* provided "as is" without express or implied warranty. *
**************************************************************************/
-/*
-$Log$
-Revision 1.2 2000/06/15 07:58:48 morsch
-Code from MUON-dev joined
+/* $Id$ */
-Revision 1.1.2.3 2000/06/12 10:11:34 morsch
-Dummy copy constructor and assignment operator added
+///////////////////////////////////////////////////
+//
+// Reconstructed track
+// in
+// ALICE
+// dimuon
+// spectrometer
+//
+///////////////////////////////////////////////////
+
+#include "AliMUONTrack.h"
-Revision 1.1.2.2 2000/06/09 12:58:05 gosset
-Removed comment beginnings in Log sections of .cxx files
-Suppressed most violations of coding rules
+#include "AliMUONTrackParam.h"
+#include "AliMUONHitForRec.h"
+#include "AliMUONObjectPair.h"
+#include "AliMUONConstants.h"
+#include "AliMUONTrackExtrap.h"
-Revision 1.1.2.1 2000/06/07 14:44:53 gosset
-Addition of files for track reconstruction in C++
-*/
+#include "AliLog.h"
+
+#include <TMath.h>
+#include <TMatrixD.h>
+
+#include <Riostream.h>
+
+/// \cond CLASSIMP
+ClassImp(AliMUONTrack) // Class implementation in ROOT context
+/// \endcond
//__________________________________________________________________________
-//
-// Reconstructed track in ALICE dimuon spectrometer
-//__________________________________________________________________________
+AliMUONTrack::AliMUONTrack()
+ : TObject(),
+ fTrackParamAtVertex(),
+ fTrackParamAtHit(0x0),
+ fHitForRecAtHit(0x0),
+ fNTrackHits(0),
+ fFitWithVertex(kFALSE),
+ fVertex(0x0),
+ fFitWithMCS(kFALSE),
+ fHitWeightsNonBending(0x0),
+ fHitWeightsBending(0x0),
+ fGlobalChi2(-1.),
+ fImproved(kFALSE),
+ fMatchTrigger(-1),
+ floTrgNum(-1),
+ fChi2MatchTrigger(0.),
+ fTrackID(0),
+ fHitsPatternInTrigCh(0),
+ fLocalTrigger(234)
+{
+ /// Default constructor
+}
-#include "AliMUONTrack.h"
+ //__________________________________________________________________________
+AliMUONTrack::AliMUONTrack(AliMUONObjectPair *segment)
+ : TObject(),
+ fTrackParamAtVertex(),
+ fTrackParamAtHit(0x0),
+ fHitForRecAtHit(0x0),
+ fNTrackHits(0),
+ fFitWithVertex(kFALSE),
+ fVertex(0x0),
+ fFitWithMCS(kFALSE),
+ fHitWeightsNonBending(0x0),
+ fHitWeightsBending(0x0),
+ fGlobalChi2(0.),
+ fImproved(kFALSE),
+ fMatchTrigger(-1),
+ floTrgNum(-1),
+ fChi2MatchTrigger(0.),
+ fTrackID(0),
+ fHitsPatternInTrigCh(0),
+ fLocalTrigger(234)
+{
+ /// Constructor from thw hitForRec's
-#include <iostream.h>
+ fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
+ fTrackParamAtHit->SetOwner(kTRUE);
+ fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
+ fHitForRecAtHit->SetOwner(kTRUE);
+
+ if (!segment) return; //AZ
+
+ // Pointers to hits from the segment
+ AliMUONHitForRec* hit1 = (AliMUONHitForRec*) segment->First();
+ AliMUONHitForRec* hit2 = (AliMUONHitForRec*) segment->Second();
+
+ // check sorting in -Z (spectro z<0)
+ if (hit1->GetZ() < hit2->GetZ()) {
+ hit1 = hit2;
+ hit2 = (AliMUONHitForRec*) segment->First();
+ }
+
+ // order the hits into the track according to the station the segment belong to
+ //(the hit first attached is the one from which we will start the tracking procedure)
+ if (hit1->GetChamberNumber() == 8) {
+ AddTrackParamAtHit(0,hit1);
+ AddTrackParamAtHit(0,hit2);
+ } else {
+ AddTrackParamAtHit(0,hit2);
+ AddTrackParamAtHit(0,hit1);
+ }
+
+ AliMUONTrackParam* trackParamAtFirstHit = (AliMUONTrackParam*) fTrackParamAtHit->First();
+ AliMUONHitForRec* firstHit = trackParamAtFirstHit->GetHitForRecPtr();
+ AliMUONTrackParam* trackParamAtLastHit = (AliMUONTrackParam*) fTrackParamAtHit->Last();
+ AliMUONHitForRec* lastHit = trackParamAtLastHit->GetHitForRecPtr();
+
+
+ // Compute track parameters
+ Double_t dZ = firstHit->GetZ() - lastHit->GetZ();
+ // Non bending plane
+ Double_t nonBendingCoor1 = firstHit->GetNonBendingCoor();
+ Double_t nonBendingCoor2 = lastHit->GetNonBendingCoor();
+ Double_t nonBendingSlope = (nonBendingCoor1 - nonBendingCoor2) / dZ;
+ // Bending plane
+ Double_t bendingCoor1 = firstHit->GetBendingCoor();
+ Double_t bendingCoor2 = lastHit->GetBendingCoor();
+ Double_t bendingSlope = (bendingCoor1 - bendingCoor2) / dZ;
+ // Inverse bending momentum
+ Double_t bendingImpact = bendingCoor1 - firstHit->GetZ() * bendingSlope;
+ Double_t inverseBendingMomentum = 1. / AliMUONTrackExtrap::GetBendingMomentumFromImpactParam(bendingImpact);
+
+
+ // Set track parameters at first hit
+ trackParamAtFirstHit->SetNonBendingCoor(nonBendingCoor1);
+ trackParamAtFirstHit->SetNonBendingSlope(nonBendingSlope);
+ trackParamAtFirstHit->SetBendingCoor(bendingCoor1);
+ trackParamAtFirstHit->SetBendingSlope(bendingSlope);
+ trackParamAtFirstHit->SetInverseBendingMomentum(inverseBendingMomentum);
+
+
+ // Set track parameters at last hit
+ trackParamAtLastHit->SetNonBendingCoor(nonBendingCoor2);
+ trackParamAtLastHit->SetNonBendingSlope(nonBendingSlope);
+ trackParamAtLastHit->SetBendingCoor(bendingCoor2);
+ trackParamAtLastHit->SetBendingSlope(bendingSlope);
+ trackParamAtLastHit->SetInverseBendingMomentum(inverseBendingMomentum);
+
+
+ // Compute and set track parameters covariances at first hit
+ TMatrixD paramCov1(5,5);
+ paramCov1.Zero();
+ // Non bending plane
+ paramCov1(0,0) = firstHit->GetNonBendingReso2();
+ paramCov1(0,1) = firstHit->GetNonBendingReso2() / dZ;
+ paramCov1(1,0) = paramCov1(0,1);
+ paramCov1(1,1) = ( firstHit->GetNonBendingReso2() + lastHit->GetNonBendingReso2() ) / dZ / dZ;
+ // Bending plane
+ paramCov1(2,2) = firstHit->GetBendingReso2();
+ paramCov1(2,3) = firstHit->GetBendingReso2() / dZ;
+ paramCov1(3,2) = paramCov1(2,3);
+ paramCov1(3,3) = ( firstHit->GetBendingReso2() + lastHit->GetBendingReso2() ) / dZ / dZ;
+ // Inverse bending momentum (50% error)
+ paramCov1(4,4) = 0.5*inverseBendingMomentum * 0.5*inverseBendingMomentum;
+ // Set covariances
+ trackParamAtFirstHit->SetCovariances(paramCov1);
+
+
+ // Compute and set track parameters covariances at last hit (as if the first hit did not exist)
+ TMatrixD paramCov2(5,5);
+ paramCov2.Zero();
+ // Non bending plane
+ paramCov2(0,0) = paramCov1(0,0);
+ paramCov2(1,1) = 100.*paramCov1(1,1);
+ // Bending plane
+ paramCov2(2,2) = paramCov1(2,2);
+ paramCov2(3,3) = 100.*paramCov1(3,3);
+ // Inverse bending momentum
+ paramCov2(4,4) = paramCov1(4,4);
+ // Set covariances
+ trackParamAtLastHit->SetCovariances(paramCov2);
+
+
+ // Flag first hit as being removable
+ trackParamAtFirstHit->SetRemovable(kTRUE);
+
+ // Flag last hit as being removable
+ trackParamAtLastHit->SetRemovable(kTRUE);
+
+}
-#include <TClonesArray.h>
-#include <TMinuit.h>
+ //__________________________________________________________________________
+AliMUONTrack::AliMUONTrack (const AliMUONTrack& track)
+ : TObject(track),
+ fTrackParamAtVertex(track.fTrackParamAtVertex),
+ fTrackParamAtHit(0x0),
+ fHitForRecAtHit(0x0),
+ fNTrackHits(track.fNTrackHits),
+ fFitWithVertex(track.fFitWithVertex),
+ fVertex(0x0),
+ fFitWithMCS(track.fFitWithMCS),
+ fHitWeightsNonBending(0x0),
+ fHitWeightsBending(0x0),
+ fGlobalChi2(track.fGlobalChi2),
+ fImproved(track.fImproved),
+ fMatchTrigger(track.fMatchTrigger),
+ floTrgNum(track.floTrgNum),
+ fChi2MatchTrigger(track.fChi2MatchTrigger),
+ fTrackID(track.fTrackID),
+ fHitsPatternInTrigCh(track.fHitsPatternInTrigCh),
+ fLocalTrigger(track.fLocalTrigger)
+{
+ ///copy constructor
+ Int_t maxIndex = 0;
+
+ // necessary to make a copy of the objects and not only the pointers in TClonesArray.
+ if (track.fTrackParamAtHit) {
+ maxIndex = (track.fTrackParamAtHit)->GetEntriesFast();
+ fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",maxIndex);
+ for (Int_t index = 0; index < maxIndex; index++) {
+ new ((*fTrackParamAtHit)[index]) AliMUONTrackParam(*(AliMUONTrackParam*)track.fTrackParamAtHit->At(index));
+ }
+ }
+
+ // necessary to make a copy of the objects and not only the pointers in TClonesArray.
+ if (track.fHitForRecAtHit) {
+ maxIndex = (track.fHitForRecAtHit)->GetEntriesFast();
+ fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",maxIndex);
+ for (Int_t index = 0; index < maxIndex; index++) {
+ new ((*fHitForRecAtHit)[index]) AliMUONHitForRec(*(AliMUONHitForRec*)track.fHitForRecAtHit->At(index));
+ }
+ }
+
+ // copy vertex used during the tracking procedure if any
+ if (track.fVertex) fVertex = new AliMUONHitForRec(*(track.fVertex));
+
+ // copy hit weights matrices if any
+ if (track.fHitWeightsNonBending) fHitWeightsNonBending = new TMatrixD(*(track.fHitWeightsNonBending));
+ if (track.fHitWeightsBending) fHitWeightsBending = new TMatrixD(*(track.fHitWeightsBending));
+
+}
-#include "AliMUONEventReconstructor.h"
-#include "AliMUONHitForRec.h"
-#include "AliMUONSegment.h"
-#include "AliMUONTrackHit.h"
+ //__________________________________________________________________________
+AliMUONTrack & AliMUONTrack::operator=(const AliMUONTrack& track)
+{
+ /// Asignment operator
+ // check assignement to self
+ if (this == &track)
+ return *this;
-#include <stdlib.h>
+ // base class assignement
+ TObject::operator=(track);
-static AliMUONTrack *trackBeingFitted;
-static AliMUONTrackParam *trackParamBeingFitted;
+ fTrackParamAtVertex = track.fTrackParamAtVertex;
-// Function to be minimized with Minuit
-void TrackChi2(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag);
+ Int_t maxIndex = 0;
+
+ // necessary to make a copy of the objects and not only the pointers in TClonesArray.
+ if (track.fTrackParamAtHit) {
+ if (fTrackParamAtHit) fTrackParamAtHit->Clear();
+ else fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
+ maxIndex = (track.fTrackParamAtHit)->GetEntriesFast();
+ for (Int_t index = 0; index < maxIndex; index++) {
+ new ((*fTrackParamAtHit)[fTrackParamAtHit->GetEntriesFast()])
+ AliMUONTrackParam(*(AliMUONTrackParam*)(track.fTrackParamAtHit)->At(index));
+ }
+ } else if (fTrackParamAtHit) {
+ delete fTrackParamAtHit;
+ fTrackParamAtHit = 0x0;
+ }
-ClassImp(AliMUONTrack) // Class implementation in ROOT context
+ // necessary to make a copy of the objects and not only the pointers in TClonesArray.
+ if (track.fHitForRecAtHit) {
+ if (fHitForRecAtHit) fHitForRecAtHit->Clear();
+ else fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
+ maxIndex = (track.fHitForRecAtHit)->GetEntriesFast();
+ for (Int_t index = 0; index < maxIndex; index++) {
+ new ((*fHitForRecAtHit)[fHitForRecAtHit->GetEntriesFast()])
+ AliMUONHitForRec(*(AliMUONHitForRec*)(track.fHitForRecAtHit)->At(index));
+ }
+ } else if (fHitForRecAtHit) {
+ delete fHitForRecAtHit;
+ fHitForRecAtHit = 0x0;
+ }
+
+ // copy vertex used during the tracking procedure if any.
+ if (track.fVertex) {
+ if (fVertex) *fVertex = *(track.fVertex);
+ else fVertex = new AliMUONHitForRec(*(track.fVertex));
+ } else if (fVertex) {
+ delete fVertex;
+ fVertex = 0x0;
+ }
+
+ // copy hit weights matrix if any
+ if (track.fHitWeightsNonBending) {
+ if (fHitWeightsNonBending) {
+ fHitWeightsNonBending->ResizeTo(*(track.fHitWeightsNonBending));
+ *fHitWeightsNonBending = *(track.fHitWeightsNonBending);
+ } else fHitWeightsNonBending = new TMatrixD(*(track.fHitWeightsNonBending));
+ } else if (fHitWeightsNonBending) {
+ delete fHitWeightsNonBending;
+ fHitWeightsNonBending = 0x0;
+ }
+
+ // copy hit weights matrix if any
+ if (track.fHitWeightsBending) {
+ if (fHitWeightsBending) {
+ fHitWeightsBending->ResizeTo(*(track.fHitWeightsBending));
+ *fHitWeightsBending = *(track.fHitWeightsBending);
+ } else fHitWeightsBending = new TMatrixD(*(track.fHitWeightsBending));
+ } else if (fHitWeightsBending) {
+ delete fHitWeightsBending;
+ fHitWeightsBending = 0x0;
+ }
+
+ fNTrackHits = track.fNTrackHits;
+ fFitWithVertex = track.fFitWithVertex;
+ fFitWithMCS = track.fFitWithMCS;
+ fGlobalChi2 = track.fGlobalChi2;
+ fImproved = track.fImproved;
+ fMatchTrigger = track.fMatchTrigger;
+ floTrgNum = track.floTrgNum;
+ fChi2MatchTrigger = track.fChi2MatchTrigger;
+ fTrackID = track.fTrackID;
+ fHitsPatternInTrigCh = track.fHitsPatternInTrigCh;
+ fLocalTrigger = track.fLocalTrigger;
+
+ return *this;
+}
//__________________________________________________________________________
-AliMUONTrack::AliMUONTrack(AliMUONSegment* BegSegment, AliMUONSegment* EndSegment, AliMUONEventReconstructor* EventReconstructor)
+AliMUONTrack::~AliMUONTrack()
{
- // Constructor from two Segment's
- fEventReconstructor = EventReconstructor; // link back to EventReconstructor
- // memory allocation for the TClonesArray of reconstructed TrackHit's
- fTrackHitsPtr = new TClonesArray("AliMUONTrackHit", 10);
- fNTrackHits = 0;
- AddSegment(BegSegment); // add hits from BegSegment
- AddSegment(EndSegment); // add hits from EndSegment
- fTrackHitsPtr->Sort(); // sort TrackHits according to increasing Z
- SetTrackParamAtVertex(); // set track parameters at vertex
- return;
+ /// Destructor
+ delete fTrackParamAtHit;
+ delete fHitForRecAtHit;
+ delete fVertex;
+ delete fHitWeightsNonBending;
+ delete fHitWeightsBending;
}
//__________________________________________________________________________
-AliMUONTrack::AliMUONTrack(AliMUONSegment* Segment, AliMUONHitForRec* HitForRec, AliMUONEventReconstructor* EventReconstructor)
+void AliMUONTrack::Clear(Option_t* opt)
{
- // Constructor from one Segment and one HitForRec
- fEventReconstructor = EventReconstructor; // link back to EventReconstructor
- // memory allocation for the TClonesArray of reconstructed TrackHit's
- fTrackHitsPtr = new TClonesArray("AliMUONTrackHit", 10);
- fNTrackHits = 0;
- AddSegment(Segment); // add hits from Segment
- AddHitForRec(HitForRec); // add HitForRec
- fTrackHitsPtr->Sort(); // sort TrackHits according to increasing Z
- SetTrackParamAtVertex(); // set track parameters at vertex
- return;
+ /// Clear arrays
+ if ( fTrackParamAtHit ) fTrackParamAtHit->Clear(opt);
+ if ( fHitForRecAtHit ) fHitForRecAtHit->Clear(opt);
+ delete fVertex; fVertex = 0x0;
+ delete fHitWeightsNonBending; fHitWeightsNonBending = 0x0;
+ delete fHitWeightsBending; fHitWeightsBending = 0x0;
}
-AliMUONTrack::AliMUONTrack (const AliMUONTrack& MUONTrack)
+ //__________________________________________________________________________
+void AliMUONTrack::AddTrackParamAtHit(const AliMUONTrackParam *trackParam, AliMUONHitForRec *hitForRec)
{
-// Dummy copy constructor
+ /// Add TrackParamAtHit if "trackParam" != NULL
+ /// else create empty TrackParamAtHit and set the z position to the one of "hitForRec" if any
+ /// Update link to HitForRec if "hitForRec" != NULL
+ if (!fTrackParamAtHit) {
+ fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
+ fNTrackHits = 0;
+ }
+ AliMUONTrackParam* trackParamAtHit;
+ if (trackParam) {
+ trackParamAtHit = new ((*fTrackParamAtHit)[fNTrackHits]) AliMUONTrackParam(*trackParam);
+ if (hitForRec) {
+ if (hitForRec->GetZ() != trackParam->GetZ())
+ AliWarning("Added track parameters at a different z position than the one of the attached hit");
+ }
+ } else {
+ trackParamAtHit = new ((*fTrackParamAtHit)[fNTrackHits]) AliMUONTrackParam();
+ if (hitForRec) ((AliMUONTrackParam*) fTrackParamAtHit->UncheckedAt(fNTrackHits))->SetZ(hitForRec->GetZ());
+ }
+ if (hitForRec) trackParamAtHit->SetHitForRecPtr(hitForRec);
+ fNTrackHits++;
}
-AliMUONTrack & AliMUONTrack::operator=(const AliMUONTrack& MUONTrack)
+ //__________________________________________________________________________
+void AliMUONTrack::RemoveTrackParamAtHit(AliMUONTrackParam *trackParam)
{
-// Dummy assignment operator
- return *this;
+ /// Remove trackParam from the array of TrackParamAtHit
+ if (!fTrackParamAtHit) {
+ AliWarning("array fTrackParamAtHit does not exist");
+ return;
+ }
+
+ if (!fTrackParamAtHit->Remove(trackParam)) {
+ AliWarning("object to remove does not exist in array fTrackParamAtHit");
+ return;
+ }
+
+ fTrackParamAtHit->Compress();
+ fNTrackHits--;
}
-// Inline functions for Get and Set: inline removed because it does not work !!!!
-AliMUONTrackParam* AliMUONTrack::GetTrackParamAtVertex(void) {
- // Get pointer to fTrackParamAtVertex
- return &fTrackParamAtVertex;}
-AliMUONTrackParam* AliMUONTrack::GetTrackParamAtFirstHit(void) {
- // Get pointer to TrackParamAtFirstHit
- return ((AliMUONTrackHit*) (fTrackHitsPtr->First()))->GetTrackParam();}
-TClonesArray* AliMUONTrack::GetTrackHitsPtr(void) {
- // Get fTrackHitsPtr
- return fTrackHitsPtr;}
-Int_t AliMUONTrack::GetNTrackHits(void) {
- // Get fNTrackHits
- return fNTrackHits;}
+ //__________________________________________________________________________
+void AliMUONTrack::AddHitForRecAtHit(const AliMUONHitForRec *hitForRec)
+{
+ /// Add hitForRec to the array of hitForRec at hit
+ if (!fHitForRecAtHit)
+ fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
+
+ if (!hitForRec)
+ AliFatal("AliMUONTrack::AddHitForRecAtHit: hitForRec == NULL");
+
+ new ((*fHitForRecAtHit)[fHitForRecAtHit->GetEntriesFast()]) AliMUONHitForRec(*hitForRec);
+}
//__________________________________________________________________________
-void AliMUONTrack::RecursiveDump(void)
+void AliMUONTrack::UpdateTrackParamAtHit()
{
- // Recursive dump of AliMUONTrack, i.e. with dump of TrackHit's and HitForRec's
- AliMUONTrackHit *trackHit;
- AliMUONHitForRec *hitForRec;
- cout << "Recursive dump of Track: " << this << endl;
- // Track
- this->Dump();
- for (Int_t trackHitIndex = 0; trackHitIndex < fNTrackHits; trackHitIndex++) {
- trackHit = (AliMUONTrackHit*) ((*fTrackHitsPtr)[trackHitIndex]);
- // TrackHit
- cout << "TrackHit: " << trackHit << " (index: " << trackHitIndex << ")" << endl;
- trackHit->Dump();
- hitForRec = trackHit->GetHitForRecPtr();
- // HitForRec
- cout << "HitForRec: " << hitForRec << endl;
- hitForRec->Dump();
+ /// Update track parameters at each attached hit
+
+ if (fNTrackHits == 0) {
+ AliWarning("no hit attached to the track");
+ return;
}
- return;
+
+ Double_t z;
+ AliMUONTrackParam* startingTrackParam = (AliMUONTrackParam*) fTrackParamAtHit->First();
+ AliMUONTrackParam* trackParamAtHit = (AliMUONTrackParam*) fTrackParamAtHit->After(startingTrackParam);
+ while (trackParamAtHit) {
+
+ // save current z
+ z = trackParamAtHit->GetZ();
+
+ // reset track parameters and their covariances
+ trackParamAtHit->SetParameters(startingTrackParam->GetParameters());
+ trackParamAtHit->SetZ(startingTrackParam->GetZ());
+
+ // extrapolation to the given z
+ AliMUONTrackExtrap::ExtrapToZ(trackParamAtHit, z);
+
+ // prepare next step
+ startingTrackParam = trackParamAtHit;
+ trackParamAtHit = (AliMUONTrackParam*) (fTrackParamAtHit->After(trackParamAtHit));
+ }
+
}
//__________________________________________________________________________
-void AliMUONTrack::Fit(AliMUONTrackParam *TrackParam, Int_t NParam)
+void AliMUONTrack::UpdateCovTrackParamAtHit()
{
- // Fit the current track ("this"),
- // starting with track parameters pointed to by "TrackParam",
- // and with 3 or 5 parameters ("NParam"):
- // 3 if one keeps X and Y fixed in "TrackParam",
- // 5 if one lets them vary.
- if ((NParam != 3) && (NParam != 5)) {
- cout << "ERROR in AliMUONTrack::Fit, NParam = " << NParam;
- cout << " , i.e. neither 3 nor 5 ====> EXIT" << endl;
- exit(0); // right instruction for exit ????
- }
- Int_t error = 0;
- Double_t arg[1], benC, errorParam, invBenP, lower, nonBenC, upper, x, y;
- TString parName;
- TMinuit *minuit = new TMinuit(5);
- trackBeingFitted = this; // for the track to be known from the function to minimize
- trackParamBeingFitted = TrackParam; // for the track parameters to be known from the function to minimize; possible to use only Minuit parameters ????
- minuit->mninit(5, 10, 7); // sysrd, syswr, syssa: useful ????
- // how to go faster ???? choice of Minuit parameters like EDM ????
- minuit->SetFCN(TrackChi2);
- minuit->SetPrintLevel(1); // More printing !!!!
- // set first 3 parameters (try with no limits for the search: min=max=0)
- minuit->mnparm(0, "InvBenP",
- TrackParam->GetInverseBendingMomentum(),
- 0.003, 0.0, 0.0, error);
- minuit->mnparm(1, "BenS",
- TrackParam->GetBendingSlope(),
- 0.001, 0.0, 0.0, error);
- minuit->mnparm(2, "NonBenS",
- TrackParam->GetNonBendingSlope(),
- 0.001, 0.0, 0.0, error);
- if (NParam == 5) {
- // set last 2 parameters (try with no limits for the search: min=max=0)
- minuit->mnparm(3, "X",
- TrackParam->GetNonBendingCoor(),
- 0.03, 0.0, 0.0, error);
- minuit->mnparm(4, "Y",
- TrackParam->GetBendingCoor(),
- 0.10, 0.0, 0.0, error);
- }
- // search without gradient calculation in the function
- minuit->mnexcm("SET NOGRADIENT", arg, 0, error);
- // minimization
- minuit->mnexcm("MINIMIZE", arg, 0, error);
- // exit from Minuit
- minuit->mnexcm("EXIT", arg, 0, error); // necessary ????
- // print results
- minuit->mnpout(0, parName, invBenP, errorParam, lower, upper, error);
- minuit->mnpout(1, parName, benC, errorParam, lower, upper, error);
- minuit->mnpout(2, parName, nonBenC, errorParam, lower, upper, error);
- if (NParam == 5) {
- minuit->mnpout(3, parName, x, errorParam, lower, upper, error);
- minuit->mnpout(4, parName, y, errorParam, lower, upper, error);
- }
- // result of the fit into track parameters
- TrackParam->SetInverseBendingMomentum(invBenP);
- TrackParam->SetBendingSlope(benC);
- TrackParam->SetNonBendingSlope(nonBenC);
- if (NParam == 5) {
- TrackParam->SetNonBendingCoor(x);
- TrackParam->SetBendingCoor(y);
- }
- trackBeingFitted = NULL;
- delete minuit;
+ /// Update track parameters and their covariances at each attached hit
+
+ if (fNTrackHits == 0) {
+ AliWarning("no hit attached to the track");
+ return;
+ }
+
+ Double_t z;
+ AliMUONTrackParam* startingTrackParam = (AliMUONTrackParam*) fTrackParamAtHit->First();
+ AliMUONTrackParam* trackParamAtHit = (AliMUONTrackParam*) fTrackParamAtHit->After(startingTrackParam);
+ while (trackParamAtHit) {
+
+ // save current z
+ z = trackParamAtHit->GetZ();
+
+ // reset track parameters and their covariances
+ trackParamAtHit->SetParameters(startingTrackParam->GetParameters());
+ trackParamAtHit->SetZ(startingTrackParam->GetZ());
+ trackParamAtHit->SetCovariances(startingTrackParam->GetCovariances());
+
+ // extrapolation to the given z
+ AliMUONTrackExtrap::ExtrapToZCov(trackParamAtHit, z);
+
+ // prepare next step
+ startingTrackParam = trackParamAtHit;
+ trackParamAtHit = (AliMUONTrackParam*) (fTrackParamAtHit->After(trackParamAtHit));
+ }
+
}
//__________________________________________________________________________
-void AliMUONTrack::AddSegment(AliMUONSegment* Segment)
+void AliMUONTrack::SetVertex(const AliMUONHitForRec* vertex)
{
- // Add Segment
- AddHitForRec(Segment->GetHitForRec1()); // 1st hit
- AddHitForRec(Segment->GetHitForRec2()); // 2nd hit
+ /// Set the vertex used during the tracking procedure
+ if (!fVertex) fVertex = new AliMUONHitForRec(*vertex);
+ else *fVertex = *vertex;
}
+
//__________________________________________________________________________
-void AliMUONTrack::AddHitForRec(AliMUONHitForRec* HitForRec)
+Bool_t AliMUONTrack::ComputeLocalChi2(Bool_t accountForMCS)
{
- // Add HitForRec
- new ((*fTrackHitsPtr)[fNTrackHits]) AliMUONTrackHit(HitForRec);
- fNTrackHits++;
+ /// Compute the removable hit contribution to the chi2 of the track
+ /// accounting for multiple scattering or not according to the flag
+ /// - Also recompute the weight matrices of the attached hits if accountForMCS=kTRUE
+ /// - Assume that track parameters at each hit are corrects
+ /// - Return kFALSE if computation failed
+
+ // Check hits (if the first one exist, assume that the other ones exit too!)
+ AliMUONTrackParam* trackParamAtHit = (AliMUONTrackParam*) fTrackParamAtHit->First();
+ if (!trackParamAtHit->GetHitForRecPtr()) {
+ AliWarning("hit is missing");
+ return kFALSE;
+ }
+
+ if (accountForMCS) { // Compute local chi2 taking into account multiple scattering effects
+
+ // Compute MCS covariance matrix only once
+ TMatrixD mcsCovariances(AliMUONConstants::NTrackingCh(),AliMUONConstants::NTrackingCh());
+ ComputeMCSCovariances(mcsCovariances);
+
+ // Make sure hit weights are consistent with following calculations
+ if (!ComputeHitWeights(&mcsCovariances)) {
+ AliWarning("cannot take into account the multiple scattering effects");
+ return ComputeLocalChi2(kFALSE);
+ }
+
+ // Compute chi2 of the track
+ Double_t globalChi2 = ComputeGlobalChi2(kTRUE);
+ if (globalChi2 < 0.) return kFALSE;
+
+ // Loop over removable hits and compute their local chi2
+ AliMUONTrackParam* trackParamAtHit1;
+ AliMUONHitForRec *hitForRec, *discardedHit;
+ Int_t hitNumber1, hitNumber2, currentHitNumber1, currentHitNumber2;
+ TMatrixD hitWeightsNB(fNTrackHits-1,fNTrackHits-1);
+ TMatrixD hitWeightsB(fNTrackHits-1,fNTrackHits-1);
+ Double_t *dX = new Double_t[fNTrackHits-1];
+ Double_t *dY = new Double_t[fNTrackHits-1];
+ Double_t globalChi2b;
+ while (trackParamAtHit) {
+
+ discardedHit = trackParamAtHit->GetHitForRecPtr();
+
+ // Recompute hit weights without the current hit
+ if (!ComputeHitWeights(hitWeightsNB, hitWeightsB, &mcsCovariances, discardedHit)) {
+ AliWarning("cannot take into account the multiple scattering effects");
+ ComputeLocalChi2(kFALSE);
+ }
+
+ // Compute track chi2 without the current hit
+ globalChi2b = 0.;
+ currentHitNumber1 = 0;
+ for (hitNumber1 = 0; hitNumber1 < fNTrackHits ; hitNumber1++) {
+ trackParamAtHit1 = (AliMUONTrackParam*) fTrackParamAtHit->UncheckedAt(hitNumber1);
+ hitForRec = trackParamAtHit1->GetHitForRecPtr();
+
+ if (hitForRec == discardedHit) continue;
+
+ // Compute and save residuals
+ dX[currentHitNumber1] = hitForRec->GetNonBendingCoor() - trackParamAtHit1->GetNonBendingCoor();
+ dY[currentHitNumber1] = hitForRec->GetBendingCoor() - trackParamAtHit1->GetBendingCoor();
+
+ currentHitNumber2 = 0;
+ for (hitNumber2 = 0; hitNumber2 < hitNumber1; hitNumber2++) {
+ hitForRec = ((AliMUONTrackParam*) fTrackParamAtHit->UncheckedAt(hitNumber2))->GetHitForRecPtr();
+
+ if (hitForRec == discardedHit) continue;
+
+ // Add contribution from covariances
+ globalChi2b += (hitWeightsNB(currentHitNumber1, currentHitNumber2) +
+ hitWeightsNB(currentHitNumber2, currentHitNumber1)) * dX[currentHitNumber1] * dX[currentHitNumber2] +
+ (hitWeightsB(currentHitNumber1, currentHitNumber2) +
+ hitWeightsB(currentHitNumber2, currentHitNumber1)) * dY[currentHitNumber1] * dY[currentHitNumber2];
+
+ currentHitNumber2++;
+ }
+
+ // Add contribution from variances
+ globalChi2b += hitWeightsNB(currentHitNumber1, currentHitNumber1) * dX[currentHitNumber1] * dX[currentHitNumber1] +
+ hitWeightsB(currentHitNumber1, currentHitNumber1) * dY[currentHitNumber1] * dY[currentHitNumber1];
+
+ currentHitNumber1++;
+ }
+
+ // Set local chi2
+ trackParamAtHit->SetLocalChi2(globalChi2 - globalChi2b);
+
+ trackParamAtHit = (AliMUONTrackParam*) fTrackParamAtHit->After(trackParamAtHit);
+ }
+
+ delete [] dX;
+ delete [] dY;
+
+ } else { // without multiple scattering effects
+
+ AliMUONHitForRec *discardedHit;
+ Double_t dX, dY;
+ while (trackParamAtHit) {
+
+ // compute chi2 of removable hits only
+ if (!trackParamAtHit->IsRemovable()) {
+ trackParamAtHit = (AliMUONTrackParam*) fTrackParamAtHit->After(trackParamAtHit);
+ continue;
+ }
+
+ discardedHit = trackParamAtHit->GetHitForRecPtr();
+
+ // Compute residuals
+ dX = discardedHit->GetNonBendingCoor() - trackParamAtHit->GetNonBendingCoor();
+ dY = discardedHit->GetBendingCoor() - trackParamAtHit->GetBendingCoor();
+
+ // Set local chi2
+ trackParamAtHit->SetLocalChi2(dX * dX / discardedHit->GetNonBendingReso2() + dY * dY / discardedHit->GetBendingReso2());
+
+ trackParamAtHit = (AliMUONTrackParam*) fTrackParamAtHit->After(trackParamAtHit);
+ }
+
+ }
+
+
+ return kTRUE;
+
+}
+
+ //__________________________________________________________________________
+Double_t AliMUONTrack::ComputeGlobalChi2(Bool_t accountForMCS)
+{
+ /// Compute the chi2 of the track accounting for multiple scattering or not according to the flag
+ /// - Assume that track parameters at each hit are corrects
+ /// - Assume the hits weights matrices are corrects
+ /// - Return negative value if chi2 computation failed
+
+ // Check hits (if the first one exist, assume that the other ones exit too!)
+ AliMUONTrackParam* trackParamAtHit = (AliMUONTrackParam*) fTrackParamAtHit->First();
+ if (!trackParamAtHit->GetHitForRecPtr()) {
+ AliWarning("hit is missing");
+ return -1.;
+ }
+
+ Double_t chi2 = 0.;
+
+ if (accountForMCS) {
+
+ // Check the weight matrices
+ Bool_t weightsAvailable = kTRUE;
+ if (!fHitWeightsNonBending || !fHitWeightsBending) weightsAvailable = kFALSE;
+ else if (fHitWeightsNonBending->GetNrows() != fNTrackHits || fHitWeightsNonBending->GetNcols() != fNTrackHits ||
+ fHitWeightsBending->GetNrows() != fNTrackHits || fHitWeightsBending->GetNcols() != fNTrackHits) weightsAvailable = kFALSE;
+
+ // if weight matrices are not available compute chi2 without MCS
+ if (!weightsAvailable) {
+ AliWarning("hit weights including multiple scattering effects are not available\n\t\t --> compute chi2 WITHOUT multiple scattering");
+ return ComputeGlobalChi2(kFALSE);
+ }
+
+ // Compute chi2
+ AliMUONHitForRec *hitForRec;
+ Double_t *dX = new Double_t[fNTrackHits];
+ Double_t *dY = new Double_t[fNTrackHits];
+ Int_t hitNumber1, hitNumber2;
+ for (hitNumber1 = 0; hitNumber1 < fNTrackHits ; hitNumber1++) {
+ trackParamAtHit = (AliMUONTrackParam*) fTrackParamAtHit->UncheckedAt(hitNumber1);
+ hitForRec = trackParamAtHit->GetHitForRecPtr();
+ dX[hitNumber1] = hitForRec->GetNonBendingCoor() - trackParamAtHit->GetNonBendingCoor();
+ dY[hitNumber1] = hitForRec->GetBendingCoor() - trackParamAtHit->GetBendingCoor();
+ for (hitNumber2 = 0; hitNumber2 < hitNumber1; hitNumber2++) {
+ chi2 += ((*fHitWeightsNonBending)(hitNumber1, hitNumber2) + (*fHitWeightsNonBending)(hitNumber2, hitNumber1)) * dX[hitNumber1] * dX[hitNumber2] +
+ ((*fHitWeightsBending)(hitNumber1, hitNumber2) + (*fHitWeightsBending)(hitNumber2, hitNumber1)) * dY[hitNumber1] * dY[hitNumber2];
+ }
+ chi2 += ((*fHitWeightsNonBending)(hitNumber1, hitNumber1) * dX[hitNumber1] * dX[hitNumber1]) +
+ ((*fHitWeightsBending)(hitNumber1, hitNumber1) * dY[hitNumber1] * dY[hitNumber1]);
+ }
+ delete [] dX;
+ delete [] dY;
+
+ } else {
+
+ AliMUONHitForRec *hitForRec;
+ Double_t dX, dY;
+ for (Int_t hitNumber = 0; hitNumber < fNTrackHits ; hitNumber++) {
+ trackParamAtHit = (AliMUONTrackParam*) fTrackParamAtHit->UncheckedAt(hitNumber);
+ hitForRec = trackParamAtHit->GetHitForRecPtr();
+ dX = hitForRec->GetNonBendingCoor() - trackParamAtHit->GetNonBendingCoor();
+ dY = hitForRec->GetBendingCoor() - trackParamAtHit->GetBendingCoor();
+ chi2 += dX * dX / hitForRec->GetNonBendingReso2() + dY * dY / hitForRec->GetBendingReso2();
+ }
+
+ }
+
+ return chi2;
+
}
//__________________________________________________________________________
-void AliMUONTrack::SetTrackParamAtHit(Int_t indexHit, AliMUONTrackParam *TrackParam)
+Bool_t AliMUONTrack::ComputeHitWeights(TMatrixD* mcsCovariances)
{
- // Set track parameters at TrackHit with index "indexHit"
- // from the track parameters pointed to by "TrackParam".
- AliMUONTrackHit* trackHit = (AliMUONTrackHit*) ((*fTrackHitsPtr)[indexHit]);
- trackHit->SetTrackParam(TrackParam);
+ /// Compute the weight matrices of the attached hits, in non bending and bending direction,
+ /// accounting for multiple scattering correlations and hits resolution
+ /// - Use the provided MCS covariance matrix if any (otherwise build it temporarily)
+ /// - Assume that track parameters at each hit are corrects
+ /// - Return kFALSE if computation failed
+
+ // Alocate memory
+ if (!fHitWeightsNonBending) fHitWeightsNonBending = new TMatrixD(fNTrackHits,fNTrackHits);
+ if (!fHitWeightsBending) fHitWeightsBending = new TMatrixD(fNTrackHits,fNTrackHits);
+
+ // Check hits (if the first one exist, assume that the other ones exit too!)
+ if (!((AliMUONTrackParam*) fTrackParamAtHit->First())->GetHitForRecPtr()) {
+ AliWarning("hit is missing");
+ fHitWeightsNonBending->ResizeTo(0,0);
+ fHitWeightsBending->ResizeTo(0,0);
+ return kFALSE;
+ }
+
+ // Compute weights matrices
+ if (!ComputeHitWeights(*fHitWeightsNonBending, *fHitWeightsBending, mcsCovariances)) return kFALSE;
+
+ return kTRUE;
+
}
//__________________________________________________________________________
-void AliMUONTrack::SetTrackParamAtVertex()
+Bool_t AliMUONTrack::ComputeHitWeights(TMatrixD& hitWeightsNB, TMatrixD& hitWeightsB, TMatrixD* mcsCovariances, AliMUONHitForRec* discardedHit) const
{
- // 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 *trackParam =
- &fTrackParamAtVertex; // pointer to track parameters
- // Pointer to HitForRec of first TrackHit
- AliMUONHitForRec *firstHit =
- ((AliMUONTrackHit*) (fTrackHitsPtr->First()))->GetHitForRecPtr();
- // Pointer to HitForRec of last TrackHit
- AliMUONHitForRec *lastHit =
- ((AliMUONTrackHit*) (fTrackHitsPtr->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;
- trackParam->SetBendingSlope(bendingSlope);
- // impact parameter
- Double_t impactParam =
- firstHit->GetBendingCoor() - bendingSlope * firstHit->GetZ(); // same if from firstHit and lastHit ????
- // signed bending momentum
- Double_t signedBendingMomentum =
- fEventReconstructor->GetBendingMomentumFromImpactParam(impactParam);
- trackParam->SetInverseBendingMomentum(1.0 / signedBendingMomentum);
- // bending slope at vertex
- trackParam->
- SetBendingSlope(bendingSlope +
- impactParam / fEventReconstructor->GetSimpleBPosition());
- // non bending slope
- Double_t nonBendingSlope =
- (firstHit->GetNonBendingCoor() - lastHit->GetNonBendingCoor()) / deltaZ;
- trackParam->SetNonBendingSlope(nonBendingSlope);
- // vertex coordinates at (0,0,0)
- trackParam->SetZ(0.0);
- trackParam->SetBendingCoor(0.0);
- trackParam->SetNonBendingCoor(0.0);
+ /// Compute the weight matrices, in non bending and bending direction,
+ /// of the other attached hits assuming the discarded one does not exist
+ /// accounting for multiple scattering correlations and hits resolution
+ /// - Use the provided MCS covariance matrix if any (otherwise build it temporarily)
+ /// - Return kFALSE if computation failed
+
+ // Check MCS covariance matrix and recompute it if need
+ Bool_t deleteMCSCov = kFALSE;
+ if (!mcsCovariances) {
+
+ // build MCS covariance matrix
+ mcsCovariances = new TMatrixD(AliMUONConstants::NTrackingCh(),AliMUONConstants::NTrackingCh());
+ deleteMCSCov = kTRUE;
+ ComputeMCSCovariances(*mcsCovariances);
+
+ } else {
+
+ // check MCS covariance matrix size
+ if (mcsCovariances->GetNrows() != AliMUONConstants::NTrackingCh() || mcsCovariances->GetNcols() != AliMUONConstants::NTrackingCh()) {
+ ComputeMCSCovariances(*mcsCovariances);
+ }
+
+ }
+
+ // Resize the weights matrices; alocate memory
+ if (discardedHit) {
+ hitWeightsNB.ResizeTo(fNTrackHits-1,fNTrackHits-1);
+ hitWeightsB.ResizeTo(fNTrackHits-1,fNTrackHits-1);
+ } else {
+ hitWeightsNB.ResizeTo(fNTrackHits,fNTrackHits);
+ hitWeightsB.ResizeTo(fNTrackHits,fNTrackHits);
+ }
+
+ // Define variables
+ AliMUONHitForRec *hitForRec1, *hitForRec2;
+ Int_t chamber1, chamber2, currentHitNumber1, currentHitNumber2;
+
+ // Compute the covariance matrices
+ currentHitNumber1 = 0;
+ for (Int_t hitNumber1 = 0; hitNumber1 < fNTrackHits; hitNumber1++) {
+ hitForRec1 = ((AliMUONTrackParam*) fTrackParamAtHit->UncheckedAt(hitNumber1))->GetHitForRecPtr();
+
+ if (hitForRec1 == discardedHit) continue;
+
+ chamber1 = hitForRec1->GetChamberNumber();
+
+ // Loop over next hits
+ currentHitNumber2 = currentHitNumber1;
+ for (Int_t hitNumber2 = hitNumber1; hitNumber2 < fNTrackHits; hitNumber2++) {
+ hitForRec2 = ((AliMUONTrackParam*) fTrackParamAtHit->UncheckedAt(hitNumber2))->GetHitForRecPtr();
+
+ if (hitForRec2 == discardedHit) continue;
+
+ chamber2 = hitForRec2->GetChamberNumber();
+
+ // Fill with MCS covariances
+ hitWeightsNB(currentHitNumber1, currentHitNumber2) = (*mcsCovariances)(chamber1,chamber2);
+
+ // Equal contribution from multiple scattering in non bending and bending directions
+ hitWeightsB(currentHitNumber1, currentHitNumber2) = hitWeightsNB(currentHitNumber1, currentHitNumber2);
+
+ // Add contribution from hit resolution to diagonal element and symmetrize the matrix
+ if (currentHitNumber1 == currentHitNumber2) {
+
+ // In non bending plane
+ hitWeightsNB(currentHitNumber1, currentHitNumber1) += hitForRec1->GetNonBendingReso2();
+ // In bending plane
+ hitWeightsB(currentHitNumber1, currentHitNumber1) += hitForRec1->GetBendingReso2();
+
+ } else {
+
+ // In non bending plane
+ hitWeightsNB(currentHitNumber2, currentHitNumber1) = hitWeightsNB(currentHitNumber1, currentHitNumber2);
+ // In bending plane
+ hitWeightsB(currentHitNumber2, currentHitNumber1) = hitWeightsB(currentHitNumber1, currentHitNumber2);
+
+ }
+
+ currentHitNumber2++;
+ }
+
+ currentHitNumber1++;
+ }
+
+ // Inversion of covariance matrices to get the weights
+ if (hitWeightsNB.Determinant() != 0 && hitWeightsB.Determinant() != 0) {
+ hitWeightsNB.Invert();
+ hitWeightsB.Invert();
+ } else {
+ AliWarning(" Determinant = 0");
+ hitWeightsNB.ResizeTo(0,0);
+ hitWeightsB.ResizeTo(0,0);
+ if(deleteMCSCov) delete mcsCovariances;
+ return kFALSE;
+ }
+
+ if(deleteMCSCov) delete mcsCovariances;
+
+ return kTRUE;
+
}
//__________________________________________________________________________
-void TrackChi2(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag)
+void AliMUONTrack::ComputeMCSCovariances(TMatrixD& mcsCovariances) const
{
- // 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.
- AliMUONTrackHit* hit;
- AliMUONTrackParam param1;
- Int_t hitNumber;
- Double_t zHit;
- Chi2 = 0.0; // initialize Chi2
- // copy of track parameters to be fitted
- param1 = *trackParamBeingFitted;
- // 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
- for (hitNumber = 0; hitNumber < trackBeingFitted->GetNTrackHits(); hitNumber++) {
- hit = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber];
- zHit = hit->GetHitForRecPtr()->GetZ();
- // do something special if 2 hits with same Z ????
- // security against infinite loop ????
- (¶m1)->ExtrapToZ(zHit); // extrapolation
- hit->SetTrackParam(¶m1);
- // 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 =
- hit->GetHitForRecPtr()->GetNonBendingCoor() - (¶m1)->GetNonBendingCoor();
- Double_t dY =
- hit->GetHitForRecPtr()->GetBendingCoor() - (¶m1)->GetBendingCoor();
- Chi2 =
- Chi2 +
- dX * dX / hit->GetHitForRecPtr()->GetNonBendingReso2() +
- dY * dY / hit->GetHitForRecPtr()->GetBendingReso2();
+ /// Compute the multiple scattering covariance matrix
+ /// - Assume that track parameters at each hit are corrects
+ /// - Return kFALSE if computation failed
+
+ // Make sure the size of the covariance matrix is correct
+ Int_t nChambers = AliMUONConstants::NTrackingCh();
+ mcsCovariances.ResizeTo(nChambers,nChambers);
+
+ // check for too many track hits
+ if (fNTrackHits > nChambers) {
+ AliWarning("more than 1 hit per chamber!!");
+ mcsCovariances.Zero();
+ return;
}
+
+ // Define variables
+ AliMUONTrackParam* trackParamAtHit;
+ AliMUONHitForRec *hitForRec;
+ AliMUONTrackParam extrapTrackParam;
+ Int_t currentChamber, expectedChamber;
+ Double_t *mcsAngle2 = new Double_t[nChambers];
+ Double_t *zMCS = new Double_t[nChambers];
+
+ // Compute multiple scattering dispersion angle at each chamber
+ // and save the z position where it is calculated
+ currentChamber = 0;
+ expectedChamber = 0;
+ for (Int_t hitNumber = 0; hitNumber < fNTrackHits; hitNumber++) {
+ trackParamAtHit = (AliMUONTrackParam*) fTrackParamAtHit->UncheckedAt(hitNumber);
+ hitForRec = trackParamAtHit->GetHitForRecPtr();
+
+ // look for missing chambers if any
+ currentChamber = hitForRec->GetChamberNumber();
+ while (currentChamber > expectedChamber) {
+
+ // Save the z position where MCS dispersion is calculated
+ zMCS[expectedChamber] = AliMUONConstants::DefaultChamberZ(expectedChamber);
+
+ // Do not take into account MCS in chambers prior the first hit
+ if (hitNumber > 0) {
+
+ // Get track parameters at missing chamber z
+ extrapTrackParam = *trackParamAtHit;
+ AliMUONTrackExtrap::ExtrapToZ(&extrapTrackParam, zMCS[expectedChamber]);
+
+ // Save multiple scattering dispersion angle in missing chamber
+ mcsAngle2[expectedChamber] = AliMUONTrackExtrap::GetMCSAngle2(extrapTrackParam,AliMUONConstants::ChamberThicknessInX0(),1.);
+
+ } else mcsAngle2[expectedChamber] = 0.;
+
+ expectedChamber++;
+ }
+
+ // Save z position where MCS dispersion is calculated
+ zMCS[currentChamber] = trackParamAtHit->GetZ();
+
+ // Save multiple scattering dispersion angle in current chamber
+ mcsAngle2[currentChamber] = AliMUONTrackExtrap::GetMCSAngle2(*trackParamAtHit,AliMUONConstants::ChamberThicknessInX0(),1.);
+
+ expectedChamber++;
+ }
+
+ // complete array of z if last hit is on the last but one chamber
+ if (currentChamber != nChambers-1) zMCS[nChambers-1] = AliMUONConstants::DefaultChamberZ(nChambers-1);
+
+
+ // Compute the covariance matrix
+ for (Int_t chamber1 = 0; chamber1 < nChambers; chamber1++) {
+
+ for (Int_t chamber2 = chamber1; chamber2 < nChambers; chamber2++) {
+
+ // Initialization to 0 (diagonal plus upper triangular part)
+ mcsCovariances(chamber1, chamber2) = 0.;
+
+ // Compute contribution from multiple scattering in upstream chambers
+ for (currentChamber = 0; currentChamber < chamber1; currentChamber++) {
+ mcsCovariances(chamber1, chamber2) += (zMCS[chamber1] - zMCS[currentChamber]) * (zMCS[chamber2] - zMCS[currentChamber]) * mcsAngle2[currentChamber];
+ }
+
+ // Symetrize the matrix
+ mcsCovariances(chamber2, chamber1) = mcsCovariances(chamber1, chamber2);
+ }
+
+ }
+
+ delete [] mcsAngle2;
+ delete [] zMCS;
+
+}
+
+ //__________________________________________________________________________
+Int_t AliMUONTrack::HitsInCommon(AliMUONTrack* track) const
+{
+ /// Returns the number of hits in common between the current track ("this")
+ /// and the track pointed to by "track".
+ Int_t hitsInCommon = 0;
+ AliMUONTrackParam *trackParamAtHit1, *trackParamAtHit2;
+ // Loop over hits of first track
+ trackParamAtHit1 = (AliMUONTrackParam*) this->fTrackParamAtHit->First();
+ while (trackParamAtHit1) {
+ // Loop over hits of second track
+ trackParamAtHit2 = (AliMUONTrackParam*) track->fTrackParamAtHit->First();
+ while (trackParamAtHit2) {
+ // Increment "hitsInCommon" if both TrackParamAtHits point to the same HitForRec
+ if ((trackParamAtHit1->GetHitForRecPtr()) == (trackParamAtHit2->GetHitForRecPtr())) {
+ hitsInCommon++;
+ break;
+ }
+ trackParamAtHit2 = (AliMUONTrackParam*) track->fTrackParamAtHit->After(trackParamAtHit2);
+ } // trackParamAtHit2
+ trackParamAtHit1 = (AliMUONTrackParam*) this->fTrackParamAtHit->After(trackParamAtHit1);
+ } // trackParamAtHit1
+ return hitsInCommon;
+}
+
+ //__________________________________________________________________________
+Double_t AliMUONTrack::GetNormalizedChi2() const
+{
+ /// return the chi2 value divided by the number of degrees of freedom (or 1.e10 if ndf < 0)
+
+ Double_t numberOfDegFree = (2. * fNTrackHits - 5.);
+ if (numberOfDegFree > 0.) return fGlobalChi2 / numberOfDegFree;
+ else return 1.e10;
}
+
+ //__________________________________________________________________________
+Bool_t* AliMUONTrack::CompatibleTrack(AliMUONTrack * track, Double_t sigma2Cut) const
+{
+ /// Return kTRUE/kFALSE for each chamber if hit is compatible or not
+ TClonesArray *hitArray, *thisHitArray;
+ AliMUONHitForRec *hit, *thisHit;
+ Int_t chamberNumber;
+ Float_t deltaZ;
+ Float_t deltaZMax = 1.; // 1 cm
+ Float_t chi2 = 0;
+ Bool_t *nCompHit = new Bool_t[AliMUONConstants::NTrackingCh()];
+
+ for ( Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) {
+ nCompHit[ch] = kFALSE;
+ }
+
+ thisHitArray = this->GetHitForRecAtHit();
+
+ hitArray = track->GetHitForRecAtHit();
+
+ for (Int_t iHthis = 0; iHthis < thisHitArray->GetEntriesFast(); iHthis++) {
+ thisHit = (AliMUONHitForRec*) thisHitArray->At(iHthis);
+ chamberNumber = thisHit->GetChamberNumber();
+ if (chamberNumber < 0 || chamberNumber > AliMUONConstants::NTrackingCh()) continue;
+ nCompHit[chamberNumber] = kFALSE;
+ for (Int_t iH = 0; iH < hitArray->GetEntriesFast(); iH++) {
+ hit = (AliMUONHitForRec*) hitArray->At(iH);
+ deltaZ = TMath::Abs(thisHit->GetZ() - hit->GetZ());
+ chi2 = thisHit->NormalizedChi2WithHitForRec(hit,sigma2Cut); // set cut to 4 sigmas
+ if (chi2 < 3. && deltaZ < deltaZMax) {
+ nCompHit[chamberNumber] = kTRUE;
+ break;
+ }
+ }
+ }
+
+ return nCompHit;
+}
+
+ //__________________________________________________________________________
+void AliMUONTrack::RecursiveDump(void) const
+{
+ /// Recursive dump of AliMUONTrack, i.e. with dump of TrackParamAtHit's and attached HitForRec's
+ AliMUONTrackParam *trackParamAtHit;
+ AliMUONHitForRec *hitForRec;
+ cout << "Recursive dump of Track: " << this << endl;
+ // Track
+ this->Dump();
+ for (Int_t trackHitIndex = 0; trackHitIndex < fNTrackHits; trackHitIndex++) {
+ trackParamAtHit = (AliMUONTrackParam*) ((*fTrackParamAtHit)[trackHitIndex]);
+ // TrackHit
+ cout << "TrackParamAtHit: " << trackParamAtHit << " (index: " << trackHitIndex << ")" << endl;
+ trackParamAtHit->Dump();
+ hitForRec = trackParamAtHit->GetHitForRecPtr();
+ // HitForRec
+ cout << "HitForRec: " << hitForRec << endl;
+ hitForRec->Dump();
+ }
+ return;
+}
+
+//_____________________________________________-
+void AliMUONTrack::Print(Option_t*) const
+{
+ /// Printing Track information
+
+ cout << "<AliMUONTrack> No.Clusters=" << setw(2) << GetNTrackHits() <<
+ ", Match2Trig=" << setw(1) << GetMatchTrigger() <<
+ ", LoTrgNum=" << setw(3) << GetLoTrgNum() <<
+ ", Chi2-tracking-trigger=" << setw(8) << setprecision(5) << GetChi2MatchTrigger();
+ cout << Form(" HitTriggerPattern %x",fHitsPatternInTrigCh) << endl;
+ GetTrackParamAtHit()->First()->Print("FULL");
+}
+
+//__________________________________________________________________________
+void AliMUONTrack::SetLocalTrigger(Int_t loCirc, Int_t loStripX, Int_t loStripY, Int_t loDev, Int_t loLpt, Int_t loHpt)
+{
+ /// pack the local trigger information and store
+
+ if (loCirc < 0 || loCirc > 233) return;
+
+ fLocalTrigger = 0;
+ fLocalTrigger += loCirc;
+ fLocalTrigger += loStripX << 8;
+ fLocalTrigger += loStripY << 13;
+ fLocalTrigger += loDev << 17;
+ fLocalTrigger += loLpt << 22;
+ fLocalTrigger += loHpt << 24;
+
+}
+