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 resolution square
+ trackCandidate.SetVertexErrXY2(nonBendingReso2,bendingReso2);
}
//__________________________________________________________________________
-void AliMUONTrackReconstructor::Fit(AliMUONTrack *Track, Int_t FitStart, Int_t FitMCS)
+void AliMUONTrackReconstructor::Fit(AliMUONTrack &track, Bool_t includeMCS, Bool_t fitWithVertex, Bool_t calcCov)
{
- /// Fit the track "Track",
- /// with or without multiple Coulomb scattering according to "FitMCS",
- /// starting, according to "FitStart",
- /// with track parameters at vertex or at the first TrackHit.
-
- if ((FitStart != 0) && (FitStart != 1)) {
- cout << "ERROR in AliMUONTrackReconstructor::Fit(...)" << endl;
- cout << "FitStart = " << FitStart << " is neither 0 nor 1" << endl;
- exit(0);
- }
- if ((FitMCS != 0) && (FitMCS != 1)) {
- cout << "ERROR in AliMUONTrackReconstructor::Fit(...)" << endl;
- cout << "FitMCS = " << FitMCS << " is neither 0 nor 1" << endl;
- exit(0);
- }
+ /// Fit the track
+ /// w/wo multiple Coulomb scattering according to "includeMCS".
+ /// w/wo constraining the vertex according to "fitWithVertex".
+ /// calculating or not the covariance matrix according to "calcCov".
- Double_t arg[1], benC, errorParam, invBenP, lower, nonBenC, upper, x, y;
- char parName[50];
+ Double_t benC, errorParam, invBenP, nonBenC, x, y;
AliMUONTrackParam *trackParam;
- // Check if Minuit is initialized...
- fgFitter = TVirtualFitter::Fitter(Track,5);
- fgFitter->Clear(); // necessary ???? probably yes
- // how to reset the printout number at every fit ????
- // is there any risk to leave it like that ????
- // how to go faster ???? choice of Minuit parameters like EDM ????
- // choice of function to be minimized according to fFitMCS
- if (FitMCS == 0) fgFitter->SetFCN(TrackChi2);
- else fgFitter->SetFCN(TrackChi2MCS);
- // Switch off printout
- arg[0] = -1;
- fgFitter->ExecuteCommand("SET PRINT", arg, 1); // More printing !!!!
+ Double_t arg[1], fedm, errdef, globalChi2;
+ Int_t npari, nparx;
+ Int_t status, covStatus;
+
+ // Instantiate gMinuit if not already done
+ if (!gMinuit) gMinuit = new TMinuit(6);
+ // Clear MINUIT parameters
+ gMinuit->mncler();
+ // Give the fitted track to MINUIT
+ gMinuit->SetObjectFit(&track);
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) {
+ // Define print level
+ arg[0] = 1;
+ gMinuit->mnexcm("SET PRI", arg, 1, status);
+ // Print covariance matrix
+ gMinuit->mnexcm("SHO COV", arg, 0, status);
+ } else {
+ arg[0] = -1;
+ gMinuit->mnexcm("SET PRI", arg, 1, status);
+ }
// No warnings
- fgFitter->ExecuteCommand("SET NOW", arg, 0);
- // Parameters according to "fFitStart"
- // (should be a function to be used at every place where needed ????)
- if (FitStart == 0) trackParam = Track->GetTrackParamAtVertex();
- else trackParam = (AliMUONTrackParam*) (Track->GetTrackParamAtHit()->First());
- // set first 3 Minuit parameters
- // could be tried with no limits for the search (min=max=0) ????
- fgFitter->SetParameter(0, "InvBenP",
- trackParam->GetInverseBendingMomentum(),
- 0.003, -0.4, 0.4);
- fgFitter->SetParameter(1, "BenS",
- trackParam->GetBendingSlope(),
- 0.001, -0.5, 0.5);
- fgFitter->SetParameter(2, "NonBenS",
- trackParam->GetNonBendingSlope(),
- 0.001, -0.5, 0.5);
- if (FitStart == 1) {
- // set last 2 Minuit parameters when we start from first track hit
- // mandatory limits in Bending to avoid NaN values of parameters
- fgFitter->SetParameter(3, "X",
- trackParam->GetNonBendingCoor(),
- 0.03, -500.0, 500.0);
- // mandatory limits in non Bending to avoid NaN values of parameters
- fgFitter->SetParameter(4, "Y",
- trackParam->GetBendingCoor(),
- 0.10, -500.0, 500.0);
+ gMinuit->mnexcm("SET NOW", arg, 0, status);
+ // Define strategy
+ //arg[0] = 2;
+ //gMinuit->mnexcm("SET STR", arg, 1, status);
+
+ // set flag w/wo multiple scattering according to "includeMCS"
+ track.FitWithMCS(includeMCS);
+ if (includeMCS) {
+ // compute cluster weights only once
+ if (!track.ComputeClusterWeights()) {
+ AliWarning("cannot take into account the multiple scattering effects");
+ track.FitWithMCS(kFALSE);
+ }
}
- // search without gradient calculation in the function
- fgFitter->ExecuteCommand("SET NOGRADIENT", arg, 0);
+
+ track.FitWithVertex(fitWithVertex);
+ if (fitWithVertex) SetVertexErrXY2ForFit(track);
+
+ // Set fitting function
+ gMinuit->SetFCN(TrackChi2);
+
+ // Set fitted parameters (!! The order is very important for the covariance matrix !!)
+ trackParam = (AliMUONTrackParam*) (track.GetTrackParamAtCluster()->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
- fgFitter->ExecuteCommand("MINIMIZE", arg, 0);
- // exit from Minuit
- // fgFitter->ExecuteCommand("EXIT", arg, 0); // necessary ????
+ 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")
- fgFitter->GetParameter(0, parName, invBenP, errorParam, lower, upper);
- trackParam->SetInverseBendingMomentum(invBenP);
- fgFitter->GetParameter(1, parName, benC, errorParam, lower, upper);
- trackParam->SetBendingSlope(benC);
- fgFitter->GetParameter(2, parName, nonBenC, errorParam, lower, upper);
+ gMinuit->GetParameter(0, x, errorParam);
+ trackParam->SetNonBendingCoor(x);
+ gMinuit->GetParameter(1, nonBenC, errorParam);
trackParam->SetNonBendingSlope(nonBenC);
- if (FitStart == 1) {
- fgFitter->GetParameter(3, parName, x, errorParam, lower, upper);
- trackParam->SetNonBendingCoor(x);
- fgFitter->GetParameter(4, parName, y, errorParam, lower, upper);
- trackParam->SetBendingCoor(y);
- }
+ 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
- Double_t fedm, errdef, fitFMin;
- Int_t npari, nparx;
- fgFitter->GetStats(fitFMin, fedm, errdef, npari, nparx);
- Track->SetFitFMin(fitFMin);
+ gMinuit->mnstat(globalChi2, fedm, errdef, npari, nparx, covStatus);
+ track.SetGlobalChi2(globalChi2);
+
+ // Get the covariance matrix if required
+ if (calcCov) {
+ // Covariance matrix according to HESSE status
+ // If problem then keep only the diagonal terms (variances)
+ Double_t matrix[5][5];
+ gMinuit->mnemat(&matrix[0][0],5);
+ if (covStatus == 3) trackParam->SetCovariances(matrix);
+ else trackParam->SetVariances(matrix);
+ } else trackParam->DeleteCovariances();
+
}
//__________________________________________________________________________
-void TrackChi2(Int_t &NParam, Double_t * /*Gradient*/, Double_t &Chi2, Double_t *Param, Int_t /*Flag*/)
+void TrackChi2(Int_t & /*nParam*/, Double_t * /*gradient*/, Double_t &chi2, Double_t *param, Int_t /*flag*/)
{
- /// Return the "Chi2" to be minimized with Minuit for track fitting,
- /// with "NParam" parameters
- /// and their current values in array pointed to by "Param".
- /// Assumes that the track hits are sorted according to increasing Z.
- /// Track parameters at each TrackHit are updated accordingly.
- /// Multiple Coulomb scattering is not taken into account
- AliMUONTrack *trackBeingFitted;
- AliMUONTrackParam param1;
- AliMUONTrackParam* trackParamAtHit;
- AliMUONHitForRec* hitForRec;
- Chi2 = 0.0; // initialize Chi2
- // copy of track parameters to be fitted
- trackBeingFitted = (AliMUONTrack*) AliMUONTrackReconstructor::Fitter()->GetObjectFit();
- // 3 parameters means fit track candidate from parameters at vertex (X_vertex and Y_vertex are fixed)
- if (NParam == 3) param1 = *(trackBeingFitted->GetTrackParamAtVertex());
- else param1 = *((AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->First()));
- // Minuit parameters to be fitted into this copy
- param1.SetInverseBendingMomentum(Param[0]);
- param1.SetBendingSlope(Param[1]);
- param1.SetNonBendingSlope(Param[2]);
- if (NParam == 5) {
- param1.SetNonBendingCoor(Param[3]);
- param1.SetBendingCoor(Param[4]);
- }
- // Follow track through all planes of track hits
- trackParamAtHit = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->First());
- while (trackParamAtHit) {
- hitForRec = trackParamAtHit->GetHitForRecPtr();
- // extrapolation to the plane of the hitForRec attached to the current trackParamAtHit
- AliMUONTrackExtrap::ExtrapToZ(¶m1, hitForRec->GetZ());
- // update track parameters of the current hit
- trackParamAtHit->SetTrackParam(param1);
- // Increment Chi2
- // done hit per hit, with hit resolution,
- // and not with point and angle like in "reco_muon.F" !!!!
- // Needs to add multiple scattering contribution ????
- Double_t dX = hitForRec->GetNonBendingCoor() - param1.GetNonBendingCoor();
- Double_t dY = hitForRec->GetBendingCoor() - param1.GetBendingCoor();
- Chi2 = Chi2 + dX * dX / hitForRec->GetNonBendingReso2() + dY * dY / hitForRec->GetBendingReso2();
- trackParamAtHit = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->After(trackParamAtHit));
+ /// Return the "Chi2" to be minimized with Minuit for track fitting.
+ /// Assumes that the trackParamAtCluster are sorted according to increasing Z.
+ /// Track parameters at each cluster are updated accordingly.
+ /// Vertex is used according to the flag "trackBeingFitted->GetFitWithVertex()".
+ /// Multiple Coulomb scattering is taken into account according to the flag "trackBeingFitted->GetFitWithMCS()".
+
+ AliMUONTrack *trackBeingFitted = (AliMUONTrack*) gMinuit->GetObjectFit();
+ AliMUONTrackParam* trackParamAtCluster = (AliMUONTrackParam*) trackBeingFitted->GetTrackParamAtCluster()->First();
+ Double_t dX, dY;
+ chi2 = 0.; // initialize chi2
+
+ // update track parameters
+ trackParamAtCluster->SetNonBendingCoor(param[0]);
+ trackParamAtCluster->SetNonBendingSlope(param[1]);
+ trackParamAtCluster->SetBendingCoor(param[2]);
+ trackParamAtCluster->SetBendingSlope(param[3]);
+ trackParamAtCluster->SetInverseBendingMomentum(param[4]);
+ trackBeingFitted->UpdateTrackParamAtCluster();
+
+ // Take the vertex into account in the fit if required
+ if (trackBeingFitted->FitWithVertex()) {
+ Double_t nonBendingReso2,bendingReso2;
+ trackBeingFitted->GetVertexErrXY2(nonBendingReso2,bendingReso2);
+ if (nonBendingReso2 == 0. || bendingReso2 == 0.) chi2 += 1.e10;
+ else {
+ AliMUONTrackParam paramAtVertex(*trackParamAtCluster);
+ AliMUONTrackExtrap::ExtrapToZ(¶mAtVertex, 0.); // vextex position = (0,0,0)
+ dX = paramAtVertex.GetNonBendingCoor();
+ dY = paramAtVertex.GetBendingCoor();
+ chi2 += dX * dX / nonBendingReso2 + dY * dY / bendingReso2;
+ }
}
+
+ // compute chi2 w/wo multiple scattering
+ chi2 += trackBeingFitted->ComputeGlobalChi2(trackBeingFitted->FitWithMCS());
+
}
//__________________________________________________________________________
-void TrackChi2MCS(Int_t &NParam, Double_t * /*Gradient*/, Double_t &Chi2, Double_t *Param, Int_t /*Flag*/)
+void AliMUONTrackReconstructor::ComplementTracks(const AliMUONVClusterStore& clusterStore)
{
- /// Return the "Chi2" to be minimized with Minuit for track fitting,
- /// with "NParam" parameters
- /// and their current values in array pointed to by "Param".
- /// Assumes that the track hits are sorted according to increasing Z.
- /// Track parameters at each TrackHit are updated accordingly.
- /// Multiple Coulomb scattering is taken into account with covariance matrix.
- AliMUONTrack *trackBeingFitted;
- AliMUONTrackParam param1;
- AliMUONTrackParam* trackParamAtHit;
- AliMUONHitForRec* hitForRec;
- Chi2 = 0.0; // initialize Chi2
- // copy of track parameters to be fitted
- trackBeingFitted = (AliMUONTrack*) AliMUONTrackReconstructor::Fitter()->GetObjectFit();
- // 3 parameters means fit track candidate from parameters at vertex (X_vertex and Y_vertex are fixed)
- if (NParam == 3) param1 = *(trackBeingFitted->GetTrackParamAtVertex());
- else param1 = *((AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->First()));
- // Minuit parameters to be fitted into this copy
- param1.SetInverseBendingMomentum(Param[0]);
- param1.SetBendingSlope(Param[1]);
- param1.SetNonBendingSlope(Param[2]);
- if (NParam == 5) {
- param1.SetNonBendingCoor(Param[3]);
- param1.SetBendingCoor(Param[4]);
- }
-
- Int_t chCurrent, chPrev = 0, hitNumber, hitNumber1, hitNumber2, hitNumber3;
- Double_t z1, z2, z3;
- AliMUONTrackParam *trackParamAtHit1, *trackParamAtHit2, *trackParamAtHit3;
- AliMUONHitForRec *hitForRec1, *hitForRec2;
- Double_t hbc1, hbc2, pbc1, pbc2;
- Double_t hnbc1, hnbc2, pnbc1, pnbc2;
- Int_t numberOfHit = trackBeingFitted->GetNTrackHits();
- TMatrixD *covBending = new TMatrixD(numberOfHit, numberOfHit);
- TMatrixD *covNonBending = new TMatrixD(numberOfHit, numberOfHit);
- Double_t *msa2 = new Double_t[numberOfHit];
-
- // Predicted coordinates and multiple scattering angles are first calculated
- for (hitNumber = 0; hitNumber < numberOfHit; hitNumber++) {
- trackParamAtHit = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber));
- hitForRec = trackParamAtHit->GetHitForRecPtr();
- // extrapolation to the plane of the hitForRec attached to the current trackParamAtHit
- AliMUONTrackExtrap::ExtrapToZ(¶m1, hitForRec->GetZ());
- // update track parameters of the current hit
- trackParamAtHit->SetTrackParam(param1);
- // square of multiple scattering angle at current hit, with one chamber
- msa2[hitNumber] = MultipleScatteringAngle2(¶m1);
- // correction for eventual missing hits or multiple hits in a chamber,
- // according to the number of chambers
- // between the current hit and the previous one
- chCurrent = hitForRec->GetChamberNumber();
- if (hitNumber > 0) msa2[hitNumber] = msa2[hitNumber] * (chCurrent - chPrev);
- chPrev = chCurrent;
- }
-
- // Calculates the covariance matrix
- for (hitNumber1 = 0; hitNumber1 < numberOfHit; hitNumber1++) {
- trackParamAtHit1 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber1));
- hitForRec1 = trackParamAtHit1->GetHitForRecPtr();
- z1 = hitForRec1->GetZ();
- for (hitNumber2 = hitNumber1; hitNumber2 < numberOfHit; hitNumber2++) {
- trackParamAtHit2 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber2));
- z2 = trackParamAtHit2->GetHitForRecPtr()->GetZ();
- // initialization to 0 (diagonal plus upper triangular part)
- (*covBending)(hitNumber2, hitNumber1) = 0.0;
- // contribution from multiple scattering in bending plane:
- // loop over upstream hits
- for (hitNumber3 = 0; hitNumber3 < hitNumber1; hitNumber3++) {
- trackParamAtHit3 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber3));
- z3 = trackParamAtHit3->GetHitForRecPtr()->GetZ();
- (*covBending)(hitNumber2, hitNumber1) = (*covBending)(hitNumber2, hitNumber1) + ((z1 - z3) * (z2 - z3) * msa2[hitNumber3]);
- }
- // equal contribution from multiple scattering in non bending plane
- (*covNonBending)(hitNumber2, hitNumber1) = (*covBending)(hitNumber2, hitNumber1);
- if (hitNumber1 == hitNumber2) {
- // Diagonal elements: add contribution from position measurements
- // in bending plane
- (*covBending)(hitNumber2, hitNumber1) = (*covBending)(hitNumber2, hitNumber1) + hitForRec1->GetBendingReso2();
- // and in non bending plane
- (*covNonBending)(hitNumber2, hitNumber1) = (*covNonBending)(hitNumber2, hitNumber1) + hitForRec1->GetNonBendingReso2();
- } else {
- // Non diagonal elements: symmetrization
- // for bending plane
- (*covBending)(hitNumber1, hitNumber2) = (*covBending)(hitNumber2, hitNumber1);
- // and non bending plane
- (*covNonBending)(hitNumber1, hitNumber2) = (*covNonBending)(hitNumber2, hitNumber1);
- }
- } // for (hitNumber2 = hitNumber1;...
- } // for (hitNumber1 = 0;...
+ /// 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 chi2OfCluster, bestChi2OfCluster;
+ Double_t sigmaCut2 = AliMUONReconstructor::GetRecoParam()->GetSigmaCutForTracking() *
+ AliMUONReconstructor::GetRecoParam()->GetSigmaCutForTracking();
+ Bool_t foundOneCluster, trackModified;
+ AliMUONVCluster* cluster;
+ AliMUONTrackParam *trackParam, *nextTrackParam, copyOfTrackParam, trackParamAtCluster, bestTrackParamAtCluster;
+
+ // Remove double track to complete only "good" tracks
+ RemoveDoubleTracks();
+
+ AliMUONTrack *track = (AliMUONTrack*) fRecTracksPtr->First();
+ while (track) {
+ trackModified = kFALSE;
- // Inversion of covariance matrices
- // with "mnvertLocal", local "mnvert" function of Minuit.
- // One cannot use directly "mnvert" since "TVirtualFitter" does not know it.
- // One will have to replace this local function by the right inversion function
- // from a specialized Root package for symmetric positive definite matrices,
- // when available!!!!
- Int_t ifailBending;
- mnvertLocal(&((*covBending)(0,0)), numberOfHit, numberOfHit, numberOfHit, ifailBending);
- Int_t ifailNonBending;
- mnvertLocal(&((*covNonBending)(0,0)), numberOfHit, numberOfHit, numberOfHit, ifailNonBending);
-
- // It would be worth trying to calculate the inverse of the covariance matrix
- // only once per fit, since it cannot change much in principle,
- // and it would save a lot of computing time !!!!
-
- // Calculates Chi2
- if ((ifailBending == 0) && (ifailNonBending == 0)) {
- // with Multiple Scattering if inversion correct
- for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) {
- trackParamAtHit1 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber1));
- hitForRec1 = trackParamAtHit1->GetHitForRecPtr();
- hbc1 = hitForRec1->GetBendingCoor();
- pbc1 = trackParamAtHit1->GetBendingCoor();
- hnbc1 = hitForRec1->GetNonBendingCoor();
- pnbc1 = trackParamAtHit1->GetNonBendingCoor();
- for (hitNumber2 = 0; hitNumber2 < numberOfHit; hitNumber2++) {
- trackParamAtHit2 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber2));
- hitForRec2 = trackParamAtHit2->GetHitForRecPtr();
- hbc2 = hitForRec2->GetBendingCoor();
- pbc2 = trackParamAtHit2->GetBendingCoor();
- hnbc2 = hitForRec2->GetNonBendingCoor();
- pnbc2 = trackParamAtHit2->GetNonBendingCoor();
- Chi2 += ((*covBending)(hitNumber2, hitNumber1) * (hbc1 - pbc1) * (hbc2 - pbc2)) +
- ((*covNonBending)(hitNumber2, hitNumber1) * (hnbc1 - pnbc1) * (hnbc2 - pnbc2));
+ trackParam = (AliMUONTrackParam*)track->GetTrackParamAtCluster()->First();
+ while (trackParam) {
+ foundOneCluster = kFALSE;
+ bestChi2OfCluster = 2. * sigmaCut2; // 2 because 2 quantities in chi2
+ chamberId = trackParam->GetClusterPtr()->GetChamberId();
+ detElemId = trackParam->GetClusterPtr()->GetDetElemId();
+
+ // prepare nextTrackParam before adding new cluster because of the sorting
+ nextTrackParam = (AliMUONTrackParam*)track->GetTrackParamAtCluster()->After(trackParam);
+
+ // recover track parameters from local fit and put them into a copy of trackParam
+ copyOfTrackParam.SetZ(trackParam->GetZ());
+ copyOfTrackParam.SetParameters(trackParam->GetSmoothParameters());
+ copyOfTrackParam.SetCovariances(trackParam->GetSmoothCovariances());
+
+ // Create iterators to loop over clusters in current chamber
+ TIter nextInCh(clusterStore.CreateChamberIterator(chamberId,chamberId));
+
+ // look for one second candidate in the same chamber
+ while ( ( cluster = static_cast<AliMUONVCluster*>(nextInCh()) ) ) {
+
+ // look for a cluster in another detection element
+ if (cluster->GetDetElemId() == detElemId) continue;
+
+ // try to add the current cluster fast
+ if (!TryOneClusterFast(copyOfTrackParam, cluster)) continue;
+
+ // try to add the current cluster accurately
+ chi2OfCluster = TryOneCluster(copyOfTrackParam, cluster, trackParamAtCluster);
+
+ // if better chi2 then prepare to add this cluster to the track
+ if (chi2OfCluster < bestChi2OfCluster) {
+ bestChi2OfCluster = chi2OfCluster;
+ bestTrackParamAtCluster = trackParamAtCluster;
+ foundOneCluster = kTRUE;
+ }
+
}
+
+ // add new cluster if any
+ if (foundOneCluster) {
+ UpdateTrack(*track,bestTrackParamAtCluster);
+ bestTrackParamAtCluster.SetAloneInChamber(kFALSE);
+ trackParam->SetAloneInChamber(kFALSE);
+ trackModified = kTRUE;
+ }
+
+ trackParam = nextTrackParam;
}
- } else {
- // without Multiple Scattering if inversion impossible
- for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) {
- trackParamAtHit1 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber1));
- hitForRec1 = trackParamAtHit1->GetHitForRecPtr();
- hbc1 = hitForRec1->GetBendingCoor();
- pbc1 = trackParamAtHit1->GetBendingCoor();
- hnbc1 = hitForRec1->GetNonBendingCoor();
- pnbc1 = trackParamAtHit1->GetNonBendingCoor();
- Chi2 += ((hbc1 - pbc1) * (hbc1 - pbc1) / hitForRec1->GetBendingReso2()) +
- ((hnbc1 - pnbc1) * (hnbc1 - pnbc1) / hitForRec1->GetNonBendingReso2());
- }
+
+ // re-fit track parameters if needed
+ if (trackModified) Fit(*track, kTRUE, kFALSE, kTRUE);
+
+ track = (AliMUONTrack*) fRecTracksPtr->After(track);
}
- delete covBending;
- delete covNonBending;
- delete [] msa2;
-}
-
-Double_t MultipleScatteringAngle2(AliMUONTrackParam *param)
-{
- /// Returns square of multiple Coulomb scattering angle
- /// from TrackParamAtHit pointed to by "param"
- Double_t slopeBending, slopeNonBending, radiationLength, inverseBendingMomentum2, inverseTotalMomentum2;
- Double_t varMultipleScatteringAngle;
- // Better implementation in AliMUONTrack class ????
- slopeBending = param->GetBendingSlope();
- slopeNonBending = param->GetNonBendingSlope();
- // thickness in radiation length for the current track,
- // taking local angle into account
- radiationLength = AliMUONConstants::DefaultChamberThicknessInX0() *
- TMath::Sqrt(1.0 + slopeBending*slopeBending + slopeNonBending*slopeNonBending);
- inverseBendingMomentum2 = param->GetInverseBendingMomentum() * param->GetInverseBendingMomentum();
- inverseTotalMomentum2 = inverseBendingMomentum2 * (1.0 + slopeBending * slopeBending) /
- (1.0 + slopeBending *slopeBending + slopeNonBending * slopeNonBending);
- varMultipleScatteringAngle = 0.0136 * (1.0 + 0.038 * TMath::Log(radiationLength));
- // The velocity is assumed to be 1 !!!!
- varMultipleScatteringAngle = inverseTotalMomentum2 * radiationLength * varMultipleScatteringAngle * varMultipleScatteringAngle;
- return varMultipleScatteringAngle;
-}
-
-//______________________________________________________________________________
- void mnvertLocal(Double_t *a, Int_t l, Int_t, Int_t n, Int_t &ifail)
-{
-///*-*-*-*-*-*-*-*-*-*-*-*Inverts a symmetric matrix*-*-*-*-*-*-*-*-*-*-*-*-*
-///*-* ==========================
-///*-* inverts a symmetric matrix. matrix is first scaled to
-///*-* have all ones on the diagonal (equivalent to change of units)
-///*-* but no pivoting is done since matrix is positive-definite.
-///*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
-
- // taken from TMinuit package of Root (l>=n)
- // fVERTs, fVERTq and fVERTpp changed to localVERTs, localVERTq and localVERTpp
- // Double_t localVERTs[n], localVERTq[n], localVERTpp[n];
- Double_t * localVERTs = new Double_t[n];
- Double_t * localVERTq = new Double_t[n];
- Double_t * localVERTpp = new Double_t[n];
- // fMaxint changed to localMaxint
- Int_t localMaxint = n;
-
- /* System generated locals */
- Int_t aOffset;
-
- /* Local variables */
- Double_t si;
- Int_t i, j, k, kp1, km1;
-
- /* Parameter adjustments */
- aOffset = l + 1;
- a -= aOffset;
-
- /* Function Body */
- ifail = 0;
- if (n < 1) goto L100;
- if (n > localMaxint) goto L100;
-//*-*- scale matrix by sqrt of diag elements
- for (i = 1; i <= n; ++i) {
- si = a[i + i*l];
- if (si <= 0) goto L100;
- localVERTs[i-1] = 1 / TMath::Sqrt(si);
- }
- for (i = 1; i <= n; ++i) {
- for (j = 1; j <= n; ++j) {
- a[i + j*l] = a[i + j*l]*localVERTs[i-1]*localVERTs[j-1];
- }
- }
-//*-*- . . . start main loop . . . .
- for (i = 1; i <= n; ++i) {
- k = i;
-//*-*- preparation for elimination step1
- if (a[k + k*l] != 0) localVERTq[k-1] = 1 / a[k + k*l];
- else goto L100;
- localVERTpp[k-1] = 1;
- a[k + k*l] = 0;
- kp1 = k + 1;
- km1 = k - 1;
- if (km1 < 0) goto L100;
- else if (km1 == 0) goto L50;
- else goto L40;
-L40:
- for (j = 1; j <= km1; ++j) {
- localVERTpp[j-1] = a[j + k*l];
- localVERTq[j-1] = a[j + k*l]*localVERTq[k-1];
- a[j + k*l] = 0;
- }
-L50:
- if (k - n < 0) goto L51;
- else if (k - n == 0) goto L60;
- else goto L100;
-L51:
- for (j = kp1; j <= n; ++j) {
- localVERTpp[j-1] = a[k + j*l];
- localVERTq[j-1] = -a[k + j*l]*localVERTq[k-1];
- a[k + j*l] = 0;
- }
-//*-*- elimination proper
-L60:
- for (j = 1; j <= n; ++j) {
- for (k = j; k <= n; ++k) { a[j + k*l] += localVERTpp[j-1]*localVERTq[k-1]; }
- }
- }
-//*-*- elements of left diagonal and unscaling
- for (j = 1; j <= n; ++j) {
- for (k = 1; k <= j; ++k) {
- a[k + j*l] = a[k + j*l]*localVERTs[k-1]*localVERTs[j-1];
- a[j + k*l] = a[k + j*l];
- }
- }
- delete [] localVERTs;
- delete [] localVERTq;
- delete [] localVERTpp;
- return;
-//*-*- failure return
-L100:
- delete [] localVERTs;
- delete [] localVERTq;
- delete [] localVERTpp;
- ifail = 1;
-} /* mnvertLocal */
-
- //__________________________________________________________________________
-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;
- Int_t hitsInCommon, nHits1, nHits2;
- Bool_t removedTrack1;
- // Loop over first track of the pair
- track1 = (AliMUONTrack*) fRecTracksPtr->First();
- while (track1) {
- removedTrack1 = kFALSE;
- nHits1 = track1->GetNTrackHits();
- // Loop over second track of the pair
- track2 = (AliMUONTrack*) fRecTracksPtr->After(track1);
- while (track2) {
- nHits2 = track2->GetNTrackHits();
- // number of hits in common between two tracks
- hitsInCommon = track1->HitsInCommon(track2);
- // check for identical tracks
- if ((4 * hitsInCommon) >= (nHits1 + nHits2)) {
- // decide which track to remove
- if ((nHits1 > nHits2) || ((nHits1 == nHits2) && (track1->GetFitFMin() < track2->GetFitFMin()))) {
- // remove track2 and continue the second loop with the track next to track2
- trackToRemove = track2;
- track2 = (AliMUONTrack*) fRecTracksPtr->After(track2);
- fRecTracksPtr->Remove(trackToRemove);
- fNRecTracks--;
- fRecTracksPtr->Compress(); // this is essential to retrieve the TClonesArray afterwards
- } else {
- // else remove track1 and continue the first loop with the track next to track1
- trackToRemove = track1;
- track1 = (AliMUONTrack*) fRecTracksPtr->After(track1);
- fRecTracksPtr->Remove(trackToRemove);
- fNRecTracks--;
- fRecTracksPtr->Compress(); // this is essential to retrieve the TClonesArray afterwards
- removedTrack1 = kTRUE;
- break;
- }
- } else track2 = (AliMUONTrack*) fRecTracksPtr->After(track2);
- } // track2
- if (removedTrack1) continue;
- track1 = (AliMUONTrack*) fRecTracksPtr->After(track1);
- } // track1
- return;
}
//__________________________________________________________________________
-void AliMUONTrackReconstructor::UpdateHitForRecAtHit()
+void AliMUONTrackReconstructor::ImproveTracks()
{
- /// Set cluster parameters after track fitting. Fill fHitForRecAtHit of AliMUONTrack's
- AliMUONTrack *track;
- AliMUONTrackParam *trackParamAtHit;
+ /// 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 *trackParamAtCluster, *worstTrackParamAtCluster, *previousTrackParam, *nextTrackParam;
+ Double_t sigmaCut2 = AliMUONReconstructor::GetRecoParam()->GetSigmaCutForImprovement() *
+ AliMUONReconstructor::GetRecoParam()->GetSigmaCutForImprovement();
+
+ // Remove double track to improve only "good" tracks
+ RemoveDoubleTracks();
+
track = (AliMUONTrack*) fRecTracksPtr->First();
while (track) {
- trackParamAtHit = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->First());
- while (trackParamAtHit) {
- track->AddHitForRecAtHit(trackParamAtHit->GetHitForRecPtr());
- trackParamAtHit = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->After(trackParamAtHit));
+
+ // prepare next track in case the actual track is suppressed
+ nextTrack = (AliMUONTrack*) fRecTracksPtr->After(track);
+
+ while (!track->IsImproved()) {
+
+ // Update track parameters and covariances
+ track->UpdateCovTrackParamAtCluster();
+
+ // Compute local chi2 of each clusters
+ track->ComputeLocalChi2(kTRUE);
+
+ // Look for the cluster to remove
+ worstTrackParamAtCluster = NULL;
+ worstLocalChi2 = 0.;
+ trackParamAtCluster = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->First();
+ while (trackParamAtCluster) {
+
+ // Pick up cluster with the worst chi2
+ localChi2 = trackParamAtCluster->GetLocalChi2();
+ if (localChi2 > worstLocalChi2) {
+ worstLocalChi2 = localChi2;
+ worstTrackParamAtCluster = trackParamAtCluster;
+ }
+
+ trackParamAtCluster = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->After(trackParamAtCluster);
+ }
+
+ // Check if bad cluster found
+ if (!worstTrackParamAtCluster) {
+ 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 the worst cluster is not removable then remove the entire track
+ if (!worstTrackParamAtCluster->IsRemovable() && worstTrackParamAtCluster->IsAloneInChamber()) {
+ fRecTracksPtr->Remove(track);
+ fNRecTracks--;
+ break;
+ }
+
+ // Reset the second cluster in the same station as being not removable
+ // or reset the second cluster in the same chamber as being alone
+ worstChamber = worstTrackParamAtCluster->GetClusterPtr()->GetChamberId();
+ previousTrackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->Before(worstTrackParamAtCluster);
+ nextTrackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->After(worstTrackParamAtCluster);
+ if (worstTrackParamAtCluster->IsAloneInChamber()) { // Worst cluster removable and alone in chamber
+
+ if (worstChamber%2 == 0) { // Modify flags in next chamber
+
+ nextTrackParam->SetRemovable(kFALSE);
+ if (!nextTrackParam->IsAloneInChamber()) // Make sure both clusters in second chamber are not removable anymore
+ ((AliMUONTrackParam*) track->GetTrackParamAtCluster()->After(nextTrackParam))->SetRemovable(kFALSE);
+
+ } else { // Modify flags in previous chamber
+
+ previousTrackParam->SetRemovable(kFALSE);
+ if (!previousTrackParam->IsAloneInChamber()) // Make sure both clusters in second chamber are not removable anymore
+ ((AliMUONTrackParam*) track->GetTrackParamAtCluster()->Before(previousTrackParam))->SetRemovable(kFALSE);
+
+ }
+
+ } else { // Worst cluster not alone in its chamber
+
+ if (previousTrackParam) previousChamber = previousTrackParam->GetClusterPtr()->GetChamberId();
+ else previousChamber = -1;
+
+ if (previousChamber == worstChamber) { // the second cluster on the same chamber is the previous one
+
+ previousTrackParam->SetAloneInChamber(kTRUE);
+ // transfert the removability to the second cluster
+ if (worstTrackParamAtCluster->IsRemovable()) previousTrackParam->SetRemovable(kTRUE);
+
+ } else { // the second cluster on the same chamber is the next one
+
+ nextTrackParam->SetAloneInChamber(kTRUE);
+ // transfert the removability to the second cluster
+ if (worstTrackParamAtCluster->IsRemovable()) nextTrackParam->SetRemovable(kTRUE);
+
+ }
+
+ }
+
+ // Remove the worst cluster
+ track->RemoveTrackParamAtCluster(worstTrackParamAtCluster);
+
+ // Re-fit the track:
+ // Take into account the multiple scattering
+ // Calculate the track parameter covariance matrix
+ Fit(*track, kTRUE, kFALSE, kTRUE);
+
+ // Printout for debuging
+ if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
+ cout << "ImproveTracks: track " << fRecTracksPtr->IndexOf(track)+1 << " improved " << endl;
+ }
+
}
- track = (AliMUONTrack*) fRecTracksPtr->After(track);
+
+ track = nextTrack;
}
- return;
+
+ // compress the array in case of some tracks have been removed
+ fRecTracksPtr->Compress();
+
}
//__________________________________________________________________________
-void AliMUONTrackReconstructor::EventDump(void)
+void AliMUONTrackReconstructor::Finalize()
{
- /// Dump reconstructed event (track parameters at vertex and at first hit),
- /// and the particle parameters
+ /// Recompute track parameters and covariances at each attached cluster from those at the first one
+
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++) {
- 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 = (AliMUONTrackParam*) track->GetTrackParamAtHit()->First();
- 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));
+
+ track = (AliMUONTrack*) fRecTracksPtr->First();
+ while (track) {
+
+ // update track parameters if not already done
+ if (!track->IsImproved()) track->UpdateCovTrackParamAtCluster();
+
+ track = (AliMUONTrack*) fRecTracksPtr->After(track);
+
}
- // 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;
+
}
-
git://git.uio.no / u / mrichter / AliRoot.git / blobdiff