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 "AliMUONConstants.h"
31 #include "AliMUONTrackExtrap.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 (at least one cluster per requested station)
456 Int_t nClusters = GetNClusters();
457 AliMUONTrackParam *trackParam;
458 Int_t currentStation(0);
459 UInt_t presentStationMask(0);
461 for (Int_t i = 0; i < nClusters; i++) {
462 trackParam = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(i);
463 currentStation = trackParam->GetClusterPtr()->GetChamberId()/2;
464 presentStationMask |= ( 1 << currentStation );
467 return ( (requestedStationMask & presentStationMask) == requestedStationMask );
470 //__________________________________________________________________________
471 void AliMUONTrack::TagRemovableClusters(UInt_t requestedStationMask) {
472 /// Identify clusters that can be removed from the track,
473 /// with the only requirement to have at least 1 cluster per requested station
475 Int_t nClusters = GetNClusters();
476 AliMUONTrackParam *trackParam, *nextTrackParam;
477 Int_t currentCh, nextCh;
479 // reset flags to kFALSE for all clusters in required station
480 for (Int_t i = 0; i < nClusters; i++) {
481 trackParam = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(i);
482 Int_t stationId = ( 1 << (trackParam->GetClusterPtr()->GetChamberId()/2) );
483 UInt_t m = ( 1 << stationId );
484 if ( m & requestedStationMask )
485 trackParam->SetRemovable(kFALSE);
486 else trackParam->SetRemovable(kTRUE);
489 // loop over track parameters
490 for (Int_t i = 0; i < nClusters; i++) {
491 trackParam = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(i);
493 currentCh = trackParam->GetClusterPtr()->GetChamberId();
495 // loop over next track parameters
496 for (Int_t j = i+1; j < nClusters; j++) {
497 nextTrackParam = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(j);
499 nextCh = nextTrackParam->GetClusterPtr()->GetChamberId();
501 // check if the 2 clusters are on the same station
502 if (nextCh/2 != currentCh/2) break;
504 // set clusters in the same station as being removable
505 trackParam->SetRemovable(kTRUE);
506 nextTrackParam->SetRemovable(kTRUE);
514 //__________________________________________________________________________
515 Bool_t AliMUONTrack::ComputeLocalChi2(Bool_t accountForMCS)
517 /// Compute each cluster contribution to the chi2 of the track
518 /// accounting for multiple scattering or not according to the flag
519 /// - Also recompute the weight matrices of the attached clusters if accountForMCS=kTRUE
520 /// - Assume that track parameters at each cluster are corrects
521 /// - Return kFALSE if computation failed
522 AliDebug(1,"Enter ComputeLocalChi2");
524 if (!fTrackParamAtCluster) {
525 AliWarning("no cluster attached to this track");
529 if (accountForMCS) { // Compute local chi2 taking into account multiple scattering effects
531 // Compute MCS covariance matrix only once
532 Int_t nClusters = GetNClusters();
533 TMatrixD mcsCovariances(nClusters,nClusters);
534 ComputeMCSCovariances(mcsCovariances);
536 // Make sure cluster weights are consistent with following calculations
537 if (!ComputeClusterWeights(&mcsCovariances)) {
538 AliWarning("cannot take into account the multiple scattering effects");
539 return ComputeLocalChi2(kFALSE);
542 // Compute chi2 of the track
543 Double_t globalChi2 = ComputeGlobalChi2(kTRUE);
544 if (globalChi2 < 0.) return kFALSE;
546 // Loop over removable clusters and compute their local chi2
547 AliMUONTrackParam* trackParamAtCluster1;
548 AliMUONVCluster *cluster, *discardedCluster;
549 Int_t iCluster1, iCluster2, iCurrentCluster1, iCurrentCluster2;
550 TMatrixD clusterWeightsNB(nClusters-1,nClusters-1);
551 TMatrixD clusterWeightsB(nClusters-1,nClusters-1);
552 Double_t *dX = new Double_t[nClusters-1];
553 Double_t *dY = new Double_t[nClusters-1];
554 Double_t globalChi2b;
555 AliMUONTrackParam* trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->First();
556 while (trackParamAtCluster) {
558 discardedCluster = trackParamAtCluster->GetClusterPtr();
560 // Recompute cluster weights without the current cluster
561 if (!ComputeClusterWeights(clusterWeightsNB, clusterWeightsB, &mcsCovariances, discardedCluster)) {
562 AliWarning("cannot take into account the multiple scattering effects");
565 return ComputeLocalChi2(kFALSE);
568 // Compute track chi2 without the current cluster
570 iCurrentCluster1 = 0;
571 for (iCluster1 = 0; iCluster1 < nClusters ; iCluster1++) {
572 trackParamAtCluster1 = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster1);
573 cluster = trackParamAtCluster1->GetClusterPtr();
575 if (cluster == discardedCluster) continue;
577 // Compute and save residuals
578 dX[iCurrentCluster1] = cluster->GetX() - trackParamAtCluster1->GetNonBendingCoor();
579 dY[iCurrentCluster1] = cluster->GetY() - trackParamAtCluster1->GetBendingCoor();
581 iCurrentCluster2 = 0;
582 for (iCluster2 = 0; iCluster2 < iCluster1; iCluster2++) {
583 cluster = ((AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster2))->GetClusterPtr();
585 if (cluster == discardedCluster) continue;
587 // Add contribution from covariances
588 globalChi2b += (clusterWeightsNB(iCurrentCluster1, iCurrentCluster2) +
589 clusterWeightsNB(iCurrentCluster2, iCurrentCluster1)) * dX[iCurrentCluster1] * dX[iCurrentCluster2] +
590 (clusterWeightsB(iCurrentCluster1, iCurrentCluster2) +
591 clusterWeightsB(iCurrentCluster2, iCurrentCluster1)) * dY[iCurrentCluster1] * dY[iCurrentCluster2];
596 // Add contribution from variances
597 globalChi2b += clusterWeightsNB(iCurrentCluster1, iCurrentCluster1) * dX[iCurrentCluster1] * dX[iCurrentCluster1] +
598 clusterWeightsB(iCurrentCluster1, iCurrentCluster1) * dY[iCurrentCluster1] * dY[iCurrentCluster1];
604 trackParamAtCluster->SetLocalChi2(globalChi2 - globalChi2b);
606 trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->After(trackParamAtCluster);
612 } else { // without multiple scattering effects
614 AliMUONVCluster *discardedCluster;
616 AliMUONTrackParam* trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->First();
617 while (trackParamAtCluster) {
619 discardedCluster = trackParamAtCluster->GetClusterPtr();
622 dX = discardedCluster->GetX() - trackParamAtCluster->GetNonBendingCoor();
623 dY = discardedCluster->GetY() - trackParamAtCluster->GetBendingCoor();
626 trackParamAtCluster->SetLocalChi2(dX * dX / discardedCluster->GetErrX2() + dY * dY / discardedCluster->GetErrY2());
628 trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->After(trackParamAtCluster);
637 //__________________________________________________________________________
638 Double_t AliMUONTrack::ComputeGlobalChi2(Bool_t accountForMCS)
640 /// Compute the chi2 of the track accounting for multiple scattering or not according to the flag
641 /// - Assume that track parameters at each cluster are corrects
642 /// - Assume the cluster weights matrices are corrects
643 /// - Return negative value if chi2 computation failed
644 AliDebug(1,"Enter ComputeGlobalChi2");
646 if (!fTrackParamAtCluster) {
647 AliWarning("no cluster attached to this track");
655 // Check the weight matrices. If weight matrices are not available compute chi2 without MCS
656 if (!fClusterWeightsNonBending || !fClusterWeightsBending) {
657 AliWarning("cluster weights including multiple scattering effects are not available\n\t\t --> compute chi2 WITHOUT multiple scattering");
658 return ComputeGlobalChi2(kFALSE);
660 Int_t nClusters = GetNClusters();
661 if (fClusterWeightsNonBending->GetNrows() != nClusters || fClusterWeightsBending->GetNcols() != nClusters) {
662 AliWarning("cluster weights including multiple scattering effects are not available\n\t\t --> compute chi2 WITHOUT multiple scattering");
663 return ComputeGlobalChi2(kFALSE);
667 AliMUONVCluster *cluster;
668 Double_t *dX = new Double_t[nClusters];
669 Double_t *dY = new Double_t[nClusters];
670 AliMUONTrackParam* trackParamAtCluster;
671 for (Int_t iCluster1 = 0; iCluster1 < nClusters; iCluster1++) {
672 trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster1);
673 cluster = trackParamAtCluster->GetClusterPtr();
674 dX[iCluster1] = cluster->GetX() - trackParamAtCluster->GetNonBendingCoor();
675 dY[iCluster1] = cluster->GetY() - trackParamAtCluster->GetBendingCoor();
676 for (Int_t iCluster2 = 0; iCluster2 < iCluster1; iCluster2++) {
677 chi2 += ((*fClusterWeightsNonBending)(iCluster1, iCluster2) + (*fClusterWeightsNonBending)(iCluster2, iCluster1)) * dX[iCluster1] * dX[iCluster2] +
678 ((*fClusterWeightsBending)(iCluster1, iCluster2) + (*fClusterWeightsBending)(iCluster2, iCluster1)) * dY[iCluster1] * dY[iCluster2];
680 chi2 += ((*fClusterWeightsNonBending)(iCluster1, iCluster1) * dX[iCluster1] * dX[iCluster1]) +
681 ((*fClusterWeightsBending)(iCluster1, iCluster1) * dY[iCluster1] * dY[iCluster1]);
688 AliMUONVCluster *cluster;
690 AliMUONTrackParam* trackParamAtCluster;
691 Int_t nClusters = GetNClusters();
692 for (Int_t iCluster = 0; iCluster < nClusters ; iCluster++) {
693 trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster);
694 cluster = trackParamAtCluster->GetClusterPtr();
695 dX = cluster->GetX() - trackParamAtCluster->GetNonBendingCoor();
696 dY = cluster->GetY() - trackParamAtCluster->GetBendingCoor();
697 chi2 += dX * dX / cluster->GetErrX2() + dY * dY / cluster->GetErrY2();
706 //__________________________________________________________________________
707 Bool_t AliMUONTrack::ComputeClusterWeights(TMatrixD* mcsCovariances)
709 /// Compute the weight matrices of the attached clusters, in non bending and bending direction,
710 /// accounting for multiple scattering correlations and cluster resolution
711 /// - Use the provided MCS covariance matrix if any (otherwise build it temporarily)
712 /// - Assume that track parameters at each cluster are corrects
713 /// - Return kFALSE if computation failed
714 AliDebug(1,"Enter ComputeClusterWeights1");
716 if (!fTrackParamAtCluster) {
717 AliWarning("no cluster attached to this track");
722 Int_t nClusters = GetNClusters();
723 if (!fClusterWeightsNonBending) fClusterWeightsNonBending = new TMatrixD(nClusters,nClusters);
724 if (!fClusterWeightsBending) fClusterWeightsBending = new TMatrixD(nClusters,nClusters);
726 // Compute weights matrices
727 if (!ComputeClusterWeights(*fClusterWeightsNonBending, *fClusterWeightsBending, mcsCovariances)) return kFALSE;
733 //__________________________________________________________________________
734 Bool_t AliMUONTrack::ComputeClusterWeights(TMatrixD& clusterWeightsNB, TMatrixD& clusterWeightsB,
735 TMatrixD* mcsCovariances, AliMUONVCluster* discardedCluster) const
737 /// Compute the weight matrices, in non bending and bending direction,
738 /// of the other attached clusters assuming the discarded one does not exist
739 /// accounting for multiple scattering correlations and cluster resolution
740 /// - Use the provided MCS covariance matrix if any (otherwise build it temporarily)
741 /// - Return kFALSE if computation failed
742 AliDebug(1,"Enter ComputeClusterWeights2");
744 // Check MCS covariance matrix and recompute it if need
745 Int_t nClusters = GetNClusters();
746 Bool_t deleteMCSCov = kFALSE;
747 if (!mcsCovariances) {
748 mcsCovariances = new TMatrixD(nClusters,nClusters);
749 deleteMCSCov = kTRUE;
750 ComputeMCSCovariances(*mcsCovariances);
753 // Resize the weights matrices; alocate memory
754 if (discardedCluster) {
755 clusterWeightsNB.ResizeTo(nClusters-1,nClusters-1);
756 clusterWeightsB.ResizeTo(nClusters-1,nClusters-1);
758 clusterWeightsNB.ResizeTo(nClusters,nClusters);
759 clusterWeightsB.ResizeTo(nClusters,nClusters);
763 AliMUONVCluster *cluster1, *cluster2;
764 Int_t iCurrentCluster1, iCurrentCluster2;
766 // Compute the covariance matrices
767 iCurrentCluster1 = 0;
768 for (Int_t iCluster1 = 0; iCluster1 < nClusters; iCluster1++) {
769 cluster1 = ((AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster1))->GetClusterPtr();
771 if (cluster1 == discardedCluster) continue;
773 // Loop over next clusters
774 iCurrentCluster2 = iCurrentCluster1;
775 for (Int_t iCluster2 = iCluster1; iCluster2 < nClusters; iCluster2++) {
776 cluster2 = ((AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster2))->GetClusterPtr();
778 if (cluster2 == discardedCluster) continue;
780 // Fill with MCS covariances
781 clusterWeightsNB(iCurrentCluster1, iCurrentCluster2) = (*mcsCovariances)(iCluster1,iCluster2);
783 // Equal contribution from multiple scattering in non bending and bending directions
784 clusterWeightsB(iCurrentCluster1, iCurrentCluster2) = clusterWeightsNB(iCurrentCluster1, iCurrentCluster2);
786 // Add contribution from cluster resolution to diagonal element and symmetrize the matrix
787 if (iCurrentCluster1 == iCurrentCluster2) {
789 // In non bending plane
790 clusterWeightsNB(iCurrentCluster1, iCurrentCluster1) += cluster1->GetErrX2();
792 clusterWeightsB(iCurrentCluster1, iCurrentCluster1) += cluster1->GetErrY2();
796 // In non bending plane
797 clusterWeightsNB(iCurrentCluster2, iCurrentCluster1) = clusterWeightsNB(iCurrentCluster1, iCurrentCluster2);
799 clusterWeightsB(iCurrentCluster2, iCurrentCluster1) = clusterWeightsB(iCurrentCluster1, iCurrentCluster2);
809 // Inversion of covariance matrices to get the weights
810 if (clusterWeightsNB.Determinant() != 0 && clusterWeightsB.Determinant() != 0) {
811 clusterWeightsNB.Invert();
812 clusterWeightsB.Invert();
814 AliWarning(" Determinant = 0");
815 clusterWeightsNB.ResizeTo(0,0);
816 clusterWeightsB.ResizeTo(0,0);
817 if(deleteMCSCov) delete mcsCovariances;
821 if(deleteMCSCov) delete mcsCovariances;
827 //__________________________________________________________________________
828 void AliMUONTrack::ComputeMCSCovariances(TMatrixD& mcsCovariances) const
830 /// Compute the multiple scattering covariance matrix
831 /// (assume that track parameters at each cluster are corrects)
832 AliDebug(1,"Enter ComputeMCSCovariances");
834 // Reset the size of the covariance matrix if needed
835 Int_t nClusters = GetNClusters();
836 if (mcsCovariances.GetNrows() != nClusters) mcsCovariances.ResizeTo(nClusters,nClusters);
839 Int_t nChambers = AliMUONConstants::NTrackingCh();
840 AliMUONTrackParam* trackParamAtCluster;
841 AliMUONTrackParam extrapTrackParam;
842 Int_t currentChamber = 0, expectedChamber = 0, size = 0;
843 Double_t *mcsAngle2 = new Double_t[2*nChambers];
844 Double_t *zMCS = new Double_t[2*nChambers];
845 Int_t *indices = new Int_t[2*nClusters];
847 // Compute multiple scattering dispersion angle at each chamber
848 // and save the z position where it is calculated
849 for (Int_t iCluster = 0; iCluster < nClusters; iCluster++) {
850 trackParamAtCluster = (AliMUONTrackParam*) fTrackParamAtCluster->UncheckedAt(iCluster);
852 // look for missing chambers if any
853 currentChamber = trackParamAtCluster->GetClusterPtr()->GetChamberId();
854 while (currentChamber > expectedChamber) {
856 // Save the z position where MCS dispersion is calculated
857 zMCS[size] = AliMUONConstants::DefaultChamberZ(expectedChamber);
859 // Do not take into account MCS in chambers prior the first cluster
862 // Get track parameters at missing chamber z
863 extrapTrackParam = *trackParamAtCluster;
864 AliMUONTrackExtrap::ExtrapToZ(&extrapTrackParam, zMCS[size]);
866 // Save multiple scattering dispersion angle in missing chamber
867 mcsAngle2[size] = AliMUONTrackExtrap::GetMCSAngle2(extrapTrackParam,AliMUONConstants::ChamberThicknessInX0(),1.);
869 } else mcsAngle2[size] = 0.;
875 // Save z position where MCS dispersion is calculated
876 zMCS[size] = trackParamAtCluster->GetZ();
878 // Save multiple scattering dispersion angle in current chamber
879 mcsAngle2[size] = AliMUONTrackExtrap::GetMCSAngle2(*trackParamAtCluster,AliMUONConstants::ChamberThicknessInX0(),1.);
881 // Save indice in zMCS array corresponding to the current cluster
882 indices[iCluster] = size;
884 expectedChamber = currentChamber + 1;
888 // complete array of z if last cluster is on the last but one chamber
889 if (currentChamber != nChambers-1) zMCS[size++] = AliMUONConstants::DefaultChamberZ(nChambers-1);
891 // Compute the covariance matrix
892 for (Int_t iCluster1 = 0; iCluster1 < nClusters; iCluster1++) {
894 for (Int_t iCluster2 = iCluster1; iCluster2 < nClusters; iCluster2++) {
896 // Initialization to 0 (diagonal plus upper triangular part)
897 mcsCovariances(iCluster1,iCluster2) = 0.;
899 // Compute contribution from multiple scattering in upstream chambers
900 for (Int_t k = 0; k < indices[iCluster1]; k++) {
901 mcsCovariances(iCluster1,iCluster2) += (zMCS[indices[iCluster1]] - zMCS[k]) * (zMCS[indices[iCluster2]] - zMCS[k]) * mcsAngle2[k];
904 // Symetrize the matrix
905 mcsCovariances(iCluster2,iCluster1) = mcsCovariances(iCluster1,iCluster2);
916 //__________________________________________________________________________
917 Int_t AliMUONTrack::ClustersInCommon(AliMUONTrack* track) const
919 /// Returns the number of clusters in common between the current track ("this")
920 /// and the track pointed to by "track".
921 if (!fTrackParamAtCluster || !this->fTrackParamAtCluster) return 0;
922 Int_t clustersInCommon = 0;
923 AliMUONTrackParam *trackParamAtCluster1, *trackParamAtCluster2;
924 // Loop over clusters of first track
925 trackParamAtCluster1 = (AliMUONTrackParam*) this->fTrackParamAtCluster->First();
926 while (trackParamAtCluster1) {
927 // Loop over clusters of second track
928 trackParamAtCluster2 = (AliMUONTrackParam*) track->fTrackParamAtCluster->First();
929 while (trackParamAtCluster2) {
930 // Increment "clustersInCommon" if both trackParamAtCluster1 & 2 point to the same cluster
931 if ((trackParamAtCluster1->GetClusterPtr()) == (trackParamAtCluster2->GetClusterPtr())) {
935 trackParamAtCluster2 = (AliMUONTrackParam*) track->fTrackParamAtCluster->After(trackParamAtCluster2);
936 } // trackParamAtCluster2
937 trackParamAtCluster1 = (AliMUONTrackParam*) this->fTrackParamAtCluster->After(trackParamAtCluster1);
938 } // trackParamAtCluster1
939 return clustersInCommon;
942 //__________________________________________________________________________
943 Double_t AliMUONTrack::GetNormalizedChi2() const
945 /// return the chi2 value divided by the number of degrees of freedom (or 1.e10 if ndf < 0)
947 Double_t numberOfDegFree = (2. * GetNClusters() - 5.);
948 if (numberOfDegFree > 0.) return fGlobalChi2 / numberOfDegFree;
949 else return fGlobalChi2; // system is under-constraint
952 //__________________________________________________________________________
953 Bool_t* AliMUONTrack::CompatibleTrack(AliMUONTrack *track, Double_t sigmaCut) const
955 /// for each chamber: return kTRUE (kFALSE) if clusters are compatible (not compatible)
956 AliMUONTrackParam *trackParamAtCluster1, *trackParamAtCluster2;
957 AliMUONVCluster *cluster1, *cluster2;
958 Double_t chi2, dX, dY, dZ;
959 Double_t chi2Max = sigmaCut * sigmaCut;
960 Double_t dZMax = 1.; // 1 cm
962 Bool_t *compatibleCluster = new Bool_t[AliMUONConstants::NTrackingCh()];
963 for ( Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) compatibleCluster[ch] = kFALSE;
965 if (!fTrackParamAtCluster || !this->fTrackParamAtCluster) return compatibleCluster;
967 // Loop over clusters of first track
968 trackParamAtCluster1 = (AliMUONTrackParam*) this->fTrackParamAtCluster->First();
969 while (trackParamAtCluster1) {
971 cluster1 = trackParamAtCluster1->GetClusterPtr();
973 // Loop over clusters of second track
974 trackParamAtCluster2 = (AliMUONTrackParam*) track->fTrackParamAtCluster->First();
975 while (trackParamAtCluster2) {
977 cluster2 = trackParamAtCluster2->GetClusterPtr();
980 trackParamAtCluster2 = (AliMUONTrackParam*) track->fTrackParamAtCluster->After(trackParamAtCluster2);
983 dZ = cluster1->GetZ() - cluster2->GetZ();
984 if (dZ > dZMax) continue;
986 // non bending direction
987 dX = cluster1->GetX() - cluster2->GetX();
988 chi2 = dX * dX / (cluster1->GetErrX2() + cluster2->GetErrX2());
989 if (chi2 > chi2Max) continue;
992 dY = cluster1->GetY() - cluster2->GetY();
993 chi2 = dY * dY / (cluster1->GetErrY2() + cluster2->GetErrY2());
994 if (chi2 > chi2Max) continue;
996 compatibleCluster[cluster1->GetChamberId()] = kTRUE;
1000 trackParamAtCluster1 = (AliMUONTrackParam*) this->fTrackParamAtCluster->After(trackParamAtCluster1);
1003 return compatibleCluster;
1006 //__________________________________________________________________________
1007 void AliMUONTrack::SetTrackParamAtVertex(const AliMUONTrackParam* trackParam)
1009 /// set track parameters at vertex
1010 if (trackParam == 0x0) return;
1011 if (fTrackParamAtVertex) *fTrackParamAtVertex = *trackParam;
1012 else fTrackParamAtVertex = new AliMUONTrackParam(*trackParam);
1015 //__________________________________________________________________________
1016 void AliMUONTrack::RecursiveDump() const
1018 /// Recursive dump of AliMUONTrack, i.e. with dump of trackParamAtCluster and attached clusters
1019 AliMUONTrackParam *trackParamAtCluster;
1020 AliMUONVCluster *cluster;
1021 cout << "Recursive dump of Track: " << this << endl;
1024 for (Int_t iCluster = 0; iCluster < GetNClusters(); iCluster++) {
1025 trackParamAtCluster = (AliMUONTrackParam*) ((*fTrackParamAtCluster)[iCluster]);
1026 // trackParamAtCluster
1027 cout << "trackParamAtCluster: " << trackParamAtCluster << " (index: " << iCluster << ")" << endl;
1028 trackParamAtCluster->Dump();
1029 cluster = trackParamAtCluster->GetClusterPtr();
1031 cout << "cluster: " << cluster << endl;
1037 //_____________________________________________-
1038 void AliMUONTrack::Print(Option_t*) const
1040 /// Printing Track information
1042 cout << "<AliMUONTrack> No.Clusters=" << setw(2) << GetNClusters() <<
1043 ", Match2Trig=" << setw(1) << GetMatchTrigger() <<
1044 ", LoTrgNum=" << setw(3) << GetLoTrgNum() <<
1045 ", Chi2-tracking-trigger=" << setw(8) << setprecision(5) << GetChi2MatchTrigger();
1046 cout << Form(" HitTriggerPattern %x",fHitsPatternInTrigCh) << endl;
1047 if (fTrackParamAtCluster) fTrackParamAtCluster->First()->Print("FULL");
1050 //__________________________________________________________________________
1051 void AliMUONTrack::SetLocalTrigger(Int_t loCirc, Int_t loStripX, Int_t loStripY, Int_t loDev, Int_t loLpt, Int_t loHpt)
1053 /// pack the local trigger information and store
1055 if (loCirc < 0) return;
1058 fLocalTrigger += loCirc;
1059 fLocalTrigger += loStripX << 8;
1060 fLocalTrigger += loStripY << 13;
1061 fLocalTrigger += loDev << 17;
1062 fLocalTrigger += loLpt << 22;
1063 fLocalTrigger += loHpt << 24;