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 /// \class AliMUONTrackReconstructor
19 /// MUON track reconstructor using the original method
21 /// This class contains as data:
22 /// - the parameters for the track reconstruction
24 /// It contains as methods, among others:
25 /// - MakeTracks to build the tracks
29 #include <Riostream.h>
32 #include "AliMUONVTrackReconstructor.h"
33 #include "AliMUONTrackReconstructor.h"
34 #include "AliMUONData.h"
35 #include "AliMUONConstants.h"
36 #include "AliMUONRawCluster.h"
37 #include "AliMUONHitForRec.h"
38 #include "AliMUONSegment.h"
39 #include "AliMUONTrack.h"
40 #include "AliMUONTrackParam.h"
41 #include "AliMUONTrackExtrap.h"
43 #include <TVirtualFitter.h>
45 // Functions to be minimized with Minuit
46 void TrackChi2(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag);
47 void TrackChi2MCS(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag);
49 void mnvertLocal(Double_t* a, Int_t l, Int_t m, Int_t n, Int_t& ifail);
51 Double_t MultipleScatteringAngle2(AliMUONTrackParam *param);
54 ClassImp(AliMUONTrackReconstructor) // Class implementation in ROOT context
57 //************* Defaults parameters for reconstruction
58 const Double_t AliMUONTrackReconstructor::fgkDefaultMaxChi2 = 100.0;
60 TVirtualFitter* AliMUONTrackReconstructor::fgFitter = 0x0;
62 //__________________________________________________________________________
63 AliMUONTrackReconstructor::AliMUONTrackReconstructor(AliMUONData* data)
64 : AliMUONVTrackReconstructor(data),
65 fMaxChi2(fgkDefaultMaxChi2)
67 /// Constructor for class AliMUONTrackReconstructor
69 // Memory allocation for the TClonesArray of reconstructed tracks
70 fRecTracksPtr = new TClonesArray("AliMUONTrack", 10);
73 //__________________________________________________________________________
74 AliMUONTrackReconstructor::~AliMUONTrackReconstructor(void)
76 /// Destructor for class AliMUONTrackReconstructor
80 //__________________________________________________________________________
81 void AliMUONTrackReconstructor::AddHitsForRecFromRawClusters()
83 /// To add to the list of hits for reconstruction all the raw clusters
85 AliMUONHitForRec *hitForRec;
86 AliMUONRawCluster *clus;
87 Int_t iclus, nclus, nTRentries;
88 TClonesArray *rawclusters;
89 AliDebug(1,"Enter AddHitsForRecFromRawClusters");
91 treeR = fMUONData->TreeR();
93 AliError("TreeR must be loaded");
97 nTRentries = Int_t(treeR->GetEntries());
99 if (!(fMUONData->IsRawClusterBranchesInTree())) {
100 AliError(Form("RawCluster information is not avalaible, nTRentries = %d not equal to 1",nTRentries));
104 fMUONData->SetTreeAddress("RC");
105 fMUONData->GetRawClusters(); // only one entry
107 // Loop over tracking chambers
108 for (Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) {
109 // number of HitsForRec to 0 for the chamber
110 fNHitsForRecPerChamber[ch] = 0;
111 // index of first HitForRec for the chamber
112 if (ch == 0) fIndexOfFirstHitForRecPerChamber[ch] = 0;
113 else fIndexOfFirstHitForRecPerChamber[ch] = fNHitsForRec;
114 rawclusters =fMUONData->RawClusters(ch);
115 nclus = (Int_t) (rawclusters->GetEntries());
116 // Loop over (cathode correlated) raw clusters
117 for (iclus = 0; iclus < nclus; iclus++) {
118 clus = (AliMUONRawCluster*) rawclusters->UncheckedAt(iclus);
119 // new AliMUONHitForRec from raw cluster
120 // and increment number of AliMUONHitForRec's (total and in chamber)
121 hitForRec = new ((*fHitsForRecPtr)[fNHitsForRec]) AliMUONHitForRec(clus);
123 (fNHitsForRecPerChamber[ch])++;
124 // more information into HitForRec
125 hitForRec->SetBendingReso2(clus->GetErrY() * clus->GetErrY());
126 hitForRec->SetNonBendingReso2(clus->GetErrX() * clus->GetErrX());
127 // original raw cluster
128 hitForRec->SetChamberNumber(ch);
129 hitForRec->SetHitNumber(iclus);
130 // Z coordinate of the raw cluster (cm)
131 hitForRec->SetZ(clus->GetZ(0));
134 cout << "Chamber " << ch <<
135 " raw cluster " << iclus << " : " << endl;
137 cout << "AliMUONHitForRec number (1...): " << fNHitsForRec << endl;
138 hitForRec->Print("full");
140 } // end of cluster loop
141 } // end of chamber loop
142 SortHitsForRecWithIncreasingChamber();
144 AliDebug(1,"End of AddHitsForRecFromRawClusters");
145 if (AliLog::GetGlobalDebugLevel() > 0) {
146 AliDebug(1, Form("NHitsForRec: %d",fNHitsForRec));
147 for (Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) {
148 AliDebug(1, Form("Chamber(0...): %d",ch));
149 AliDebug(1, Form("NHitsForRec: %d", fNHitsForRecPerChamber[ch]));
150 AliDebug(1, Form("Index(first HitForRec): %d", fIndexOfFirstHitForRecPerChamber[ch]));
151 for (Int_t hit = fIndexOfFirstHitForRecPerChamber[ch];
152 hit < fIndexOfFirstHitForRecPerChamber[ch] + fNHitsForRecPerChamber[ch];
154 AliDebug(1, Form("HitForRec index(0...): %d",hit));
155 ((*fHitsForRecPtr)[hit])->Dump();
163 //__________________________________________________________________________
164 void AliMUONTrackReconstructor::MakeSegments(void)
166 /// To make the list of segments in all stations,
167 /// from the list of hits to be reconstructed
168 AliDebug(1,"Enter MakeSegments");
169 // Loop over stations
170 for (Int_t st = 0; st < AliMUONConstants::NTrackingCh()/2; st++) MakeSegmentsPerStation(st);
173 cout << "end of MakeSegments" << endl;
174 for (Int_t st = 0; st < AliMUONConstants::NTrackingCh()/2; st++)
176 cout << "station " << st
177 << " has " << fNSegments[st] << " segments:"
179 for (Int_t seg = 0; seg < fNSegments[st]; seg++)
181 ((*fSegmentsPtr[st])[seg])->Print();
188 //__________________________________________________________________________
189 void AliMUONTrackReconstructor::MakeTracks(void)
191 /// To make the tracks from the list of segments and points in all stations
192 AliDebug(1,"Enter MakeTracks");
193 // Look for candidates from at least 3 aligned points in stations(1..) 4 and 5
194 MakeTrackCandidates();
195 // Follow tracks in stations(1..) 3, 2 and 1
197 // Remove double tracks
198 RemoveDoubleTracks();
199 UpdateHitForRecAtHit();
202 //__________________________________________________________________________
203 void AliMUONTrackReconstructor::MakeTrackCandidates(void)
205 /// To make track candidates
206 /// with at least 3 aligned points in stations(1..) 4 and 5
207 /// (two Segment's or one Segment and one HitForRec)
208 Int_t begStation, iBegSegment, nbCan1Seg1Hit, nbCan2Seg;
209 AliMUONSegment *begSegment;
210 AliDebug(1,"Enter MakeTrackCandidates");
211 // Loop over stations(1..) 5 and 4 for the beginning segment
212 for (begStation = 4; begStation > 2; begStation--) {
213 // Loop over segments in the beginning station
214 for (iBegSegment = 0; iBegSegment < fNSegments[begStation]; iBegSegment++) {
215 // pointer to segment
216 begSegment = (AliMUONSegment*) ((*fSegmentsPtr[begStation])[iBegSegment]);
217 AliDebug(2,Form("Look for TrackCandidate's with Segment %d in Station(0..) %d", iBegSegment, begStation));
218 // Look for track candidates with two segments,
219 // "begSegment" and all compatible segments in other station.
220 // Only for beginning station(1..) 5
221 // because candidates with 2 segments have to looked for only once.
223 nbCan2Seg = MakeTrackCandidatesWithTwoSegments(begSegment);
224 // Look for track candidates with one segment and one point,
225 // "begSegment" and all compatible HitForRec's in other station.
226 // Only if "begSegment" does not belong already to a track candidate.
227 // Is that a too strong condition ????
228 if (!(begSegment->GetInTrack()))
229 nbCan1Seg1Hit = MakeTrackCandidatesWithOneSegmentAndOnePoint(begSegment);
230 } // for (iBegSegment = 0;...
231 } // for (begStation = 4;...
235 //__________________________________________________________________________
236 Int_t AliMUONTrackReconstructor::MakeTrackCandidatesWithTwoSegments(AliMUONSegment *BegSegment)
238 /// To make track candidates with two segments in stations(1..) 4 and 5,
239 /// the first segment being pointed to by "BegSegment".
240 /// Returns the number of such track candidates.
241 Int_t endStation, iEndSegment, nbCan2Seg;
242 AliMUONSegment *endSegment;
243 AliMUONSegment *extrapSegment = NULL;
244 AliMUONTrack *recTrack;
246 AliDebug(1,"Enter MakeTrackCandidatesWithTwoSegments");
247 // Station for the end segment
248 endStation = 7 - (BegSegment->GetHitForRec1())->GetChamberNumber() / 2;
249 // multiple scattering factor corresponding to one chamber
251 GetBendingMomentumFromImpactParam(BegSegment->GetBendingImpact());
252 mcsFactor = fChamberThicknessInX0 * mcsFactor * mcsFactor;
253 // linear extrapolation to end station
254 // number of candidates with 2 segments to 0
256 // Loop over segments in the end station
257 for (iEndSegment = 0; iEndSegment < fNSegments[endStation]; iEndSegment++) {
258 // pointer to segment
259 endSegment = (AliMUONSegment*) ((*fSegmentsPtr[endStation])[iEndSegment]);
260 // test compatibility between current segment and "extrapSegment"
261 // 4 because 4 quantities in chi2
263 BegSegment->CreateSegmentFromLinearExtrapToStation(endSegment->GetZ(), mcsFactor);
265 NormalizedChi2WithSegment(extrapSegment,
266 fMaxSigma2Distance)) <= 4.0) {
267 // both segments compatible:
268 // make track candidate from "begSegment" and "endSegment"
269 AliDebug(2,Form("TrackCandidate with Segment %d in Station(0..) %d", iEndSegment, endStation));
270 // flag for both segments in one track:
271 // to be done in track constructor ????
272 BegSegment->SetInTrack(kTRUE);
273 endSegment->SetInTrack(kTRUE);
274 recTrack = new ((*fRecTracksPtr)[fNRecTracks]) AliMUONTrack(BegSegment, endSegment);
275 // Set track parameters at vertex from last stations 4 & 5
276 CalcTrackParamAtVertex(recTrack);
278 if (AliLog::GetGlobalDebugLevel() > 1) recTrack->RecursiveDump();
279 // increment number of track candidates with 2 segments
282 delete extrapSegment; // should not delete HitForRec's it points to !!!!
283 } // for (iEndSegment = 0;...
287 //__________________________________________________________________________
288 Int_t AliMUONTrackReconstructor::MakeTrackCandidatesWithOneSegmentAndOnePoint(AliMUONSegment *BegSegment)
290 /// To make track candidates with one segment and one point
291 /// in stations(1..) 4 and 5,
292 /// the segment being pointed to by "BegSegment".
293 Int_t ch, ch1, ch2, endStation, iHit, iHitMax, iHitMin, nbCan1Seg1Hit;
294 AliMUONHitForRec *extrapHitForRec= NULL;
295 AliMUONHitForRec *hit;
296 AliMUONTrack *recTrack;
298 AliDebug(1,"Enter MakeTrackCandidatesWithOneSegmentAndOnePoint");
299 // station for the end point
300 endStation = 7 - (BegSegment->GetHitForRec1())->GetChamberNumber() / 2;
301 // multiple scattering factor corresponding to one chamber
303 GetBendingMomentumFromImpactParam(BegSegment->GetBendingImpact());
304 mcsFactor = fChamberThicknessInX0 * mcsFactor * mcsFactor;
305 // first and second chambers(0..) in the end station
306 ch1 = 2 * endStation;
308 // number of candidates to 0
310 // Loop over chambers of the end station
311 for (ch = ch2; ch >= ch1; ch--) {
312 // limits for the hit index in the loop
313 iHitMin = fIndexOfFirstHitForRecPerChamber[ch];
314 iHitMax = iHitMin + fNHitsForRecPerChamber[ch];
315 // Loop over HitForRec's in the chamber
316 for (iHit = iHitMin; iHit < iHitMax; iHit++) {
317 // pointer to HitForRec
318 hit = (AliMUONHitForRec*) ((*fHitsForRecPtr)[iHit]);
319 // test compatibility between current HitForRec and "extrapHitForRec"
320 // 2 because 2 quantities in chi2
321 // linear extrapolation to chamber
323 BegSegment->CreateHitForRecFromLinearExtrapToChamber( hit->GetZ(), mcsFactor);
325 NormalizedChi2WithHitForRec(extrapHitForRec,
326 fMaxSigma2Distance)) <= 2.0) {
327 // both HitForRec's compatible:
328 // make track candidate from begSegment and current HitForRec
329 AliDebug(2, Form("TrackCandidate with HitForRec %d in Chamber(0..) %d", iHit, ch));
330 // flag for beginning segments in one track:
331 // to be done in track constructor ????
332 BegSegment->SetInTrack(kTRUE);
333 recTrack = new ((*fRecTracksPtr)[fNRecTracks]) AliMUONTrack(BegSegment, hit);
334 // Set track parameters at vertex from last stations 4 & 5
335 CalcTrackParamAtVertex(recTrack);
336 // the right place to eliminate "double counting" ???? how ????
338 if (AliLog::GetGlobalDebugLevel() > 1) recTrack->RecursiveDump();
339 // increment number of track candidates
342 delete extrapHitForRec;
343 } // for (iHit = iHitMin;...
344 } // for (ch = ch2;...
345 return nbCan1Seg1Hit;
348 //__________________________________________________________________________
349 void AliMUONTrackReconstructor::CalcTrackParamAtVertex(AliMUONTrack *Track) const
351 /// Set track parameters at vertex.
352 /// TrackHit's are assumed to be only in stations(1..) 4 and 5,
353 /// and sorted according to increasing Z.
354 /// Parameters are calculated from information in HitForRec's
355 /// of first and last TrackHit's.
356 AliMUONTrackParam *trackParamVertex = Track->GetTrackParamAtVertex(); // pointer to track parameters at vertex
357 // Pointer to HitForRec attached to first TrackParamAtHit
358 AliMUONHitForRec *firstHit = ((AliMUONTrackParam*) (Track->GetTrackParamAtHit()->First()))->GetHitForRecPtr();
359 // Pointer to HitForRec attached to last TrackParamAtHit
360 AliMUONHitForRec *lastHit = ((AliMUONTrackParam*) (Track->GetTrackParamAtHit()->Last()))->GetHitForRecPtr();
361 // Z difference between first and last hits
362 Double_t deltaZ = firstHit->GetZ() - lastHit->GetZ();
363 // bending slope in stations(1..) 4 and 5
364 Double_t bendingSlope = (firstHit->GetBendingCoor() - lastHit->GetBendingCoor()) / deltaZ;
365 trackParamVertex->SetBendingSlope(bendingSlope);
367 Double_t impactParam = firstHit->GetBendingCoor() - bendingSlope * firstHit->GetZ();
368 // signed bending momentum
369 trackParamVertex->SetInverseBendingMomentum(1.0 / GetBendingMomentumFromImpactParam(impactParam));
370 // bending slope at vertex
371 trackParamVertex->SetBendingSlope(bendingSlope + impactParam / fSimpleBPosition);
373 trackParamVertex->SetNonBendingSlope((firstHit->GetNonBendingCoor() - lastHit->GetNonBendingCoor()) / deltaZ);
374 // vertex coordinates at (0,0,0)
375 trackParamVertex->SetZ(0.0);
376 trackParamVertex->SetBendingCoor(0.0);
377 trackParamVertex->SetNonBendingCoor(0.0);
380 //__________________________________________________________________________
381 void AliMUONTrackReconstructor::FollowTracks(void)
383 /// Follow tracks in stations(1..) 3, 2 and 1
384 // too long: should be made more modular !!!!
385 AliMUONHitForRec *bestHit, *extrapHit, *hit;
386 AliMUONSegment *bestSegment, *extrapSegment, *segment;
387 AliMUONTrack *track, *nextTrack;
388 AliMUONTrackParam *trackParam1, trackParam[2], trackParamVertex;
389 // -1 to avoid compilation warnings
390 Int_t ch = -1, chInStation, chBestHit = -1, iHit, iSegment, station, trackIndex;
391 Double_t bestChi2, chi2, dZ1, dZ2, dZ3, maxSigma2Distance, mcsFactor;
392 Double_t bendingMomentum, chi2Norm = 0.;
395 // local maxSigma2Distance, for easy increase in testing
396 maxSigma2Distance = fMaxSigma2Distance;
397 AliDebug(2,"Enter FollowTracks");
398 // Loop over track candidates
399 track = (AliMUONTrack*) fRecTracksPtr->First();
403 nextTrack = (AliMUONTrack*) fRecTracksPtr->After(track); // prepare next track
404 AliDebug(2,Form("FollowTracks: track candidate(0..): %d", trackIndex));
405 // Fit track candidate from parameters at vertex
406 // -> with 3 parameters (X_vertex and Y_vertex are fixed)
407 // without multiple Coulomb scattering
409 if (AliLog::GetGlobalDebugLevel()> 2) {
410 cout << "FollowTracks: track candidate(0..): " << trackIndex
411 << " after fit in stations(0..) 3 and 4" << endl;
412 track->RecursiveDump();
414 // Loop over stations(1..) 3, 2 and 1
415 // something SPECIAL for stations 2 and 1 for majority 3 coincidence ????
416 // otherwise: majority coincidence 2 !!!!
417 for (station = 2; station >= 0; station--) {
418 // Track parameters at first track hit (smallest Z)
419 trackParam1 = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->First());
420 // extrapolation to station
421 AliMUONTrackExtrap::ExtrapToStation(trackParam1, station, trackParam);
422 extrapSegment = new AliMUONSegment(); // empty segment
423 // multiple scattering factor corresponding to one chamber
424 // and momentum in bending plane (not total)
425 mcsFactor = 0.0136 * trackParam1->GetInverseBendingMomentum();
426 mcsFactor = fChamberThicknessInX0 * mcsFactor * mcsFactor;
427 // Z difference from previous station
428 dZ1 = AliMUONConstants::DefaultChamberZ(2 * station) -
429 AliMUONConstants::DefaultChamberZ(2 * station + 2);
430 // Z difference between the two previous stations
431 dZ2 = AliMUONConstants::DefaultChamberZ(2 * station + 2) -
432 AliMUONConstants::DefaultChamberZ(2 * station + 4);
433 // Z difference between the two chambers in the previous station
434 dZ3 = AliMUONConstants::DefaultChamberZ(2 * station) -
435 AliMUONConstants::DefaultChamberZ(2 * station + 1);
436 extrapSegment->SetBendingCoorReso2(fBendingResolution * fBendingResolution);
437 extrapSegment->SetNonBendingCoorReso2(fNonBendingResolution * fNonBendingResolution);
438 extrapSegment->UpdateFromStationTrackParam(trackParam, mcsFactor, dZ1, dZ2, dZ3, station,
439 trackParam1->GetInverseBendingMomentum());
442 if (AliLog::GetGlobalDebugLevel() > 2) {
443 cout << "FollowTracks: track candidate(0..): " << trackIndex
444 << " Look for segment in station(0..): " << station << endl;
447 // Loop over segments in station
448 for (iSegment = 0; iSegment < fNSegments[station]; iSegment++) {
449 // Look for best compatible Segment in station
450 // should consider all possibilities ????
451 // multiple scattering ????
452 // separation in 2 functions: Segment and HitForRec ????
453 segment = (AliMUONSegment*) ((*fSegmentsPtr[station])[iSegment]);
454 // correction of corrected segment (fBendingCoor and fNonBendingCoor)
455 // according to real Z value of "segment" and slopes of "extrapSegment"
456 AliMUONTrackExtrap::ExtrapToZ(&(trackParam[0]), segment->GetZ());
457 AliMUONTrackExtrap::ExtrapToZ(&(trackParam[1]), segment->GetZ()); // now same as trackParam[0] !?!?!?!?!?!
458 extrapSegment->SetBendingCoor((&(trackParam[0]))->GetBendingCoor());
459 extrapSegment->SetNonBendingCoor((&(trackParam[0]))->GetNonBendingCoor());
460 extrapSegment->SetBendingSlope((&(trackParam[0]))->GetBendingSlope());
461 extrapSegment->SetNonBendingSlope((&(trackParam[0]))->GetNonBendingSlope());
462 chi2 = segment->NormalizedChi2WithSegment(extrapSegment, maxSigma2Distance);
463 if (chi2 < bestChi2) {
464 // update best Chi2 and Segment if better found
465 bestSegment = segment;
470 // best segment found: add it to track candidate
471 AliMUONTrackExtrap::ExtrapToZ(&(trackParam[0]), bestSegment->GetZ());
472 track->AddTrackParamAtHit(&(trackParam[0]),bestSegment->GetHitForRec1());
473 AliMUONTrackExtrap::ExtrapToZ(&(trackParam[1]), bestSegment->GetZ()); // now same as trackParam[0] !?!?!?!?!?!
474 track->AddTrackParamAtHit(&(trackParam[1]),bestSegment->GetHitForRec2());
475 AliDebug(3, Form("FollowTracks: track candidate(0..): %d Added segment in station(0..): %d", trackIndex, station));
476 if (AliLog::GetGlobalDebugLevel()>2) track->RecursiveDump();
478 // No best segment found:
479 // Look for best compatible HitForRec in station:
480 // should consider all possibilities ????
481 // multiple scattering ???? do about like for extrapSegment !!!!
482 extrapHit = new AliMUONHitForRec(); // empty hit
485 AliDebug(3, Form("FollowTracks: track candidate(0..): %d Segment not found, look for hit in station(0..): %d ",
486 trackIndex, station));
488 // Loop over chambers of the station
489 for (chInStation = 0; chInStation < 2; chInStation++) {
490 ch = 2 * station + chInStation;
491 for (iHit = fIndexOfFirstHitForRecPerChamber[ch]; iHit < fIndexOfFirstHitForRecPerChamber[ch]+fNHitsForRecPerChamber[ch]; iHit++) {
492 hit = (AliMUONHitForRec*) ((*fHitsForRecPtr)[iHit]);
493 // coordinates of extrapolated hit
494 AliMUONTrackExtrap::ExtrapToZ(&(trackParam[chInStation]), hit->GetZ());
495 extrapHit->SetBendingCoor((&(trackParam[chInStation]))->GetBendingCoor());
496 extrapHit->SetNonBendingCoor((&(trackParam[chInStation]))->GetNonBendingCoor());
497 // resolutions from "extrapSegment"
498 extrapHit->SetBendingReso2(extrapSegment->GetBendingCoorReso2());
499 extrapHit->SetNonBendingReso2(extrapSegment->GetNonBendingCoorReso2());
500 // Loop over hits in the chamber
501 // condition for hit not already in segment ????
502 chi2 = hit->NormalizedChi2WithHitForRec(extrapHit, maxSigma2Distance);
503 if (chi2 < bestChi2) {
504 // update best Chi2 and HitForRec if better found
507 chBestHit = chInStation;
512 // best hit found: add it to track candidate
513 AliMUONTrackExtrap::ExtrapToZ(&(trackParam[chBestHit]), bestHit->GetZ());
514 track->AddTrackParamAtHit(&(trackParam[chBestHit]),bestHit);
515 if (AliLog::GetGlobalDebugLevel() > 2) {
516 cout << "FollowTracks: track candidate(0..): " << trackIndex
517 << " Added hit in station(0..): " << station << endl;
518 track->RecursiveDump();
521 // Remove current track candidate
522 // and corresponding TrackHit's, ...
523 fRecTracksPtr->Remove(track);
525 delete extrapSegment;
527 break; // stop the search for this candidate:
528 // exit from the loop over station
532 delete extrapSegment;
533 // Sort TrackParamAtHit according to increasing Z
534 track->GetTrackParamAtHit()->Sort();
535 // Update track parameters at first track hit (smallest Z)
536 trackParam1 = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->First());
537 bendingMomentum = 0.;
538 if (TMath::Abs(trackParam1->GetInverseBendingMomentum()) > 0.)
539 bendingMomentum = TMath::Abs(1/(trackParam1->GetInverseBendingMomentum()));
540 // Track removed if bendingMomentum not in window [min, max]
541 if ((bendingMomentum < fMinBendingMomentum) || (bendingMomentum > fMaxBendingMomentum)) {
542 fRecTracksPtr->Remove(track);
544 break; // stop the search for this candidate:
545 // exit from the loop over station
547 // Track fit from parameters at first hit
548 // -> with 5 parameters (momentum and position)
549 // with multiple Coulomb scattering if all stations
550 if (station == 0) Fit(track,1,1);
551 // without multiple Coulomb scattering if not all stations
553 Double_t numberOfDegFree = (2.0 * track->GetNTrackHits() - 5);
554 if (numberOfDegFree > 0) {
555 chi2Norm = track->GetFitFMin() / numberOfDegFree;
559 // Track removed if normalized chi2 too high
560 if (chi2Norm > fMaxChi2) {
561 fRecTracksPtr->Remove(track);
563 break; // stop the search for this candidate:
564 // exit from the loop over station
566 if (AliLog::GetGlobalDebugLevel() > 2) {
567 cout << "FollowTracks: track candidate(0..): " << trackIndex
568 << " after fit from station(0..): " << station << " to 4" << endl;
569 track->RecursiveDump();
571 // Track extrapolation to the vertex through the absorber (Branson)
572 // after going through the first station
574 trackParamVertex = *((AliMUONTrackParam*) (track->GetTrackParamAtHit()->First()));
575 AliMUONTrackExtrap::ExtrapToVertex(&trackParamVertex, 0., 0., 0.);
576 track->SetTrackParamAtVertex(&trackParamVertex);
577 if (AliLog::GetGlobalDebugLevel() > 0) {
578 cout << "FollowTracks: track candidate(0..): " << trackIndex
579 << " after extrapolation to vertex" << endl;
580 track->RecursiveDump();
583 } // for (station = 2;...
584 // go really to next track
587 // Compression of track array (necessary after Remove)
588 fRecTracksPtr->Compress();
592 //__________________________________________________________________________
593 void AliMUONTrackReconstructor::Fit(AliMUONTrack *Track, Int_t FitStart, Int_t FitMCS)
595 /// Fit the track "Track",
596 /// with or without multiple Coulomb scattering according to "FitMCS",
597 /// starting, according to "FitStart",
598 /// with track parameters at vertex or at the first TrackHit.
600 if ((FitStart != 0) && (FitStart != 1)) {
601 cout << "ERROR in AliMUONTrackReconstructor::Fit(...)" << endl;
602 cout << "FitStart = " << FitStart << " is neither 0 nor 1" << endl;
605 if ((FitMCS != 0) && (FitMCS != 1)) {
606 cout << "ERROR in AliMUONTrackReconstructor::Fit(...)" << endl;
607 cout << "FitMCS = " << FitMCS << " is neither 0 nor 1" << endl;
611 Double_t arg[1], benC, errorParam, invBenP, lower, nonBenC, upper, x, y;
613 AliMUONTrackParam *trackParam;
614 // Check if Minuit is initialized...
615 fgFitter = TVirtualFitter::Fitter(Track,5);
616 fgFitter->Clear(); // necessary ???? probably yes
617 // how to reset the printout number at every fit ????
618 // is there any risk to leave it like that ????
619 // how to go faster ???? choice of Minuit parameters like EDM ????
620 // choice of function to be minimized according to fFitMCS
621 if (FitMCS == 0) fgFitter->SetFCN(TrackChi2);
622 else fgFitter->SetFCN(TrackChi2MCS);
623 // Switch off printout
625 fgFitter->ExecuteCommand("SET PRINT", arg, 1); // More printing !!!!
627 fgFitter->ExecuteCommand("SET NOW", arg, 0);
628 // Parameters according to "fFitStart"
629 // (should be a function to be used at every place where needed ????)
630 if (FitStart == 0) trackParam = Track->GetTrackParamAtVertex();
631 else trackParam = (AliMUONTrackParam*) (Track->GetTrackParamAtHit()->First());
632 // set first 3 Minuit parameters
633 // could be tried with no limits for the search (min=max=0) ????
634 fgFitter->SetParameter(0, "InvBenP",
635 trackParam->GetInverseBendingMomentum(),
637 fgFitter->SetParameter(1, "BenS",
638 trackParam->GetBendingSlope(),
640 fgFitter->SetParameter(2, "NonBenS",
641 trackParam->GetNonBendingSlope(),
644 // set last 2 Minuit parameters when we start from first track hit
645 // mandatory limits in Bending to avoid NaN values of parameters
646 fgFitter->SetParameter(3, "X",
647 trackParam->GetNonBendingCoor(),
648 0.03, -500.0, 500.0);
649 // mandatory limits in non Bending to avoid NaN values of parameters
650 fgFitter->SetParameter(4, "Y",
651 trackParam->GetBendingCoor(),
652 0.10, -500.0, 500.0);
654 // search without gradient calculation in the function
655 fgFitter->ExecuteCommand("SET NOGRADIENT", arg, 0);
657 fgFitter->ExecuteCommand("MINIMIZE", arg, 0);
659 // fgFitter->ExecuteCommand("EXIT", arg, 0); // necessary ????
660 // get results into "invBenP", "benC", "nonBenC" ("x", "y")
661 fgFitter->GetParameter(0, parName, invBenP, errorParam, lower, upper);
662 trackParam->SetInverseBendingMomentum(invBenP);
663 fgFitter->GetParameter(1, parName, benC, errorParam, lower, upper);
664 trackParam->SetBendingSlope(benC);
665 fgFitter->GetParameter(2, parName, nonBenC, errorParam, lower, upper);
666 trackParam->SetNonBendingSlope(nonBenC);
668 fgFitter->GetParameter(3, parName, x, errorParam, lower, upper);
669 trackParam->SetNonBendingCoor(x);
670 fgFitter->GetParameter(4, parName, y, errorParam, lower, upper);
671 trackParam->SetBendingCoor(y);
673 // global result of the fit
674 Double_t fedm, errdef, fitFMin;
676 fgFitter->GetStats(fitFMin, fedm, errdef, npari, nparx);
677 Track->SetFitFMin(fitFMin);
680 //__________________________________________________________________________
681 void TrackChi2(Int_t &NParam, Double_t * /*Gradient*/, Double_t &Chi2, Double_t *Param, Int_t /*Flag*/)
683 /// Return the "Chi2" to be minimized with Minuit for track fitting,
684 /// with "NParam" parameters
685 /// and their current values in array pointed to by "Param".
686 /// Assumes that the track hits are sorted according to increasing Z.
687 /// Track parameters at each TrackHit are updated accordingly.
688 /// Multiple Coulomb scattering is not taken into account
689 AliMUONTrack *trackBeingFitted;
690 AliMUONTrackParam param1;
691 AliMUONTrackParam* trackParamAtHit;
692 AliMUONHitForRec* hitForRec;
693 Chi2 = 0.0; // initialize Chi2
694 // copy of track parameters to be fitted
695 trackBeingFitted = (AliMUONTrack*) AliMUONTrackReconstructor::Fitter()->GetObjectFit();
696 // 3 parameters means fit track candidate from parameters at vertex (X_vertex and Y_vertex are fixed)
697 if (NParam == 3) param1 = *(trackBeingFitted->GetTrackParamAtVertex());
698 else param1 = *((AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->First()));
699 // Minuit parameters to be fitted into this copy
700 param1.SetInverseBendingMomentum(Param[0]);
701 param1.SetBendingSlope(Param[1]);
702 param1.SetNonBendingSlope(Param[2]);
704 param1.SetNonBendingCoor(Param[3]);
705 param1.SetBendingCoor(Param[4]);
707 // Follow track through all planes of track hits
708 trackParamAtHit = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->First());
709 while (trackParamAtHit) {
710 hitForRec = trackParamAtHit->GetHitForRecPtr();
711 // extrapolation to the plane of the hitForRec attached to the current trackParamAtHit
712 AliMUONTrackExtrap::ExtrapToZ(¶m1, hitForRec->GetZ());
713 // update track parameters of the current hit
714 trackParamAtHit->SetTrackParam(param1);
716 // done hit per hit, with hit resolution,
717 // and not with point and angle like in "reco_muon.F" !!!!
718 // Needs to add multiple scattering contribution ????
719 Double_t dX = hitForRec->GetNonBendingCoor() - param1.GetNonBendingCoor();
720 Double_t dY = hitForRec->GetBendingCoor() - param1.GetBendingCoor();
721 Chi2 = Chi2 + dX * dX / hitForRec->GetNonBendingReso2() + dY * dY / hitForRec->GetBendingReso2();
722 trackParamAtHit = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->After(trackParamAtHit));
726 //__________________________________________________________________________
727 void TrackChi2MCS(Int_t &NParam, Double_t * /*Gradient*/, Double_t &Chi2, Double_t *Param, Int_t /*Flag*/)
729 /// Return the "Chi2" to be minimized with Minuit for track fitting,
730 /// with "NParam" parameters
731 /// and their current values in array pointed to by "Param".
732 /// Assumes that the track hits are sorted according to increasing Z.
733 /// Track parameters at each TrackHit are updated accordingly.
734 /// Multiple Coulomb scattering is taken into account with covariance matrix.
735 AliMUONTrack *trackBeingFitted;
736 AliMUONTrackParam param1;
737 AliMUONTrackParam* trackParamAtHit;
738 AliMUONHitForRec* hitForRec;
739 Chi2 = 0.0; // initialize Chi2
740 // copy of track parameters to be fitted
741 trackBeingFitted = (AliMUONTrack*) AliMUONTrackReconstructor::Fitter()->GetObjectFit();
742 // 3 parameters means fit track candidate from parameters at vertex (X_vertex and Y_vertex are fixed)
743 if (NParam == 3) param1 = *(trackBeingFitted->GetTrackParamAtVertex());
744 else param1 = *((AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->First()));
745 // Minuit parameters to be fitted into this copy
746 param1.SetInverseBendingMomentum(Param[0]);
747 param1.SetBendingSlope(Param[1]);
748 param1.SetNonBendingSlope(Param[2]);
750 param1.SetNonBendingCoor(Param[3]);
751 param1.SetBendingCoor(Param[4]);
754 Int_t chCurrent, chPrev = 0, hitNumber, hitNumber1, hitNumber2, hitNumber3;
756 AliMUONTrackParam *trackParamAtHit1, *trackParamAtHit2, *trackParamAtHit3;
757 AliMUONHitForRec *hitForRec1, *hitForRec2;
758 Double_t hbc1, hbc2, pbc1, pbc2;
759 Double_t hnbc1, hnbc2, pnbc1, pnbc2;
760 Int_t numberOfHit = trackBeingFitted->GetNTrackHits();
761 TMatrixD *covBending = new TMatrixD(numberOfHit, numberOfHit);
762 TMatrixD *covNonBending = new TMatrixD(numberOfHit, numberOfHit);
763 Double_t *msa2 = new Double_t[numberOfHit];
765 // Predicted coordinates and multiple scattering angles are first calculated
766 for (hitNumber = 0; hitNumber < numberOfHit; hitNumber++) {
767 trackParamAtHit = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber));
768 hitForRec = trackParamAtHit->GetHitForRecPtr();
769 // extrapolation to the plane of the hitForRec attached to the current trackParamAtHit
770 AliMUONTrackExtrap::ExtrapToZ(¶m1, hitForRec->GetZ());
771 // update track parameters of the current hit
772 trackParamAtHit->SetTrackParam(param1);
773 // square of multiple scattering angle at current hit, with one chamber
774 msa2[hitNumber] = MultipleScatteringAngle2(¶m1);
775 // correction for eventual missing hits or multiple hits in a chamber,
776 // according to the number of chambers
777 // between the current hit and the previous one
778 chCurrent = hitForRec->GetChamberNumber();
779 if (hitNumber > 0) msa2[hitNumber] = msa2[hitNumber] * (chCurrent - chPrev);
783 // Calculates the covariance matrix
784 for (hitNumber1 = 0; hitNumber1 < numberOfHit; hitNumber1++) {
785 trackParamAtHit1 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber1));
786 hitForRec1 = trackParamAtHit1->GetHitForRecPtr();
787 z1 = hitForRec1->GetZ();
788 for (hitNumber2 = hitNumber1; hitNumber2 < numberOfHit; hitNumber2++) {
789 trackParamAtHit2 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber2));
790 z2 = trackParamAtHit2->GetHitForRecPtr()->GetZ();
791 // initialization to 0 (diagonal plus upper triangular part)
792 (*covBending)(hitNumber2, hitNumber1) = 0.0;
793 // contribution from multiple scattering in bending plane:
794 // loop over upstream hits
795 for (hitNumber3 = 0; hitNumber3 < hitNumber1; hitNumber3++) {
796 trackParamAtHit3 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber3));
797 z3 = trackParamAtHit3->GetHitForRecPtr()->GetZ();
798 (*covBending)(hitNumber2, hitNumber1) = (*covBending)(hitNumber2, hitNumber1) + ((z1 - z3) * (z2 - z3) * msa2[hitNumber3]);
800 // equal contribution from multiple scattering in non bending plane
801 (*covNonBending)(hitNumber2, hitNumber1) = (*covBending)(hitNumber2, hitNumber1);
802 if (hitNumber1 == hitNumber2) {
803 // Diagonal elements: add contribution from position measurements
805 (*covBending)(hitNumber2, hitNumber1) = (*covBending)(hitNumber2, hitNumber1) + hitForRec1->GetBendingReso2();
806 // and in non bending plane
807 (*covNonBending)(hitNumber2, hitNumber1) = (*covNonBending)(hitNumber2, hitNumber1) + hitForRec1->GetNonBendingReso2();
809 // Non diagonal elements: symmetrization
811 (*covBending)(hitNumber1, hitNumber2) = (*covBending)(hitNumber2, hitNumber1);
812 // and non bending plane
813 (*covNonBending)(hitNumber1, hitNumber2) = (*covNonBending)(hitNumber2, hitNumber1);
815 } // for (hitNumber2 = hitNumber1;...
816 } // for (hitNumber1 = 0;...
818 // Inversion of covariance matrices
819 // with "mnvertLocal", local "mnvert" function of Minuit.
820 // One cannot use directly "mnvert" since "TVirtualFitter" does not know it.
821 // One will have to replace this local function by the right inversion function
822 // from a specialized Root package for symmetric positive definite matrices,
823 // when available!!!!
825 mnvertLocal(&((*covBending)(0,0)), numberOfHit, numberOfHit, numberOfHit, ifailBending);
826 Int_t ifailNonBending;
827 mnvertLocal(&((*covNonBending)(0,0)), numberOfHit, numberOfHit, numberOfHit, ifailNonBending);
829 // It would be worth trying to calculate the inverse of the covariance matrix
830 // only once per fit, since it cannot change much in principle,
831 // and it would save a lot of computing time !!!!
834 if ((ifailBending == 0) && (ifailNonBending == 0)) {
835 // with Multiple Scattering if inversion correct
836 for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) {
837 trackParamAtHit1 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber1));
838 hitForRec1 = trackParamAtHit1->GetHitForRecPtr();
839 hbc1 = hitForRec1->GetBendingCoor();
840 pbc1 = trackParamAtHit1->GetBendingCoor();
841 hnbc1 = hitForRec1->GetNonBendingCoor();
842 pnbc1 = trackParamAtHit1->GetNonBendingCoor();
843 for (hitNumber2 = 0; hitNumber2 < numberOfHit; hitNumber2++) {
844 trackParamAtHit2 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber2));
845 hitForRec2 = trackParamAtHit2->GetHitForRecPtr();
846 hbc2 = hitForRec2->GetBendingCoor();
847 pbc2 = trackParamAtHit2->GetBendingCoor();
848 hnbc2 = hitForRec2->GetNonBendingCoor();
849 pnbc2 = trackParamAtHit2->GetNonBendingCoor();
850 Chi2 += ((*covBending)(hitNumber2, hitNumber1) * (hbc1 - pbc1) * (hbc2 - pbc2)) +
851 ((*covNonBending)(hitNumber2, hitNumber1) * (hnbc1 - pnbc1) * (hnbc2 - pnbc2));
855 // without Multiple Scattering if inversion impossible
856 for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) {
857 trackParamAtHit1 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber1));
858 hitForRec1 = trackParamAtHit1->GetHitForRecPtr();
859 hbc1 = hitForRec1->GetBendingCoor();
860 pbc1 = trackParamAtHit1->GetBendingCoor();
861 hnbc1 = hitForRec1->GetNonBendingCoor();
862 pnbc1 = trackParamAtHit1->GetNonBendingCoor();
863 Chi2 += ((hbc1 - pbc1) * (hbc1 - pbc1) / hitForRec1->GetBendingReso2()) +
864 ((hnbc1 - pnbc1) * (hnbc1 - pnbc1) / hitForRec1->GetNonBendingReso2());
869 delete covNonBending;
873 Double_t MultipleScatteringAngle2(AliMUONTrackParam *param)
875 /// Returns square of multiple Coulomb scattering angle
876 /// from TrackParamAtHit pointed to by "param"
877 Double_t slopeBending, slopeNonBending, radiationLength, inverseBendingMomentum2, inverseTotalMomentum2;
878 Double_t varMultipleScatteringAngle;
879 // Better implementation in AliMUONTrack class ????
880 slopeBending = param->GetBendingSlope();
881 slopeNonBending = param->GetNonBendingSlope();
882 // thickness in radiation length for the current track,
883 // taking local angle into account
884 radiationLength = AliMUONConstants::DefaultChamberThicknessInX0() *
885 TMath::Sqrt(1.0 + slopeBending*slopeBending + slopeNonBending*slopeNonBending);
886 inverseBendingMomentum2 = param->GetInverseBendingMomentum() * param->GetInverseBendingMomentum();
887 inverseTotalMomentum2 = inverseBendingMomentum2 * (1.0 + slopeBending * slopeBending) /
888 (1.0 + slopeBending *slopeBending + slopeNonBending * slopeNonBending);
889 varMultipleScatteringAngle = 0.0136 * (1.0 + 0.038 * TMath::Log(radiationLength));
890 // The velocity is assumed to be 1 !!!!
891 varMultipleScatteringAngle = inverseTotalMomentum2 * radiationLength * varMultipleScatteringAngle * varMultipleScatteringAngle;
892 return varMultipleScatteringAngle;
895 //______________________________________________________________________________
896 void mnvertLocal(Double_t *a, Int_t l, Int_t, Int_t n, Int_t &ifail)
898 ///*-*-*-*-*-*-*-*-*-*-*-*Inverts a symmetric matrix*-*-*-*-*-*-*-*-*-*-*-*-*
899 ///*-* ==========================
900 ///*-* inverts a symmetric matrix. matrix is first scaled to
901 ///*-* have all ones on the diagonal (equivalent to change of units)
902 ///*-* but no pivoting is done since matrix is positive-definite.
903 ///*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
905 // taken from TMinuit package of Root (l>=n)
906 // fVERTs, fVERTq and fVERTpp changed to localVERTs, localVERTq and localVERTpp
907 // Double_t localVERTs[n], localVERTq[n], localVERTpp[n];
908 Double_t * localVERTs = new Double_t[n];
909 Double_t * localVERTq = new Double_t[n];
910 Double_t * localVERTpp = new Double_t[n];
911 // fMaxint changed to localMaxint
912 Int_t localMaxint = n;
914 /* System generated locals */
917 /* Local variables */
919 Int_t i, j, k, kp1, km1;
921 /* Parameter adjustments */
927 if (n < 1) goto L100;
928 if (n > localMaxint) goto L100;
929 //*-*- scale matrix by sqrt of diag elements
930 for (i = 1; i <= n; ++i) {
932 if (si <= 0) goto L100;
933 localVERTs[i-1] = 1 / TMath::Sqrt(si);
935 for (i = 1; i <= n; ++i) {
936 for (j = 1; j <= n; ++j) {
937 a[i + j*l] = a[i + j*l]*localVERTs[i-1]*localVERTs[j-1];
940 //*-*- . . . start main loop . . . .
941 for (i = 1; i <= n; ++i) {
943 //*-*- preparation for elimination step1
944 if (a[k + k*l] != 0) localVERTq[k-1] = 1 / a[k + k*l];
946 localVERTpp[k-1] = 1;
950 if (km1 < 0) goto L100;
951 else if (km1 == 0) goto L50;
954 for (j = 1; j <= km1; ++j) {
955 localVERTpp[j-1] = a[j + k*l];
956 localVERTq[j-1] = a[j + k*l]*localVERTq[k-1];
960 if (k - n < 0) goto L51;
961 else if (k - n == 0) goto L60;
964 for (j = kp1; j <= n; ++j) {
965 localVERTpp[j-1] = a[k + j*l];
966 localVERTq[j-1] = -a[k + j*l]*localVERTq[k-1];
969 //*-*- elimination proper
971 for (j = 1; j <= n; ++j) {
972 for (k = j; k <= n; ++k) { a[j + k*l] += localVERTpp[j-1]*localVERTq[k-1]; }
975 //*-*- elements of left diagonal and unscaling
976 for (j = 1; j <= n; ++j) {
977 for (k = 1; k <= j; ++k) {
978 a[k + j*l] = a[k + j*l]*localVERTs[k-1]*localVERTs[j-1];
979 a[j + k*l] = a[k + j*l];
982 delete [] localVERTs;
983 delete [] localVERTq;
984 delete [] localVERTpp;
986 //*-*- failure return
988 delete [] localVERTs;
989 delete [] localVERTq;
990 delete [] localVERTpp;
994 //__________________________________________________________________________
995 void AliMUONTrackReconstructor::RemoveDoubleTracks(void)
997 /// To remove double tracks.
998 /// Tracks are considered identical
999 /// if they have at least half of their hits in common.
1000 /// Among two identical tracks, one keeps the track with the larger number of hits
1001 /// or, if these numbers are equal, the track with the minimum Chi2.
1002 AliMUONTrack *track1, *track2, *trackToRemove;
1003 Int_t hitsInCommon, nHits1, nHits2;
1004 Bool_t removedTrack1;
1005 // Loop over first track of the pair
1006 track1 = (AliMUONTrack*) fRecTracksPtr->First();
1008 removedTrack1 = kFALSE;
1009 nHits1 = track1->GetNTrackHits();
1010 // Loop over second track of the pair
1011 track2 = (AliMUONTrack*) fRecTracksPtr->After(track1);
1013 nHits2 = track2->GetNTrackHits();
1014 // number of hits in common between two tracks
1015 hitsInCommon = track1->HitsInCommon(track2);
1016 // check for identical tracks
1017 if ((4 * hitsInCommon) >= (nHits1 + nHits2)) {
1018 // decide which track to remove
1019 if ((nHits1 > nHits2) || ((nHits1 == nHits2) && (track1->GetFitFMin() < track2->GetFitFMin()))) {
1020 // remove track2 and continue the second loop with the track next to track2
1021 trackToRemove = track2;
1022 track2 = (AliMUONTrack*) fRecTracksPtr->After(track2);
1023 fRecTracksPtr->Remove(trackToRemove);
1025 fRecTracksPtr->Compress(); // this is essential to retrieve the TClonesArray afterwards
1027 // else remove track1 and continue the first loop with the track next to track1
1028 trackToRemove = track1;
1029 track1 = (AliMUONTrack*) fRecTracksPtr->After(track1);
1030 fRecTracksPtr->Remove(trackToRemove);
1032 fRecTracksPtr->Compress(); // this is essential to retrieve the TClonesArray afterwards
1033 removedTrack1 = kTRUE;
1036 } else track2 = (AliMUONTrack*) fRecTracksPtr->After(track2);
1038 if (removedTrack1) continue;
1039 track1 = (AliMUONTrack*) fRecTracksPtr->After(track1);
1044 //__________________________________________________________________________
1045 void AliMUONTrackReconstructor::UpdateHitForRecAtHit()
1047 /// Set cluster parameters after track fitting. Fill fHitForRecAtHit of AliMUONTrack's
1048 AliMUONTrack *track;
1049 AliMUONTrackParam *trackParamAtHit;
1050 track = (AliMUONTrack*) fRecTracksPtr->First();
1052 trackParamAtHit = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->First());
1053 while (trackParamAtHit) {
1054 track->AddHitForRecAtHit(trackParamAtHit->GetHitForRecPtr());
1055 trackParamAtHit = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->After(trackParamAtHit));
1057 track = (AliMUONTrack*) fRecTracksPtr->After(track);
1062 //__________________________________________________________________________
1063 void AliMUONTrackReconstructor::EventDump(void)
1065 /// Dump reconstructed event (track parameters at vertex and at first hit),
1066 /// and the particle parameters
1067 AliMUONTrack *track;
1068 AliMUONTrackParam *trackParam, *trackParam1;
1069 Double_t bendingSlope, nonBendingSlope, pYZ;
1070 Double_t pX, pY, pZ, x, y, z, c;
1071 Int_t trackIndex, nTrackHits;
1073 AliDebug(1,"****** enter EventDump ******");
1074 AliDebug(1, Form("Number of Reconstructed tracks : %d", fNRecTracks));
1076 fRecTracksPtr->Compress(); // for simple loop without "Next" since no hole
1077 // Loop over reconstructed tracks
1078 for (trackIndex = 0; trackIndex < fNRecTracks; trackIndex++) {
1079 AliDebug(1, Form("track number: %d", trackIndex));
1080 // function for each track for modularity ????
1081 track = (AliMUONTrack*) ((*fRecTracksPtr)[trackIndex]);
1082 nTrackHits = track->GetNTrackHits();
1083 AliDebug(1, Form("Number of track hits: %d ", nTrackHits));
1084 // track parameters at Vertex
1085 trackParam = track->GetTrackParamAtVertex();
1086 x = trackParam->GetNonBendingCoor();
1087 y = trackParam->GetBendingCoor();
1088 z = trackParam->GetZ();
1089 bendingSlope = trackParam->GetBendingSlope();
1090 nonBendingSlope = trackParam->GetNonBendingSlope();
1091 pYZ = 1/TMath::Abs(trackParam->GetInverseBendingMomentum());
1092 pZ = pYZ/TMath::Sqrt(1+bendingSlope*bendingSlope);
1093 pX = pZ * nonBendingSlope;
1094 pY = pZ * bendingSlope;
1095 c = TMath::Sign(1.0, trackParam->GetInverseBendingMomentum());
1096 AliDebug(1, Form("Track parameters at Vertex z= %f: X= %f Y= %f pX= %f pY= %f pZ= %f c= %f\n",
1097 z, x, y, pX, pY, pZ, c));
1099 // track parameters at first hit
1100 trackParam1 = (AliMUONTrackParam*) track->GetTrackParamAtHit()->First();
1101 x = trackParam1->GetNonBendingCoor();
1102 y = trackParam1->GetBendingCoor();
1103 z = trackParam1->GetZ();
1104 bendingSlope = trackParam1->GetBendingSlope();
1105 nonBendingSlope = trackParam1->GetNonBendingSlope();
1106 pYZ = 1/TMath::Abs(trackParam1->GetInverseBendingMomentum());
1107 pZ = pYZ/TMath::Sqrt(1.0 + bendingSlope * bendingSlope);
1108 pX = pZ * nonBendingSlope;
1109 pY = pZ * bendingSlope;
1110 c = TMath::Sign(1.0, trackParam1->GetInverseBendingMomentum());
1111 AliDebug(1, Form("track parameters at z= %f: X= %f Y= %f pX= %f pY= %f pZ= %f c= %f\n",
1112 z, x, y, pX, pY, pZ, c));
1114 // informations about generated particles NO !!!!!!!!
1116 // for (Int_t iPart = 0; iPart < np; iPart++) {
1117 // p = gAlice->Particle(iPart);
1118 // printf(" particle %d: type= %d px= %f py= %f pz= %f pdg= %d\n",
1119 // iPart, p->GetPdgCode(), p->Px(), p->Py(), p->Pz(), p->GetPdgCode());