1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
18 //-----------------------------------------------------------------------------
21 // Reconstructed track in ALICE dimuon spectrometer
22 //-----------------------------------------------------------------------------
24 #include "AliMUONTrack.h"
26 #include "AliMUONReconstructor.h"
27 #include "AliMUONVCluster.h"
28 #include "AliMUONVClusterStore.h"
29 #include "AliMUONObjectPair.h"
30 #include "AliMUONTrackExtrap.h"
31 #include "AliMUONConstants.h"
32 #include "AliMUONTrackParam.h"
38 #include <Riostream.h>
41 ClassImp(AliMUONTrack) // Class implementation in ROOT context
44 //__________________________________________________________________________
45 AliMUONTrack::AliMUONTrack()
47 fTrackParamAtCluster(0x0),
48 fFitWithVertex(kFALSE),
51 fClusterWeightsNonBending(0x0),
52 fClusterWeightsBending(0x0),
57 fChi2MatchTrigger(0.),
59 fTrackParamAtVertex(0x0),
60 fHitsPatternInTrigCh(0),
63 /// Default constructor
64 fVertexErrXY2[0] = 0.;
65 fVertexErrXY2[1] = 0.;
68 //__________________________________________________________________________
69 AliMUONTrack::AliMUONTrack(AliMUONObjectPair *segment, Double_t bendingVertexDispersion)
71 fTrackParamAtCluster(new TClonesArray("AliMUONTrackParam",10)),
72 fFitWithVertex(kFALSE),
75 fClusterWeightsNonBending(0x0),
76 fClusterWeightsBending(0x0),
81 fChi2MatchTrigger(0.),
83 fTrackParamAtVertex(0x0),
84 fHitsPatternInTrigCh(0),
87 /// Constructor from two clusters
89 fVertexErrXY2[0] = 0.;
90 fVertexErrXY2[1] = 0.;
92 // Pointers to clusters from the segment
93 AliMUONVCluster* firstCluster = (AliMUONVCluster*) segment->First();
94 AliMUONVCluster* lastCluster = (AliMUONVCluster*) segment->Second();
96 // Compute track parameters
97 Double_t z1 = firstCluster->GetZ();
98 Double_t z2 = lastCluster->GetZ();
99 Double_t dZ = z1 - z2;
101 Double_t nonBendingCoor1 = firstCluster->GetX();
102 Double_t nonBendingCoor2 = lastCluster->GetX();
103 Double_t nonBendingSlope = (nonBendingCoor1 - nonBendingCoor2) / dZ;
105 Double_t bendingCoor1 = firstCluster->GetY();
106 Double_t bendingCoor2 = lastCluster->GetY();
107 Double_t bendingSlope = (bendingCoor1 - bendingCoor2) / dZ;
108 // Inverse bending momentum
109 Double_t bendingImpact = bendingCoor1 - z1 * bendingSlope;
110 Double_t inverseBendingMomentum = 1. / AliMUONTrackExtrap::GetBendingMomentumFromImpactParam(bendingImpact);
112 // Set track parameters at first cluster
113 AliMUONTrackParam trackParamAtFirstCluster;
114 trackParamAtFirstCluster.SetZ(z1);
115 trackParamAtFirstCluster.SetNonBendingCoor(nonBendingCoor1);
116 trackParamAtFirstCluster.SetNonBendingSlope(nonBendingSlope);
117 trackParamAtFirstCluster.SetBendingCoor(bendingCoor1);
118 trackParamAtFirstCluster.SetBendingSlope(bendingSlope);
119 trackParamAtFirstCluster.SetInverseBendingMomentum(inverseBendingMomentum);
121 // Set track parameters at last cluster
122 AliMUONTrackParam trackParamAtLastCluster;
123 trackParamAtLastCluster.SetZ(z2);
124 trackParamAtLastCluster.SetNonBendingCoor(nonBendingCoor2);
125 trackParamAtLastCluster.SetNonBendingSlope(nonBendingSlope);
126 trackParamAtLastCluster.SetBendingCoor(bendingCoor2);
127 trackParamAtLastCluster.SetBendingSlope(bendingSlope);
128 trackParamAtLastCluster.SetInverseBendingMomentum(inverseBendingMomentum);
130 // Compute and set track parameters covariances at first cluster
131 TMatrixD paramCov(5,5);
134 paramCov(0,0) = firstCluster->GetErrX2();
135 paramCov(0,1) = firstCluster->GetErrX2() / dZ;
136 paramCov(1,0) = paramCov(0,1);
137 paramCov(1,1) = ( firstCluster->GetErrX2() + lastCluster->GetErrX2() ) / dZ / dZ;
139 paramCov(2,2) = firstCluster->GetErrY2();
140 paramCov(2,3) = firstCluster->GetErrY2() / dZ;
141 paramCov(3,2) = paramCov(2,3);
142 paramCov(3,3) = ( firstCluster->GetErrY2() + lastCluster->GetErrY2() ) / dZ / dZ;
143 // Inverse bending momentum (vertex resolution + bending slope resolution + 10% error on dipole parameters+field)
144 paramCov(4,4) = ( ( bendingVertexDispersion*bendingVertexDispersion +
145 (z1 * z1 * lastCluster->GetErrY2() + z2 * z2 * firstCluster->GetErrY2()) / dZ / dZ) /
146 bendingImpact / bendingImpact + 0.1 * 0.1) * inverseBendingMomentum * inverseBendingMomentum ;
147 paramCov(2,4) = - z2 * firstCluster->GetErrY2() * inverseBendingMomentum / bendingImpact / dZ;
148 paramCov(4,2) = paramCov(2,4);
149 paramCov(3,4) = - (z1 * lastCluster->GetErrY2() + z2 * firstCluster->GetErrY2()) * inverseBendingMomentum / bendingImpact / dZ / dZ;
150 paramCov(4,3) = paramCov(3,4);
153 trackParamAtFirstCluster.SetCovariances(paramCov);
155 // Compute and set track parameters covariances at last cluster
156 paramCov(1,0) = - paramCov(1,0);
157 paramCov(0,1) = - paramCov(0,1);
158 paramCov(3,2) = - paramCov(3,2);
159 paramCov(2,3) = - paramCov(2,3);
160 paramCov(2,4) = z1 * lastCluster->GetErrY2() * inverseBendingMomentum / bendingImpact / dZ;
161 paramCov(4,2) = paramCov(2,4);
162 trackParamAtLastCluster.SetCovariances(paramCov);
164 // Add track parameters at clusters
165 AddTrackParamAtCluster(trackParamAtFirstCluster,*firstCluster);
166 AddTrackParamAtCluster(trackParamAtLastCluster,*lastCluster);
170 //__________________________________________________________________________
171 AliMUONTrack::AliMUONTrack(const AliMUONTrack& track)
173 fTrackParamAtCluster(0x0),
174 fFitWithVertex(track.fFitWithVertex),
176 fFitWithMCS(track.fFitWithMCS),
177 fClusterWeightsNonBending(0x0),
178 fClusterWeightsBending(0x0),
179 fGlobalChi2(track.fGlobalChi2),
180 fImproved(track.fImproved),
181 fMatchTrigger(track.fMatchTrigger),
182 floTrgNum(track.floTrgNum),
183 fChi2MatchTrigger(track.fChi2MatchTrigger),
184 fTrackID(track.fTrackID),
185 fTrackParamAtVertex(0x0),
186 fHitsPatternInTrigCh(track.fHitsPatternInTrigCh),
187 fLocalTrigger(track.fLocalTrigger)
191 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
192 if (track.fTrackParamAtCluster) {
193 fTrackParamAtCluster = new TClonesArray("AliMUONTrackParam",10);
194 AliMUONTrackParam *trackParamAtCluster = (AliMUONTrackParam*) track.fTrackParamAtCluster->First();
195 while (trackParamAtCluster) {
196 new ((*fTrackParamAtCluster)[GetNClusters()]) AliMUONTrackParam(*trackParamAtCluster);
197 trackParamAtCluster = (AliMUONTrackParam*) track.fTrackParamAtCluster->After(trackParamAtCluster);
201 // copy vertex resolution square used during the tracking procedure
202 fVertexErrXY2[0] = track.fVertexErrXY2[0];
203 fVertexErrXY2[1] = track.fVertexErrXY2[1];
205 // copy cluster weights matrices if any
206 if (track.fClusterWeightsNonBending) fClusterWeightsNonBending = new TMatrixD(*(track.fClusterWeightsNonBending));
207 if (track.fClusterWeightsBending) fClusterWeightsBending = new TMatrixD(*(track.fClusterWeightsBending));
209 // copy track parameters at vertex if any
210 if (track.fTrackParamAtVertex) fTrackParamAtVertex = new AliMUONTrackParam(*(track.fTrackParamAtVertex));
214 //__________________________________________________________________________
215 AliMUONTrack & AliMUONTrack::operator=(const AliMUONTrack& track)
217 /// Asignment operator
218 // check assignement to self
222 // base class assignement
223 TObject::operator=(track);
228 // necessary to make a copy of the objects and not only the pointers in TClonesArray
229 if (track.fTrackParamAtCluster) {
230 fTrackParamAtCluster = new TClonesArray("AliMUONTrackParam",10);
231 AliMUONTrackParam *trackParamAtCluster = (AliMUONTrackParam*) track.fTrackParamAtCluster->First();
232 while (trackParamAtCluster) {
233 new ((*fTrackParamAtCluster)[GetNClusters()]) AliMUONTrackParam(*trackParamAtCluster);
234 trackParamAtCluster = (AliMUONTrackParam*) track.fTrackParamAtCluster->After(trackParamAtCluster);
238 // copy cluster weights matrix if any
239 if (track.fClusterWeightsNonBending) {
240 if (fClusterWeightsNonBending) {
241 fClusterWeightsNonBending->ResizeTo(*(track.fClusterWeightsNonBending));
242 *fClusterWeightsNonBending = *(track.fClusterWeightsNonBending);
243 } else fClusterWeightsNonBending = new TMatrixD(*(track.fClusterWeightsNonBending));
246 // copy cluster weights matrix if any
247 if (track.fClusterWeightsBending) {
248 if (fClusterWeightsBending) {
249 fClusterWeightsBending->ResizeTo(*(track.fClusterWeightsBending));
250 *fClusterWeightsBending = *(track.fClusterWeightsBending);
251 } else fClusterWeightsBending = new TMatrixD(*(track.fClusterWeightsBending));
254 // copy track parameters at vertex if any
255 if (track.fTrackParamAtVertex) {
256 if (fTrackParamAtVertex) *fTrackParamAtVertex = *(track.fTrackParamAtVertex);
257 else fTrackParamAtVertex = new AliMUONTrackParam(*(track.fTrackParamAtVertex));
260 fFitWithVertex = track.fFitWithVertex;
261 fVertexErrXY2[0] = track.fVertexErrXY2[0];
262 fVertexErrXY2[1] = track.fVertexErrXY2[1];
263 fFitWithMCS = track.fFitWithMCS;
264 fGlobalChi2 = track.fGlobalChi2;
265 fImproved = track.fImproved;
266 fMatchTrigger = track.fMatchTrigger;
267 floTrgNum = track.floTrgNum;
268 fChi2MatchTrigger = track.fChi2MatchTrigger;
269 fTrackID = track.fTrackID;
270 fHitsPatternInTrigCh = track.fHitsPatternInTrigCh;
271 fLocalTrigger = track.fLocalTrigger;
276 //__________________________________________________________________________
277 AliMUONTrack::~AliMUONTrack()
280 delete fTrackParamAtCluster;
281 delete fClusterWeightsNonBending;
282 delete fClusterWeightsBending;
283 delete fTrackParamAtVertex;
286 //__________________________________________________________________________
287 void AliMUONTrack::Clear(Option_t* opt)
290 if (opt && opt[0] == 'C' && fTrackParamAtCluster) fTrackParamAtCluster->Clear("C");
292 delete fTrackParamAtCluster;
293 fTrackParamAtCluster = 0x0;
295 delete fClusterWeightsNonBending; fClusterWeightsNonBending = 0x0;
296 delete fClusterWeightsBending; fClusterWeightsBending = 0x0;
297 delete fTrackParamAtVertex; fTrackParamAtVertex = 0x0;
300 //__________________________________________________________________________
301 void AliMUONTrack::Reset()
303 /// Reset to default values
305 fFitWithVertex = kFALSE;
306 fVertexErrXY2[0] = 0.;
307 fVertexErrXY2[1] = 0.;
308 fFitWithMCS = kFALSE;
313 fChi2MatchTrigger = 0.;
315 fHitsPatternInTrigCh = 0;
317 delete fTrackParamAtCluster; fTrackParamAtCluster = 0x0;
318 delete fClusterWeightsNonBending; fClusterWeightsNonBending = 0x0;
319 delete fClusterWeightsBending; fClusterWeightsBending = 0x0;
320 delete fTrackParamAtVertex; fTrackParamAtVertex = 0x0;
323 //__________________________________________________________________________
324 TClonesArray* AliMUONTrack::GetTrackParamAtCluster() const
326 /// return array of track parameters at cluster (create it if needed)
327 if (!fTrackParamAtCluster) fTrackParamAtCluster = new TClonesArray("AliMUONTrackParam",10);
328 return fTrackParamAtCluster;
331 //__________________________________________________________________________
332 void AliMUONTrack::AddTrackParamAtCluster(const AliMUONTrackParam &trackParam, AliMUONVCluster &cluster, Bool_t copy)
334 /// Copy given track parameters into a new TrackParamAtCluster
335 /// Link parameters with the associated cluster
336 /// If copy=kTRUE: the cluster is copied then passed the trackParam which become its owner
337 /// otherwise: make sure to do not delete the cluster until it is used by the track
339 // check chamber ID of the associated cluster
340 if (cluster.GetChamberId() < 0 || cluster.GetChamberId() > AliMUONConstants::NTrackingCh()) {
341 AliError(Form("Chamber ID of the associated cluster is not valid (ChamberId=%d)",cluster.GetChamberId()));
345 // check whether track parameters are given at the correct cluster z position
346 if (cluster.GetZ() != trackParam.GetZ()) {
347 AliError("track parameters are given at a different z position than the one of the associated cluster");
351 // add parameters to the array of track parameters
352 if (!fTrackParamAtCluster) fTrackParamAtCluster = new TClonesArray("AliMUONTrackParam",10);
353 AliMUONTrackParam* trackParamAtCluster = new ((*fTrackParamAtCluster)[GetNClusters()]) AliMUONTrackParam(trackParam);
355 // link parameters with the associated cluster or its copy
357 AliMUONVCluster *clusterCopy = static_cast<AliMUONVCluster*>(cluster.Clone());
358 trackParamAtCluster->SetClusterPtr(clusterCopy, kTRUE);
359 } else trackParamAtCluster->SetClusterPtr(&cluster);
361 // sort the array of track parameters
362 fTrackParamAtCluster->Sort();
365 //__________________________________________________________________________
366 void AliMUONTrack::RemoveTrackParamAtCluster(AliMUONTrackParam *trackParam)
368 /// Remove trackParam from the array of TrackParamAtCluster
369 if (!fTrackParamAtCluster || !fTrackParamAtCluster->Remove(trackParam)) {
370 AliWarning("object to remove does not exist in array fTrackParamAtCluster");
374 fTrackParamAtCluster->Compress();
377 //__________________________________________________________________________
378 void AliMUONTrack::UpdateTrackParamAtCluster()
380 /// Update track parameters at each attached cluster
382 if (GetNClusters() == 0) {
383 AliWarning("no cluster attached to the track");
387 AliMUONTrackParam* startingTrackParam = (AliMUONTrackParam*) fTrackParamAtCluster->First();
388 AliMUONTrackParam* trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->After(startingTrackParam);
389 while (trackParamAtCluster) {
391 // reset track parameters and their covariances
392 trackParamAtCluster->SetParameters(startingTrackParam->GetParameters());
393 trackParamAtCluster->SetZ(startingTrackParam->GetZ());
395 // extrapolation to the given z
396 AliMUONTrackExtrap::ExtrapToZ(trackParamAtCluster, trackParamAtCluster->GetClusterPtr()->GetZ());
399 startingTrackParam = trackParamAtCluster;
400 trackParamAtCluster = (AliMUONTrackParam*) (fTrackParamAtCluster->After(trackParamAtCluster));
405 //__________________________________________________________________________
406 void AliMUONTrack::UpdateCovTrackParamAtCluster()
408 /// Update track parameters and their covariances at each attached cluster
409 /// Include effects of multiple scattering in chambers
411 if (GetNClusters() == 0) {
412 AliWarning("no cluster attached to the track");
416 AliMUONTrackParam* startingTrackParam = (AliMUONTrackParam*) fTrackParamAtCluster->First();
417 AliMUONTrackParam* trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->After(startingTrackParam);
418 Int_t expectedChamber = startingTrackParam->GetClusterPtr()->GetChamberId() + 1;
419 Int_t currentChamber;
420 while (trackParamAtCluster) {
422 // reset track parameters and their covariances
423 trackParamAtCluster->SetParameters(startingTrackParam->GetParameters());
424 trackParamAtCluster->SetZ(startingTrackParam->GetZ());
425 trackParamAtCluster->SetCovariances(startingTrackParam->GetCovariances());
428 AliMUONTrackExtrap::AddMCSEffect(trackParamAtCluster,AliMUONConstants::ChamberThicknessInX0(),1.);
430 // add MCS in missing chambers if any
431 currentChamber = trackParamAtCluster->GetClusterPtr()->GetChamberId();
432 while (currentChamber > expectedChamber) {
433 // extrapolation to the missing chamber
434 AliMUONTrackExtrap::ExtrapToZCov(trackParamAtCluster, AliMUONConstants::DefaultChamberZ(expectedChamber));
436 AliMUONTrackExtrap::AddMCSEffect(trackParamAtCluster,AliMUONConstants::ChamberThicknessInX0(),1.);
440 // extrapolation to the z of the current cluster
441 AliMUONTrackExtrap::ExtrapToZCov(trackParamAtCluster, trackParamAtCluster->GetClusterPtr()->GetZ());
444 expectedChamber = currentChamber + 1;
445 startingTrackParam = trackParamAtCluster;
446 trackParamAtCluster = (AliMUONTrackParam*) (fTrackParamAtCluster->After(trackParamAtCluster));
451 //__________________________________________________________________________
452 Bool_t AliMUONTrack::IsValid(UInt_t requestedStationMask)
454 /// check the validity of the current track:
455 /// at least one cluster per requested station
456 /// and at least 2 chambers in stations 4 & 5 that contain cluster(s)
458 Int_t nClusters = GetNClusters();
459 AliMUONTrackParam *trackParam;
460 Int_t currentCh, currentSt, previousCh = -1, nChHitInSt45 = 0;
461 UInt_t presentStationMask(0);
463 // first loop over clusters
464 for (Int_t i = 0; i < nClusters; i++) {
465 trackParam = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(i);
467 currentCh = trackParam->GetClusterPtr()->GetChamberId();
468 currentSt = currentCh/2;
470 // build present station mask
471 presentStationMask |= ( 1 << currentSt );
473 // count the number of chambers in station 4 & 5 that contain cluster(s)
474 if (currentCh > 5 && currentCh != previousCh) {
476 previousCh = currentCh;
481 return (((requestedStationMask & presentStationMask) == requestedStationMask) && (nChHitInSt45 >= 2));
484 //__________________________________________________________________________
485 void AliMUONTrack::TagRemovableClusters(UInt_t requestedStationMask) {
486 /// Identify clusters that can be removed from the track,
487 /// with the only requirements to have at least 1 cluster per requested station
488 /// and at least 2 chambers over 4 in stations 4 & 5 that contain cluster(s)
490 Int_t nClusters = GetNClusters();
491 AliMUONTrackParam *trackParam, *nextTrackParam;
492 Int_t currentCh, nextCh, currentSt, nextSt, previousCh = -1, nChHitInSt45 = 0;
494 // first loop over clusters
495 for (Int_t i = 0; i < nClusters; i++) {
496 trackParam = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(i);
498 currentCh = trackParam->GetClusterPtr()->GetChamberId();
499 currentSt = currentCh/2;
501 // reset flags to kFALSE for all clusters in required station
502 if ((1 << currentSt) & requestedStationMask) trackParam->SetRemovable(kFALSE);
503 else trackParam->SetRemovable(kTRUE);
505 // count the number of chambers in station 4 & 5 that contain cluster(s)
506 if (currentCh > 5 && currentCh != previousCh) {
508 previousCh = currentCh;
513 // second loop over clusters
514 for (Int_t i = 0; i < nClusters; i++) {
515 trackParam = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(i);
517 currentCh = trackParam->GetClusterPtr()->GetChamberId();
518 currentSt = currentCh/2;
520 // make sure they are more than 2 clusters in 2 different chambers of stations 4 & 5
521 // but 2 clusters in he same chamber will still be flagged as removable
522 if (nChHitInSt45 < 3 && currentSt > 2) {
524 if (i == nClusters-1) {
526 trackParam->SetRemovable(kFALSE);
530 nextTrackParam = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(i+1);
531 nextCh = nextTrackParam->GetClusterPtr()->GetChamberId();
533 // set clusters in the same chamber as being removable
534 if (nextCh == currentCh) {
535 trackParam->SetRemovable(kTRUE);
536 nextTrackParam->SetRemovable(kTRUE);
537 i++; // skip cluster already checked
539 trackParam->SetRemovable(kFALSE);
546 // skip clusters already flag as removable
547 if (trackParam->IsRemovable()) continue;
549 // loop over next track parameters
550 for (Int_t j = i+1; j < nClusters; j++) {
551 nextTrackParam = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(j);
553 nextCh = nextTrackParam->GetClusterPtr()->GetChamberId();
556 // set clusters in the same station as being removable
557 if (nextSt == currentSt) {
558 trackParam->SetRemovable(kTRUE);
559 nextTrackParam->SetRemovable(kTRUE);
560 i++; // skip cluster already checked
571 //__________________________________________________________________________
572 Bool_t AliMUONTrack::ComputeLocalChi2(Bool_t accountForMCS)
574 /// Compute each cluster contribution to the chi2 of the track
575 /// accounting for multiple scattering or not according to the flag
576 /// - Also recompute the weight matrices of the attached clusters if accountForMCS=kTRUE
577 /// - Assume that track parameters at each cluster are corrects
578 /// - Return kFALSE if computation failed
579 AliDebug(1,"Enter ComputeLocalChi2");
581 if (!fTrackParamAtCluster) {
582 AliWarning("no cluster attached to this track");
586 if (accountForMCS) { // Compute local chi2 taking into account multiple scattering effects
588 // Compute MCS covariance matrix only once
589 Int_t nClusters = GetNClusters();
590 TMatrixD mcsCovariances(nClusters,nClusters);
591 ComputeMCSCovariances(mcsCovariances);
593 // Make sure cluster weights are consistent with following calculations
594 if (!ComputeClusterWeights(&mcsCovariances)) {
595 AliWarning("cannot take into account the multiple scattering effects");
596 return ComputeLocalChi2(kFALSE);
599 // Compute chi2 of the track
600 Double_t globalChi2 = ComputeGlobalChi2(kTRUE);
601 if (globalChi2 < 0.) return kFALSE;
603 // Loop over removable clusters and compute their local chi2
604 AliMUONTrackParam* trackParamAtCluster1;
605 AliMUONVCluster *cluster, *discardedCluster;
606 Int_t iCluster1, iCluster2, iCurrentCluster1, iCurrentCluster2;
607 TMatrixD clusterWeightsNB(nClusters-1,nClusters-1);
608 TMatrixD clusterWeightsB(nClusters-1,nClusters-1);
609 Double_t *dX = new Double_t[nClusters-1];
610 Double_t *dY = new Double_t[nClusters-1];
611 Double_t globalChi2b;
612 AliMUONTrackParam* trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->First();
613 while (trackParamAtCluster) {
615 discardedCluster = trackParamAtCluster->GetClusterPtr();
617 // Recompute cluster weights without the current cluster
618 if (!ComputeClusterWeights(clusterWeightsNB, clusterWeightsB, &mcsCovariances, discardedCluster)) {
619 AliWarning("cannot take into account the multiple scattering effects");
622 return ComputeLocalChi2(kFALSE);
625 // Compute track chi2 without the current cluster
627 iCurrentCluster1 = 0;
628 for (iCluster1 = 0; iCluster1 < nClusters ; iCluster1++) {
629 trackParamAtCluster1 = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster1);
630 cluster = trackParamAtCluster1->GetClusterPtr();
632 if (cluster == discardedCluster) continue;
634 // Compute and save residuals
635 dX[iCurrentCluster1] = cluster->GetX() - trackParamAtCluster1->GetNonBendingCoor();
636 dY[iCurrentCluster1] = cluster->GetY() - trackParamAtCluster1->GetBendingCoor();
638 iCurrentCluster2 = 0;
639 for (iCluster2 = 0; iCluster2 < iCluster1; iCluster2++) {
640 cluster = ((AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster2))->GetClusterPtr();
642 if (cluster == discardedCluster) continue;
644 // Add contribution from covariances
645 globalChi2b += (clusterWeightsNB(iCurrentCluster1, iCurrentCluster2) +
646 clusterWeightsNB(iCurrentCluster2, iCurrentCluster1)) * dX[iCurrentCluster1] * dX[iCurrentCluster2] +
647 (clusterWeightsB(iCurrentCluster1, iCurrentCluster2) +
648 clusterWeightsB(iCurrentCluster2, iCurrentCluster1)) * dY[iCurrentCluster1] * dY[iCurrentCluster2];
653 // Add contribution from variances
654 globalChi2b += clusterWeightsNB(iCurrentCluster1, iCurrentCluster1) * dX[iCurrentCluster1] * dX[iCurrentCluster1] +
655 clusterWeightsB(iCurrentCluster1, iCurrentCluster1) * dY[iCurrentCluster1] * dY[iCurrentCluster1];
661 trackParamAtCluster->SetLocalChi2(globalChi2 - globalChi2b);
663 trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->After(trackParamAtCluster);
669 } else { // without multiple scattering effects
671 AliMUONVCluster *discardedCluster;
673 AliMUONTrackParam* trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->First();
674 while (trackParamAtCluster) {
676 discardedCluster = trackParamAtCluster->GetClusterPtr();
679 dX = discardedCluster->GetX() - trackParamAtCluster->GetNonBendingCoor();
680 dY = discardedCluster->GetY() - trackParamAtCluster->GetBendingCoor();
683 trackParamAtCluster->SetLocalChi2(dX * dX / discardedCluster->GetErrX2() + dY * dY / discardedCluster->GetErrY2());
685 trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->After(trackParamAtCluster);
694 //__________________________________________________________________________
695 Double_t AliMUONTrack::ComputeGlobalChi2(Bool_t accountForMCS)
697 /// Compute the chi2 of the track accounting for multiple scattering or not according to the flag
698 /// - Assume that track parameters at each cluster are corrects
699 /// - Assume the cluster weights matrices are corrects
700 /// - Return negative value if chi2 computation failed
701 AliDebug(1,"Enter ComputeGlobalChi2");
703 if (!fTrackParamAtCluster) {
704 AliWarning("no cluster attached to this track");
712 // Check the weight matrices. If weight matrices are not available compute chi2 without MCS
713 if (!fClusterWeightsNonBending || !fClusterWeightsBending) {
714 AliWarning("cluster weights including multiple scattering effects are not available\n\t\t --> compute chi2 WITHOUT multiple scattering");
715 return ComputeGlobalChi2(kFALSE);
717 Int_t nClusters = GetNClusters();
718 if (fClusterWeightsNonBending->GetNrows() != nClusters || fClusterWeightsBending->GetNcols() != nClusters) {
719 AliWarning("cluster weights including multiple scattering effects are not available\n\t\t --> compute chi2 WITHOUT multiple scattering");
720 return ComputeGlobalChi2(kFALSE);
724 AliMUONVCluster *cluster;
725 Double_t *dX = new Double_t[nClusters];
726 Double_t *dY = new Double_t[nClusters];
727 AliMUONTrackParam* trackParamAtCluster;
728 for (Int_t iCluster1 = 0; iCluster1 < nClusters; iCluster1++) {
729 trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster1);
730 cluster = trackParamAtCluster->GetClusterPtr();
731 dX[iCluster1] = cluster->GetX() - trackParamAtCluster->GetNonBendingCoor();
732 dY[iCluster1] = cluster->GetY() - trackParamAtCluster->GetBendingCoor();
733 for (Int_t iCluster2 = 0; iCluster2 < iCluster1; iCluster2++) {
734 chi2 += ((*fClusterWeightsNonBending)(iCluster1, iCluster2) + (*fClusterWeightsNonBending)(iCluster2, iCluster1)) * dX[iCluster1] * dX[iCluster2] +
735 ((*fClusterWeightsBending)(iCluster1, iCluster2) + (*fClusterWeightsBending)(iCluster2, iCluster1)) * dY[iCluster1] * dY[iCluster2];
737 chi2 += ((*fClusterWeightsNonBending)(iCluster1, iCluster1) * dX[iCluster1] * dX[iCluster1]) +
738 ((*fClusterWeightsBending)(iCluster1, iCluster1) * dY[iCluster1] * dY[iCluster1]);
745 AliMUONVCluster *cluster;
747 AliMUONTrackParam* trackParamAtCluster;
748 Int_t nClusters = GetNClusters();
749 for (Int_t iCluster = 0; iCluster < nClusters ; iCluster++) {
750 trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster);
751 cluster = trackParamAtCluster->GetClusterPtr();
752 dX = cluster->GetX() - trackParamAtCluster->GetNonBendingCoor();
753 dY = cluster->GetY() - trackParamAtCluster->GetBendingCoor();
754 chi2 += dX * dX / cluster->GetErrX2() + dY * dY / cluster->GetErrY2();
763 //__________________________________________________________________________
764 Bool_t AliMUONTrack::ComputeClusterWeights(TMatrixD* mcsCovariances)
766 /// Compute the weight matrices of the attached clusters, in non bending and bending direction,
767 /// accounting for multiple scattering correlations and cluster resolution
768 /// - Use the provided MCS covariance matrix if any (otherwise build it temporarily)
769 /// - Assume that track parameters at each cluster are corrects
770 /// - Return kFALSE if computation failed
771 AliDebug(1,"Enter ComputeClusterWeights1");
773 if (!fTrackParamAtCluster) {
774 AliWarning("no cluster attached to this track");
779 Int_t nClusters = GetNClusters();
780 if (!fClusterWeightsNonBending) fClusterWeightsNonBending = new TMatrixD(nClusters,nClusters);
781 if (!fClusterWeightsBending) fClusterWeightsBending = new TMatrixD(nClusters,nClusters);
783 // Compute weights matrices
784 if (!ComputeClusterWeights(*fClusterWeightsNonBending, *fClusterWeightsBending, mcsCovariances)) return kFALSE;
790 //__________________________________________________________________________
791 Bool_t AliMUONTrack::ComputeClusterWeights(TMatrixD& clusterWeightsNB, TMatrixD& clusterWeightsB,
792 TMatrixD* mcsCovariances, AliMUONVCluster* discardedCluster) const
794 /// Compute the weight matrices, in non bending and bending direction,
795 /// of the other attached clusters assuming the discarded one does not exist
796 /// accounting for multiple scattering correlations and cluster resolution
797 /// - Use the provided MCS covariance matrix if any (otherwise build it temporarily)
798 /// - Return kFALSE if computation failed
799 AliDebug(1,"Enter ComputeClusterWeights2");
801 // Check MCS covariance matrix and recompute it if need
802 Int_t nClusters = GetNClusters();
803 Bool_t deleteMCSCov = kFALSE;
804 if (!mcsCovariances) {
805 mcsCovariances = new TMatrixD(nClusters,nClusters);
806 deleteMCSCov = kTRUE;
807 ComputeMCSCovariances(*mcsCovariances);
810 // Resize the weights matrices; alocate memory
811 if (discardedCluster) {
812 clusterWeightsNB.ResizeTo(nClusters-1,nClusters-1);
813 clusterWeightsB.ResizeTo(nClusters-1,nClusters-1);
815 clusterWeightsNB.ResizeTo(nClusters,nClusters);
816 clusterWeightsB.ResizeTo(nClusters,nClusters);
820 AliMUONVCluster *cluster1, *cluster2;
821 Int_t iCurrentCluster1, iCurrentCluster2;
823 // Compute the covariance matrices
824 iCurrentCluster1 = 0;
825 for (Int_t iCluster1 = 0; iCluster1 < nClusters; iCluster1++) {
826 cluster1 = ((AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster1))->GetClusterPtr();
828 if (cluster1 == discardedCluster) continue;
830 // Loop over next clusters
831 iCurrentCluster2 = iCurrentCluster1;
832 for (Int_t iCluster2 = iCluster1; iCluster2 < nClusters; iCluster2++) {
833 cluster2 = ((AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster2))->GetClusterPtr();
835 if (cluster2 == discardedCluster) continue;
837 // Fill with MCS covariances
838 clusterWeightsNB(iCurrentCluster1, iCurrentCluster2) = (*mcsCovariances)(iCluster1,iCluster2);
840 // Equal contribution from multiple scattering in non bending and bending directions
841 clusterWeightsB(iCurrentCluster1, iCurrentCluster2) = clusterWeightsNB(iCurrentCluster1, iCurrentCluster2);
843 // Add contribution from cluster resolution to diagonal element and symmetrize the matrix
844 if (iCurrentCluster1 == iCurrentCluster2) {
846 // In non bending plane
847 clusterWeightsNB(iCurrentCluster1, iCurrentCluster1) += cluster1->GetErrX2();
849 clusterWeightsB(iCurrentCluster1, iCurrentCluster1) += cluster1->GetErrY2();
853 // In non bending plane
854 clusterWeightsNB(iCurrentCluster2, iCurrentCluster1) = clusterWeightsNB(iCurrentCluster1, iCurrentCluster2);
856 clusterWeightsB(iCurrentCluster2, iCurrentCluster1) = clusterWeightsB(iCurrentCluster1, iCurrentCluster2);
866 // Inversion of covariance matrices to get the weights
867 if (clusterWeightsNB.Determinant() != 0 && clusterWeightsB.Determinant() != 0) {
868 clusterWeightsNB.Invert();
869 clusterWeightsB.Invert();
871 AliWarning(" Determinant = 0");
872 clusterWeightsNB.ResizeTo(0,0);
873 clusterWeightsB.ResizeTo(0,0);
874 if(deleteMCSCov) delete mcsCovariances;
878 if(deleteMCSCov) delete mcsCovariances;
884 //__________________________________________________________________________
885 void AliMUONTrack::ComputeMCSCovariances(TMatrixD& mcsCovariances) const
887 /// Compute the multiple scattering covariance matrix
888 /// (assume that track parameters at each cluster are corrects)
889 AliDebug(1,"Enter ComputeMCSCovariances");
891 // Reset the size of the covariance matrix if needed
892 Int_t nClusters = GetNClusters();
893 if (mcsCovariances.GetNrows() != nClusters) mcsCovariances.ResizeTo(nClusters,nClusters);
896 Int_t nChambers = AliMUONConstants::NTrackingCh();
897 AliMUONTrackParam* trackParamAtCluster;
898 AliMUONTrackParam extrapTrackParam;
899 Int_t currentChamber = 0, expectedChamber = 0, size = 0;
900 Double_t *mcsAngle2 = new Double_t[2*nChambers];
901 Double_t *zMCS = new Double_t[2*nChambers];
902 Int_t *indices = new Int_t[2*nClusters];
904 // Compute multiple scattering dispersion angle at each chamber
905 // and save the z position where it is calculated
906 for (Int_t iCluster = 0; iCluster < nClusters; iCluster++) {
907 trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster);
909 // look for missing chambers if any
910 currentChamber = trackParamAtCluster->GetClusterPtr()->GetChamberId();
911 while (currentChamber > expectedChamber) {
913 // Save the z position where MCS dispersion is calculated
914 zMCS[size] = AliMUONConstants::DefaultChamberZ(expectedChamber);
916 // Do not take into account MCS in chambers prior the first cluster
919 // Get track parameters at missing chamber z
920 extrapTrackParam = *trackParamAtCluster;
921 AliMUONTrackExtrap::ExtrapToZ(&extrapTrackParam, zMCS[size]);
923 // Save multiple scattering dispersion angle in missing chamber
924 mcsAngle2[size] = AliMUONTrackExtrap::GetMCSAngle2(extrapTrackParam,AliMUONConstants::ChamberThicknessInX0(),1.);
926 } else mcsAngle2[size] = 0.;
932 // Save z position where MCS dispersion is calculated
933 zMCS[size] = trackParamAtCluster->GetZ();
935 // Save multiple scattering dispersion angle in current chamber
936 mcsAngle2[size] = AliMUONTrackExtrap::GetMCSAngle2(*trackParamAtCluster,AliMUONConstants::ChamberThicknessInX0(),1.);
938 // Save indice in zMCS array corresponding to the current cluster
939 indices[iCluster] = size;
941 expectedChamber = currentChamber + 1;
945 // complete array of z if last cluster is on the last but one chamber
946 if (currentChamber != nChambers-1) zMCS[size++] = AliMUONConstants::DefaultChamberZ(nChambers-1);
948 // Compute the covariance matrix
949 for (Int_t iCluster1 = 0; iCluster1 < nClusters; iCluster1++) {
951 for (Int_t iCluster2 = iCluster1; iCluster2 < nClusters; iCluster2++) {
953 // Initialization to 0 (diagonal plus upper triangular part)
954 mcsCovariances(iCluster1,iCluster2) = 0.;
956 // Compute contribution from multiple scattering in upstream chambers
957 for (Int_t k = 0; k < indices[iCluster1]; k++) {
958 mcsCovariances(iCluster1,iCluster2) += (zMCS[indices[iCluster1]] - zMCS[k]) * (zMCS[indices[iCluster2]] - zMCS[k]) * mcsAngle2[k];
961 // Symetrize the matrix
962 mcsCovariances(iCluster2,iCluster1) = mcsCovariances(iCluster1,iCluster2);
973 //__________________________________________________________________________
974 Int_t AliMUONTrack::ClustersInCommon(AliMUONTrack* track, Bool_t inSt345) const
976 /// Returns the number of clusters in common between the current track ("this")
977 /// and the track pointed to by "track".
978 /// If inSt345=kTRUE only stations 3, 4 and 5 are considered.
979 if (!fTrackParamAtCluster || !this->fTrackParamAtCluster) return 0;
980 Int_t clustersInCommon = 0;
981 AliMUONTrackParam *trackParamAtCluster1, *trackParamAtCluster2;
982 // Loop over clusters of first track
983 trackParamAtCluster1 = (AliMUONTrackParam*) this->fTrackParamAtCluster->First();
984 while (trackParamAtCluster1) {
985 if ((!inSt345) || (trackParamAtCluster1->GetClusterPtr()->GetChamberId() > 3)) {
986 // Loop over clusters of second track
987 trackParamAtCluster2 = (AliMUONTrackParam*) track->fTrackParamAtCluster->First();
988 while (trackParamAtCluster2) {
989 if ((!inSt345) || (trackParamAtCluster2->GetClusterPtr()->GetChamberId() > 3)) {
990 // Increment "clustersInCommon" if both trackParamAtCluster1 & 2 point to the same cluster
991 if ((trackParamAtCluster1->GetClusterPtr()) == (trackParamAtCluster2->GetClusterPtr())) {
996 trackParamAtCluster2 = (AliMUONTrackParam*) track->fTrackParamAtCluster->After(trackParamAtCluster2);
997 } // trackParamAtCluster2
999 trackParamAtCluster1 = (AliMUONTrackParam*) this->fTrackParamAtCluster->After(trackParamAtCluster1);
1000 } // trackParamAtCluster1
1001 return clustersInCommon;
1004 //__________________________________________________________________________
1005 Int_t AliMUONTrack::GetNDF() const
1007 /// return the number of degrees of freedom
1009 Int_t ndf = 2 * GetNClusters() - 5;
1010 return (ndf > 0) ? ndf : 0;
1013 //__________________________________________________________________________
1014 Double_t AliMUONTrack::GetNormalizedChi2() const
1016 /// return the chi2 value divided by the number of degrees of freedom (or FLT_MAX if ndf <= 0)
1018 Double_t ndf = (Double_t) GetNDF();
1019 return (ndf > 0.) ? fGlobalChi2 / ndf : FLT_MAX;
1022 //__________________________________________________________________________
1023 Int_t AliMUONTrack::CompatibleTrack(AliMUONTrack* track, Double_t sigmaCut, Bool_t compatibleCluster[10]) const
1025 /// for each chamber: return kTRUE (kFALSE) if clusters are compatible (not compatible).
1026 /// nMatchClusters = number of clusters of "this" track matched with one cluster of track "track"
1027 AliMUONTrackParam *trackParamAtCluster1, *trackParamAtCluster2;
1028 AliMUONVCluster *cluster1, *cluster2;
1029 Double_t chi2, dX, dY;
1030 Double_t chi2Max = sigmaCut * sigmaCut;
1033 Int_t nMatchClusters = 0;
1034 for ( Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) compatibleCluster[ch] = kFALSE;
1036 if (!fTrackParamAtCluster || !this->fTrackParamAtCluster) return nMatchClusters;
1038 // Loop over clusters of first track
1039 trackParamAtCluster1 = (AliMUONTrackParam*) this->fTrackParamAtCluster->First();
1040 while (trackParamAtCluster1) {
1042 cluster1 = trackParamAtCluster1->GetClusterPtr();
1044 // Loop over clusters of second track
1045 trackParamAtCluster2 = (AliMUONTrackParam*) track->fTrackParamAtCluster->First();
1046 while (trackParamAtCluster2) {
1048 cluster2 = trackParamAtCluster2->GetClusterPtr();
1051 trackParamAtCluster2 = (AliMUONTrackParam*) track->fTrackParamAtCluster->After(trackParamAtCluster2);
1054 if (cluster1->GetDetElemId() != cluster2->GetDetElemId()) continue;
1057 dX = cluster1->GetX() - cluster2->GetX();
1058 dY = cluster1->GetY() - cluster2->GetY();
1059 chi2 = dX * dX / (cluster1->GetErrX2() + cluster2->GetErrX2()) + dY * dY / (cluster1->GetErrY2() + cluster2->GetErrY2());
1060 if (chi2 > 2. * chi2Max) continue; // 2 because 2 quantities in chi2
1062 compatibleCluster[cluster1->GetChamberId()] = kTRUE;
1067 trackParamAtCluster1 = (AliMUONTrackParam*) this->fTrackParamAtCluster->After(trackParamAtCluster1);
1070 return nMatchClusters;
1073 //__________________________________________________________________________
1074 void AliMUONTrack::SetTrackParamAtVertex(const AliMUONTrackParam* trackParam)
1076 /// set track parameters at vertex
1077 if (trackParam == 0x0) return;
1078 if (fTrackParamAtVertex) *fTrackParamAtVertex = *trackParam;
1079 else fTrackParamAtVertex = new AliMUONTrackParam(*trackParam);
1082 //__________________________________________________________________________
1083 void AliMUONTrack::RecursiveDump() const
1085 /// Recursive dump of AliMUONTrack, i.e. with dump of trackParamAtCluster and attached clusters
1086 AliMUONTrackParam *trackParamAtCluster;
1087 AliMUONVCluster *cluster;
1088 cout << "Recursive dump of Track: " << this << endl;
1091 for (Int_t iCluster = 0; iCluster < GetNClusters(); iCluster++) {
1092 trackParamAtCluster = (AliMUONTrackParam*) ((*fTrackParamAtCluster)[iCluster]);
1093 // trackParamAtCluster
1094 cout << "trackParamAtCluster: " << trackParamAtCluster << " (index: " << iCluster << ")" << endl;
1095 trackParamAtCluster->Dump();
1096 cluster = trackParamAtCluster->GetClusterPtr();
1098 cout << "cluster: " << cluster << endl;
1104 //_____________________________________________-
1105 void AliMUONTrack::Print(Option_t*) const
1107 /// Printing Track information
1109 cout << "<AliMUONTrack> No.Clusters=" << setw(2) << GetNClusters() <<
1110 ", Match2Trig=" << setw(1) << GetMatchTrigger() <<
1111 ", LoTrgNum=" << setw(3) << GetLoTrgNum() <<
1112 ", Chi2-tracking-trigger=" << setw(8) << setprecision(5) << GetChi2MatchTrigger();
1113 cout << Form(" HitTriggerPattern %x",fHitsPatternInTrigCh);
1114 cout << Form(" MClabel=%d",fTrackID) << endl;
1115 if (fTrackParamAtCluster) fTrackParamAtCluster->First()->Print("FULL");
1118 //__________________________________________________________________________
1119 void AliMUONTrack::SetLocalTrigger(Int_t loCirc, Int_t loStripX, Int_t loStripY, Int_t loDev, Int_t loLpt, Int_t loHpt)
1121 /// pack the local trigger information and store
1123 if (loCirc < 0) return;
1126 fLocalTrigger += loCirc;
1127 fLocalTrigger += loStripX << 8;
1128 fLocalTrigger += loStripY << 13;
1129 fLocalTrigger += loDev << 17;
1130 fLocalTrigger += loLpt << 22;
1131 fLocalTrigger += loHpt << 24;
1135 //__________________________________________________________________________
1136 void AliMUONTrack::FindMCLabel()
1138 /// Determine the MC label from the label of the attached clusters and fill fMCLabel data member:
1139 /// More than 50% of clusters, including 1 before and 1 after the dipole, must share the same label
1141 Int_t nClusters = GetNClusters();
1142 Int_t halfCluster = nClusters/2;
1147 // loop over first clusters (if nClusters left < (nClusters-halfCluster) the conditions cannot be fulfilled)
1148 for (Int_t iCluster1 = 0; iCluster1 < nClusters-halfCluster; iCluster1++) {
1149 AliMUONVCluster* cluster1 = ((AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster1))->GetClusterPtr();
1151 // if the first cluster is not on station 1 or 2 the conditions cannot be fulfilled
1152 if (cluster1->GetChamberId() > 3) return;
1154 Int_t label1 = cluster1->GetMCLabel();
1155 if (label1 < 0) continue;
1157 Int_t nIdenticalLabel = 1;
1159 // Loop over next clusters
1160 for (Int_t iCluster2 = iCluster1+1; iCluster2 < nClusters; iCluster2++) {
1161 AliMUONVCluster* cluster2 = ((AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster2))->GetClusterPtr();
1163 if (cluster2->GetMCLabel() != label1) continue;
1167 // stop as soon as conditions are fulfilled
1168 if (nIdenticalLabel > halfCluster && cluster2->GetChamberId() > 5) {