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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 | ||
16 | /* $Id$ */ | |
17 | ||
18 | //----------------------------------------------------------------------------- | |
19 | /// \class AliMUONTrackReconstructorK | |
20 | /// | |
21 | /// MUON track reconstructor using the kalman method | |
22 | /// | |
23 | /// This class contains as data: | |
24 | /// - the parameters for the track reconstruction | |
25 | /// | |
26 | /// It contains as methods, among others: | |
27 | /// - MakeTracks to build the tracks | |
28 | /// | |
29 | //----------------------------------------------------------------------------- | |
30 | ||
31 | #include "AliMUONTrackReconstructorK.h" | |
32 | ||
33 | #include "AliMUONConstants.h" | |
34 | #include "AliMUONVCluster.h" | |
35 | #include "AliMUONVClusterServer.h" | |
36 | #include "AliMUONVClusterStore.h" | |
37 | #include "AliMUONTrack.h" | |
38 | #include "AliMUONTrackParam.h" | |
39 | #include "AliMUONTrackExtrap.h" | |
40 | #include "AliMUONRecoParam.h" | |
41 | ||
42 | #include "AliMpArea.h" | |
43 | ||
44 | #include "AliLog.h" | |
45 | ||
46 | #include <Riostream.h> | |
47 | #include <TMath.h> | |
48 | #include <TMatrixD.h> | |
49 | #include <TClonesArray.h> | |
50 | ||
51 | /// \cond CLASSIMP | |
52 | ClassImp(AliMUONTrackReconstructorK) // Class implementation in ROOT context | |
53 | /// \endcond | |
54 | ||
55 | //__________________________________________________________________________ | |
56 | AliMUONTrackReconstructorK::AliMUONTrackReconstructorK(const AliMUONRecoParam* recoParam, AliMUONVClusterServer* clusterServer) | |
57 | : AliMUONVTrackReconstructor(recoParam, clusterServer) | |
58 | { | |
59 | /// Constructor | |
60 | } | |
61 | ||
62 | //__________________________________________________________________________ | |
63 | AliMUONTrackReconstructorK::~AliMUONTrackReconstructorK() | |
64 | { | |
65 | /// Destructor | |
66 | } | |
67 | ||
68 | //__________________________________________________________________________ | |
69 | Bool_t AliMUONTrackReconstructorK::MakeTrackCandidates(AliMUONVClusterStore& clusterStore) | |
70 | { | |
71 | /// To make track candidates (assuming linear propagation if AliMUONRecoParam::MakeTrackCandidatesFast() return kTRUE): | |
72 | /// Start with segments station(1..) 4 or 5 then follow track in station 5 or 4. | |
73 | /// Good candidates are made of at least three clusters if both stations are requested (two otherwise). | |
74 | /// Keep only best candidates or all of them according to the flag AliMUONRecoParam::TrackAllTracks(). | |
75 | ||
76 | TClonesArray *segments; | |
77 | AliMUONObjectPair *segment; | |
78 | AliMUONTrack *track; | |
79 | Int_t iCandidate = 0; | |
80 | Bool_t clusterFound; | |
81 | ||
82 | AliDebug(1,"Enter MakeTrackCandidates"); | |
83 | ||
84 | // Unless we're doing combined tracking, we'll clusterize all stations at once | |
85 | Int_t firstChamber(0); | |
86 | Int_t lastChamber(9); | |
87 | ||
88 | if (GetRecoParam()->CombineClusterTrackReco()) { | |
89 | // ... Here's the exception : ask the clustering to reconstruct | |
90 | // clusters *only* in station 4 and 5 for combined tracking | |
91 | firstChamber = 6; | |
92 | } | |
93 | ||
94 | for (Int_t i = firstChamber; i <= lastChamber; ++i ) | |
95 | { | |
96 | if (fClusterServer && GetRecoParam()->UseChamber(i)) fClusterServer->Clusterize(i, clusterStore, AliMpArea(), GetRecoParam()); | |
97 | } | |
98 | ||
99 | // Loop over stations(1..) 5 and 4 and make track candidates | |
100 | for (Int_t istat=4; istat>=3; istat--) { | |
101 | ||
102 | // Make segments in the station | |
103 | segments = MakeSegmentsBetweenChambers(clusterStore, 2*istat, 2*istat+1); | |
104 | ||
105 | // Loop over segments | |
106 | for (Int_t iSegment=0; iSegment<segments->GetEntriesFast(); iSegment++) { | |
107 | AliDebug(1,Form("Making primary candidate(1..) %d",++iCandidate)); | |
108 | segment = (AliMUONObjectPair*) segments->UncheckedAt(iSegment); | |
109 | ||
110 | // Transform segments to tracks and put them at the end of fRecTracksPtr | |
111 | track = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(segment,GetRecoParam()->GetBendingVertexDispersion()); | |
112 | fNRecTracks++; | |
113 | ||
114 | // Look for compatible cluster(s) in the other station | |
115 | if (GetRecoParam()->MakeTrackCandidatesFast()) clusterFound = FollowLinearTrackInStation(*track, clusterStore, 7-istat); | |
116 | else clusterFound = FollowTrackInStation(*track, clusterStore, 7-istat); | |
117 | ||
118 | // Remove track if no cluster found on a requested station | |
119 | // or abort tracking if there are too many candidates | |
120 | if (GetRecoParam()->RequestStation(7-istat)) { | |
121 | if (!clusterFound) { | |
122 | fRecTracksPtr->Remove(track); | |
123 | fNRecTracks--; | |
124 | } else if (fNRecTracks > GetRecoParam()->GetMaxTrackCandidates()) { | |
125 | AliError(Form("Too many track candidates (%d tracks). Stop tracking.", fNRecTracks)); | |
126 | delete segments; | |
127 | return kFALSE; | |
128 | } | |
129 | } else { | |
130 | if ((fNRecTracks + segments->GetEntriesFast() - iSegment - 1) > GetRecoParam()->GetMaxTrackCandidates()) { | |
131 | AliError(Form("Too many track candidates (%d tracks). Stop tracking.", fNRecTracks + segments->GetEntriesFast() - iSegment - 1)); | |
132 | delete segments; | |
133 | return kFALSE; | |
134 | } | |
135 | } | |
136 | ||
137 | } | |
138 | ||
139 | // delete the array of segments | |
140 | delete segments; | |
141 | } | |
142 | ||
143 | // Keep all different tracks if required | |
144 | if (GetRecoParam()->TrackAllTracks()) RemoveIdenticalTracks(); | |
145 | ||
146 | // Retrace tracks using Kalman filter and select them if needed | |
147 | Int_t nCurrentTracks = fRecTracksPtr->GetLast()+1; | |
148 | for (Int_t iRecTrack = 0; iRecTrack < nCurrentTracks; iRecTrack++) { | |
149 | track = (AliMUONTrack*) fRecTracksPtr->UncheckedAt(iRecTrack); | |
150 | ||
151 | // skip empty slots | |
152 | if(!track) continue; | |
153 | ||
154 | // retrace tracks using Kalman filter and remove the ones for which extrap failed or that are out of limits | |
155 | if (!RetraceTrack(*track,kTRUE) || !IsAcceptable(*((AliMUONTrackParam*)track->GetTrackParamAtCluster()->First()))) { | |
156 | fRecTracksPtr->Remove(track); | |
157 | fNRecTracks--; | |
158 | } | |
159 | ||
160 | } | |
161 | ||
162 | // Keep only the best tracks if required | |
163 | if (!GetRecoParam()->TrackAllTracks()) RemoveDoubleTracks(); | |
164 | else fRecTracksPtr->Compress(); | |
165 | ||
166 | AliDebug(1,Form("Number of good candidates = %d",fNRecTracks)); | |
167 | ||
168 | return kTRUE; | |
169 | ||
170 | } | |
171 | ||
172 | //__________________________________________________________________________ | |
173 | Bool_t AliMUONTrackReconstructorK::MakeMoreTrackCandidates(AliMUONVClusterStore& clusterStore) | |
174 | { | |
175 | /// To make extra track candidates assuming linear propagation: | |
176 | /// clustering is supposed to be already done | |
177 | /// Start with segments made of 1 cluster in each of the stations 4 and 5 then follow track in remaining chambers. | |
178 | /// Good candidates are made of at least three clusters if both stations are requested (two otherwise). | |
179 | /// Keep only best candidates or all of them according to the flag fgkTrackAllTracks. | |
180 | ||
181 | TClonesArray *segments; | |
182 | AliMUONObjectPair *segment; | |
183 | AliMUONTrack *track; | |
184 | Int_t iCandidate = 0, iCurrentTrack, nCurrentTracks; | |
185 | Int_t initialNRecTracks = fNRecTracks; | |
186 | Bool_t clusterFound; | |
187 | ||
188 | AliDebug(1,"Enter MakeMoreTrackCandidates"); | |
189 | ||
190 | // Double loop over chambers in stations(1..) 4 and 5 to make track candidates | |
191 | for (Int_t ich1 = 6; ich1 <= 7; ich1++) { | |
192 | for (Int_t ich2 = 8; ich2 <= 9; ich2++) { | |
193 | ||
194 | // Make segments between ch1 and ch2 | |
195 | segments = MakeSegmentsBetweenChambers(clusterStore, ich1, ich2); | |
196 | ||
197 | /// Remove segments already attached to a track | |
198 | RemoveUsedSegments(*segments); | |
199 | ||
200 | // Loop over segments | |
201 | for (Int_t iSegment=0; iSegment<segments->GetEntriesFast(); iSegment++) { | |
202 | AliDebug(1,Form("Making primary candidate(1..) %d",++iCandidate)); | |
203 | segment = (AliMUONObjectPair*) segments->UncheckedAt(iSegment); | |
204 | ||
205 | // Transform segments to tracks and put them at the end of fRecTracksPtr | |
206 | iCurrentTrack = fRecTracksPtr->GetLast()+1; | |
207 | track = new ((*fRecTracksPtr)[iCurrentTrack]) AliMUONTrack(segment,GetRecoParam()->GetBendingVertexDispersion()); | |
208 | fNRecTracks++; | |
209 | ||
210 | // Look for compatible cluster(s) in the second chamber of station 5 | |
211 | clusterFound = FollowLinearTrackInChamber(*track, clusterStore, 17-ich2); | |
212 | ||
213 | // skip the original track in case it has been removed | |
214 | if (GetRecoParam()->TrackAllTracks() && clusterFound) iCurrentTrack++; | |
215 | ||
216 | // loop over every new tracks | |
217 | nCurrentTracks = fRecTracksPtr->GetLast()+1; | |
218 | while (iCurrentTrack < nCurrentTracks) { | |
219 | track = (AliMUONTrack*) fRecTracksPtr->UncheckedAt(iCurrentTrack); | |
220 | ||
221 | // Look for compatible cluster(s) in the second chamber of station 4 | |
222 | FollowLinearTrackInChamber(*track, clusterStore, 13-ich1); | |
223 | ||
224 | iCurrentTrack++; | |
225 | } | |
226 | ||
227 | // abort tracking if there are too many candidates | |
228 | if ((fNRecTracks + segments->GetEntriesFast() - iSegment - 1) > GetRecoParam()->GetMaxTrackCandidates()) { | |
229 | AliError(Form("Too many track candidates (%d tracks). Stop tracking.", fNRecTracks + segments->GetEntriesFast() - iSegment - 1)); | |
230 | delete segments; | |
231 | return kFALSE; | |
232 | } | |
233 | ||
234 | } | |
235 | ||
236 | // delete the array of segments | |
237 | delete segments; | |
238 | } | |
239 | } | |
240 | ||
241 | // Retrace tracks using Kalman filter (also compute track chi2) and select them | |
242 | nCurrentTracks = fRecTracksPtr->GetLast()+1; | |
243 | for (Int_t iRecTrack = initialNRecTracks; iRecTrack < nCurrentTracks; iRecTrack++) { | |
244 | track = (AliMUONTrack*) fRecTracksPtr->UncheckedAt(iRecTrack); | |
245 | ||
246 | // skip empty slots | |
247 | if(!track) continue; | |
248 | ||
249 | // retrace tracks using Kalman filter and remove the ones for which extrap failed or that are out of limits | |
250 | if (!RetraceTrack(*track,kTRUE) || !IsAcceptable(*((AliMUONTrackParam*)track->GetTrackParamAtCluster()->First()))) { | |
251 | fRecTracksPtr->Remove(track); | |
252 | fNRecTracks--; | |
253 | } | |
254 | ||
255 | } | |
256 | ||
257 | // Keep only the best tracks if required | |
258 | if (!GetRecoParam()->TrackAllTracks()) RemoveDoubleTracks(); | |
259 | else fRecTracksPtr->Compress(); | |
260 | ||
261 | AliDebug(1,Form("Number of good candidates = %d",fNRecTracks)); | |
262 | ||
263 | return kTRUE; | |
264 | ||
265 | } | |
266 | ||
267 | //__________________________________________________________________________ | |
268 | Bool_t AliMUONTrackReconstructorK::RetraceTrack(AliMUONTrack &trackCandidate, Bool_t resetSeed) | |
269 | { | |
270 | /// Re-run the kalman filter from the most downstream cluster to the most uptream one | |
271 | /// Return kFALSE in case of failure (i.e. extrapolation problem) | |
272 | AliDebug(1,"Enter RetraceTrack"); | |
273 | ||
274 | AliMUONTrackParam* lastTrackParam = (AliMUONTrackParam*) trackCandidate.GetTrackParamAtCluster()->Last(); | |
275 | ||
276 | // Reset the "seed" (= track parameters and their covariances at last cluster) if required | |
277 | if (resetSeed) { | |
278 | ||
279 | // parameters at last cluster | |
280 | AliMUONVCluster* cluster2 = lastTrackParam->GetClusterPtr(); | |
281 | Double_t x2 = cluster2->GetX(); | |
282 | Double_t y2 = cluster2->GetY(); | |
283 | Double_t z2 = cluster2->GetZ(); | |
284 | ||
285 | // parameters at last but one cluster | |
286 | AliMUONTrackParam* previousTrackParam = (AliMUONTrackParam*) trackCandidate.GetTrackParamAtCluster()->Before(lastTrackParam); | |
287 | AliMUONVCluster* cluster1 = previousTrackParam->GetClusterPtr(); | |
288 | // make sure it is on the previous chamber (can have 2 clusters in the same chamber after "ComplementTrack") | |
289 | if (cluster2->GetChamberId() == cluster1->GetChamberId()) { | |
290 | previousTrackParam = (AliMUONTrackParam*) trackCandidate.GetTrackParamAtCluster()->Before(previousTrackParam); | |
291 | cluster1 = previousTrackParam->GetClusterPtr(); | |
292 | } | |
293 | Double_t x1 = cluster1->GetX(); | |
294 | Double_t y1 = cluster1->GetY(); | |
295 | Double_t z1 = cluster1->GetZ(); | |
296 | ||
297 | // reset track parameters | |
298 | Double_t dZ = z1 - z2; | |
299 | lastTrackParam->SetNonBendingCoor(x2); | |
300 | lastTrackParam->SetBendingCoor(y2); | |
301 | lastTrackParam->SetZ(z2); | |
302 | lastTrackParam->SetNonBendingSlope((x1 - x2) / dZ); | |
303 | lastTrackParam->SetBendingSlope((y1 - y2) / dZ); | |
304 | Double_t bendingImpact = y2 - z2 * lastTrackParam->GetBendingSlope(); | |
305 | Double_t inverseBendingMomentum = 1. / AliMUONTrackExtrap::GetBendingMomentumFromImpactParam(bendingImpact); | |
306 | lastTrackParam->SetInverseBendingMomentum(inverseBendingMomentum); | |
307 | ||
308 | // => Reset track parameter covariances at last cluster (as if the other clusters did not exist) | |
309 | TMatrixD lastParamCov(5,5); | |
310 | lastParamCov.Zero(); | |
311 | // Non bending plane | |
312 | lastParamCov(0,0) = cluster2->GetErrX2(); | |
313 | lastParamCov(0,1) = - cluster2->GetErrX2() / dZ; | |
314 | lastParamCov(1,0) = lastParamCov(0,1); | |
315 | lastParamCov(1,1) = ( 1000. * cluster1->GetErrX2() + cluster2->GetErrX2() ) / dZ / dZ; | |
316 | // Bending plane | |
317 | lastParamCov(2,2) = cluster2->GetErrY2(); | |
318 | lastParamCov(2,3) = - cluster2->GetErrY2() / dZ; | |
319 | lastParamCov(3,2) = lastParamCov(2,3); | |
320 | lastParamCov(3,3) = ( 1000. * cluster1->GetErrY2() + cluster2->GetErrY2() ) / dZ / dZ; | |
321 | // Inverse bending momentum (vertex resolution + bending slope resolution + 10% error on dipole parameters+field) | |
322 | if (AliMUONTrackExtrap::IsFieldON()) { | |
323 | lastParamCov(4,4) = ((GetRecoParam()->GetBendingVertexDispersion() * | |
324 | GetRecoParam()->GetBendingVertexDispersion() + | |
325 | (z1 * z1 * cluster2->GetErrY2() + z2 * z2 * 1000. * cluster1->GetErrY2()) / dZ / dZ) / | |
326 | bendingImpact / bendingImpact + 0.1 * 0.1) * inverseBendingMomentum * inverseBendingMomentum; | |
327 | lastParamCov(2,4) = z1 * cluster2->GetErrY2() * inverseBendingMomentum / bendingImpact / dZ; | |
328 | lastParamCov(4,2) = lastParamCov(2,4); | |
329 | lastParamCov(3,4) = - (z1 * cluster2->GetErrY2() + z2 * 1000. * cluster1->GetErrY2()) * | |
330 | inverseBendingMomentum / bendingImpact / dZ / dZ; | |
331 | lastParamCov(4,3) = lastParamCov(3,4); | |
332 | } else lastParamCov(4,4) = inverseBendingMomentum*inverseBendingMomentum; | |
333 | lastTrackParam->SetCovariances(lastParamCov); | |
334 | ||
335 | // Reset the track chi2 | |
336 | lastTrackParam->SetTrackChi2(0.); | |
337 | ||
338 | } | |
339 | ||
340 | // Redo the tracking | |
341 | return RetracePartialTrack(trackCandidate, lastTrackParam); | |
342 | ||
343 | } | |
344 | ||
345 | //__________________________________________________________________________ | |
346 | Bool_t AliMUONTrackReconstructorK::RetracePartialTrack(AliMUONTrack &trackCandidate, const AliMUONTrackParam* startingTrackParam) | |
347 | { | |
348 | /// Re-run the kalman filter from the cluster attached to startingTrackParam to the most uptream cluster | |
349 | /// Return kFALSE in case of failure (i.e. extrapolation problem) | |
350 | AliDebug(1,"Enter RetracePartialTrack"); | |
351 | ||
352 | // Printout for debuging | |
353 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
354 | cout << "RetracePartialTrack: track chi2 before re-tracking: " << trackCandidate.GetGlobalChi2() << endl; | |
355 | } | |
356 | ||
357 | // Reset the track chi2 | |
358 | trackCandidate.SetGlobalChi2(startingTrackParam->GetTrackChi2()); | |
359 | ||
360 | // loop over attached clusters until the first one and recompute track parameters and covariances using kalman filter | |
361 | Bool_t extrapStatus = kTRUE; | |
362 | Int_t expectedChamber = startingTrackParam->GetClusterPtr()->GetChamberId() - 1; | |
363 | Int_t currentChamber; | |
364 | Double_t addChi2TrackAtCluster; | |
365 | AliMUONTrackParam* trackParamAtCluster = (AliMUONTrackParam*) trackCandidate.GetTrackParamAtCluster()->Before(startingTrackParam); | |
366 | while (trackParamAtCluster) { | |
367 | ||
368 | // reset track parameters and their covariances | |
369 | trackParamAtCluster->SetParameters(startingTrackParam->GetParameters()); | |
370 | trackParamAtCluster->SetZ(startingTrackParam->GetZ()); | |
371 | trackParamAtCluster->SetCovariances(startingTrackParam->GetCovariances()); | |
372 | ||
373 | // add MCS effect | |
374 | AliMUONTrackExtrap::AddMCSEffect(trackParamAtCluster,AliMUONConstants::ChamberThicknessInX0(expectedChamber+1),-1.); | |
375 | ||
376 | // reset propagator for smoother | |
377 | if (GetRecoParam()->UseSmoother()) trackParamAtCluster->ResetPropagator(); | |
378 | ||
379 | // add MCS in missing chambers if any | |
380 | currentChamber = trackParamAtCluster->GetClusterPtr()->GetChamberId(); | |
381 | while (currentChamber < expectedChamber) { | |
382 | // extrapolation to the missing chamber (update the propagator) | |
383 | if (!AliMUONTrackExtrap::ExtrapToZCov(trackParamAtCluster, AliMUONConstants::DefaultChamberZ(expectedChamber), | |
384 | GetRecoParam()->UseSmoother())) extrapStatus = kFALSE; | |
385 | // add MCS effect | |
386 | AliMUONTrackExtrap::AddMCSEffect(trackParamAtCluster,AliMUONConstants::ChamberThicknessInX0(expectedChamber),-1.); | |
387 | expectedChamber--; | |
388 | } | |
389 | ||
390 | // extrapolation to the plane of the cluster attached to the current trackParamAtCluster (update the propagator) | |
391 | if (!AliMUONTrackExtrap::ExtrapToZCov(trackParamAtCluster, trackParamAtCluster->GetClusterPtr()->GetZ(), | |
392 | GetRecoParam()->UseSmoother())) extrapStatus = kFALSE; | |
393 | ||
394 | if (GetRecoParam()->UseSmoother()) { | |
395 | // save extrapolated parameters for smoother | |
396 | trackParamAtCluster->SetExtrapParameters(trackParamAtCluster->GetParameters()); | |
397 | ||
398 | // save extrapolated covariance matrix for smoother | |
399 | trackParamAtCluster->SetExtrapCovariances(trackParamAtCluster->GetCovariances()); | |
400 | } | |
401 | ||
402 | // Compute new track parameters using kalman filter | |
403 | addChi2TrackAtCluster = RunKalmanFilter(*trackParamAtCluster); | |
404 | ||
405 | // Update the track chi2 | |
406 | trackCandidate.SetGlobalChi2(trackCandidate.GetGlobalChi2() + addChi2TrackAtCluster); | |
407 | trackParamAtCluster->SetTrackChi2(trackCandidate.GetGlobalChi2()); | |
408 | ||
409 | // prepare next step | |
410 | expectedChamber = currentChamber - 1; | |
411 | startingTrackParam = trackParamAtCluster; | |
412 | trackParamAtCluster = (AliMUONTrackParam*) (trackCandidate.GetTrackParamAtCluster()->Before(startingTrackParam)); | |
413 | } | |
414 | ||
415 | // Printout for debuging | |
416 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
417 | cout << "RetracePartialTrack: track chi2 after re-tracking: " << trackCandidate.GetGlobalChi2() << endl; | |
418 | } | |
419 | ||
420 | // set global chi2 to max value in case of problem during track extrapolation | |
421 | if (!extrapStatus) trackCandidate.SetGlobalChi2(2.*AliMUONTrack::MaxChi2()); | |
422 | return extrapStatus; | |
423 | ||
424 | } | |
425 | ||
426 | //__________________________________________________________________________ | |
427 | Bool_t AliMUONTrackReconstructorK::FollowTracks(AliMUONVClusterStore& clusterStore) | |
428 | { | |
429 | /// Follow tracks in stations(1..) 3, 2 and 1 | |
430 | AliDebug(1,"Enter FollowTracks"); | |
431 | ||
432 | AliMUONTrack *track; | |
433 | Int_t currentNRecTracks; | |
434 | ||
435 | for (Int_t station = 2; station >= 0; station--) { | |
436 | ||
437 | // Save the actual number of reconstructed track in case of | |
438 | // tracks are added or suppressed during the tracking procedure | |
439 | // !! Do not compress fRecTracksPtr until the end of the loop over tracks !! | |
440 | currentNRecTracks = fNRecTracks; | |
441 | ||
442 | for (Int_t iRecTrack = 0; iRecTrack <currentNRecTracks; iRecTrack++) { | |
443 | AliDebug(1,Form("FollowTracks: track candidate(1..) %d", iRecTrack+1)); | |
444 | ||
445 | track = (AliMUONTrack*) fRecTracksPtr->UncheckedAt(iRecTrack); | |
446 | ||
447 | // Look for compatible cluster(s) in station(0..) "station" | |
448 | if (!FollowTrackInStation(*track, clusterStore, station)) { | |
449 | ||
450 | // Try to recover track if required | |
451 | if (GetRecoParam()->RecoverTracks()) { | |
452 | ||
453 | // work on a copy of the track if this station is not required | |
454 | // to keep the case where no cluster is reconstructed as a possible candidate | |
455 | if (!GetRecoParam()->RequestStation(station)) { | |
456 | track = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(*track); | |
457 | fNRecTracks++; | |
458 | } | |
459 | ||
460 | // try to recover | |
461 | if (!RecoverTrack(*track, clusterStore, station)) { | |
462 | // remove track if no cluster found | |
463 | fRecTracksPtr->Remove(track); | |
464 | fNRecTracks--; | |
465 | } | |
466 | ||
467 | } else if (GetRecoParam()->RequestStation(station)) { | |
468 | // remove track if no cluster found | |
469 | fRecTracksPtr->Remove(track); | |
470 | fNRecTracks--; | |
471 | } | |
472 | ||
473 | } | |
474 | ||
475 | // abort tracking if there are too many candidates | |
476 | if (GetRecoParam()->RequestStation(station)) { | |
477 | if (fNRecTracks > GetRecoParam()->GetMaxTrackCandidates()) { | |
478 | AliError(Form("Too many track candidates (%d tracks). Stop tracking.", fNRecTracks)); | |
479 | return kFALSE; | |
480 | } | |
481 | } else { | |
482 | if ((fNRecTracks + currentNRecTracks - iRecTrack - 1) > GetRecoParam()->GetMaxTrackCandidates()) { | |
483 | AliError(Form("Too many track candidates (%d tracks). Stop tracking.", fNRecTracks + currentNRecTracks - iRecTrack - 1)); | |
484 | return kFALSE; | |
485 | } | |
486 | } | |
487 | ||
488 | } | |
489 | ||
490 | fRecTracksPtr->Compress(); // this is essential before checking tracks | |
491 | ||
492 | // Keep only the best tracks if required | |
493 | if (!GetRecoParam()->TrackAllTracks()) RemoveDoubleTracks(); | |
494 | ||
495 | } | |
496 | ||
497 | return kTRUE; | |
498 | ||
499 | } | |
500 | ||
501 | //__________________________________________________________________________ | |
502 | Bool_t AliMUONTrackReconstructorK::FollowTrackInChamber(AliMUONTrack &trackCandidate, AliMUONVClusterStore& clusterStore, Int_t nextChamber) | |
503 | { | |
504 | /// Follow trackCandidate in chamber(0..) nextChamber and search for compatible cluster(s) | |
505 | /// Keep all possibilities or only the best one(s) according to the flag fgkTrackAllTracks: | |
506 | /// kTRUE: duplicate "trackCandidate" if there are several possibilities and add the new tracks at the end of | |
507 | /// fRecTracksPtr to avoid conficts with other track candidates at this current stage of the tracking procedure. | |
508 | /// Remove the obsolete "trackCandidate" at the end. | |
509 | /// kFALSE: add only the best cluster(s) to the "trackCandidate". Try to add a couple of clusters in priority. | |
510 | /// return kTRUE if new cluster(s) have been found (otherwise return kFALSE) | |
511 | AliDebug(1,Form("Enter FollowTrackInChamber(1..) %d", nextChamber+1)); | |
512 | ||
513 | Double_t chi2OfCluster; | |
514 | Double_t maxChi2OfCluster = 2. * GetRecoParam()->GetSigmaCutForTracking() * | |
515 | GetRecoParam()->GetSigmaCutForTracking(); // 2 because 2 quantities in chi2 | |
516 | Double_t addChi2TrackAtCluster; | |
517 | Double_t bestAddChi2TrackAtCluster = AliMUONTrack::MaxChi2(); | |
518 | Bool_t foundOneCluster = kFALSE; | |
519 | AliMUONTrack *newTrack = 0x0; | |
520 | AliMUONVCluster *cluster; | |
521 | AliMUONTrackParam extrapTrackParamAtCh; | |
522 | AliMUONTrackParam extrapTrackParamAtCluster; | |
523 | AliMUONTrackParam bestTrackParamAtCluster; | |
524 | ||
525 | // Get track parameters according to the propagation direction | |
526 | if (nextChamber > 7) extrapTrackParamAtCh = *(AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->Last(); | |
527 | else extrapTrackParamAtCh = *(AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->First(); | |
528 | ||
529 | // Printout for debuging | |
530 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) { | |
531 | cout<<endl<<"Track parameters and covariances at first cluster:"<<endl; | |
532 | extrapTrackParamAtCh.GetParameters().Print(); | |
533 | extrapTrackParamAtCh.GetCovariances().Print(); | |
534 | } | |
535 | ||
536 | // Add MCS effect | |
537 | Int_t currentChamber = extrapTrackParamAtCh.GetClusterPtr()->GetChamberId(); | |
538 | AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(currentChamber),-1.); | |
539 | ||
540 | // reset propagator for smoother | |
541 | if (GetRecoParam()->UseSmoother()) extrapTrackParamAtCh.ResetPropagator(); | |
542 | ||
543 | // Add MCS in the missing chamber(s) if any | |
544 | while (currentChamber > nextChamber + 1) { | |
545 | // extrapolation to the missing chamber | |
546 | currentChamber--; | |
547 | if (!AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(currentChamber), | |
548 | GetRecoParam()->UseSmoother())) return kFALSE; | |
549 | // add MCS effect | |
550 | AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(currentChamber),-1.); | |
551 | } | |
552 | ||
553 | //Extrapolate trackCandidate to chamber | |
554 | if (!AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(nextChamber), | |
555 | GetRecoParam()->UseSmoother())) return kFALSE; | |
556 | ||
557 | // Printout for debuging | |
558 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) { | |
559 | cout<<endl<<"Track parameters and covariances at first cluster extrapolated to z = "<<AliMUONConstants::DefaultChamberZ(nextChamber)<<":"<<endl; | |
560 | extrapTrackParamAtCh.GetParameters().Print(); | |
561 | extrapTrackParamAtCh.GetCovariances().Print(); | |
562 | } | |
563 | ||
564 | // Printout for debuging | |
565 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
566 | cout << "FollowTrackInChamber: look for clusters in chamber(1..): " << nextChamber+1 << endl; | |
567 | } | |
568 | ||
569 | // Ask the clustering to reconstruct new clusters around the track position in the current chamber | |
570 | // except for station 4 and 5 that are already entirely clusterized | |
571 | if (GetRecoParam()->CombineClusterTrackReco()) { | |
572 | if (nextChamber < 6) AskForNewClustersInChamber(extrapTrackParamAtCh, clusterStore, nextChamber); | |
573 | } | |
574 | ||
575 | // Create iterators to loop over clusters in both chambers | |
576 | TIter next(clusterStore.CreateChamberIterator(nextChamber,nextChamber)); | |
577 | ||
578 | // look for candidates in chamber | |
579 | while ( ( cluster = static_cast<AliMUONVCluster*>(next()) ) ) { | |
580 | ||
581 | // try to add the current cluster fast | |
582 | if (!TryOneClusterFast(extrapTrackParamAtCh, cluster)) continue; | |
583 | ||
584 | // try to add the current cluster accuratly | |
585 | chi2OfCluster = TryOneCluster(extrapTrackParamAtCh, cluster, extrapTrackParamAtCluster, | |
586 | GetRecoParam()->UseSmoother()); | |
587 | ||
588 | // if good chi2 then consider to add cluster | |
589 | if (chi2OfCluster < maxChi2OfCluster) { | |
590 | ||
591 | if (GetRecoParam()->UseSmoother()) { | |
592 | // save extrapolated parameters for smoother | |
593 | extrapTrackParamAtCluster.SetExtrapParameters(extrapTrackParamAtCluster.GetParameters()); | |
594 | ||
595 | // save extrapolated covariance matrix for smoother | |
596 | extrapTrackParamAtCluster.SetExtrapCovariances(extrapTrackParamAtCluster.GetCovariances()); | |
597 | } | |
598 | ||
599 | // Compute new track parameters including new cluster using kalman filter | |
600 | addChi2TrackAtCluster = RunKalmanFilter(extrapTrackParamAtCluster); | |
601 | ||
602 | // skip track out of limits | |
603 | if (!IsAcceptable(extrapTrackParamAtCluster)) continue; | |
604 | ||
605 | // remember a cluster was found | |
606 | foundOneCluster = kTRUE; | |
607 | ||
608 | // Printout for debuging | |
609 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
610 | cout << "FollowTrackInChamber: found one cluster in chamber(1..): " << nextChamber+1 | |
611 | << " (Chi2 = " << chi2OfCluster << ")" << endl; | |
612 | cluster->Print(); | |
613 | } | |
614 | ||
615 | if (GetRecoParam()->TrackAllTracks()) { | |
616 | // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new cluster | |
617 | newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate); | |
618 | UpdateTrack(*newTrack,extrapTrackParamAtCluster,addChi2TrackAtCluster); | |
619 | fNRecTracks++; | |
620 | ||
621 | // Printout for debuging | |
622 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
623 | cout << "FollowTrackInChamber: added one cluster in chamber(1..): " << nextChamber+1 << endl; | |
624 | if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); | |
625 | } | |
626 | ||
627 | } else if (addChi2TrackAtCluster < bestAddChi2TrackAtCluster) { | |
628 | // keep track of the best cluster | |
629 | bestAddChi2TrackAtCluster = addChi2TrackAtCluster; | |
630 | bestTrackParamAtCluster = extrapTrackParamAtCluster; | |
631 | } | |
632 | ||
633 | } | |
634 | ||
635 | } | |
636 | ||
637 | // fill out the best track if required else clean up the fRecTracksPtr array | |
638 | if (!GetRecoParam()->TrackAllTracks()) { | |
639 | if (foundOneCluster) { | |
640 | UpdateTrack(trackCandidate,bestTrackParamAtCluster,bestAddChi2TrackAtCluster); | |
641 | ||
642 | // Printout for debuging | |
643 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
644 | cout << "FollowTrackInChamber: added the best cluster in chamber(1..): " << bestTrackParamAtCluster.GetClusterPtr()->GetChamberId()+1 << endl; | |
645 | if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); | |
646 | } | |
647 | ||
648 | } else return kFALSE; | |
649 | ||
650 | } else if (foundOneCluster) { | |
651 | ||
652 | // remove obsolete track | |
653 | fRecTracksPtr->Remove(&trackCandidate); | |
654 | fNRecTracks--; | |
655 | ||
656 | } else return kFALSE; | |
657 | ||
658 | return kTRUE; | |
659 | ||
660 | } | |
661 | ||
662 | //__________________________________________________________________________ | |
663 | Bool_t AliMUONTrackReconstructorK::FollowTrackInStation(AliMUONTrack &trackCandidate, AliMUONVClusterStore& clusterStore, Int_t nextStation) | |
664 | { | |
665 | /// Follow trackCandidate in station(0..) nextStation and search for compatible cluster(s) | |
666 | /// Keep all possibilities or only the best one(s) according to the flag fgkTrackAllTracks: | |
667 | /// kTRUE: duplicate "trackCandidate" if there are several possibilities and add the new tracks at the end of | |
668 | /// fRecTracksPtr to avoid conficts with other track candidates at this current stage of the tracking procedure. | |
669 | /// Remove the obsolete "trackCandidate" at the end. | |
670 | /// kFALSE: add only the best cluster(s) to the "trackCandidate". Try to add a couple of clusters in priority. | |
671 | /// return kTRUE if new cluster(s) have been found (otherwise return kFALSE) | |
672 | AliDebug(1,Form("Enter FollowTrackInStation(1..) %d", nextStation+1)); | |
673 | ||
674 | // Order the chamber according to the propagation direction (tracking starts with chamber 2): | |
675 | // - nextStation == station(1...) 5 => forward propagation | |
676 | // - nextStation < station(1...) 5 => backward propagation | |
677 | Int_t ch1, ch2; | |
678 | if (nextStation==4) { | |
679 | ch1 = 2*nextStation+1; | |
680 | ch2 = 2*nextStation; | |
681 | } else { | |
682 | ch1 = 2*nextStation; | |
683 | ch2 = 2*nextStation+1; | |
684 | } | |
685 | ||
686 | Double_t chi2OfCluster; | |
687 | Double_t maxChi2OfCluster = 2. * GetRecoParam()->GetSigmaCutForTracking() * | |
688 | GetRecoParam()->GetSigmaCutForTracking(); // 2 because 2 quantities in chi2 | |
689 | Double_t addChi2TrackAtCluster1; | |
690 | Double_t addChi2TrackAtCluster2; | |
691 | Double_t bestAddChi2TrackAtCluster1 = AliMUONTrack::MaxChi2(); | |
692 | Double_t bestAddChi2TrackAtCluster2 = AliMUONTrack::MaxChi2(); | |
693 | Bool_t foundOneCluster = kFALSE; | |
694 | Bool_t foundTwoClusters = kFALSE; | |
695 | AliMUONTrack *newTrack = 0x0; | |
696 | AliMUONVCluster *clusterCh1, *clusterCh2; | |
697 | AliMUONTrackParam extrapTrackParam; | |
698 | AliMUONTrackParam extrapTrackParamAtCh; | |
699 | AliMUONTrackParam extrapTrackParamAtCluster1; | |
700 | AliMUONTrackParam extrapTrackParamAtCluster2; | |
701 | AliMUONTrackParam bestTrackParamAtCluster1; | |
702 | AliMUONTrackParam bestTrackParamAtCluster2; | |
703 | ||
704 | // Get track parameters according to the propagation direction | |
705 | if (nextStation==4) extrapTrackParamAtCh = *(AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->Last(); | |
706 | else extrapTrackParamAtCh = *(AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->First(); | |
707 | ||
708 | // Printout for debuging | |
709 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) { | |
710 | cout<<endl<<"Track parameters and covariances at first cluster:"<<endl; | |
711 | extrapTrackParamAtCh.GetParameters().Print(); | |
712 | extrapTrackParamAtCh.GetCovariances().Print(); | |
713 | } | |
714 | ||
715 | // Add MCS effect | |
716 | Int_t currentChamber = extrapTrackParamAtCh.GetClusterPtr()->GetChamberId(); | |
717 | AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(currentChamber),-1.); | |
718 | ||
719 | // reset propagator for smoother | |
720 | if (GetRecoParam()->UseSmoother()) extrapTrackParamAtCh.ResetPropagator(); | |
721 | ||
722 | // Add MCS in the missing chamber(s) if any | |
723 | while (ch1 < ch2 && currentChamber > ch2 + 1) { | |
724 | // extrapolation to the missing chamber | |
725 | currentChamber--; | |
726 | if (!AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(currentChamber), | |
727 | GetRecoParam()->UseSmoother())) return kFALSE; | |
728 | // add MCS effect | |
729 | AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(currentChamber),-1.); | |
730 | } | |
731 | ||
732 | //Extrapolate trackCandidate to chamber "ch2" | |
733 | if (!AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(ch2), | |
734 | GetRecoParam()->UseSmoother())) return kFALSE; | |
735 | ||
736 | // Printout for debuging | |
737 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) { | |
738 | cout<<endl<<"Track parameters and covariances at first cluster extrapolated to z = "<<AliMUONConstants::DefaultChamberZ(ch2)<<":"<<endl; | |
739 | extrapTrackParamAtCh.GetParameters().Print(); | |
740 | extrapTrackParamAtCh.GetCovariances().Print(); | |
741 | } | |
742 | ||
743 | // Printout for debuging | |
744 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
745 | cout << "FollowTrackInStation: look for clusters in chamber(1..): " << ch2+1 << endl; | |
746 | } | |
747 | ||
748 | // Ask the clustering to reconstruct new clusters around the track position in the current station | |
749 | // except for station 4 and 5 that are already entirely clusterized | |
750 | if (GetRecoParam()->CombineClusterTrackReco()) { | |
751 | if (nextStation < 3) AskForNewClustersInStation(extrapTrackParamAtCh, clusterStore, nextStation); | |
752 | } | |
753 | ||
754 | Int_t nClusters = clusterStore.GetSize(); | |
755 | Bool_t *clusterCh1Used = new Bool_t[nClusters]; | |
756 | for (Int_t i = 0; i < nClusters; i++) clusterCh1Used[i] = kFALSE; | |
757 | Int_t iCluster1; | |
758 | ||
759 | // Create iterators to loop over clusters in both chambers | |
760 | TIter nextInCh1(clusterStore.CreateChamberIterator(ch1,ch1)); | |
761 | TIter nextInCh2(clusterStore.CreateChamberIterator(ch2,ch2)); | |
762 | ||
763 | // look for candidates in chamber 2 | |
764 | while ( ( clusterCh2 = static_cast<AliMUONVCluster*>(nextInCh2()) ) ) { | |
765 | ||
766 | // try to add the current cluster fast | |
767 | if (!TryOneClusterFast(extrapTrackParamAtCh, clusterCh2)) continue; | |
768 | ||
769 | // try to add the current cluster accuratly | |
770 | chi2OfCluster = TryOneCluster(extrapTrackParamAtCh, clusterCh2, extrapTrackParamAtCluster2, | |
771 | GetRecoParam()->UseSmoother()); | |
772 | ||
773 | // if good chi2 then try to attach a cluster in the other chamber too | |
774 | if (chi2OfCluster < maxChi2OfCluster) { | |
775 | ||
776 | if (GetRecoParam()->UseSmoother()) { | |
777 | // save extrapolated parameters for smoother | |
778 | extrapTrackParamAtCluster2.SetExtrapParameters(extrapTrackParamAtCluster2.GetParameters()); | |
779 | ||
780 | // save extrapolated covariance matrix for smoother | |
781 | extrapTrackParamAtCluster2.SetExtrapCovariances(extrapTrackParamAtCluster2.GetCovariances()); | |
782 | } | |
783 | ||
784 | // Compute new track parameters including "clusterCh2" using kalman filter | |
785 | addChi2TrackAtCluster2 = RunKalmanFilter(extrapTrackParamAtCluster2); | |
786 | ||
787 | // skip track out of limits | |
788 | if (!IsAcceptable(extrapTrackParamAtCluster2)) continue; | |
789 | ||
790 | // Printout for debuging | |
791 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
792 | cout << "FollowTrackInStation: found one cluster in chamber(1..): " << ch2+1 | |
793 | << " (Chi2 = " << chi2OfCluster << ")" << endl; | |
794 | clusterCh2->Print(); | |
795 | cout << " look for second clusters in chamber(1..): " << ch1+1 << " ..." << endl; | |
796 | } | |
797 | ||
798 | // copy new track parameters for next step | |
799 | extrapTrackParam = extrapTrackParamAtCluster2; | |
800 | ||
801 | // add MCS effect | |
802 | AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParam,AliMUONConstants::ChamberThicknessInX0(ch2),-1.); | |
803 | ||
804 | // reset propagator for smoother | |
805 | if (GetRecoParam()->UseSmoother()) extrapTrackParam.ResetPropagator(); | |
806 | ||
807 | //Extrapolate track parameters to chamber "ch1" | |
808 | Bool_t normalExtrap = AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParam, AliMUONConstants::DefaultChamberZ(ch1), | |
809 | GetRecoParam()->UseSmoother()); | |
810 | ||
811 | // reset cluster iterator of chamber 1 | |
812 | nextInCh1.Reset(); | |
813 | iCluster1 = -1; | |
814 | ||
815 | // look for second candidates in chamber 1 | |
816 | Bool_t foundSecondCluster = kFALSE; | |
817 | if (normalExtrap) while ( ( clusterCh1 = static_cast<AliMUONVCluster*>(nextInCh1()) ) ) { | |
818 | iCluster1++; | |
819 | ||
820 | // try to add the current cluster fast | |
821 | if (!TryOneClusterFast(extrapTrackParam, clusterCh1)) continue; | |
822 | ||
823 | // try to add the current cluster accuratly | |
824 | chi2OfCluster = TryOneCluster(extrapTrackParam, clusterCh1, extrapTrackParamAtCluster1, | |
825 | GetRecoParam()->UseSmoother()); | |
826 | ||
827 | // if good chi2 then consider to add the 2 clusters to the "trackCandidate" | |
828 | if (chi2OfCluster < maxChi2OfCluster) { | |
829 | ||
830 | if (GetRecoParam()->UseSmoother()) { | |
831 | // save extrapolated parameters for smoother | |
832 | extrapTrackParamAtCluster1.SetExtrapParameters(extrapTrackParamAtCluster1.GetParameters()); | |
833 | ||
834 | // save extrapolated covariance matrix for smoother | |
835 | extrapTrackParamAtCluster1.SetExtrapCovariances(extrapTrackParamAtCluster1.GetCovariances()); | |
836 | } | |
837 | ||
838 | // Compute new track parameters including "clusterCh1" using kalman filter | |
839 | addChi2TrackAtCluster1 = RunKalmanFilter(extrapTrackParamAtCluster1); | |
840 | ||
841 | // skip track out of limits | |
842 | if (!IsAcceptable(extrapTrackParamAtCluster1)) continue; | |
843 | ||
844 | // remember a second cluster was found | |
845 | foundSecondCluster = kTRUE; | |
846 | foundTwoClusters = kTRUE; | |
847 | ||
848 | // Printout for debuging | |
849 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
850 | cout << "FollowTrackInStation: found one cluster in chamber(1..): " << ch1+1 | |
851 | << " (Chi2 = " << chi2OfCluster << ")" << endl; | |
852 | clusterCh1->Print(); | |
853 | } | |
854 | ||
855 | if (GetRecoParam()->TrackAllTracks()) { | |
856 | // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new clusters | |
857 | newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate); | |
858 | UpdateTrack(*newTrack,extrapTrackParamAtCluster1,extrapTrackParamAtCluster2,addChi2TrackAtCluster1,addChi2TrackAtCluster2); | |
859 | fNRecTracks++; | |
860 | ||
861 | // Tag clusterCh1 as used | |
862 | clusterCh1Used[iCluster1] = kTRUE; | |
863 | ||
864 | // Printout for debuging | |
865 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
866 | cout << "FollowTrackInStation: added two clusters in station(1..): " << nextStation+1 << endl; | |
867 | if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); | |
868 | } | |
869 | ||
870 | } else if (addChi2TrackAtCluster1+addChi2TrackAtCluster2 < bestAddChi2TrackAtCluster1+bestAddChi2TrackAtCluster2) { | |
871 | // keep track of the best couple of clusters | |
872 | bestAddChi2TrackAtCluster1 = addChi2TrackAtCluster1; | |
873 | bestAddChi2TrackAtCluster2 = addChi2TrackAtCluster2; | |
874 | bestTrackParamAtCluster1 = extrapTrackParamAtCluster1; | |
875 | bestTrackParamAtCluster2 = extrapTrackParamAtCluster2; | |
876 | } | |
877 | ||
878 | } | |
879 | ||
880 | } | |
881 | ||
882 | // if no clusterCh1 found then consider to add clusterCh2 only | |
883 | if (!foundSecondCluster) { | |
884 | ||
885 | // remember a cluster was found | |
886 | foundOneCluster = kTRUE; | |
887 | ||
888 | if (GetRecoParam()->TrackAllTracks()) { | |
889 | // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new cluster | |
890 | newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate); | |
891 | UpdateTrack(*newTrack,extrapTrackParamAtCluster2,addChi2TrackAtCluster2); | |
892 | fNRecTracks++; | |
893 | ||
894 | // Printout for debuging | |
895 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
896 | cout << "FollowTrackInStation: added one cluster in chamber(1..): " << ch2+1 << endl; | |
897 | if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); | |
898 | } | |
899 | ||
900 | } else if (!foundTwoClusters && addChi2TrackAtCluster2 < bestAddChi2TrackAtCluster1) { | |
901 | // keep track of the best single cluster except if a couple of clusters has already been found | |
902 | bestAddChi2TrackAtCluster1 = addChi2TrackAtCluster2; | |
903 | bestTrackParamAtCluster1 = extrapTrackParamAtCluster2; | |
904 | } | |
905 | ||
906 | } | |
907 | ||
908 | } | |
909 | ||
910 | } | |
911 | ||
912 | // look for candidates in chamber 1 not already attached to a track | |
913 | // if we want to keep all possible tracks or if no good couple of clusters has been found | |
914 | if (GetRecoParam()->TrackAllTracks() || !foundTwoClusters) { | |
915 | ||
916 | // add MCS effect for next step | |
917 | AliMUONTrackExtrap::AddMCSEffect(&extrapTrackParamAtCh,AliMUONConstants::ChamberThicknessInX0(ch2),-1.); | |
918 | ||
919 | //Extrapolate trackCandidate to chamber "ch1" | |
920 | Bool_t normalExtrap = AliMUONTrackExtrap::ExtrapToZCov(&extrapTrackParamAtCh, AliMUONConstants::DefaultChamberZ(ch1), | |
921 | GetRecoParam()->UseSmoother()); | |
922 | ||
923 | // Printout for debuging | |
924 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) { | |
925 | cout<<endl<<"Track parameters and covariances at first cluster extrapolated to z = "<<AliMUONConstants::DefaultChamberZ(ch1)<<":"<<endl; | |
926 | extrapTrackParamAtCh.GetParameters().Print(); | |
927 | extrapTrackParamAtCh.GetCovariances().Print(); | |
928 | } | |
929 | ||
930 | // Printout for debuging | |
931 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
932 | cout << "FollowTrackInStation: look for single clusters in chamber(1..): " << ch1+1 << endl; | |
933 | } | |
934 | ||
935 | // reset cluster iterator of chamber 1 | |
936 | nextInCh1.Reset(); | |
937 | iCluster1 = -1; | |
938 | ||
939 | // look for second candidates in chamber 1 | |
940 | if (normalExtrap) while ( ( clusterCh1 = static_cast<AliMUONVCluster*>(nextInCh1()) ) ) { | |
941 | iCluster1++; | |
942 | ||
943 | if (clusterCh1Used[iCluster1]) continue; // Skip clusters already used | |
944 | ||
945 | // try to add the current cluster fast | |
946 | if (!TryOneClusterFast(extrapTrackParamAtCh, clusterCh1)) continue; | |
947 | ||
948 | // try to add the current cluster accuratly | |
949 | chi2OfCluster = TryOneCluster(extrapTrackParamAtCh, clusterCh1, extrapTrackParamAtCluster1, | |
950 | GetRecoParam()->UseSmoother()); | |
951 | ||
952 | // if good chi2 then consider to add clusterCh1 | |
953 | // We do not try to attach a cluster in the other chamber too since it has already been done above | |
954 | if (chi2OfCluster < maxChi2OfCluster) { | |
955 | ||
956 | if (GetRecoParam()->UseSmoother()) { | |
957 | // save extrapolated parameters for smoother | |
958 | extrapTrackParamAtCluster1.SetExtrapParameters(extrapTrackParamAtCluster1.GetParameters()); | |
959 | ||
960 | // save extrapolated covariance matrix for smoother | |
961 | extrapTrackParamAtCluster1.SetExtrapCovariances(extrapTrackParamAtCluster1.GetCovariances()); | |
962 | } | |
963 | ||
964 | // Compute new track parameters including "clusterCh1" using kalman filter | |
965 | addChi2TrackAtCluster1 = RunKalmanFilter(extrapTrackParamAtCluster1); | |
966 | ||
967 | // skip track out of limits | |
968 | if (!IsAcceptable(extrapTrackParamAtCluster1)) continue; | |
969 | ||
970 | // remember a cluster was found | |
971 | foundOneCluster = kTRUE; | |
972 | ||
973 | // Printout for debuging | |
974 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
975 | cout << "FollowTrackInStation: found one cluster in chamber(1..): " << ch1+1 | |
976 | << " (Chi2 = " << chi2OfCluster << ")" << endl; | |
977 | clusterCh1->Print(); | |
978 | } | |
979 | ||
980 | if (GetRecoParam()->TrackAllTracks()) { | |
981 | // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new cluster | |
982 | newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(trackCandidate); | |
983 | UpdateTrack(*newTrack,extrapTrackParamAtCluster1,addChi2TrackAtCluster1); | |
984 | fNRecTracks++; | |
985 | ||
986 | // Printout for debuging | |
987 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
988 | cout << "FollowTrackInStation: added one cluster in chamber(1..): " << ch1+1 << endl; | |
989 | if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); | |
990 | } | |
991 | ||
992 | } else if (addChi2TrackAtCluster1 < bestAddChi2TrackAtCluster1) { | |
993 | // keep track of the best single cluster except if a couple of clusters has already been found | |
994 | bestAddChi2TrackAtCluster1 = addChi2TrackAtCluster1; | |
995 | bestTrackParamAtCluster1 = extrapTrackParamAtCluster1; | |
996 | } | |
997 | ||
998 | } | |
999 | ||
1000 | } | |
1001 | ||
1002 | } | |
1003 | ||
1004 | // fill out the best track if required else clean up the fRecTracksPtr array | |
1005 | if (!GetRecoParam()->TrackAllTracks()) { | |
1006 | if (foundTwoClusters) { | |
1007 | UpdateTrack(trackCandidate,bestTrackParamAtCluster1,bestTrackParamAtCluster2,bestAddChi2TrackAtCluster1,bestAddChi2TrackAtCluster2); | |
1008 | ||
1009 | // Printout for debuging | |
1010 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
1011 | cout << "FollowTrackInStation: added the two best clusters in station(1..): " << nextStation+1 << endl; | |
1012 | if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); | |
1013 | } | |
1014 | ||
1015 | } else if (foundOneCluster) { | |
1016 | UpdateTrack(trackCandidate,bestTrackParamAtCluster1,bestAddChi2TrackAtCluster1); | |
1017 | ||
1018 | // Printout for debuging | |
1019 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
1020 | cout << "FollowTrackInStation: added the best cluster in chamber(1..): " << bestTrackParamAtCluster1.GetClusterPtr()->GetChamberId()+1 << endl; | |
1021 | if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); | |
1022 | } | |
1023 | ||
1024 | } else { | |
1025 | delete [] clusterCh1Used; | |
1026 | return kFALSE; | |
1027 | } | |
1028 | ||
1029 | } else if (foundOneCluster || foundTwoClusters) { | |
1030 | ||
1031 | // remove obsolete track | |
1032 | fRecTracksPtr->Remove(&trackCandidate); | |
1033 | fNRecTracks--; | |
1034 | ||
1035 | } else { | |
1036 | delete [] clusterCh1Used; | |
1037 | return kFALSE; | |
1038 | } | |
1039 | ||
1040 | delete [] clusterCh1Used; | |
1041 | return kTRUE; | |
1042 | ||
1043 | } | |
1044 | ||
1045 | //__________________________________________________________________________ | |
1046 | Double_t AliMUONTrackReconstructorK::RunKalmanFilter(AliMUONTrackParam &trackParamAtCluster) | |
1047 | { | |
1048 | /// Compute new track parameters and their covariances including new cluster using kalman filter | |
1049 | /// return the additional track chi2 | |
1050 | AliDebug(1,"Enter RunKalmanFilter"); | |
1051 | ||
1052 | // Get actual track parameters (p) | |
1053 | TMatrixD param(trackParamAtCluster.GetParameters()); | |
1054 | ||
1055 | // Get new cluster parameters (m) | |
1056 | AliMUONVCluster *cluster = trackParamAtCluster.GetClusterPtr(); | |
1057 | TMatrixD clusterParam(5,1); | |
1058 | clusterParam.Zero(); | |
1059 | clusterParam(0,0) = cluster->GetX(); | |
1060 | clusterParam(2,0) = cluster->GetY(); | |
1061 | ||
1062 | // Compute the actual parameter weight (W) | |
1063 | TMatrixD paramWeight(trackParamAtCluster.GetCovariances()); | |
1064 | if (paramWeight.Determinant() != 0) { | |
1065 | paramWeight.Invert(); | |
1066 | } else { | |
1067 | AliWarning(" Determinant = 0"); | |
1068 | return 2.*AliMUONTrack::MaxChi2(); | |
1069 | } | |
1070 | ||
1071 | // Compute the new cluster weight (U) | |
1072 | TMatrixD clusterWeight(5,5); | |
1073 | clusterWeight.Zero(); | |
1074 | clusterWeight(0,0) = 1. / cluster->GetErrX2(); | |
1075 | clusterWeight(2,2) = 1. / cluster->GetErrY2(); | |
1076 | ||
1077 | // Compute the new parameters covariance matrix ( (W+U)^-1 ) | |
1078 | TMatrixD newParamCov(paramWeight,TMatrixD::kPlus,clusterWeight); | |
1079 | if (newParamCov.Determinant() != 0) { | |
1080 | newParamCov.Invert(); | |
1081 | } else { | |
1082 | AliWarning(" Determinant = 0"); | |
1083 | return 2.*AliMUONTrack::MaxChi2(); | |
1084 | } | |
1085 | ||
1086 | // Save the new parameters covariance matrix | |
1087 | trackParamAtCluster.SetCovariances(newParamCov); | |
1088 | ||
1089 | // Compute the new parameters (p' = ((W+U)^-1)U(m-p) + p) | |
1090 | TMatrixD tmp(clusterParam,TMatrixD::kMinus,param); | |
1091 | TMatrixD tmp2(clusterWeight,TMatrixD::kMult,tmp); // U(m-p) | |
1092 | TMatrixD newParam(newParamCov,TMatrixD::kMult,tmp2); // ((W+U)^-1)U(m-p) | |
1093 | newParam += param; // ((W+U)^-1)U(m-p) + p | |
1094 | ||
1095 | // Save the new parameters | |
1096 | trackParamAtCluster.SetParameters(newParam); | |
1097 | ||
1098 | // Compute the additional chi2 (= ((p'-p)^-1)W(p'-p) + ((p'-m)^-1)U(p'-m)) | |
1099 | tmp = newParam; // p' | |
1100 | tmp -= param; // (p'-p) | |
1101 | TMatrixD tmp3(paramWeight,TMatrixD::kMult,tmp); // W(p'-p) | |
1102 | TMatrixD addChi2Track(tmp,TMatrixD::kTransposeMult,tmp3); // ((p'-p)^-1)W(p'-p) | |
1103 | tmp = newParam; // p' | |
1104 | tmp -= clusterParam; // (p'-m) | |
1105 | TMatrixD tmp4(clusterWeight,TMatrixD::kMult,tmp); // U(p'-m) | |
1106 | addChi2Track += TMatrixD(tmp,TMatrixD::kTransposeMult,tmp4); // ((p'-p)^-1)W(p'-p) + ((p'-m)^-1)U(p'-m) | |
1107 | ||
1108 | return addChi2Track(0,0); | |
1109 | ||
1110 | } | |
1111 | ||
1112 | //__________________________________________________________________________ | |
1113 | void AliMUONTrackReconstructorK::UpdateTrack(AliMUONTrack &track, AliMUONTrackParam &trackParamAtCluster, Double_t addChi2) | |
1114 | { | |
1115 | /// Add 1 cluster to the track candidate | |
1116 | /// Update chi2 of the track | |
1117 | ||
1118 | // Flag cluster as being (not) removable | |
1119 | if (GetRecoParam()->RequestStation(trackParamAtCluster.GetClusterPtr()->GetChamberId()/2)) | |
1120 | trackParamAtCluster.SetRemovable(kFALSE); | |
1121 | else trackParamAtCluster.SetRemovable(kTRUE); | |
1122 | trackParamAtCluster.SetLocalChi2(0.); // --> Local chi2 not used | |
1123 | ||
1124 | // Update the track chi2 into trackParamAtCluster | |
1125 | trackParamAtCluster.SetTrackChi2(track.GetGlobalChi2() + addChi2); | |
1126 | ||
1127 | // Update the chi2 of the new track | |
1128 | track.SetGlobalChi2(trackParamAtCluster.GetTrackChi2()); | |
1129 | ||
1130 | // Update array of TrackParamAtCluster | |
1131 | track.AddTrackParamAtCluster(trackParamAtCluster,*(trackParamAtCluster.GetClusterPtr())); | |
1132 | ||
1133 | } | |
1134 | ||
1135 | //__________________________________________________________________________ | |
1136 | void AliMUONTrackReconstructorK::UpdateTrack(AliMUONTrack &track, AliMUONTrackParam &trackParamAtCluster1, AliMUONTrackParam &trackParamAtCluster2, | |
1137 | Double_t addChi2AtCluster1, Double_t addChi2AtCluster2) | |
1138 | { | |
1139 | /// Add 2 clusters to the track candidate (order is important) | |
1140 | /// Update track and local chi2 | |
1141 | ||
1142 | // Update local chi2 at first cluster | |
1143 | AliMUONVCluster* cluster1 = trackParamAtCluster1.GetClusterPtr(); | |
1144 | Double_t deltaX = trackParamAtCluster1.GetNonBendingCoor() - cluster1->GetX(); | |
1145 | Double_t deltaY = trackParamAtCluster1.GetBendingCoor() - cluster1->GetY(); | |
1146 | Double_t localChi2AtCluster1 = deltaX*deltaX / cluster1->GetErrX2() + | |
1147 | deltaY*deltaY / cluster1->GetErrY2(); | |
1148 | trackParamAtCluster1.SetLocalChi2(localChi2AtCluster1); | |
1149 | ||
1150 | // Flag first cluster as being removable | |
1151 | trackParamAtCluster1.SetRemovable(kTRUE); | |
1152 | ||
1153 | // Update local chi2 at second cluster | |
1154 | AliMUONVCluster* cluster2 = trackParamAtCluster2.GetClusterPtr(); | |
1155 | AliMUONTrackParam extrapTrackParamAtCluster2(trackParamAtCluster1); | |
1156 | AliMUONTrackExtrap::ExtrapToZ(&extrapTrackParamAtCluster2, trackParamAtCluster2.GetZ()); | |
1157 | deltaX = extrapTrackParamAtCluster2.GetNonBendingCoor() - cluster2->GetX(); | |
1158 | deltaY = extrapTrackParamAtCluster2.GetBendingCoor() - cluster2->GetY(); | |
1159 | Double_t localChi2AtCluster2 = deltaX*deltaX / cluster2->GetErrX2() + | |
1160 | deltaY*deltaY / cluster2->GetErrY2(); | |
1161 | trackParamAtCluster2.SetLocalChi2(localChi2AtCluster2); | |
1162 | ||
1163 | // Flag second cluster as being removable | |
1164 | trackParamAtCluster2.SetRemovable(kTRUE); | |
1165 | ||
1166 | // Update the track chi2 into trackParamAtCluster2 | |
1167 | trackParamAtCluster2.SetTrackChi2(track.GetGlobalChi2() + addChi2AtCluster2); | |
1168 | ||
1169 | // Update the track chi2 into trackParamAtCluster1 | |
1170 | trackParamAtCluster1.SetTrackChi2(trackParamAtCluster2.GetTrackChi2() + addChi2AtCluster1); | |
1171 | ||
1172 | // Update the chi2 of the new track | |
1173 | track.SetGlobalChi2(trackParamAtCluster1.GetTrackChi2()); | |
1174 | ||
1175 | // Update array of trackParamAtCluster | |
1176 | track.AddTrackParamAtCluster(trackParamAtCluster1,*cluster1); | |
1177 | track.AddTrackParamAtCluster(trackParamAtCluster2,*cluster2); | |
1178 | ||
1179 | } | |
1180 | ||
1181 | //__________________________________________________________________________ | |
1182 | Bool_t AliMUONTrackReconstructorK::RecoverTrack(AliMUONTrack &trackCandidate, AliMUONVClusterStore& clusterStore, Int_t nextStation) | |
1183 | { | |
1184 | /// Try to recover the track candidate in the next station | |
1185 | /// by removing the worst of the two clusters attached in the current station | |
1186 | /// Return kTRUE if recovering succeeds | |
1187 | AliDebug(1,"Enter RecoverTrack"); | |
1188 | ||
1189 | // Do not try to recover track until we have attached cluster(s) on station(1..) 3 | |
1190 | if (nextStation > 1) return kFALSE; | |
1191 | ||
1192 | Int_t worstClusterNumber = -1; | |
1193 | Double_t localChi2, worstLocalChi2 = -1.; | |
1194 | ||
1195 | // Look for the cluster to remove | |
1196 | for (Int_t clusterNumber = 0; clusterNumber < 2; clusterNumber++) { | |
1197 | AliMUONTrackParam *trackParamAtCluster = (AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->UncheckedAt(clusterNumber); | |
1198 | ||
1199 | // check if current cluster is in the previous station | |
1200 | if (trackParamAtCluster->GetClusterPtr()->GetChamberId()/2 != nextStation+1) break; | |
1201 | ||
1202 | // check if current cluster is removable | |
1203 | if (!trackParamAtCluster->IsRemovable()) return kFALSE; | |
1204 | ||
1205 | // reset the current cluster as being not removable if it is on a required station | |
1206 | if (GetRecoParam()->RequestStation(nextStation+1)) trackParamAtCluster->SetRemovable(kFALSE); | |
1207 | ||
1208 | // Pick up cluster with the worst chi2 | |
1209 | localChi2 = trackParamAtCluster->GetLocalChi2(); | |
1210 | if (localChi2 > worstLocalChi2) { | |
1211 | worstLocalChi2 = localChi2; | |
1212 | worstClusterNumber = clusterNumber; | |
1213 | } | |
1214 | } | |
1215 | ||
1216 | // check if worst cluster found | |
1217 | if (worstClusterNumber < 0) return kFALSE; | |
1218 | ||
1219 | // Remove the worst cluster | |
1220 | trackCandidate.RemoveTrackParamAtCluster((AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->UncheckedAt(worstClusterNumber)); | |
1221 | ||
1222 | // Re-calculate track parameters at the (new) first cluster | |
1223 | if (!RetracePartialTrack(trackCandidate,(AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->UncheckedAt(1))) return kFALSE; | |
1224 | ||
1225 | // skip track out of limits | |
1226 | if (!IsAcceptable(*((AliMUONTrackParam*)trackCandidate.GetTrackParamAtCluster()->First()))) return kFALSE; | |
1227 | ||
1228 | // Look for new cluster(s) in next station | |
1229 | return FollowTrackInStation(trackCandidate, clusterStore, nextStation); | |
1230 | ||
1231 | } | |
1232 | ||
1233 | //__________________________________________________________________________ | |
1234 | Bool_t AliMUONTrackReconstructorK::RunSmoother(AliMUONTrack &track) | |
1235 | { | |
1236 | /// Compute new track parameters and their covariances using smoother | |
1237 | AliDebug(1,"Enter UseSmoother"); | |
1238 | ||
1239 | AliMUONTrackParam *previousTrackParam = (AliMUONTrackParam*) track.GetTrackParamAtCluster()->First(); | |
1240 | ||
1241 | // Smoothed parameters and covariances at first cluster = filtered parameters and covariances | |
1242 | previousTrackParam->SetSmoothParameters(previousTrackParam->GetParameters()); | |
1243 | previousTrackParam->SetSmoothCovariances(previousTrackParam->GetCovariances()); | |
1244 | ||
1245 | AliMUONTrackParam *currentTrackParam = (AliMUONTrackParam*) track.GetTrackParamAtCluster()->After(previousTrackParam); | |
1246 | ||
1247 | // Save local chi2 at first cluster = last additional chi2 provided by Kalman | |
1248 | previousTrackParam->SetLocalChi2(previousTrackParam->GetTrackChi2() - currentTrackParam->GetTrackChi2()); | |
1249 | ||
1250 | // if the track contains only 2 clusters simply copy the filtered parameters | |
1251 | if (track.GetNClusters() == 2) { | |
1252 | currentTrackParam->SetSmoothParameters(currentTrackParam->GetParameters()); | |
1253 | currentTrackParam->SetSmoothCovariances(currentTrackParam->GetCovariances()); | |
1254 | currentTrackParam->SetLocalChi2(currentTrackParam->GetTrackChi2()); | |
1255 | return kTRUE; | |
1256 | } | |
1257 | ||
1258 | while (currentTrackParam) { | |
1259 | ||
1260 | // Get variables | |
1261 | const TMatrixD &extrapParameters = previousTrackParam->GetExtrapParameters(); // X(k+1 k) | |
1262 | const TMatrixD &filteredParameters = currentTrackParam->GetParameters(); // X(k k) | |
1263 | const TMatrixD &previousSmoothParameters = previousTrackParam->GetSmoothParameters(); // X(k+1 n) | |
1264 | const TMatrixD &propagator = previousTrackParam->GetPropagator(); // F(k) | |
1265 | const TMatrixD &extrapCovariances = previousTrackParam->GetExtrapCovariances(); // C(k+1 k) | |
1266 | const TMatrixD &filteredCovariances = currentTrackParam->GetCovariances(); // C(k k) | |
1267 | const TMatrixD &previousSmoothCovariances = previousTrackParam->GetSmoothCovariances(); // C(k+1 n) | |
1268 | ||
1269 | // Compute smoother gain: A(k) = C(kk) * F(k)^t * (C(k+1 k))^-1 | |
1270 | TMatrixD extrapWeight(extrapCovariances); | |
1271 | if (extrapWeight.Determinant() != 0) { | |
1272 | extrapWeight.Invert(); // (C(k+1 k))^-1 | |
1273 | } else { | |
1274 | AliWarning(" Determinant = 0"); | |
1275 | return kFALSE; | |
1276 | } | |
1277 | TMatrixD smootherGain(filteredCovariances,TMatrixD::kMultTranspose,propagator); // C(kk) * F(k)^t | |
1278 | smootherGain *= extrapWeight; // C(kk) * F(k)^t * (C(k+1 k))^-1 | |
1279 | ||
1280 | // Compute smoothed parameters: X(k n) = X(k k) + A(k) * (X(k+1 n) - X(k+1 k)) | |
1281 | TMatrixD tmpParam(previousSmoothParameters,TMatrixD::kMinus,extrapParameters); // X(k+1 n) - X(k+1 k) | |
1282 | TMatrixD smoothParameters(smootherGain,TMatrixD::kMult,tmpParam); // A(k) * (X(k+1 n) - X(k+1 k)) | |
1283 | smoothParameters += filteredParameters; // X(k k) + A(k) * (X(k+1 n) - X(k+1 k)) | |
1284 | ||
1285 | // Save smoothed parameters | |
1286 | currentTrackParam->SetSmoothParameters(smoothParameters); | |
1287 | ||
1288 | // Compute smoothed covariances: C(k n) = C(k k) + A(k) * (C(k+1 n) - C(k+1 k)) * (A(k))^t | |
1289 | TMatrixD tmpCov(previousSmoothCovariances,TMatrixD::kMinus,extrapCovariances); // C(k+1 n) - C(k+1 k) | |
1290 | TMatrixD tmpCov2(tmpCov,TMatrixD::kMultTranspose,smootherGain); // (C(k+1 n) - C(k+1 k)) * (A(k))^t | |
1291 | TMatrixD smoothCovariances(smootherGain,TMatrixD::kMult,tmpCov2); // A(k) * (C(k+1 n) - C(k+1 k)) * (A(k))^t | |
1292 | smoothCovariances += filteredCovariances; // C(k k) + A(k) * (C(k+1 n) - C(k+1 k)) * (A(k))^t | |
1293 | ||
1294 | // Save smoothed covariances | |
1295 | currentTrackParam->SetSmoothCovariances(smoothCovariances); | |
1296 | ||
1297 | // Compute smoothed residual: r(k n) = cluster - X(k n) | |
1298 | AliMUONVCluster* cluster = currentTrackParam->GetClusterPtr(); | |
1299 | TMatrixD smoothResidual(2,1); | |
1300 | smoothResidual.Zero(); | |
1301 | smoothResidual(0,0) = cluster->GetX() - smoothParameters(0,0); | |
1302 | smoothResidual(1,0) = cluster->GetY() - smoothParameters(2,0); | |
1303 | ||
1304 | // Compute weight of smoothed residual: W(k n) = (clusterCov - C(k n))^-1 | |
1305 | TMatrixD smoothResidualWeight(2,2); | |
1306 | smoothResidualWeight(0,0) = cluster->GetErrX2() - smoothCovariances(0,0); | |
1307 | smoothResidualWeight(0,1) = - smoothCovariances(0,2); | |
1308 | smoothResidualWeight(1,0) = - smoothCovariances(2,0); | |
1309 | smoothResidualWeight(1,1) = cluster->GetErrY2() - smoothCovariances(2,2); | |
1310 | if (smoothResidualWeight.Determinant() != 0) { | |
1311 | smoothResidualWeight.Invert(); | |
1312 | } else { | |
1313 | AliWarning(" Determinant = 0"); | |
1314 | return kFALSE; | |
1315 | } | |
1316 | ||
1317 | // Compute local chi2 = (r(k n))^t * W(k n) * r(k n) | |
1318 | TMatrixD tmpChi2(smoothResidual,TMatrixD::kTransposeMult,smoothResidualWeight); // (r(k n))^t * W(k n) | |
1319 | TMatrixD localChi2(tmpChi2,TMatrixD::kMult,smoothResidual); // (r(k n))^t * W(k n) * r(k n) | |
1320 | ||
1321 | // Save local chi2 | |
1322 | currentTrackParam->SetLocalChi2(localChi2(0,0)); | |
1323 | ||
1324 | previousTrackParam = currentTrackParam; | |
1325 | currentTrackParam = (AliMUONTrackParam*) track.GetTrackParamAtCluster()->After(previousTrackParam); | |
1326 | } | |
1327 | ||
1328 | return kTRUE; | |
1329 | ||
1330 | } | |
1331 | ||
1332 | //__________________________________________________________________________ | |
1333 | Bool_t AliMUONTrackReconstructorK::ComplementTracks(const AliMUONVClusterStore& clusterStore) | |
1334 | { | |
1335 | /// Complete tracks by adding missing clusters (if there is an overlap between | |
1336 | /// two detection elements, the track may have two clusters in the same chamber). | |
1337 | /// Recompute track parameters and covariances at each clusters. | |
1338 | /// Remove tracks getting abnormal (i.e. extrapolation failed...) after being complemented. | |
1339 | /// Return kTRUE if one or more tracks have been complemented or removed. | |
1340 | AliDebug(1,"Enter ComplementTracks"); | |
1341 | ||
1342 | Int_t chamberId, detElemId; | |
1343 | Double_t chi2OfCluster, addChi2TrackAtCluster, bestAddChi2TrackAtCluster; | |
1344 | Double_t maxChi2OfCluster = 2. * GetRecoParam()->GetSigmaCutForTracking() * | |
1345 | GetRecoParam()->GetSigmaCutForTracking(); // 2 because 2 quantities in chi2 | |
1346 | Bool_t foundOneCluster, trackModified, hasChanged = kFALSE; | |
1347 | AliMUONVCluster *cluster; | |
1348 | AliMUONTrackParam *trackParam, *previousTrackParam, *nextTrackParam, trackParamAtCluster, bestTrackParamAtCluster; | |
1349 | AliMUONTrack *nextTrack; | |
1350 | ||
1351 | AliMUONTrack *track = (AliMUONTrack*) fRecTracksPtr->First(); | |
1352 | while (track) { | |
1353 | trackModified = kFALSE; | |
1354 | ||
1355 | trackParam = (AliMUONTrackParam*)track->GetTrackParamAtCluster()->First(); | |
1356 | previousTrackParam = trackParam; | |
1357 | while (trackParam) { | |
1358 | foundOneCluster = kFALSE; | |
1359 | bestAddChi2TrackAtCluster = AliMUONTrack::MaxChi2(); | |
1360 | chamberId = trackParam->GetClusterPtr()->GetChamberId(); | |
1361 | detElemId = trackParam->GetClusterPtr()->GetDetElemId(); | |
1362 | ||
1363 | // prepare nextTrackParam before adding new cluster because of the sorting | |
1364 | nextTrackParam = (AliMUONTrackParam*)track->GetTrackParamAtCluster()->After(trackParam); | |
1365 | ||
1366 | // Create iterators to loop over clusters in current chamber | |
1367 | TIter nextInCh(clusterStore.CreateChamberIterator(chamberId,chamberId)); | |
1368 | ||
1369 | // look for one second candidate in the same chamber | |
1370 | while ( ( cluster = static_cast<AliMUONVCluster*>(nextInCh()) ) ) { | |
1371 | ||
1372 | // look for a cluster in another detection element | |
1373 | if (cluster->GetDetElemId() == detElemId) continue; | |
1374 | ||
1375 | // try to add the current cluster fast | |
1376 | if (!TryOneClusterFast(*trackParam, cluster)) continue; | |
1377 | ||
1378 | // try to add the current cluster accurately | |
1379 | // never use track parameters at last cluster because the covariance matrix is meaningless | |
1380 | if (nextTrackParam) chi2OfCluster = TryOneCluster(*trackParam, cluster, trackParamAtCluster); | |
1381 | else chi2OfCluster = TryOneCluster(*previousTrackParam, cluster, trackParamAtCluster); | |
1382 | ||
1383 | // if good chi2 then consider to add this cluster to the track | |
1384 | if (chi2OfCluster < maxChi2OfCluster) { | |
1385 | ||
1386 | // Compute local track parameters including current cluster using kalman filter | |
1387 | addChi2TrackAtCluster = RunKalmanFilter(trackParamAtCluster); | |
1388 | ||
1389 | // keep track of the best cluster | |
1390 | if (addChi2TrackAtCluster < bestAddChi2TrackAtCluster) { | |
1391 | bestAddChi2TrackAtCluster = addChi2TrackAtCluster; | |
1392 | bestTrackParamAtCluster = trackParamAtCluster; | |
1393 | foundOneCluster = kTRUE; | |
1394 | } | |
1395 | ||
1396 | } | |
1397 | ||
1398 | } | |
1399 | ||
1400 | // add new cluster if any | |
1401 | if (foundOneCluster) { | |
1402 | ||
1403 | // Printout for debuging | |
1404 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
1405 | cout << "ComplementTracks: found one cluster in chamber(1..): " << chamberId+1 << endl; | |
1406 | bestTrackParamAtCluster.GetClusterPtr()->Print(); | |
1407 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) { | |
1408 | cout<<endl<<"Track parameters and covariances at cluster:"<<endl; | |
1409 | bestTrackParamAtCluster.GetParameters().Print(); | |
1410 | bestTrackParamAtCluster.GetCovariances().Print(); | |
1411 | } | |
1412 | } | |
1413 | ||
1414 | trackParam->SetRemovable(kTRUE); | |
1415 | bestTrackParamAtCluster.SetRemovable(kTRUE); | |
1416 | track->AddTrackParamAtCluster(bestTrackParamAtCluster,*(bestTrackParamAtCluster.GetClusterPtr())); | |
1417 | trackModified = kTRUE; | |
1418 | hasChanged = kTRUE; | |
1419 | } | |
1420 | ||
1421 | previousTrackParam = trackParam; | |
1422 | trackParam = nextTrackParam; | |
1423 | } | |
1424 | ||
1425 | // prepare next track | |
1426 | nextTrack = (AliMUONTrack*) fRecTracksPtr->After(track); | |
1427 | ||
1428 | // re-compute track parameters using kalman filter if needed | |
1429 | if (trackModified && !RetraceTrack(*track,kTRUE)) { | |
1430 | AliWarning("track modified but problem occur during refitting --> remove track"); | |
1431 | fRecTracksPtr->Remove(track); | |
1432 | fNRecTracks--; | |
1433 | } | |
1434 | ||
1435 | track = nextTrack; | |
1436 | } | |
1437 | ||
1438 | return hasChanged; | |
1439 | ||
1440 | } | |
1441 | ||
1442 | //__________________________________________________________________________ | |
1443 | void AliMUONTrackReconstructorK::ImproveTrack(AliMUONTrack &track) | |
1444 | { | |
1445 | /// Improve the given track by removing removable clusters with local chi2 highter than the defined cut | |
1446 | /// Removable clusters are identified by the method AliMUONTrack::TagRemovableClusters() | |
1447 | /// Recompute track parameters and covariances at the remaining clusters | |
1448 | /// and if something goes wrong (i.e. extrapolation failed...) set track chi2 to max value | |
1449 | AliDebug(1,"Enter ImproveTrack"); | |
1450 | ||
1451 | Double_t localChi2, worstLocalChi2; | |
1452 | AliMUONTrackParam *trackParamAtCluster, *worstTrackParamAtCluster, *nextTrackParam, *next2nextTrackParam; | |
1453 | Int_t nextChamber, next2nextChamber; | |
1454 | Bool_t smoothed; | |
1455 | Double_t sigmaCut2 = GetRecoParam()->GetSigmaCutForImprovement() * | |
1456 | GetRecoParam()->GetSigmaCutForImprovement(); | |
1457 | ||
1458 | while (!track.IsImproved()) { | |
1459 | ||
1460 | // identify removable clusters | |
1461 | track.TagRemovableClusters(GetRecoParam()->RequestedStationMask()); | |
1462 | ||
1463 | // Run smoother if required | |
1464 | smoothed = kFALSE; | |
1465 | if (GetRecoParam()->UseSmoother()) smoothed = RunSmoother(track); | |
1466 | ||
1467 | // Use standard procedure to compute local chi2 if smoother not required or not working | |
1468 | if (!smoothed) { | |
1469 | ||
1470 | // Update track parameters and covariances | |
1471 | if (!track.UpdateCovTrackParamAtCluster()) { | |
1472 | AliWarning("unable to update track parameters and covariances --> stop improvement"); | |
1473 | // restore the kalman parameters | |
1474 | RetraceTrack(track,kTRUE); | |
1475 | break; | |
1476 | } | |
1477 | ||
1478 | // Compute local chi2 of each clusters | |
1479 | track.ComputeLocalChi2(kTRUE); | |
1480 | } | |
1481 | ||
1482 | // Look for the cluster to remove | |
1483 | worstTrackParamAtCluster = 0x0; | |
1484 | worstLocalChi2 = -1.; | |
1485 | trackParamAtCluster = (AliMUONTrackParam*)track.GetTrackParamAtCluster()->First(); | |
1486 | while (trackParamAtCluster) { | |
1487 | ||
1488 | // save parameters into smooth parameters in case of smoother did not work properly | |
1489 | if (GetRecoParam()->UseSmoother() && !smoothed) { | |
1490 | trackParamAtCluster->SetSmoothParameters(trackParamAtCluster->GetParameters()); | |
1491 | trackParamAtCluster->SetSmoothCovariances(trackParamAtCluster->GetCovariances()); | |
1492 | } | |
1493 | ||
1494 | // Pick up cluster with the worst chi2 | |
1495 | localChi2 = trackParamAtCluster->GetLocalChi2(); | |
1496 | if (localChi2 > worstLocalChi2) { | |
1497 | worstLocalChi2 = localChi2; | |
1498 | worstTrackParamAtCluster = trackParamAtCluster; | |
1499 | } | |
1500 | ||
1501 | trackParamAtCluster = (AliMUONTrackParam*)track.GetTrackParamAtCluster()->After(trackParamAtCluster); | |
1502 | } | |
1503 | ||
1504 | // Check whether the worst chi2 is under requirement or not | |
1505 | if (worstLocalChi2 < 2. * sigmaCut2) { // 2 because 2 quantities in chi2 | |
1506 | track.SetImproved(kTRUE); | |
1507 | break; | |
1508 | } | |
1509 | ||
1510 | // if the worst cluster is not removable then stop improvement | |
1511 | if (!worstTrackParamAtCluster->IsRemovable()) { | |
1512 | // restore the kalman parameters in case they have been lost | |
1513 | if (!smoothed) RetraceTrack(track,kTRUE); | |
1514 | break; | |
1515 | } | |
1516 | ||
1517 | // get track parameters at cluster next to the one to be removed | |
1518 | nextTrackParam = (AliMUONTrackParam*) track.GetTrackParamAtCluster()->After(worstTrackParamAtCluster); | |
1519 | ||
1520 | // Remove the worst cluster | |
1521 | track.RemoveTrackParamAtCluster(worstTrackParamAtCluster); | |
1522 | ||
1523 | // Re-calculate track parameters | |
1524 | // - from the cluster immediately downstream the one suppressed | |
1525 | // - or from the begining - if parameters have been re-computed using the standard method (kalman parameters have been lost) | |
1526 | // - or if the removed cluster was used to compute the tracking seed | |
1527 | Bool_t normalExtrap; | |
1528 | if (smoothed && nextTrackParam) { | |
1529 | ||
1530 | nextChamber = nextTrackParam->GetClusterPtr()->GetChamberId(); | |
1531 | next2nextTrackParam = nextTrackParam; | |
1532 | do { | |
1533 | ||
1534 | next2nextChamber = next2nextTrackParam->GetClusterPtr()->GetChamberId(); | |
1535 | next2nextTrackParam = (AliMUONTrackParam*) track.GetTrackParamAtCluster()->After(next2nextTrackParam); | |
1536 | ||
1537 | } while (next2nextTrackParam && (next2nextChamber == nextChamber)); | |
1538 | ||
1539 | if (next2nextChamber == nextChamber) normalExtrap = RetraceTrack(track,kTRUE); | |
1540 | else normalExtrap = RetracePartialTrack(track,nextTrackParam); | |
1541 | ||
1542 | } else normalExtrap = RetraceTrack(track,kTRUE); | |
1543 | ||
1544 | // stop in case of extrapolation problem | |
1545 | if (!normalExtrap) { | |
1546 | AliWarning("track partially improved but problem occur during refitting --> stop improvement"); | |
1547 | break; | |
1548 | } | |
1549 | ||
1550 | // Printout for debuging | |
1551 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructorK") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
1552 | cout << "ImproveTracks: track " << fRecTracksPtr->IndexOf(&track)+1 << " improved " << endl; | |
1553 | } | |
1554 | ||
1555 | } | |
1556 | ||
1557 | } | |
1558 | ||
1559 | //__________________________________________________________________________ | |
1560 | Bool_t AliMUONTrackReconstructorK::FinalizeTrack(AliMUONTrack &track) | |
1561 | { | |
1562 | /// Update track parameters and covariances at each attached cluster | |
1563 | /// using smoother if required, if not already done | |
1564 | /// return kFALSE if the track cannot be extrapolated uo to the last chamber | |
1565 | ||
1566 | AliMUONTrackParam *trackParamAtCluster; | |
1567 | Bool_t smoothed = kFALSE; | |
1568 | ||
1569 | // update track parameters (using smoother if required) if not already done | |
1570 | if (track.IsImproved()) smoothed = GetRecoParam()->UseSmoother(); | |
1571 | else { | |
1572 | if (GetRecoParam()->UseSmoother()) smoothed = RunSmoother(track); | |
1573 | if (!smoothed) { | |
1574 | if (track.UpdateCovTrackParamAtCluster()) track.ComputeLocalChi2(kTRUE); | |
1575 | else { | |
1576 | AliWarning("finalization failed due to extrapolation problem"); | |
1577 | return kFALSE; | |
1578 | } | |
1579 | } | |
1580 | } | |
1581 | ||
1582 | // copy smoothed parameters and covariances if any | |
1583 | if (smoothed) { | |
1584 | ||
1585 | trackParamAtCluster = (AliMUONTrackParam*) (track.GetTrackParamAtCluster()->First()); | |
1586 | while (trackParamAtCluster) { | |
1587 | ||
1588 | trackParamAtCluster->SetParameters(trackParamAtCluster->GetSmoothParameters()); | |
1589 | trackParamAtCluster->SetCovariances(trackParamAtCluster->GetSmoothCovariances()); | |
1590 | ||
1591 | trackParamAtCluster = (AliMUONTrackParam*) (track.GetTrackParamAtCluster()->After(trackParamAtCluster)); | |
1592 | } | |
1593 | ||
1594 | } | |
1595 | ||
1596 | return kTRUE; | |
1597 | ||
1598 | } | |
1599 | ||
1600 | //__________________________________________________________________________ | |
1601 | Bool_t AliMUONTrackReconstructorK::RefitTrack(AliMUONTrack &track, Bool_t enableImprovement) | |
1602 | { | |
1603 | /// re-fit the given track | |
1604 | AliDebug(1,"Enter RefitTrack"); | |
1605 | ||
1606 | // check validity of the track (i.e. at least 2 chambers hit on stations 4 and 5) | |
1607 | if (!track.IsValid(0)) { | |
1608 | AliWarning("the track is not valid --> unable to refit"); | |
1609 | return kFALSE; | |
1610 | } | |
1611 | ||
1612 | // re-compute track parameters and covariances using Kalman filter | |
1613 | if (!RetraceTrack(track,kTRUE)) { | |
1614 | AliWarning("bad track refitting due to extrapolation failure"); | |
1615 | return kFALSE; | |
1616 | } | |
1617 | ||
1618 | // Improve the reconstructed tracks if required | |
1619 | track.SetImproved(kFALSE); | |
1620 | if (enableImprovement && GetRecoParam()->ImproveTracks()) ImproveTrack(track); | |
1621 | ||
1622 | // Fill AliMUONTrack data members | |
1623 | if (track.GetGlobalChi2() < AliMUONTrack::MaxChi2()) return FinalizeTrack(track); | |
1624 | else { | |
1625 | AliWarning("track not finalized due to extrapolation failure"); | |
1626 | return kFALSE; | |
1627 | } | |
1628 | ||
1629 | } | |
1630 |