Fixes for #86059: Install data when ALICE_ROOT does not point to source (Christian)
[u/mrichter/AliRoot.git] / MUON / AliMUONTrackReconstructor.cxx
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a9e2aefa 1/**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
3 * *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
6 * *
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 **************************************************************************/
15
cc87ebcd 16/* $Id$ */
17
3d1463c8 18//-----------------------------------------------------------------------------
7945aae7 19/// \class AliMUONTrackReconstructor
20/// MUON track reconstructor using the original method
21///
22/// This class contains as data:
23/// - the parameters for the track reconstruction
24///
25/// It contains as methods, among others:
26/// - MakeTracks to build the tracks
3d1463c8 27//-----------------------------------------------------------------------------
a9e2aefa 28
29f1b13a 29#include "AliMUONTrackReconstructor.h"
7ec3b9cf 30
29fc2c86 31#include "AliMUONConstants.h"
96ebe67e 32#include "AliMUONVCluster.h"
1fef78c8 33#include "AliMUONVClusterServer.h"
96ebe67e 34#include "AliMUONVClusterStore.h"
a9e2aefa 35#include "AliMUONTrack.h"
37827b29 36#include "AliMUONTrackParam.h"
37#include "AliMUONTrackExtrap.h"
5a240757 38#include "AliMUONRecoParam.h"
b709ac13 39
1fef78c8 40#include "AliMpArea.h"
41
8c343c7c 42#include "AliLog.h"
af743f54 43
208f139e 44#include <TMinuit.h>
af743f54 45#include <Riostream.h>
ea94c18b 46#include <TMath.h>
af743f54 47#include <TMatrixD.h>
ce8cd162 48#include <TClonesArray.h>
a9e2aefa 49
de2cd600 50// Functions to be minimized with Minuit
ea94c18b 51void TrackChi2(Int_t &nParam, Double_t *gradient, Double_t &chi2, Double_t *param, Int_t flag);
de2cd600 52
7945aae7 53/// \cond CLASSIMP
29f1b13a 54ClassImp(AliMUONTrackReconstructor) // Class implementation in ROOT context
7945aae7 55/// \endcond
a9e2aefa 56
019df241 57 //__________________________________________________________________________
a0dc65b4 58AliMUONTrackReconstructor::AliMUONTrackReconstructor(const AliMUONRecoParam* recoParam, AliMUONVClusterServer* clusterServer)
59 : AliMUONVTrackReconstructor(recoParam,clusterServer)
a9e2aefa 60{
96ebe67e 61 /// Constructor
a9e2aefa 62}
9cbdf048 63
019df241 64 //__________________________________________________________________________
ea94c18b 65AliMUONTrackReconstructor::~AliMUONTrackReconstructor()
a9e2aefa 66{
ea94c18b 67/// Destructor
68}
276c44b7 69
70 //__________________________________________________________________________
89c8d66d 71Bool_t AliMUONTrackReconstructor::MakeTrackCandidates(AliMUONVClusterStore& clusterStore)
de2cd600 72{
019df241 73 /// To make track candidates (assuming linear propagation if the flag fgkMakeTrackCandidatesFast is set to kTRUE):
208f139e 74 /// Start with segments station(1..) 4 or 5 then follow track in station 5 or 4.
96ebe67e 75 /// Good candidates are made of at least three clusters.
208f139e 76 /// Keep only best candidates or all of them according to the flag fgkTrackAllTracks.
b709ac13 77
208f139e 78 TClonesArray *segments;
208f139e 79 AliMUONTrack *track;
208f139e 80 Int_t iCandidate = 0;
96ebe67e 81 Bool_t clusterFound;
208f139e 82
de2cd600 83 AliDebug(1,"Enter MakeTrackCandidates");
de2cd600 84
3a7acd03 85 // Unless we're doing combined tracking, we'll clusterize all stations at once
86 Int_t firstChamber(0);
87 Int_t lastChamber(9);
88
a0dc65b4 89 if (GetRecoParam()->CombineClusterTrackReco()) {
3a7acd03 90 // ... Here's the exception : ask the clustering to reconstruct
91 // clusters *only* in station 4 and 5 for combined tracking
92 firstChamber = 6;
93 }
94
95 for (Int_t i = firstChamber; i <= lastChamber; ++i )
96 {
35be7ed7 97 if (fClusterServer && GetRecoParam()->UseChamber(i)) fClusterServer->Clusterize(i, clusterStore, AliMpArea(), GetRecoParam());
1fef78c8 98 }
99
208f139e 100 // Loop over stations(1..) 5 and 4 and make track candidates
ea94c18b 101 for (Int_t istat=4; istat>=3; istat--) {
102
208f139e 103 // Make segments in the station
9bf6860b 104 segments = MakeSegmentsBetweenChambers(clusterStore, 2*istat, 2*istat+1);
ea94c18b 105
208f139e 106 // Loop over segments
7ec3b9cf 107 for (Int_t iseg=0; iseg<segments->GetEntriesFast(); iseg++)
108 {
208f139e 109 AliDebug(1,Form("Making primary candidate(1..) %d",++iCandidate));
ea94c18b 110
208f139e 111 // Transform segments to tracks and put them at the end of fRecTracksPtr
a0dc65b4 112 track = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack((AliMUONObjectPair*)((*segments)[iseg]),GetRecoParam()->GetBendingVertexDispersion());
a9e2aefa 113 fNRecTracks++;
ea94c18b 114
96ebe67e 115 // Look for compatible cluster(s) in the other station
a0dc65b4 116 if (GetRecoParam()->MakeTrackCandidatesFast())
96ebe67e 117 clusterFound = FollowLinearTrackInStation(*track, clusterStore, 7-istat);
118 else clusterFound = FollowTrackInStation(*track, clusterStore, 7-istat);
019df241 119
89c8d66d 120 // Remove track if no cluster found on a requested station
121 // or abort tracking if there are too many candidates
6b191dea 122 if (GetRecoParam()->RequestStation(7-istat)) {
123 if (!clusterFound) {
124 fRecTracksPtr->Remove(track);
125 fNRecTracks--;
126 } else if (fNRecTracks > GetRecoParam()->GetMaxTrackCandidates()) {
4ea3f013 127 AliError(Form("Too many track candidates (%d tracks). Stop tracking.", fNRecTracks));
6b191dea 128 return kFALSE;
129 }
130 } else {
131 if ((fNRecTracks + segments->GetEntriesFast() - iseg - 1) > GetRecoParam()->GetMaxTrackCandidates()) {
4ea3f013 132 AliError(Form("Too many track candidates (%d tracks). Stop tracking.", fNRecTracks + segments->GetEntriesFast() - iseg - 1));
6b191dea 133 return kFALSE;
134 }
ea94c18b 135 }
136
a9e2aefa 137 }
ea94c18b 138
208f139e 139 }
ea94c18b 140
208f139e 141 // Keep all different tracks or only the best ones as required
a0dc65b4 142 if (GetRecoParam()->TrackAllTracks()) RemoveIdenticalTracks();
208f139e 143 else RemoveDoubleTracks();
144
145 AliDebug(1,Form("Number of good candidates = %d",fNRecTracks));
146
89c8d66d 147 return kTRUE;
148
a9e2aefa 149}
150
151 //__________________________________________________________________________
89c8d66d 152Bool_t AliMUONTrackReconstructor::MakeMoreTrackCandidates(AliMUONVClusterStore& clusterStore)
9bf6860b 153{
154 /// To make extra track candidates (assuming linear propagation if the flag fgkMakeTrackCandidatesFast is set to kTRUE):
155 /// clustering is supposed to be already done
156 /// Start with segments made of 1 cluster in each of the stations 4 and 5 then follow track in remaining chambers.
157 /// Good candidates are made of at least three clusters if both station are requested (two otherwise).
158 /// Keep only best candidates or all of them according to the flag fgkTrackAllTracks.
159
160 TClonesArray *segments;
89c8d66d 161 AliMUONObjectPair *segment;
9bf6860b 162 AliMUONTrack *track;
163 Int_t iCandidate = 0, iCurrentTrack, nCurrentTracks;
164 Bool_t clusterFound;
165
166 AliDebug(1,"Enter MakeMoreTrackCandidates");
167
168 // Double loop over chambers in stations(1..) 4 and 5 to make track candidates
169 for (Int_t ich1 = 6; ich1 <= 7; ich1++) {
170 for (Int_t ich2 = 8; ich2 <= 9; ich2++) {
171
172 // Make segments in the station
173 segments = MakeSegmentsBetweenChambers(clusterStore, ich1, ich2);
174
89c8d66d 175 /// Remove segments already attached to a track
176 RemoveUsedSegments(*segments);
177
9bf6860b 178 // Loop over segments
89c8d66d 179 for (Int_t iSegment=0; iSegment<segments->GetEntriesFast(); iSegment++)
9bf6860b 180 {
181 AliDebug(1,Form("Making primary candidate(1..) %d",++iCandidate));
89c8d66d 182 segment = (AliMUONObjectPair*) segments->UncheckedAt(iSegment);
9bf6860b 183
184 // Transform segments to tracks and put them at the end of fRecTracksPtr
185 iCurrentTrack = fRecTracksPtr->GetLast()+1;
89c8d66d 186 track = new ((*fRecTracksPtr)[iCurrentTrack]) AliMUONTrack(segment,GetRecoParam()->GetBendingVertexDispersion());
9bf6860b 187 fNRecTracks++;
188
189 // Look for compatible cluster(s) in the second chamber of station 5
89c8d66d 190 clusterFound = FollowLinearTrackInChamber(*track, clusterStore, 17-ich2);
9bf6860b 191
192 // skip the original track in case it has been removed
a0dc65b4 193 if (GetRecoParam()->TrackAllTracks() && clusterFound) iCurrentTrack++;
9bf6860b 194
195 // loop over every new tracks
196 nCurrentTracks = fRecTracksPtr->GetLast()+1;
197 while (iCurrentTrack < nCurrentTracks) {
198 track = (AliMUONTrack*) fRecTracksPtr->UncheckedAt(iCurrentTrack);
199
200 // Look for compatible cluster(s) in the second chamber of station 4
89c8d66d 201 FollowLinearTrackInChamber(*track, clusterStore, 13-ich1);
9bf6860b 202
203 iCurrentTrack++;
204 }
205
89c8d66d 206 // abort tracking if there are too many candidates
6b191dea 207 if ((fNRecTracks + segments->GetEntriesFast() - iSegment - 1) > GetRecoParam()->GetMaxTrackCandidates()) {
4ea3f013 208 AliError(Form("Too many track candidates (%d tracks). Stop tracking.", fNRecTracks + segments->GetEntriesFast() - iSegment - 1));
89c8d66d 209 return kFALSE;
210 }
211
9bf6860b 212 }
213
9bf6860b 214 }
215 }
216
89c8d66d 217 // Keep only the best tracks if required
218 if (!GetRecoParam()->TrackAllTracks()) RemoveDoubleTracks();
219 else fRecTracksPtr->Compress();
9bf6860b 220
221 AliDebug(1,Form("Number of good candidates = %d",fNRecTracks));
222
89c8d66d 223 return kTRUE;
224
9bf6860b 225}
226
227 //__________________________________________________________________________
89c8d66d 228Bool_t AliMUONTrackReconstructor::FollowTracks(AliMUONVClusterStore& clusterStore)
a9e2aefa 229{
2457f726 230 /// Follow tracks in stations(1..) 3, 2 and 1
208f139e 231 AliDebug(1,"Enter FollowTracks");
232
04b5ea16 233 AliMUONTrack *track, *nextTrack;
b709ac13 234 AliMUONTrackParam *trackParam, *nextTrackParam;
af743f54 235 Int_t currentNRecTracks;
208f139e 236
a0dc65b4 237 Double_t sigmaCut2 = GetRecoParam()->GetSigmaCutForTracking() *
238 GetRecoParam()->GetSigmaCutForTracking();
3304fa09 239
208f139e 240 for (Int_t station = 2; station >= 0; station--) {
ea94c18b 241
208f139e 242 // Save the actual number of reconstructed track in case of
243 // tracks are added or suppressed during the tracking procedure
244 // !! Do not compress fRecTracksPtr until the end of the loop over tracks !!
af743f54 245 currentNRecTracks = fNRecTracks;
ea94c18b 246
af743f54 247 for (Int_t iRecTrack = 0; iRecTrack <currentNRecTracks; iRecTrack++) {
208f139e 248 AliDebug(1,Form("FollowTracks: track candidate(1..) %d", iRecTrack+1));
ea94c18b 249
208f139e 250 track = (AliMUONTrack*) fRecTracksPtr->UncheckedAt(iRecTrack);
ea94c18b 251
208f139e 252 // Fit the track:
253 // Do not take into account the multiple scattering to speed up the fit
254 // Calculate the track parameter covariance matrix
9bf6860b 255 // If there is no cluster out of station 4 or 5 then use the vertex to better constrain the fit
256 if (((AliMUONTrackParam*) track->GetTrackParamAtCluster()->First())->GetClusterPtr()->GetChamberId() > 5)
257 Fit(*track, kFALSE, kTRUE, kTRUE);
96ebe67e 258 else Fit(*track, kFALSE, kFALSE, kTRUE);
ea94c18b 259
6b191dea 260 // remove tracks out of limits
261 if (!IsAcceptable(*((AliMUONTrackParam*)track->GetTrackParamAtCluster()->First()))) {
262 fRecTracksPtr->Remove(track);
263 fNRecTracks--;
264 continue;
89c8d66d 265 }
266
267 // remove track if the normalized chi2 is too high
268 if (track->GetNormalizedChi2() > sigmaCut2) {
9bf6860b 269 fRecTracksPtr->Remove(track);
89c8d66d 270 fNRecTracks--;
271 continue;
208f139e 272 }
ea94c18b 273
b709ac13 274 // save parameters from fit into smoothed parameters to complete track afterward
a0dc65b4 275 if (GetRecoParam()->ComplementTracks()) {
b709ac13 276
277 if (station==2) { // save track parameters on stations 4 and 5
278
279 // extrapolate track parameters and covariances at each cluster
4ea3f013 280 // remove the track in case of failure
281 if (!track->UpdateCovTrackParamAtCluster()) {
282 fRecTracksPtr->Remove(track);
283 fNRecTracks--;
284 continue;
285 }
b709ac13 286
287 // save them
96ebe67e 288 trackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->First();
b709ac13 289 while (trackParam) {
290 trackParam->SetSmoothParameters(trackParam->GetParameters());
291 trackParam->SetSmoothCovariances(trackParam->GetCovariances());
96ebe67e 292 trackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->After(trackParam);
b709ac13 293 }
294
295 } else { // or save track parameters on last station only
296
96ebe67e 297 trackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->First();
9bf6860b 298 if (trackParam->GetClusterPtr()->GetChamberId() < 2*(station+2)) {
b709ac13 299
9bf6860b 300 // save parameters from fit
301 trackParam->SetSmoothParameters(trackParam->GetParameters());
302 trackParam->SetSmoothCovariances(trackParam->GetCovariances());
b709ac13 303
9bf6860b 304 // save parameters extrapolated to the second chamber of the same station if it has been hit
305 nextTrackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->After(trackParam);
306 if (nextTrackParam->GetClusterPtr()->GetChamberId() < 2*(station+2)) {
307
308 // reset parameters and covariances
309 nextTrackParam->SetParameters(trackParam->GetParameters());
310 nextTrackParam->SetZ(trackParam->GetZ());
311 nextTrackParam->SetCovariances(trackParam->GetCovariances());
312
313 // extrapolate them to the z of the corresponding cluster
4ea3f013 314 // remove the track in case of failure
315 if (!AliMUONTrackExtrap::ExtrapToZCov(nextTrackParam, nextTrackParam->GetClusterPtr()->GetZ())) {
316 fRecTracksPtr->Remove(track);
317 fNRecTracks--;
318 continue;
319 }
9bf6860b 320
321 // save them
322 nextTrackParam->SetSmoothParameters(nextTrackParam->GetParameters());
323 nextTrackParam->SetSmoothCovariances(nextTrackParam->GetCovariances());
324
325 }
b709ac13 326
327 }
328
329 }
330
331 }
332
96ebe67e 333 // Look for compatible cluster(s) in station(0..) "station"
9bf6860b 334 if (!FollowTrackInStation(*track, clusterStore, station)) {
335
336 // Try to recover track if required
a0dc65b4 337 if (GetRecoParam()->RecoverTracks()) {
9bf6860b 338
339 // work on a copy of the track if this station is not required
340 // to keep the case where no cluster is reconstructed as a possible candidate
a0dc65b4 341 if (!GetRecoParam()->RequestStation(station)) {
9bf6860b 342 track = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(*track);
343 fNRecTracks++;
344 }
345
346 // try to recover
347 if (!RecoverTrack(*track, clusterStore, station)) {
348 // remove track if no cluster found
349 fRecTracksPtr->Remove(track);
350 fNRecTracks--;
351 }
352
a0dc65b4 353 } else if (GetRecoParam()->RequestStation(station)) {
9bf6860b 354 // remove track if no cluster found
355 fRecTracksPtr->Remove(track);
356 fNRecTracks--;
357 }
358
ea94c18b 359 }
360
89c8d66d 361 // abort tracking if there are too many candidates
362 if (fNRecTracks > GetRecoParam()->GetMaxTrackCandidates()) {
4ea3f013 363 AliError(Form("Too many track candidates (%d tracks). Stop tracking.", fNRecTracks));
89c8d66d 364 return kFALSE;
365 }
366
208f139e 367 }
ea94c18b 368
208f139e 369 // Compress fRecTracksPtr for the next step
370 fRecTracksPtr->Compress();
ea94c18b 371
208f139e 372 // Keep only the best tracks if required
a0dc65b4 373 if (!GetRecoParam()->TrackAllTracks()) RemoveDoubleTracks();
ea94c18b 374
208f139e 375 }
376
96ebe67e 377 // Last fit of track candidates with all stations
208f139e 378 // Take into account the multiple scattering and remove bad tracks
379 Int_t trackIndex = -1;
04b5ea16 380 track = (AliMUONTrack*) fRecTracksPtr->First();
04b5ea16 381 while (track) {
ea94c18b 382
04b5ea16 383 trackIndex++;
384 nextTrack = (AliMUONTrack*) fRecTracksPtr->After(track); // prepare next track
ea94c18b 385
96ebe67e 386 Fit(*track, kTRUE, kFALSE, kTRUE);
ea94c18b 387
208f139e 388 // Printout for debuging
389 if (AliLog::GetGlobalDebugLevel() >= 3) {
390 cout << "FollowTracks: track candidate(0..) " << trackIndex << " after final fit" << endl;
a9e2aefa 391 track->RecursiveDump();
208f139e 392 }
ea94c18b 393
208f139e 394 // Remove the track if the normalized chi2 is too high
3304fa09 395 if (track->GetNormalizedChi2() > sigmaCut2) {
208f139e 396 fRecTracksPtr->Remove(track);
397 fNRecTracks--;
6d9a2d45 398 track = nextTrack;
399 continue;
a9e2aefa 400 }
ea94c18b 401
b709ac13 402 // save parameters from fit into smoothed parameters to complete track afterward
a0dc65b4 403 if (GetRecoParam()->ComplementTracks()) {
b709ac13 404
96ebe67e 405 trackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->First();
9bf6860b 406 if (trackParam->GetClusterPtr()->GetChamberId() < 2) {
b709ac13 407
9bf6860b 408 // save parameters from fit
409 trackParam->SetSmoothParameters(trackParam->GetParameters());
410 trackParam->SetSmoothCovariances(trackParam->GetCovariances());
b709ac13 411
9bf6860b 412 // save parameters extrapolated to the second chamber of the same station if it has been hit
413 nextTrackParam = (AliMUONTrackParam*) track->GetTrackParamAtCluster()->After(trackParam);
414 if (nextTrackParam->GetClusterPtr()->GetChamberId() < 2) {
415
416 // reset parameters and covariances
417 nextTrackParam->SetParameters(trackParam->GetParameters());
418 nextTrackParam->SetZ(trackParam->GetZ());
419 nextTrackParam->SetCovariances(trackParam->GetCovariances());
420
421 // extrapolate them to the z of the corresponding cluster
4ea3f013 422 // remove the track in case of failure
423 if (!AliMUONTrackExtrap::ExtrapToZCov(nextTrackParam, nextTrackParam->GetClusterPtr()->GetZ())) {
424 fRecTracksPtr->Remove(track);
425 fNRecTracks--;
426 track = nextTrack;
427 continue;
428 }
9bf6860b 429
430 // save them
431 nextTrackParam->SetSmoothParameters(nextTrackParam->GetParameters());
432 nextTrackParam->SetSmoothCovariances(nextTrackParam->GetCovariances());
433
434 }
b709ac13 435
436 }
437
438 }
439
208f139e 440 track = nextTrack;
ea94c18b 441
208f139e 442 }
ea94c18b 443
208f139e 444 fRecTracksPtr->Compress();
445
89c8d66d 446 return kTRUE;
447
208f139e 448}
1a38e749 449
208f139e 450 //__________________________________________________________________________
9bf6860b 451Bool_t AliMUONTrackReconstructor::FollowTrackInChamber(AliMUONTrack &trackCandidate, AliMUONVClusterStore& clusterStore, Int_t nextChamber)
452{
453 /// Follow trackCandidate in chamber(0..) nextChamber and search for compatible cluster(s)
454 /// Keep all possibilities or only the best one(s) according to the flag fgkTrackAllTracks:
455 /// kTRUE: duplicate "trackCandidate" if there are several possibilities and add the new tracks at the end of
456 /// fRecTracksPtr to avoid conficts with other track candidates at this current stage of the tracking procedure.
457 /// Remove the obsolete "trackCandidate" at the end.
458 /// kFALSE: add only the best cluster(s) to the "trackCandidate". Try to add a couple of clusters in priority.
459 AliDebug(1,Form("Enter FollowTrackInChamber(1..) %d", nextChamber+1));
460
4ea3f013 461 Double_t chi2WithOneCluster = AliMUONTrack::MaxChi2();
a0dc65b4 462 Double_t maxChi2WithOneCluster = 2. * GetRecoParam()->GetSigmaCutForTracking() *
463 GetRecoParam()->GetSigmaCutForTracking(); // 2 because 2 quantities in chi2
9bf6860b 464 Double_t bestChi2WithOneCluster = maxChi2WithOneCluster;
465 Bool_t foundOneCluster = kFALSE;
466 AliMUONTrack *newTrack = 0x0;
467 AliMUONVCluster *cluster;
468 AliMUONTrackParam extrapTrackParam;
469 AliMUONTrackParam extrapTrackParamAtCh;
470 AliMUONTrackParam extrapTrackParamAtCluster;
471 AliMUONTrackParam bestTrackParamAtCluster;
472
473 // Get track parameters according to the propagation direction
474 if (nextChamber > 7) extrapTrackParamAtCh = *(AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->Last();
475 else extrapTrackParamAtCh = *(AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->First();
476
477 // Printout for debuging
478 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) {
479 cout<<endl<<"Track parameters and covariances at first cluster:"<<endl;
480 extrapTrackParamAtCh.GetParameters().Print();
481 extrapTrackParamAtCh.GetCovariances().Print();
482 }
483
484 // Add MCS effect
4663da9f 485 Int_t currentChamber = extrapTrackParamAtCh.GetClusterPtr()->GetChamberId();
486 AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(currentChamber),-1.);
9bf6860b 487
488 // Add MCS in the missing chamber(s) if any
9bf6860b 489 while (currentChamber > nextChamber + 1) {
490 // extrapolation to the missing chamber
491 currentChamber--;
4ea3f013 492 if (!AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(currentChamber))) return kFALSE;
9bf6860b 493 // add MCS effect
4663da9f 494 AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(currentChamber),-1.);
9bf6860b 495 }
496
497 //Extrapolate trackCandidate to chamber
4ea3f013 498 if (!AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(nextChamber))) return kFALSE;
9bf6860b 499
500 // Printout for debuging
501 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) {
502 cout<<endl<<"Track parameters and covariances at first cluster extrapolated to z = "<<AliMUONConstants::DefaultChamberZ(nextChamber)<<":"<<endl;
503 extrapTrackParamAtCh.GetParameters().Print();
504 extrapTrackParamAtCh.GetCovariances().Print();
505 }
506
507 // Printout for debuging
508 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
509 cout << "FollowTrackInStation: look for clusters in chamber(1..): " << nextChamber+1 << endl;
510 }
511
512 // Ask the clustering to reconstruct new clusters around the track position in the current chamber
513 // except for station 4 and 5 that are already entirely clusterized
a0dc65b4 514 if (GetRecoParam()->CombineClusterTrackReco()) {
9bf6860b 515 if (nextChamber < 6) AskForNewClustersInChamber(extrapTrackParamAtCh, clusterStore, nextChamber);
516 }
517
518 // Create iterators to loop over clusters in both chambers
519 TIter next(clusterStore.CreateChamberIterator(nextChamber,nextChamber));
520
521 // look for cluster in chamber
522 while ( ( cluster = static_cast<AliMUONVCluster*>(next()) ) ) {
523
524 // try to add the current cluster fast
525 if (!TryOneClusterFast(extrapTrackParamAtCh, cluster)) continue;
526
527 // try to add the current cluster accuratly
528 chi2WithOneCluster = TryOneCluster(extrapTrackParamAtCh, cluster, extrapTrackParamAtCluster);
529
530 // if good chi2 then consider to add cluster
531 if (chi2WithOneCluster < maxChi2WithOneCluster) {
532 foundOneCluster = kTRUE;
533
534 // Printout for debuging
535 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
536 cout << "FollowTrackInStation: found one cluster in chamber(1..): " << nextChamber+1
537 << " (Chi2 = " << chi2WithOneCluster << ")" << endl;
538 cluster->Print();
539 }
540
a0dc65b4 541 if (GetRecoParam()->TrackAllTracks()) {
9bf6860b 542 // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new cluster
543 newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate);
544 UpdateTrack(*newTrack,extrapTrackParamAtCluster);
545 fNRecTracks++;
546
547 // Printout for debuging
548 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
549 cout << "FollowTrackInStation: added one cluster in chamber(1..): " << nextChamber+1 << endl;
550 if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
551 }
552
553 } else if (chi2WithOneCluster < bestChi2WithOneCluster) {
554 // keep track of the best single cluster except if a couple of clusters has already been found
555 bestChi2WithOneCluster = chi2WithOneCluster;
556 bestTrackParamAtCluster = extrapTrackParamAtCluster;
557 }
558
559 }
560
561 }
562
563 // fill out the best track if required else clean up the fRecTracksPtr array
a0dc65b4 564 if (!GetRecoParam()->TrackAllTracks()) {
9bf6860b 565 if (foundOneCluster) {
566 UpdateTrack(trackCandidate,bestTrackParamAtCluster);
567
568 // Printout for debuging
569 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
570 cout << "FollowTrackInStation: added the best cluster in chamber(1..): " << bestTrackParamAtCluster.GetClusterPtr()->GetChamberId()+1 << endl;
571 if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
572 }
573
574 } else return kFALSE;
575
576 } else if (foundOneCluster) {
577
578 // remove obsolete track
579 fRecTracksPtr->Remove(&trackCandidate);
580 fNRecTracks--;
581
582 } else return kFALSE;
583
584 return kTRUE;
585
586}
587
588 //__________________________________________________________________________
1fef78c8 589Bool_t AliMUONTrackReconstructor::FollowTrackInStation(AliMUONTrack &trackCandidate, AliMUONVClusterStore& clusterStore, Int_t nextStation)
208f139e 590{
96ebe67e 591 /// Follow trackCandidate in station(0..) nextStation and search for compatible cluster(s)
208f139e 592 /// Keep all possibilities or only the best one(s) according to the flag fgkTrackAllTracks:
593 /// kTRUE: duplicate "trackCandidate" if there are several possibilities and add the new tracks at the end of
594 /// fRecTracksPtr to avoid conficts with other track candidates at this current stage of the tracking procedure.
595 /// Remove the obsolete "trackCandidate" at the end.
96ebe67e 596 /// kFALSE: add only the best cluster(s) to the "trackCandidate". Try to add a couple of clusters in priority.
208f139e 597 AliDebug(1,Form("Enter FollowTrackInStation(1..) %d", nextStation+1));
598
ea94c18b 599 // Order the chamber according to the propagation direction (tracking starts with chamber 2):
600 // - nextStation == station(1...) 5 => forward propagation
601 // - nextStation < station(1...) 5 => backward propagation
602 Int_t ch1, ch2;
603 if (nextStation==4) {
604 ch1 = 2*nextStation+1;
605 ch2 = 2*nextStation;
606 } else {
607 ch1 = 2*nextStation;
608 ch2 = 2*nextStation+1;
609 }
610
4ea3f013 611 Double_t chi2WithOneCluster = AliMUONTrack::MaxChi2();
612 Double_t chi2WithTwoClusters = AliMUONTrack::MaxChi2();
a0dc65b4 613 Double_t maxChi2WithOneCluster = 2. * GetRecoParam()->GetSigmaCutForTracking() *
614 GetRecoParam()->GetSigmaCutForTracking(); // 2 because 2 quantities in chi2
615 Double_t maxChi2WithTwoClusters = 4. * GetRecoParam()->GetSigmaCutForTracking() *
616 GetRecoParam()->GetSigmaCutForTracking(); // 4 because 4 quantities in chi2
96ebe67e 617 Double_t bestChi2WithOneCluster = maxChi2WithOneCluster;
618 Double_t bestChi2WithTwoClusters = maxChi2WithTwoClusters;
619 Bool_t foundOneCluster = kFALSE;
620 Bool_t foundTwoClusters = kFALSE;
208f139e 621 AliMUONTrack *newTrack = 0x0;
96ebe67e 622 AliMUONVCluster *clusterCh1, *clusterCh2;
019df241 623 AliMUONTrackParam extrapTrackParam;
7332f213 624 AliMUONTrackParam extrapTrackParamAtCh;
96ebe67e 625 AliMUONTrackParam extrapTrackParamAtCluster1;
626 AliMUONTrackParam extrapTrackParamAtCluster2;
627 AliMUONTrackParam bestTrackParamAtCluster1;
628 AliMUONTrackParam bestTrackParamAtCluster2;
629
7332f213 630 // Get track parameters according to the propagation direction
631 if (nextStation==4) extrapTrackParamAtCh = *(AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->Last();
632 else extrapTrackParamAtCh = *(AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->First();
ea94c18b 633
9bf6860b 634 // Printout for debuging
635 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) {
636 cout<<endl<<"Track parameters and covariances at first cluster:"<<endl;
637 extrapTrackParamAtCh.GetParameters().Print();
638 extrapTrackParamAtCh.GetCovariances().Print();
639 }
640
ea94c18b 641 // Add MCS effect
4663da9f 642 Int_t currentChamber = extrapTrackParamAtCh.GetClusterPtr()->GetChamberId();
643 AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(currentChamber),-1.);
ea94c18b 644
9bf6860b 645 // Add MCS in the missing chamber(s) if any
9bf6860b 646 while (ch1 < ch2 && currentChamber > ch2 + 1) {
ea94c18b 647 // extrapolation to the missing chamber
9bf6860b 648 currentChamber--;
4ea3f013 649 if (!AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(currentChamber))) return kFALSE;
ea94c18b 650 // add MCS effect
4663da9f 651 AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(currentChamber),-1.);
ea94c18b 652 }
653
654 //Extrapolate trackCandidate to chamber "ch2"
4ea3f013 655 if (!AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(ch2))) return kFALSE;
ea94c18b 656
208f139e 657 // Printout for debuging
658 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) {
9bf6860b 659 cout<<endl<<"Track parameters and covariances at first cluster extrapolated to z = "<<AliMUONConstants::DefaultChamberZ(ch2)<<":"<<endl;
660 extrapTrackParamAtCh.GetParameters().Print();
019df241 661 extrapTrackParamAtCh.GetCovariances().Print();
208f139e 662 }
ea94c18b 663
208f139e 664 // Printout for debuging
665 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
96ebe67e 666 cout << "FollowTrackInStation: look for clusters in chamber(1..): " << ch2+1 << endl;
208f139e 667 }
ea94c18b 668
1fef78c8 669 // Ask the clustering to reconstruct new clusters around the track position in the current station
670 // except for station 4 and 5 that are already entirely clusterized
a0dc65b4 671 if (GetRecoParam()->CombineClusterTrackReco()) {
1fef78c8 672 if (nextStation < 3) AskForNewClustersInStation(extrapTrackParamAtCh, clusterStore, nextStation);
673 }
674
4ea3f013 675 Int_t nClusters = clusterStore.GetSize();
676 Bool_t *clusterCh1Used = new Bool_t[nClusters];
677 for (Int_t i = 0; i < nClusters; i++) clusterCh1Used[i] = kFALSE;
678 Int_t iCluster1;
679
96ebe67e 680 // Create iterators to loop over clusters in both chambers
681 TIter nextInCh1(clusterStore.CreateChamberIterator(ch1,ch1));
682 TIter nextInCh2(clusterStore.CreateChamberIterator(ch2,ch2));
683
684 // look for candidates in chamber 2
685 while ( ( clusterCh2 = static_cast<AliMUONVCluster*>(nextInCh2()) ) ) {
ea94c18b 686
96ebe67e 687 // try to add the current cluster fast
688 if (!TryOneClusterFast(extrapTrackParamAtCh, clusterCh2)) continue;
019df241 689
96ebe67e 690 // try to add the current cluster accuratly
691 chi2WithOneCluster = TryOneCluster(extrapTrackParamAtCh, clusterCh2, extrapTrackParamAtCluster2);
ea94c18b 692
96ebe67e 693 // if good chi2 then try to attach a cluster in the other chamber too
694 if (chi2WithOneCluster < maxChi2WithOneCluster) {
695 Bool_t foundSecondCluster = kFALSE;
ea94c18b 696
208f139e 697 // Printout for debuging
698 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
96ebe67e 699 cout << "FollowTrackInStation: found one cluster in chamber(1..): " << ch2+1
700 << " (Chi2 = " << chi2WithOneCluster << ")" << endl;
9bf6860b 701 clusterCh2->Print();
96ebe67e 702 cout << " look for second clusters in chamber(1..): " << ch1+1 << " ..." << endl;
a9e2aefa 703 }
ea94c18b 704
705 // add MCS effect for next step
4663da9f 706 AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCluster2,AliMUONConstants::ChamberThicknessInX0(ch2),-1.);
ea94c18b 707
019df241 708 // copy new track parameters for next step
96ebe67e 709 extrapTrackParam = extrapTrackParamAtCluster2;
019df241 710
711 //Extrapolate track parameters to chamber "ch1"
4ea3f013 712 Bool_t normalExtrap = AliMUONTrackExtrap::ExtrapToZ(&extrapTrackParam, AliMUONConstants::DefaultChamberZ(ch1));
019df241 713
96ebe67e 714 // reset cluster iterator of chamber 1
715 nextInCh1.Reset();
716 iCluster1 = -1;
717
718 // look for second candidates in chamber 1
4ea3f013 719 if (normalExtrap) while ( ( clusterCh1 = static_cast<AliMUONVCluster*>(nextInCh1()) ) ) {
96ebe67e 720 iCluster1++;
ea94c18b 721
96ebe67e 722 // try to add the current cluster fast
723 if (!TryOneClusterFast(extrapTrackParam, clusterCh1)) continue;
019df241 724
4ea3f013 725 // try to add the current cluster accurately
96ebe67e 726 chi2WithTwoClusters = TryTwoClusters(extrapTrackParamAtCluster2, clusterCh1, extrapTrackParamAtCluster1);
ea94c18b 727
96ebe67e 728 // if good chi2 then create a new track by adding the 2 clusters to the "trackCandidate"
729 if (chi2WithTwoClusters < maxChi2WithTwoClusters) {
730 foundSecondCluster = kTRUE;
731 foundTwoClusters = kTRUE;
ea94c18b 732
733 // Printout for debuging
734 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
96ebe67e 735 cout << "FollowTrackInStation: found second cluster in chamber(1..): " << ch1+1
9bf6860b 736 << " (Global Chi2 = " << chi2WithTwoClusters << ")" << endl;
737 clusterCh1->Print();
ea94c18b 738 }
739
a0dc65b4 740 if (GetRecoParam()->TrackAllTracks()) {
96ebe67e 741 // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new clusters
ea94c18b 742 newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate);
96ebe67e 743 UpdateTrack(*newTrack,extrapTrackParamAtCluster1,extrapTrackParamAtCluster2);
208f139e 744 fNRecTracks++;
ea94c18b 745
96ebe67e 746 // Tag clusterCh1 as used
747 clusterCh1Used[iCluster1] = kTRUE;
ea94c18b 748
208f139e 749 // Printout for debuging
750 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
96ebe67e 751 cout << "FollowTrackInStation: added two clusters in station(1..): " << nextStation+1 << endl;
208f139e 752 if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
a9e2aefa 753 }
ea94c18b 754
96ebe67e 755 } else if (chi2WithTwoClusters < bestChi2WithTwoClusters) {
756 // keep track of the best couple of clusters
757 bestChi2WithTwoClusters = chi2WithTwoClusters;
758 bestTrackParamAtCluster1 = extrapTrackParamAtCluster1;
759 bestTrackParamAtCluster2 = extrapTrackParamAtCluster2;
208f139e 760 }
ea94c18b 761
a9e2aefa 762 }
ea94c18b 763
d0bfce8d 764 }
ea94c18b 765
96ebe67e 766 // if no clusterCh1 found then consider to add clusterCh2 only
767 if (!foundSecondCluster) {
768 foundOneCluster = kTRUE;
ea94c18b 769
a0dc65b4 770 if (GetRecoParam()->TrackAllTracks()) {
96ebe67e 771 // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new cluster
ea94c18b 772 newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate);
96ebe67e 773 UpdateTrack(*newTrack,extrapTrackParamAtCluster2);
208f139e 774 fNRecTracks++;
ea94c18b 775
208f139e 776 // Printout for debuging
777 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
96ebe67e 778 cout << "FollowTrackInStation: added one cluster in chamber(1..): " << ch2+1 << endl;
208f139e 779 if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
780 }
ea94c18b 781
96ebe67e 782 } else if (!foundTwoClusters && chi2WithOneCluster < bestChi2WithOneCluster) {
783 // keep track of the best single cluster except if a couple of clusters has already been found
784 bestChi2WithOneCluster = chi2WithOneCluster;
785 bestTrackParamAtCluster1 = extrapTrackParamAtCluster2;
208f139e 786 }
ea94c18b 787
d0bfce8d 788 }
ea94c18b 789
208f139e 790 }
ea94c18b 791
208f139e 792 }
ea94c18b 793
208f139e 794 // look for candidates in chamber 1 not already attached to a track
96ebe67e 795 // if we want to keep all possible tracks or if no good couple of clusters has been found
a0dc65b4 796 if (GetRecoParam()->TrackAllTracks() || !foundTwoClusters) {
ea94c18b 797
ea94c18b 798 // add MCS effect for next step
4663da9f 799 AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(ch2),-1.);
019df241 800
801 //Extrapolate trackCandidate to chamber "ch1"
4ea3f013 802 Bool_t normalExtrap = AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(ch1));
019df241 803
9bf6860b 804 // Printout for debuging
805 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) {
806 cout<<endl<<"Track parameters and covariances at first cluster extrapolated to z = "<<AliMUONConstants::DefaultChamberZ(ch1)<<":"<<endl;
807 extrapTrackParamAtCh.GetParameters().Print();
808 extrapTrackParamAtCh.GetCovariances().Print();
809 }
810
811 // Printout for debuging
812 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
813 cout << "FollowTrackInStation: look for single clusters in chamber(1..): " << ch1+1 << endl;
814 }
815
96ebe67e 816 // reset cluster iterator of chamber 1
817 nextInCh1.Reset();
818 iCluster1 = -1;
819
820 // look for second candidates in chamber 1
4ea3f013 821 if (normalExtrap) while ( ( clusterCh1 = static_cast<AliMUONVCluster*>(nextInCh1()) ) ) {
96ebe67e 822 iCluster1++;
ea94c18b 823
96ebe67e 824 if (clusterCh1Used[iCluster1]) continue; // Skip cluster already used
ea94c18b 825
96ebe67e 826 // try to add the current cluster fast
827 if (!TryOneClusterFast(extrapTrackParamAtCh, clusterCh1)) continue;
019df241 828
96ebe67e 829 // try to add the current cluster accuratly
830 chi2WithOneCluster = TryOneCluster(extrapTrackParamAtCh, clusterCh1, extrapTrackParamAtCluster1);
9bf6860b 831
96ebe67e 832 // if good chi2 then consider to add clusterCh1
833 // We do not try to attach a cluster in the other chamber too since it has already been done above
834 if (chi2WithOneCluster < maxChi2WithOneCluster) {
835 foundOneCluster = kTRUE;
9bf6860b 836
ea94c18b 837 // Printout for debuging
838 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
96ebe67e 839 cout << "FollowTrackInStation: found one cluster in chamber(1..): " << ch1+1
840 << " (Chi2 = " << chi2WithOneCluster << ")" << endl;
9bf6860b 841 clusterCh1->Print();
ea94c18b 842 }
843
a0dc65b4 844 if (GetRecoParam()->TrackAllTracks()) {
96ebe67e 845 // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new cluster
ea94c18b 846 newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate);
96ebe67e 847 UpdateTrack(*newTrack,extrapTrackParamAtCluster1);
208f139e 848 fNRecTracks++;
ea94c18b 849
850 // Printout for debuging
208f139e 851 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
96ebe67e 852 cout << "FollowTrackInStation: added one cluster in chamber(1..): " << ch1+1 << endl;
208f139e 853 if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
854 }
ea94c18b 855
96ebe67e 856 } else if (chi2WithOneCluster < bestChi2WithOneCluster) {
857 // keep track of the best single cluster except if a couple of clusters has already been found
858 bestChi2WithOneCluster = chi2WithOneCluster;
859 bestTrackParamAtCluster1 = extrapTrackParamAtCluster1;
208f139e 860 }
ea94c18b 861
d0bfce8d 862 }
ea94c18b 863
208f139e 864 }
ea94c18b 865
208f139e 866 }
ea94c18b 867
208f139e 868 // fill out the best track if required else clean up the fRecTracksPtr array
a0dc65b4 869 if (!GetRecoParam()->TrackAllTracks()) {
96ebe67e 870 if (foundTwoClusters) {
871 UpdateTrack(trackCandidate,bestTrackParamAtCluster1,bestTrackParamAtCluster2);
ea94c18b 872
208f139e 873 // Printout for debuging
874 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
96ebe67e 875 cout << "FollowTrackInStation: added the two best clusters in station(1..): " << nextStation+1 << endl;
208f139e 876 if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
a9e2aefa 877 }
ea94c18b 878
96ebe67e 879 } else if (foundOneCluster) {
880 UpdateTrack(trackCandidate,bestTrackParamAtCluster1);
ea94c18b 881
208f139e 882 // Printout for debuging
883 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
96ebe67e 884 cout << "FollowTrackInStation: added the best cluster in chamber(1..): " << bestTrackParamAtCluster1.GetClusterPtr()->GetChamberId()+1 << endl;
208f139e 885 if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump();
04b5ea16 886 }
ea94c18b 887
dd230855 888 } else {
96ebe67e 889 delete [] clusterCh1Used;
dd230855 890 return kFALSE;
891 }
ea94c18b 892
96ebe67e 893 } else if (foundOneCluster || foundTwoClusters) {
ea94c18b 894
895 // remove obsolete track
896 fRecTracksPtr->Remove(&trackCandidate);
897 fNRecTracks--;
898
dd230855 899 } else {
96ebe67e 900 delete [] clusterCh1Used;
dd230855 901 return kFALSE;
902 }
ea94c18b 903
96ebe67e 904 delete [] clusterCh1Used;
ea94c18b 905 return kTRUE;
906
907}
908
909 //__________________________________________________________________________
96ebe67e 910Double_t AliMUONTrackReconstructor::TryTwoClusters(const AliMUONTrackParam &trackParamAtCluster1, AliMUONVCluster* cluster2,
911 AliMUONTrackParam &trackParamAtCluster2)
ea94c18b 912{
96ebe67e 913/// Test the compatibility between the track and the 2 clusters together (using trackParam's covariance matrix):
914/// return the corresponding Chi2 accounting for covariances between the 2 clusters
915/// return trackParamAtCluster1 & 2
ea94c18b 916
96ebe67e 917 // extrapolate track parameters at the z position of the second cluster (no need to extrapolate the covariances)
4ea3f013 918 // and set pointer to cluster into trackParamAtCluster
96ebe67e 919 trackParamAtCluster2.SetParameters(trackParamAtCluster1.GetParameters());
920 trackParamAtCluster2.SetZ(trackParamAtCluster1.GetZ());
96ebe67e 921 trackParamAtCluster2.SetClusterPtr(cluster2);
4ea3f013 922 if (!AliMUONTrackExtrap::ExtrapToZ(&trackParamAtCluster2, cluster2->GetZ())) return 2.*AliMUONTrack::MaxChi2();
ea94c18b 923
96ebe67e 924 // Set differences between track and the 2 clusters in the bending and non bending directions
925 AliMUONVCluster* cluster1 = trackParamAtCluster1.GetClusterPtr();
ea94c18b 926 TMatrixD dPos(4,1);
96ebe67e 927 dPos(0,0) = cluster1->GetX() - trackParamAtCluster1.GetNonBendingCoor();
928 dPos(1,0) = cluster1->GetY() - trackParamAtCluster1.GetBendingCoor();
929 dPos(2,0) = cluster2->GetX() - trackParamAtCluster2.GetNonBendingCoor();
930 dPos(3,0) = cluster2->GetY() - trackParamAtCluster2.GetBendingCoor();
ea94c18b 931
96ebe67e 932 // Calculate the error matrix from the track parameter covariances at first cluster
ea94c18b 933 TMatrixD error(4,4);
934 error.Zero();
96ebe67e 935 if (trackParamAtCluster1.CovariancesExist()) {
936 // Save track parameters at first cluster
937 TMatrixD paramAtCluster1Save(trackParamAtCluster1.GetParameters());
938
939 // Save track coordinates at second cluster
940 Double_t nonBendingCoor2 = trackParamAtCluster2.GetNonBendingCoor();
941 Double_t bendingCoor2 = trackParamAtCluster2.GetBendingCoor();
ea94c18b 942
96ebe67e 943 // copy track parameters at first cluster for jacobian calculation
944 AliMUONTrackParam trackParam(trackParamAtCluster1);
ea94c18b 945
96ebe67e 946 // Get the pointer to the parameter covariance matrix at first cluster
947 const TMatrixD& kParamCov = trackParam.GetCovariances();
ea94c18b 948
949 // Calculate the jacobian related to the transformation between track parameters
96ebe67e 950 // at first cluster and track coordinates at the 2 cluster z-positions
ea94c18b 951 TMatrixD jacob(4,5);
952 jacob.Zero();
96ebe67e 953 // first derivative at the first cluster:
ea94c18b 954 jacob(0,0) = 1.; // dx1/dx
955 jacob(1,2) = 1.; // dy1/dy
96ebe67e 956 // first derivative at the second cluster:
ea94c18b 957 TMatrixD dParam(5,1);
6b191dea 958 Double_t direction[5] = {-1.,-1.,1.,1.,-1.};
ea94c18b 959 for (Int_t i=0; i<5; i++) {
960 // Skip jacobian calculation for parameters with no associated error
961 if (kParamCov(i,i) == 0.) continue;
962 // Small variation of parameter i only
963 for (Int_t j=0; j<5; j++) {
964 if (j==i) {
965 dParam(j,0) = TMath::Sqrt(kParamCov(i,i));
6b191dea 966 dParam(j,0) *= TMath::Sign(1.,direction[j]*paramAtCluster1Save(j,0)); // variation always in the same direction
ea94c18b 967 } else dParam(j,0) = 0.;
968 }
969
96ebe67e 970 // Set new track parameters at first cluster
971 trackParam.SetParameters(paramAtCluster1Save);
972 trackParam.AddParameters(dParam);
973 trackParam.SetZ(cluster1->GetZ());
ea94c18b 974
96ebe67e 975 // Extrapolate new track parameters to the z position of the second cluster
4ea3f013 976 if (!AliMUONTrackExtrap::ExtrapToZ(&trackParam,cluster2->GetZ())) return 2.*AliMUONTrack::MaxChi2();
ea94c18b 977
978 // Calculate the jacobian
96ebe67e 979 jacob(2,i) = (trackParam.GetNonBendingCoor() - nonBendingCoor2) / dParam(i,0); // dx2/dParami
980 jacob(3,i) = (trackParam.GetBendingCoor() - bendingCoor2 ) / dParam(i,0); // dy2/dParami
208f139e 981 }
ea94c18b 982
983 // Calculate the error matrix
984 TMatrixD tmp(jacob,TMatrixD::kMult,kParamCov);
985 error = TMatrixD(tmp,TMatrixD::kMultTranspose,jacob);
986 }
987
96ebe67e 988 // Add cluster resolution to the error matrix
989 error(0,0) += cluster1->GetErrX2();
990 error(1,1) += cluster1->GetErrY2();
991 error(2,2) += cluster2->GetErrX2();
992 error(3,3) += cluster2->GetErrY2();
ea94c18b 993
994 // invert the error matrix for Chi2 calculation
995 if (error.Determinant() != 0) {
996 error.Invert();
208f139e 997 } else {
ea94c18b 998 AliWarning(" Determinant error=0");
4ea3f013 999 return 2.*AliMUONTrack::MaxChi2();
208f139e 1000 }
1001
ea94c18b 1002 // Compute the Chi2 value
1003 TMatrixD tmp2(dPos,TMatrixD::kTransposeMult,error);
1004 TMatrixD result(tmp2,TMatrixD::kMult,dPos);
1005
1006 return result(0,0);
1007
1008}
1009
1010 //__________________________________________________________________________
96ebe67e 1011void AliMUONTrackReconstructor::UpdateTrack(AliMUONTrack &track, AliMUONTrackParam &trackParamAtCluster)
ea94c18b 1012{
96ebe67e 1013 /// Add 1 cluster to the track candidate
ea94c18b 1014 /// Update chi2 of the track
1015
1016 // Compute local chi2
96ebe67e 1017 AliMUONVCluster* cluster = trackParamAtCluster.GetClusterPtr();
1018 Double_t deltaX = trackParamAtCluster.GetNonBendingCoor() - cluster->GetX();
1019 Double_t deltaY = trackParamAtCluster.GetBendingCoor() - cluster->GetY();
1020 Double_t localChi2 = deltaX*deltaX / cluster->GetErrX2() +
1021 deltaY*deltaY / cluster->GetErrY2();
ea94c18b 1022
96ebe67e 1023 // Flag cluster as being not removable
a0dc65b4 1024 if (GetRecoParam()->RequestStation(cluster->GetChamberId()/2))
9bf6860b 1025 trackParamAtCluster.SetRemovable(kFALSE);
1026 else trackParamAtCluster.SetRemovable(kTRUE);
96ebe67e 1027 trackParamAtCluster.SetLocalChi2(0.); // --> Local chi2 not used
5f4ceff2 1028
ea94c18b 1029 // Update the chi2 of the new track
96ebe67e 1030 track.SetGlobalChi2(track.GetGlobalChi2() + localChi2);
ea94c18b 1031
96ebe67e 1032 // Update TrackParamAtCluster
1033 track.AddTrackParamAtCluster(trackParamAtCluster,*cluster);
ea94c18b 1034
04b5ea16 1035}
1036
1037 //__________________________________________________________________________
96ebe67e 1038void AliMUONTrackReconstructor::UpdateTrack(AliMUONTrack &track, AliMUONTrackParam &trackParamAtCluster1, AliMUONTrackParam &trackParamAtCluster2)
ea94c18b 1039{
96ebe67e 1040 /// Add 2 clusters to the track candidate
ea94c18b 1041 /// Update track and local chi2
1042
96ebe67e 1043 // Update local chi2 at first cluster
1044 AliMUONVCluster* cluster1 = trackParamAtCluster1.GetClusterPtr();
1045 Double_t deltaX = trackParamAtCluster1.GetNonBendingCoor() - cluster1->GetX();
1046 Double_t deltaY = trackParamAtCluster1.GetBendingCoor() - cluster1->GetY();
1047 Double_t localChi2AtCluster1 = deltaX*deltaX / cluster1->GetErrX2() +
1048 deltaY*deltaY / cluster1->GetErrY2();
1049 trackParamAtCluster1.SetLocalChi2(localChi2AtCluster1);
ea94c18b 1050
96ebe67e 1051 // Flag first cluster as being removable
1052 trackParamAtCluster1.SetRemovable(kTRUE);
ea94c18b 1053
96ebe67e 1054 // Update local chi2 at second cluster
1055 AliMUONVCluster* cluster2 = trackParamAtCluster2.GetClusterPtr();
1056 deltaX = trackParamAtCluster2.GetNonBendingCoor() - cluster2->GetX();
1057 deltaY = trackParamAtCluster2.GetBendingCoor() - cluster2->GetY();
1058 Double_t localChi2AtCluster2 = deltaX*deltaX / cluster2->GetErrX2() +
1059 deltaY*deltaY / cluster2->GetErrY2();
1060 trackParamAtCluster2.SetLocalChi2(localChi2AtCluster2);
ea94c18b 1061
96ebe67e 1062 // Flag first cluster as being removable
1063 trackParamAtCluster2.SetRemovable(kTRUE);
ea94c18b 1064
1065 // Update the chi2 of the new track
96ebe67e 1066 track.SetGlobalChi2(track.GetGlobalChi2() + localChi2AtCluster1 + localChi2AtCluster2);
ea94c18b 1067
96ebe67e 1068 // Update TrackParamAtCluster
1069 track.AddTrackParamAtCluster(trackParamAtCluster1,*cluster1);
1070 track.AddTrackParamAtCluster(trackParamAtCluster2,*cluster2);
ea94c18b 1071
1072}
1073
1074 //__________________________________________________________________________
1fef78c8 1075Bool_t AliMUONTrackReconstructor::RecoverTrack(AliMUONTrack &trackCandidate, AliMUONVClusterStore& clusterStore, Int_t nextStation)
ea94c18b 1076{
1077 /// Try to recover the track candidate in the next station
96ebe67e 1078 /// by removing the worst of the two clusters attached in the current station
ea94c18b 1079 /// Return kTRUE if recovering succeeds
1080 AliDebug(1,"Enter RecoverTrack");
1081
96ebe67e 1082 // Do not try to recover track until we have attached cluster(s) on station(1..) 3
ea94c18b 1083 if (nextStation > 1) return kFALSE;
1084
96ebe67e 1085 Int_t worstClusterNumber = -1;
9bf6860b 1086 Double_t localChi2, worstLocalChi2 = -1.;
ea94c18b 1087
96ebe67e 1088 // Look for the cluster to remove
1089 for (Int_t clusterNumber = 0; clusterNumber < 2; clusterNumber++) {
1090 AliMUONTrackParam *trackParamAtCluster = (AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->UncheckedAt(clusterNumber);
ea94c18b 1091
9bf6860b 1092 // check if current cluster is in the previous station
1093 if (trackParamAtCluster->GetClusterPtr()->GetChamberId()/2 != nextStation+1) break;
1094
96ebe67e 1095 // check if current cluster is removable
1096 if (!trackParamAtCluster->IsRemovable()) return kFALSE;
ea94c18b 1097
9bf6860b 1098 // reset the current cluster as beig not removable if it is on a required station
a0dc65b4 1099 if (GetRecoParam()->RequestStation(nextStation+1)) trackParamAtCluster->SetRemovable(kFALSE);
9bf6860b 1100
96ebe67e 1101 // Pick up cluster with the worst chi2
1102 localChi2 = trackParamAtCluster->GetLocalChi2();
ea94c18b 1103 if (localChi2 > worstLocalChi2) {
1104 worstLocalChi2 = localChi2;
96ebe67e 1105 worstClusterNumber = clusterNumber;
ea94c18b 1106 }
9bf6860b 1107
ea94c18b 1108 }
1109
9bf6860b 1110 // check if worst cluster found
1111 if (worstClusterNumber < 0) return kFALSE;
ea94c18b 1112
96ebe67e 1113 // Remove the worst cluster
1114 trackCandidate.RemoveTrackParamAtCluster((AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->UncheckedAt(worstClusterNumber));
ea94c18b 1115
1116 // Re-fit the track:
1117 // Do not take into account the multiple scattering to speed up the fit
1118 // Calculate the track parameter covariance matrix
96ebe67e 1119 Fit(trackCandidate, kFALSE, kFALSE, kTRUE);
ea94c18b 1120
4ea3f013 1121 // skip track if the normalized chi2 is too high
1122 if (trackCandidate.GetNormalizedChi2() > GetRecoParam()->GetSigmaCutForTracking() * GetRecoParam()->GetSigmaCutForTracking()) return kFALSE;
1123
6b191dea 1124 // skip track out of limits
1125 if (!IsAcceptable(*((AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->First()))) return kFALSE;
89c8d66d 1126
96ebe67e 1127 // Look for new cluster(s) in next station
1128 return FollowTrackInStation(trackCandidate,clusterStore,nextStation);
ea94c18b 1129
1130}
1131
1132 //__________________________________________________________________________
96ebe67e 1133void AliMUONTrackReconstructor::SetVertexErrXY2ForFit(AliMUONTrack &trackCandidate)
de2cd600 1134{
96ebe67e 1135 /// Compute the vertex resolution square from natural vertex dispersion and
208f139e 1136 /// multiple scattering effets according to trackCandidate path in absorber
1137 /// It is necessary to account for multiple scattering effects here instead of during the fit of
1138 /// the "trackCandidate" to do not influence the result by changing track resolution at vertex
1139 AliDebug(1,"Enter SetVertexForFit");
de2cd600 1140
a0dc65b4 1141 Double_t nonBendingReso2 = GetRecoParam()->GetNonBendingVertexDispersion() *
1142 GetRecoParam()->GetNonBendingVertexDispersion();
1143 Double_t bendingReso2 = GetRecoParam()->GetBendingVertexDispersion() *
1144 GetRecoParam()->GetBendingVertexDispersion();
96ebe67e 1145
208f139e 1146 // add multiple scattering effets
96ebe67e 1147 AliMUONTrackParam paramAtVertex(*((AliMUONTrackParam*)(trackCandidate.GetTrackParamAtCluster()->First())));
208f139e 1148 paramAtVertex.DeleteCovariances(); // to be sure to account only for multiple scattering
4ea3f013 1149 if (!AliMUONTrackExtrap::ExtrapToZ(&paramAtVertex,AliMUONConstants::AbsZEnd())) {
1150 nonBendingReso2 = 0.;
1151 bendingReso2 = 0.;
1152 } else {
1153 AliMUONTrackExtrap::ExtrapToVertexUncorrected(&paramAtVertex,0.);
1154 const TMatrixD& kParamCov = paramAtVertex.GetCovariances();
1155 nonBendingReso2 += kParamCov(0,0);
1156 bendingReso2 += kParamCov(2,2);
1157 }
96ebe67e 1158
1159 // Set the vertex resolution square
1160 trackCandidate.SetVertexErrXY2(nonBendingReso2,bendingReso2);
208f139e 1161}
1162
1163 //__________________________________________________________________________
96ebe67e 1164void AliMUONTrackReconstructor::Fit(AliMUONTrack &track, Bool_t includeMCS, Bool_t fitWithVertex, Bool_t calcCov)
208f139e 1165{
96ebe67e 1166 /// Fit the track
1167 /// w/wo multiple Coulomb scattering according to "includeMCS".
1168 /// w/wo constraining the vertex according to "fitWithVertex".
1169 /// calculating or not the covariance matrix according to "calcCov".
7332f213 1170 AliDebug(1,"Enter Fit");
de2cd600 1171
208f139e 1172 Double_t benC, errorParam, invBenP, nonBenC, x, y;
de2cd600 1173 AliMUONTrackParam *trackParam;
96ebe67e 1174 Double_t arg[1], fedm, errdef, globalChi2;
208f139e 1175 Int_t npari, nparx;
1176 Int_t status, covStatus;
1177
8cde4af5 1178 // Instantiate gMinuit if not already done
1179 if (!gMinuit) gMinuit = new TMinuit(6);
208f139e 1180 // Clear MINUIT parameters
1181 gMinuit->mncler();
1182 // Give the fitted track to MINUIT
ea94c18b 1183 gMinuit->SetObjectFit(&track);
208f139e 1184 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) {
1185 // Define print level
1186 arg[0] = 1;
1187 gMinuit->mnexcm("SET PRI", arg, 1, status);
1188 // Print covariance matrix
1189 gMinuit->mnexcm("SHO COV", arg, 0, status);
1190 } else {
1191 arg[0] = -1;
1192 gMinuit->mnexcm("SET PRI", arg, 1, status);
1193 }
de2cd600 1194 // No warnings
208f139e 1195 gMinuit->mnexcm("SET NOW", arg, 0, status);
1196 // Define strategy
1197 //arg[0] = 2;
1198 //gMinuit->mnexcm("SET STR", arg, 1, status);
1199
ea94c18b 1200 // set flag w/wo multiple scattering according to "includeMCS"
96ebe67e 1201 track.FitWithMCS(includeMCS);
ea94c18b 1202 if (includeMCS) {
96ebe67e 1203 // compute cluster weights only once
4ea3f013 1204 if (!track.UpdateTrackParamAtCluster() || !track.ComputeClusterWeights()) {
ea94c18b 1205 AliWarning("cannot take into account the multiple scattering effects");
96ebe67e 1206 track.FitWithMCS(kFALSE);
ea94c18b 1207 }
1208 }
1209
96ebe67e 1210 track.FitWithVertex(fitWithVertex);
1211 if (fitWithVertex) SetVertexErrXY2ForFit(track);
1212
ea94c18b 1213 // Set fitting function
1214 gMinuit->SetFCN(TrackChi2);
208f139e 1215
1216 // Set fitted parameters (!! The order is very important for the covariance matrix !!)
9bf6860b 1217 // Mandatory limits to avoid NaN values of parameters
96ebe67e 1218 trackParam = (AliMUONTrackParam*) (track.GetTrackParamAtCluster()->First());
a0dc65b4 1219 Double_t maxIBM = 1. / GetRecoParam()->GetMinBendingMomentum();
208f139e 1220 gMinuit->mnparm(0, "X", trackParam->GetNonBendingCoor(), 0.03, -500.0, 500.0, status);
9bf6860b 1221 gMinuit->mnparm(1, "NonBenS", trackParam->GetNonBendingSlope(), 0.001, -1., 1., status);
208f139e 1222 gMinuit->mnparm(2, "Y", trackParam->GetBendingCoor(), 0.10, -500.0, 500.0, status);
9bf6860b 1223 gMinuit->mnparm(3, "BenS", trackParam->GetBendingSlope(), 0.001, -1.5, 1.5, status);
1224 gMinuit->mnparm(4, "InvBenP", trackParam->GetInverseBendingMomentum(), 0.003, -maxIBM, maxIBM, status);
208f139e 1225
de2cd600 1226 // minimization
208f139e 1227 gMinuit->mnexcm("MIGRAD", arg, 0, status);
1228
1229 // Calculate the covariance matrix more accurately if required
1230 if (calcCov) gMinuit->mnexcm("HESSE", arg, 0, status);
8cde4af5 1231
de2cd600 1232 // get results into "invBenP", "benC", "nonBenC" ("x", "y")
208f139e 1233 gMinuit->GetParameter(0, x, errorParam);
1234 trackParam->SetNonBendingCoor(x);
1235 gMinuit->GetParameter(1, nonBenC, errorParam);
de2cd600 1236 trackParam->SetNonBendingSlope(nonBenC);
208f139e 1237 gMinuit->GetParameter(2, y, errorParam);
1238 trackParam->SetBendingCoor(y);
1239 gMinuit->GetParameter(3, benC, errorParam);
1240 trackParam->SetBendingSlope(benC);
1241 gMinuit->GetParameter(4, invBenP, errorParam);
1242 trackParam->SetInverseBendingMomentum(invBenP);
1243
de2cd600 1244 // global result of the fit
96ebe67e 1245 gMinuit->mnstat(globalChi2, fedm, errdef, npari, nparx, covStatus);
1246 track.SetGlobalChi2(globalChi2);
208f139e 1247
1248 // Get the covariance matrix if required
1249 if (calcCov) {
1250 // Covariance matrix according to HESSE status
1251 // If problem then keep only the diagonal terms (variances)
1252 Double_t matrix[5][5];
d373bcbe 1253 for (Int_t i=0; i<5; i++) for (Int_t j=0; j<5; j++) matrix[i][j] = 0.;
208f139e 1254 gMinuit->mnemat(&matrix[0][0],5);
1255 if (covStatus == 3) trackParam->SetCovariances(matrix);
1256 else trackParam->SetVariances(matrix);
ea94c18b 1257 } else trackParam->DeleteCovariances();
208f139e 1258
de2cd600 1259}
1260
1261 //__________________________________________________________________________
ea94c18b 1262void TrackChi2(Int_t & /*nParam*/, Double_t * /*gradient*/, Double_t &chi2, Double_t *param, Int_t /*flag*/)
de2cd600 1263{
ea94c18b 1264 /// Return the "Chi2" to be minimized with Minuit for track fitting.
96ebe67e 1265 /// Assumes that the trackParamAtCluster are sorted according to increasing Z.
1266 /// Track parameters at each cluster are updated accordingly.
ea94c18b 1267 /// Vertex is used according to the flag "trackBeingFitted->GetFitWithVertex()".
1268 /// Multiple Coulomb scattering is taken into account according to the flag "trackBeingFitted->GetFitWithMCS()".
208f139e 1269
1270 AliMUONTrack *trackBeingFitted = (AliMUONTrack*) gMinuit->GetObjectFit();
96ebe67e 1271 AliMUONTrackParam* trackParamAtCluster = (AliMUONTrackParam*) trackBeingFitted->GetTrackParamAtCluster()->First();
208f139e 1272 Double_t dX, dY;
ea94c18b 1273 chi2 = 0.; // initialize chi2
208f139e 1274
ea94c18b 1275 // update track parameters
96ebe67e 1276 trackParamAtCluster->SetNonBendingCoor(param[0]);
1277 trackParamAtCluster->SetNonBendingSlope(param[1]);
1278 trackParamAtCluster->SetBendingCoor(param[2]);
1279 trackParamAtCluster->SetBendingSlope(param[3]);
1280 trackParamAtCluster->SetInverseBendingMomentum(param[4]);
4ea3f013 1281 if (!trackBeingFitted->UpdateTrackParamAtCluster()) {
1282 chi2 = 2.*AliMUONTrack::MaxChi2();
1283 return;
1284 }
208f139e 1285
1286 // Take the vertex into account in the fit if required
96ebe67e 1287 if (trackBeingFitted->FitWithVertex()) {
1288 Double_t nonBendingReso2,bendingReso2;
1289 trackBeingFitted->GetVertexErrXY2(nonBendingReso2,bendingReso2);
4ea3f013 1290 AliMUONTrackParam paramAtVertex(*trackParamAtCluster);
1291 if (nonBendingReso2 != 0. && bendingReso2 != 0. && AliMUONTrackExtrap::ExtrapToZ(&paramAtVertex, 0.)) { // vextex position = (0,0,0)
96ebe67e 1292 dX = paramAtVertex.GetNonBendingCoor();
1293 dY = paramAtVertex.GetBendingCoor();
1294 chi2 += dX * dX / nonBendingReso2 + dY * dY / bendingReso2;
4ea3f013 1295 } else {
1296 chi2 = 2.*AliMUONTrack::MaxChi2();
1297 return;
208f139e 1298 }
de2cd600 1299 }
208f139e 1300
ea94c18b 1301 // compute chi2 w/wo multiple scattering
96ebe67e 1302 chi2 += trackBeingFitted->ComputeGlobalChi2(trackBeingFitted->FitWithMCS());
b709ac13 1303
1304}
1305
1306 //__________________________________________________________________________
89c8d66d 1307Bool_t AliMUONTrackReconstructor::ComplementTracks(const AliMUONVClusterStore& clusterStore)
b709ac13 1308{
1309 /// Complete tracks by adding missing clusters (if there is an overlap between
89c8d66d 1310 /// two detection elements, the track may have two clusters in the same chamber).
1311 /// Re-fit track parameters and covariances.
1312 /// Return kTRUE if one or more tracks have been complemented.
b709ac13 1313 AliDebug(1,"Enter ComplementTracks");
1314
1315 Int_t chamberId, detElemId;
96ebe67e 1316 Double_t chi2OfCluster, bestChi2OfCluster;
a0dc65b4 1317 Double_t sigmaCut2 = GetRecoParam()->GetSigmaCutForTracking() *
1318 GetRecoParam()->GetSigmaCutForTracking();
89c8d66d 1319 Bool_t foundOneCluster, trackModified, hasChanged = kFALSE;
96ebe67e 1320 AliMUONVCluster* cluster;
1321 AliMUONTrackParam *trackParam, *nextTrackParam, copyOfTrackParam, trackParamAtCluster, bestTrackParamAtCluster;
b709ac13 1322
b709ac13 1323 AliMUONTrack *track = (AliMUONTrack*) fRecTracksPtr->First();
1324 while (track) {
1325 trackModified = kFALSE;
1326
96ebe67e 1327 trackParam = (AliMUONTrackParam*)track->GetTrackParamAtCluster()->First();
b709ac13 1328 while (trackParam) {
96ebe67e 1329 foundOneCluster = kFALSE;
1330 bestChi2OfCluster = 2. * sigmaCut2; // 2 because 2 quantities in chi2
1331 chamberId = trackParam->GetClusterPtr()->GetChamberId();
1332 detElemId = trackParam->GetClusterPtr()->GetDetElemId();
b709ac13 1333
1334 // prepare nextTrackParam before adding new cluster because of the sorting
96ebe67e 1335 nextTrackParam = (AliMUONTrackParam*)track->GetTrackParamAtCluster()->After(trackParam);
b709ac13 1336
1337 // recover track parameters from local fit and put them into a copy of trackParam
1338 copyOfTrackParam.SetZ(trackParam->GetZ());
1339 copyOfTrackParam.SetParameters(trackParam->GetSmoothParameters());
1340 copyOfTrackParam.SetCovariances(trackParam->GetSmoothCovariances());
1341
96ebe67e 1342 // Create iterators to loop over clusters in current chamber
1343 TIter nextInCh(clusterStore.CreateChamberIterator(chamberId,chamberId));
1344
b709ac13 1345 // look for one second candidate in the same chamber
96ebe67e 1346 while ( ( cluster = static_cast<AliMUONVCluster*>(nextInCh()) ) ) {
b709ac13 1347
1348 // look for a cluster in another detection element
96ebe67e 1349 if (cluster->GetDetElemId() == detElemId) continue;
b709ac13 1350
96ebe67e 1351 // try to add the current cluster fast
1352 if (!TryOneClusterFast(copyOfTrackParam, cluster)) continue;
b709ac13 1353
96ebe67e 1354 // try to add the current cluster accurately
1355 chi2OfCluster = TryOneCluster(copyOfTrackParam, cluster, trackParamAtCluster);
b709ac13 1356
1357 // if better chi2 then prepare to add this cluster to the track
96ebe67e 1358 if (chi2OfCluster < bestChi2OfCluster) {
1359 bestChi2OfCluster = chi2OfCluster;
1360 bestTrackParamAtCluster = trackParamAtCluster;
1361 foundOneCluster = kTRUE;
b709ac13 1362 }
1363
1364 }
1365
1366 // add new cluster if any
96ebe67e 1367 if (foundOneCluster) {
0e894e58 1368
1369 // Printout for debuging
1370 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
1371 cout << "ComplementTracks: found one cluster in chamber(1..): " << chamberId+1 << endl;
1372 bestTrackParamAtCluster.GetClusterPtr()->Print();
1373 cout<<endl<<"Track parameters and covariances at cluster:"<<endl;
1374 bestTrackParamAtCluster.GetParameters().Print();
1375 bestTrackParamAtCluster.GetCovariances().Print();
1376 }
1377
7332f213 1378 trackParam->SetRemovable(kTRUE);
1379 bestTrackParamAtCluster.SetRemovable(kTRUE);
1380 track->AddTrackParamAtCluster(bestTrackParamAtCluster,*(bestTrackParamAtCluster.GetClusterPtr()));
b709ac13 1381 trackModified = kTRUE;
89c8d66d 1382 hasChanged = kTRUE;
b709ac13 1383 }
1384
1385 trackParam = nextTrackParam;
1386 }
1387
1388 // re-fit track parameters if needed
96ebe67e 1389 if (trackModified) Fit(*track, kTRUE, kFALSE, kTRUE);
b709ac13 1390
1391 track = (AliMUONTrack*) fRecTracksPtr->After(track);
1392 }
ea94c18b 1393
89c8d66d 1394 return hasChanged;
1395
de2cd600 1396}
1397
1398 //__________________________________________________________________________
7332f213 1399void AliMUONTrackReconstructor::ImproveTrack(AliMUONTrack &track)
de2cd600 1400{
7332f213 1401 /// Improve the given track by removing clusters with local chi2 highter than the defined cut
ea94c18b 1402 /// Recompute track parameters and covariances at the remaining clusters
7332f213 1403 AliDebug(1,"Enter ImproveTrack");
208f139e 1404
ea94c18b 1405 Double_t localChi2, worstLocalChi2;
7332f213 1406 AliMUONTrackParam *trackParamAtCluster, *worstTrackParamAtCluster;
a0dc65b4 1407 Double_t sigmaCut2 = GetRecoParam()->GetSigmaCutForImprovement() *
1408 GetRecoParam()->GetSigmaCutForImprovement();
208f139e 1409
7332f213 1410 while (!track.IsImproved()) {
ea94c18b 1411
7332f213 1412 // identify removable clusters
a0dc65b4 1413 track.TagRemovableClusters(GetRecoParam()->RequestedStationMask());
b709ac13 1414
7332f213 1415 // Update track parameters and covariances
4ea3f013 1416 if (!track.UpdateCovTrackParamAtCluster()) {
1417 AliWarning("unable to update track parameters and covariances --> stop improvement");
1418 break;
1419 }
7332f213 1420
1421 // Compute local chi2 of each clusters
1422 track.ComputeLocalChi2(kTRUE);
1423
1424 // Look for the cluster to remove
1425 worstTrackParamAtCluster = NULL;
1426 worstLocalChi2 = 0.;
1427 trackParamAtCluster = (AliMUONTrackParam*) track.GetTrackParamAtCluster()->First();
1428 while (trackParamAtCluster) {
ea94c18b 1429
7332f213 1430 // Pick up cluster with the worst chi2
1431 localChi2 = trackParamAtCluster->GetLocalChi2();
1432 if (localChi2 > worstLocalChi2) {
1433 worstLocalChi2 = localChi2;
1434 worstTrackParamAtCluster = trackParamAtCluster;
ea94c18b 1435 }
1436
7332f213 1437 trackParamAtCluster = (AliMUONTrackParam*) track.GetTrackParamAtCluster()->After(trackParamAtCluster);
1438 }
1439
1440 // Check if worst cluster found
1441 if (!worstTrackParamAtCluster) {
1442 AliWarning("Bad local chi2 values?");
1443 break;
1444 }
1445
1446 // Check whether the worst chi2 is under requirement or not
1447 if (worstLocalChi2 < 2. * sigmaCut2) { // 2 because 2 quantities in chi2
1448 track.SetImproved(kTRUE);
1449 break;
1450 }
1451
1452 // if the worst cluster is not removable then stop improvement
1453 if (!worstTrackParamAtCluster->IsRemovable()) break;
1454
1455 // Remove the worst cluster
1456 track.RemoveTrackParamAtCluster(worstTrackParamAtCluster);
1457
1458 // Re-fit the track:
1459 // Take into account the multiple scattering
1460 // Calculate the track parameter covariance matrix
1461 Fit(track, kTRUE, kFALSE, kTRUE);
1462
1463 // Printout for debuging
1464 if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) {
1465 cout << "ImproveTracks: track " << fRecTracksPtr->IndexOf(&track)+1 << " improved " << endl;
de2cd600 1466 }
ea94c18b 1467
de2cd600 1468 }
1469
de2cd600 1470}
1471
208f139e 1472 //__________________________________________________________________________
4ea3f013 1473Bool_t AliMUONTrackReconstructor::FinalizeTrack(AliMUONTrack &track)
b8dc484b 1474{
7332f213 1475 /// Recompute track parameters and covariances at each attached cluster
1476 /// from those at the first one, if not already done
1477 AliDebug(1,"Enter FinalizeTrack");
4ea3f013 1478 if (!track.IsImproved() && !track.UpdateCovTrackParamAtCluster()) {
1479 AliWarning("finalization failed due to extrapolation problem");
1480 return kFALSE;
1481 }
1482 return kTRUE;
a9e2aefa 1483}
1484
9bf6860b 1485 //__________________________________________________________________________
b1fea02e 1486Bool_t AliMUONTrackReconstructor::RefitTrack(AliMUONTrack &track, Bool_t enableImprovement)
7deb8eb0 1487{
1488 /// re-fit the given track
1489
1490 // check validity of the track
ad3c6eda 1491 if (track.GetNClusters() < 3) {
7deb8eb0 1492 AliWarning("the track does not contain enough clusters --> unable to refit");
1493 return kFALSE;
1494 }
1495
1496 // reset the seed (i.e. parameters at first cluster) before fitting
1497 AliMUONTrackParam* firstTrackParam = (AliMUONTrackParam*) track.GetTrackParamAtCluster()->First();
1498 if (firstTrackParam->GetInverseBendingMomentum() == 0.) {
1499 AliWarning("track parameters at first chamber are not initialized --> unable to refit");
1500 return kFALSE;
1501 }
1502
1503 // compute track parameters at each cluster from parameters at the first one
1504 // necessary to compute multiple scattering effect during refitting
4ea3f013 1505 if (!track.UpdateTrackParamAtCluster()) {
1506 AliWarning("bad track refitting due to extrapolation failure");
1507 return kFALSE;
1508 }
7deb8eb0 1509
1510 // Re-fit the track:
1511 // Take into account the multiple scattering
1512 // Calculate the track parameter covariance matrix
1513 Fit(track, kTRUE, kFALSE, kTRUE);
1514
1515 // Improve the reconstructed tracks if required
b1fea02e 1516 track.SetImproved(kFALSE);
a0dc65b4 1517 if (enableImprovement && GetRecoParam()->ImproveTracks()) ImproveTrack(track);
7deb8eb0 1518
1519 // Fill AliMUONTrack data members
4ea3f013 1520 if (track.GetGlobalChi2() < AliMUONTrack::MaxChi2()) return FinalizeTrack(track);
1521 else {
1522 AliWarning("track not finalized due to extrapolation failure");
1523 return kFALSE;
1524 }
7deb8eb0 1525
1526}
1527