]>
Commit | Line | Data |
---|---|---|
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 | /// \class AliMUONTrackReconstructor | |
19 | /// MUON track reconstructor using the original method | |
20 | /// | |
21 | /// This class contains as data: | |
22 | /// - the parameters for the track reconstruction | |
23 | /// | |
24 | /// It contains as methods, among others: | |
25 | /// - MakeTracks to build the tracks | |
26 | /// | |
27 | ||
28 | #include "AliMUONTrackReconstructor.h" | |
29 | #include "AliMUONData.h" | |
30 | #include "AliMUONConstants.h" | |
31 | #include "AliMUONRawCluster.h" | |
32 | #include "AliMUONHitForRec.h" | |
33 | #include "AliMUONObjectPair.h" | |
34 | #include "AliMUONTrack.h" | |
35 | #include "AliMUONTrackParam.h" | |
36 | #include "AliMUONTrackExtrap.h" | |
37 | ||
38 | #include "AliLog.h" | |
39 | ||
40 | #include <TMinuit.h> | |
41 | #include <Riostream.h> | |
42 | #include <TMatrixD.h> | |
43 | ||
44 | // Functions to be minimized with Minuit | |
45 | void TrackChi2(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag); | |
46 | void TrackChi2MCS(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag); | |
47 | ||
48 | Double_t MultipleScatteringAngle2(AliMUONTrackParam *param); | |
49 | ||
50 | /// \cond CLASSIMP | |
51 | ClassImp(AliMUONTrackReconstructor) // Class implementation in ROOT context | |
52 | /// \endcond | |
53 | ||
54 | //************* Defaults parameters for reconstruction | |
55 | const Double_t AliMUONTrackReconstructor::fgkMaxNormChi2 = 100.0; | |
56 | const Bool_t AliMUONTrackReconstructor::fgkTrackAllTracks = kFALSE; | |
57 | ||
58 | //__________________________________________________________________________ | |
59 | AliMUONTrackReconstructor::AliMUONTrackReconstructor(AliMUONData* data) | |
60 | : AliMUONVTrackReconstructor(data) | |
61 | { | |
62 | /// Constructor for class AliMUONTrackReconstructor | |
63 | ||
64 | // Memory allocation for the TClonesArray of reconstructed tracks | |
65 | fRecTracksPtr = new TClonesArray("AliMUONTrack", 10); | |
66 | } | |
67 | ||
68 | //__________________________________________________________________________ | |
69 | AliMUONTrackReconstructor::~AliMUONTrackReconstructor(void) | |
70 | { | |
71 | /// Destructor for class AliMUONTrackReconstructor | |
72 | delete fRecTracksPtr; | |
73 | } | |
74 | ||
75 | //__________________________________________________________________________ | |
76 | void AliMUONTrackReconstructor::AddHitsForRecFromRawClusters() | |
77 | { | |
78 | /// To add to the list of hits for reconstruction all the raw clusters | |
79 | TTree *treeR; | |
80 | AliMUONHitForRec *hitForRec; | |
81 | AliMUONRawCluster *clus; | |
82 | Int_t iclus, nclus; | |
83 | TClonesArray *rawclusters; | |
84 | AliDebug(1,"Enter AddHitsForRecFromRawClusters"); | |
85 | ||
86 | treeR = fMUONData->TreeR(); | |
87 | if (!treeR) { | |
88 | AliError("TreeR must be loaded"); | |
89 | exit(0); | |
90 | } | |
91 | ||
92 | fMUONData->SetTreeAddress("RC"); | |
93 | fMUONData->GetRawClusters(); // only one entry | |
94 | ||
95 | // Loop over tracking chambers | |
96 | for (Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) { | |
97 | rawclusters =fMUONData->RawClusters(ch); | |
98 | nclus = (Int_t) (rawclusters->GetEntries()); | |
99 | // Loop over (cathode correlated) raw clusters | |
100 | for (iclus = 0; iclus < nclus; iclus++) { | |
101 | clus = (AliMUONRawCluster*) rawclusters->UncheckedAt(iclus); | |
102 | // new AliMUONHitForRec from raw cluster | |
103 | // and increment number of AliMUONHitForRec's (total and in chamber) | |
104 | hitForRec = new ((*fHitsForRecPtr)[fNHitsForRec]) AliMUONHitForRec(clus); | |
105 | fNHitsForRec++; | |
106 | // more information into HitForRec | |
107 | hitForRec->SetBendingReso2(clus->GetErrY() * clus->GetErrY()); | |
108 | hitForRec->SetNonBendingReso2(clus->GetErrX() * clus->GetErrX()); | |
109 | // original raw cluster | |
110 | hitForRec->SetChamberNumber(ch); | |
111 | hitForRec->SetHitNumber(iclus); | |
112 | // Z coordinate of the raw cluster (cm) | |
113 | hitForRec->SetZ(clus->GetZ(0)); | |
114 | if (AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 3) { | |
115 | cout << "Chamber " << ch <<" raw cluster " << iclus << " : " << endl; | |
116 | clus->Print("full"); | |
117 | cout << "AliMUONHitForRec number (1...): " << fNHitsForRec << endl; | |
118 | hitForRec->Print("full"); | |
119 | } | |
120 | } // end of cluster loop | |
121 | } // end of chamber loop | |
122 | SortHitsForRecWithIncreasingChamber(); | |
123 | ||
124 | AliDebug(1,"End of AddHitsForRecFromRawClusters"); | |
125 | if (AliLog::GetGlobalDebugLevel() > 0) { | |
126 | AliDebug(1, Form("NHitsForRec: %d",fNHitsForRec)); | |
127 | for (Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) { | |
128 | AliDebug(1, Form("Chamber(0...): %d",ch)); | |
129 | AliDebug(1, Form("NHitsForRec: %d", fNHitsForRecPerChamber[ch])); | |
130 | AliDebug(1, Form("Index(first HitForRec): %d", fIndexOfFirstHitForRecPerChamber[ch])); | |
131 | for (Int_t hit = fIndexOfFirstHitForRecPerChamber[ch]; | |
132 | hit < fIndexOfFirstHitForRecPerChamber[ch] + fNHitsForRecPerChamber[ch]; | |
133 | hit++) { | |
134 | AliDebug(1, Form("HitForRec index(0...): %d",hit)); | |
135 | ((*fHitsForRecPtr)[hit])->Dump(); | |
136 | } | |
137 | } | |
138 | } | |
139 | ||
140 | return; | |
141 | } | |
142 | ||
143 | //__________________________________________________________________________ | |
144 | void AliMUONTrackReconstructor::MakeTracks(void) | |
145 | { | |
146 | /// To make the tracks from the list of segments and points in all stations | |
147 | AliDebug(1,"Enter MakeTracks"); | |
148 | // Look for candidates from at least 3 aligned points in stations(1..) 4 and 5 | |
149 | MakeTrackCandidates(); | |
150 | // Follow tracks in stations(1..) 3, 2 and 1 | |
151 | FollowTracks(); | |
152 | // Remove double tracks | |
153 | RemoveDoubleTracks(); | |
154 | // Fill out the AliMUONTrack's | |
155 | FillMUONTrack(); | |
156 | } | |
157 | ||
158 | //__________________________________________________________________________ | |
159 | void AliMUONTrackReconstructor::MakeTrackCandidates(void) | |
160 | { | |
161 | /// To make track candidates: | |
162 | /// Start with segments station(1..) 4 or 5 then follow track in station 5 or 4. | |
163 | /// Good candidates are made of at least three hitForRec's. | |
164 | /// Keep only best candidates or all of them according to the flag fgkTrackAllTracks. | |
165 | TClonesArray *segments; | |
166 | AliMUONObjectPair *segment; | |
167 | AliMUONHitForRec *hitForRec1, *hitForRec2; | |
168 | AliMUONTrack *track; | |
169 | AliMUONTrackParam *trackParamAtFirstHit; | |
170 | Int_t iCandidate = 0; | |
171 | ||
172 | AliDebug(1,"Enter MakeTrackCandidates"); | |
173 | ||
174 | // Loop over stations(1..) 5 and 4 and make track candidates | |
175 | for (Int_t istat=4; istat>=3; istat--) { | |
176 | // Make segments in the station | |
177 | segments = MakeSegmentsInStation(istat); | |
178 | // Loop over segments | |
179 | for (Int_t iseg=0; iseg<segments->GetEntriesFast(); iseg++) { | |
180 | AliDebug(1,Form("Making primary candidate(1..) %d",++iCandidate)); | |
181 | // Transform segments to tracks and put them at the end of fRecTracksPtr | |
182 | segment = (AliMUONObjectPair*) ((*segments)[iseg]); | |
183 | hitForRec1 = (AliMUONHitForRec*) segment->First(); | |
184 | hitForRec2 = (AliMUONHitForRec*) segment->Second(); | |
185 | track = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(hitForRec1, hitForRec2); | |
186 | fNRecTracks++; | |
187 | // Add MCS effects in parameter covariances | |
188 | trackParamAtFirstHit = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->First()); | |
189 | AliMUONTrackExtrap::AddMCSEffect(trackParamAtFirstHit,AliMUONConstants::ChamberThicknessInX0(),1.); | |
190 | // Printout for debuging | |
191 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) { | |
192 | cout<<endl<<"Track parameter covariances at first hit with multiple Coulomb scattering effects:"<<endl; | |
193 | trackParamAtFirstHit->GetCovariances()->Print(); | |
194 | } | |
195 | // Look for compatible hitForRec(s) in the other station | |
196 | FollowTrackInStation(track,7-istat); | |
197 | } | |
198 | // delete the array of segments | |
199 | delete segments; | |
200 | } | |
201 | fRecTracksPtr->Compress(); // this is essential before checking tracks | |
202 | ||
203 | // Keep all different tracks or only the best ones as required | |
204 | if (fgkTrackAllTracks) RemoveIdenticalTracks(); | |
205 | else RemoveDoubleTracks(); | |
206 | ||
207 | AliDebug(1,Form("Number of good candidates = %d",fNRecTracks)); | |
208 | ||
209 | } | |
210 | ||
211 | //__________________________________________________________________________ | |
212 | void AliMUONTrackReconstructor::RemoveIdenticalTracks(void) | |
213 | { | |
214 | /// To remove identical tracks: | |
215 | /// Tracks are considered identical if they have all their hits in common. | |
216 | /// One keeps the track with the larger number of hits if need be | |
217 | AliMUONTrack *track1, *track2, *trackToRemove; | |
218 | Int_t hitsInCommon, nHits1, nHits2; | |
219 | Bool_t removedTrack1; | |
220 | // Loop over first track of the pair | |
221 | track1 = (AliMUONTrack*) fRecTracksPtr->First(); | |
222 | while (track1) { | |
223 | removedTrack1 = kFALSE; | |
224 | nHits1 = track1->GetNTrackHits(); | |
225 | // Loop over second track of the pair | |
226 | track2 = (AliMUONTrack*) fRecTracksPtr->After(track1); | |
227 | while (track2) { | |
228 | nHits2 = track2->GetNTrackHits(); | |
229 | // number of hits in common between two tracks | |
230 | hitsInCommon = track1->HitsInCommon(track2); | |
231 | // check for identical tracks | |
232 | if ((hitsInCommon == nHits1) || (hitsInCommon == nHits2)) { | |
233 | // decide which track to remove | |
234 | if (nHits2 > nHits1) { | |
235 | // remove track1 and continue the first loop with the track next to track1 | |
236 | trackToRemove = track1; | |
237 | track1 = (AliMUONTrack*) fRecTracksPtr->After(track1); | |
238 | fRecTracksPtr->Remove(trackToRemove); | |
239 | fRecTracksPtr->Compress(); // this is essential to retrieve the TClonesArray afterwards | |
240 | fNRecTracks--; | |
241 | removedTrack1 = kTRUE; | |
242 | break; | |
243 | } else { | |
244 | // remove track2 and continue the second loop with the track next to track2 | |
245 | trackToRemove = track2; | |
246 | track2 = (AliMUONTrack*) fRecTracksPtr->After(track2); | |
247 | fRecTracksPtr->Remove(trackToRemove); | |
248 | fRecTracksPtr->Compress(); // this is essential to retrieve the TClonesArray afterwards | |
249 | fNRecTracks--; | |
250 | } | |
251 | } else track2 = (AliMUONTrack*) fRecTracksPtr->After(track2); | |
252 | } // track2 | |
253 | if (removedTrack1) continue; | |
254 | track1 = (AliMUONTrack*) fRecTracksPtr->After(track1); | |
255 | } // track1 | |
256 | return; | |
257 | } | |
258 | ||
259 | //__________________________________________________________________________ | |
260 | void AliMUONTrackReconstructor::RemoveDoubleTracks(void) | |
261 | { | |
262 | /// To remove double tracks: | |
263 | /// Tracks are considered identical if more than half of the hits of the track | |
264 | /// which has the smaller number of hits are in common with the other track. | |
265 | /// Among two identical tracks, one keeps the track with the larger number of hits | |
266 | /// or, if these numbers are equal, the track with the minimum chi2. | |
267 | AliMUONTrack *track1, *track2, *trackToRemove; | |
268 | Int_t hitsInCommon, nHits1, nHits2; | |
269 | Bool_t removedTrack1; | |
270 | // Loop over first track of the pair | |
271 | track1 = (AliMUONTrack*) fRecTracksPtr->First(); | |
272 | while (track1) { | |
273 | removedTrack1 = kFALSE; | |
274 | nHits1 = track1->GetNTrackHits(); | |
275 | // Loop over second track of the pair | |
276 | track2 = (AliMUONTrack*) fRecTracksPtr->After(track1); | |
277 | while (track2) { | |
278 | nHits2 = track2->GetNTrackHits(); | |
279 | // number of hits in common between two tracks | |
280 | hitsInCommon = track1->HitsInCommon(track2); | |
281 | // check for identical tracks | |
282 | if (((nHits1 < nHits2) && (2 * hitsInCommon > nHits1)) || (2 * hitsInCommon > nHits2)) { | |
283 | // decide which track to remove | |
284 | if ((nHits1 > nHits2) || ((nHits1 == nHits2) && (track1->GetFitFMin() <= track2->GetFitFMin()))) { | |
285 | // remove track2 and continue the second loop with the track next to track2 | |
286 | trackToRemove = track2; | |
287 | track2 = (AliMUONTrack*) fRecTracksPtr->After(track2); | |
288 | fRecTracksPtr->Remove(trackToRemove); | |
289 | fRecTracksPtr->Compress(); // this is essential to retrieve the TClonesArray afterwards | |
290 | fNRecTracks--; | |
291 | } else { | |
292 | // else remove track1 and continue the first loop with the track next to track1 | |
293 | trackToRemove = track1; | |
294 | track1 = (AliMUONTrack*) fRecTracksPtr->After(track1); | |
295 | fRecTracksPtr->Remove(trackToRemove); | |
296 | fRecTracksPtr->Compress(); // this is essential to retrieve the TClonesArray afterwards | |
297 | fNRecTracks--; | |
298 | removedTrack1 = kTRUE; | |
299 | break; | |
300 | } | |
301 | } else track2 = (AliMUONTrack*) fRecTracksPtr->After(track2); | |
302 | } // track2 | |
303 | if (removedTrack1) continue; | |
304 | track1 = (AliMUONTrack*) fRecTracksPtr->After(track1); | |
305 | } // track1 | |
306 | return; | |
307 | } | |
308 | ||
309 | //__________________________________________________________________________ | |
310 | void AliMUONTrackReconstructor::FollowTracks(void) | |
311 | { | |
312 | /// Follow tracks in stations(1..) 3, 2 and 1 | |
313 | AliDebug(1,"Enter FollowTracks"); | |
314 | ||
315 | AliMUONTrack *track, *nextTrack; | |
316 | AliMUONTrackParam *trackParamAtFirstHit; | |
317 | Double_t numberOfDegFree, chi2Norm; | |
318 | Int_t currentNRecTracks; | |
319 | ||
320 | for (Int_t station = 2; station >= 0; station--) { | |
321 | // Save the actual number of reconstructed track in case of | |
322 | // tracks are added or suppressed during the tracking procedure | |
323 | // !! Do not compress fRecTracksPtr until the end of the loop over tracks !! | |
324 | currentNRecTracks = fNRecTracks; | |
325 | for (Int_t iRecTrack = 0; iRecTrack <currentNRecTracks; iRecTrack++) { | |
326 | AliDebug(1,Form("FollowTracks: track candidate(1..) %d", iRecTrack+1)); | |
327 | track = (AliMUONTrack*) fRecTracksPtr->UncheckedAt(iRecTrack); | |
328 | // Fit the track: | |
329 | // Do not take into account the multiple scattering to speed up the fit | |
330 | // Calculate the track parameter covariance matrix | |
331 | // If "station" is station(1..) 3 then use the vertex to better constrain the fit | |
332 | if (station==2) { | |
333 | SetVertexForFit(track); | |
334 | track->SetFitWithVertex(kTRUE); | |
335 | } else track->SetFitWithVertex(kFALSE); | |
336 | Fit(track,kFALSE, kTRUE); | |
337 | // Remove the track if the normalized chi2 is too high | |
338 | numberOfDegFree = (2. * track->GetNTrackHits() - 5.); | |
339 | if (numberOfDegFree > 0) chi2Norm = track->GetFitFMin() / numberOfDegFree; | |
340 | else chi2Norm = 1.e10; | |
341 | if (chi2Norm > fgkMaxNormChi2) { | |
342 | fRecTracksPtr->Remove(track); | |
343 | fNRecTracks--; | |
344 | continue; | |
345 | } | |
346 | // Add MCS effects in parameter covariances | |
347 | trackParamAtFirstHit = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->First()); | |
348 | AliMUONTrackExtrap::AddMCSEffect(trackParamAtFirstHit,AliMUONConstants::ChamberThicknessInX0(),1.); | |
349 | // Printout for debuging | |
350 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) { | |
351 | cout<<endl<<"Track parameter covariances at first hit with multiple Coulomb scattering effects:"<<endl; | |
352 | trackParamAtFirstHit->GetCovariances()->Print(); | |
353 | } | |
354 | // Look for compatible hitForRec in station(0..) "station" | |
355 | FollowTrackInStation(track,station); | |
356 | } | |
357 | // Compress fRecTracksPtr for the next step | |
358 | fRecTracksPtr->Compress(); | |
359 | // Keep only the best tracks if required | |
360 | if (!fgkTrackAllTracks) RemoveDoubleTracks(); | |
361 | } | |
362 | ||
363 | // Last fit of track candidates with all station | |
364 | // Take into account the multiple scattering and remove bad tracks | |
365 | Int_t trackIndex = -1; | |
366 | track = (AliMUONTrack*) fRecTracksPtr->First(); | |
367 | while (track) { | |
368 | trackIndex++; | |
369 | nextTrack = (AliMUONTrack*) fRecTracksPtr->After(track); // prepare next track | |
370 | track->SetFitWithVertex(kFALSE); // just to be sure | |
371 | Fit(track,kTRUE, kFALSE); | |
372 | // Printout for debuging | |
373 | if (AliLog::GetGlobalDebugLevel() >= 3) { | |
374 | cout << "FollowTracks: track candidate(0..) " << trackIndex << " after final fit" << endl; | |
375 | track->RecursiveDump(); | |
376 | } | |
377 | // Remove the track if the normalized chi2 is too high | |
378 | numberOfDegFree = (2.0 * track->GetNTrackHits() - 5); | |
379 | if (numberOfDegFree > 0) chi2Norm = track->GetFitFMin() / numberOfDegFree; | |
380 | else chi2Norm = 1.e10; | |
381 | if (chi2Norm > fgkMaxNormChi2) { | |
382 | fRecTracksPtr->Remove(track); | |
383 | fNRecTracks--; | |
384 | } | |
385 | track = nextTrack; | |
386 | } | |
387 | fRecTracksPtr->Compress(); | |
388 | ||
389 | } | |
390 | ||
391 | //__________________________________________________________________________ | |
392 | void AliMUONTrackReconstructor::FollowTrackInStation(AliMUONTrack* trackCandidate, Int_t nextStation) | |
393 | { | |
394 | /// Follow trackCandidate in station(0..) nextStation and search for compatible HitForRec(s) | |
395 | /// Keep all possibilities or only the best one(s) according to the flag fgkTrackAllTracks: | |
396 | /// kTRUE: duplicate "trackCandidate" if there are several possibilities and add the new tracks at the end of | |
397 | /// fRecTracksPtr to avoid conficts with other track candidates at this current stage of the tracking procedure. | |
398 | /// Remove the obsolete "trackCandidate" at the end. | |
399 | /// kFALSE: add only the best hit(s) to the "trackCandidate". Try to add a couple of hits in priority. | |
400 | AliDebug(1,Form("Enter FollowTrackInStation(1..) %d", nextStation+1)); | |
401 | ||
402 | Int_t ch1 = 2*nextStation; | |
403 | Int_t ch2 = 2*nextStation+1; | |
404 | Double_t zCh2 = AliMUONConstants::DefaultChamberZ(ch2); | |
405 | Double_t chi2WithOneHitForRec = 1.e10; | |
406 | Double_t chi2WithTwoHitForRec = 1.e10; | |
407 | Double_t maxChi2WithOneHitForRec = 2.*fgkMaxNormChi2; // 2 because 2 quantities in chi2 | |
408 | Double_t maxChi2WithTwoHitForRec = 4.*fgkMaxNormChi2; // 4 because 4 quantities in chi2 | |
409 | Double_t bestChi2WithOneHitForRec = maxChi2WithOneHitForRec; | |
410 | Double_t bestChi2WithTwoHitForRec = maxChi2WithTwoHitForRec; | |
411 | AliMUONTrack *newTrack = 0x0; | |
412 | AliMUONHitForRec *hitForRecCh1, *hitForRecCh2; | |
413 | AliMUONHitForRec *bestHitForRec1 = 0x0, *bestHitForRec2 = 0x0; | |
414 | Bool_t *hitForRecCh1Used = new Bool_t[fNHitsForRecPerChamber[ch1]]; | |
415 | for (Int_t hit1 = 0; hit1 < fNHitsForRecPerChamber[ch1]; hit1++) hitForRecCh1Used[hit1] = kFALSE; | |
416 | // | |
417 | //Extrapolate trackCandidate to chamber "ch2" to save computing time in the next steps | |
418 | AliMUONTrackParam *extrapTrackParamPtr = trackCandidate->GetExtrapTrackParam(); | |
419 | *extrapTrackParamPtr = *((AliMUONTrackParam*)(trackCandidate->GetTrackParamAtHit()->First())); | |
420 | AliMUONTrackExtrap::ExtrapToZCov(extrapTrackParamPtr, zCh2); | |
421 | AliMUONTrackParam extrapTrackParamSave(*extrapTrackParamPtr); | |
422 | // | |
423 | // Printout for debuging | |
424 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) { | |
425 | TMatrixD* paramCovForDebug = extrapTrackParamPtr->GetCovariances(); | |
426 | cout<<endl<<"Track parameter covariances at first hit extrapolated to z = "<<zCh2<<":"<<endl; | |
427 | paramCovForDebug->Print(); | |
428 | } | |
429 | // | |
430 | // look for candidates in chamber 2 | |
431 | // Printout for debuging | |
432 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
433 | cout << "FollowTrackInStation: look for hits in chamber(1..): " << ch2+1 << endl; | |
434 | } | |
435 | for (Int_t hit2 = 0; hit2 < fNHitsForRecPerChamber[ch2]; hit2++) { | |
436 | hitForRecCh2 = (AliMUONHitForRec*) fHitsForRecPtr->UncheckedAt(fIndexOfFirstHitForRecPerChamber[ch2]+hit2); | |
437 | // extrapolate track parameters and covariances only once for this hit | |
438 | AliMUONTrackExtrap::ExtrapToZCov(extrapTrackParamPtr, hitForRecCh2->GetZ()); | |
439 | chi2WithOneHitForRec = trackCandidate->TryOneHitForRec(hitForRecCh2); | |
440 | // if good chi2 then try to attach a hitForRec in the other chamber too | |
441 | if (chi2WithOneHitForRec < maxChi2WithOneHitForRec) { | |
442 | // Printout for debuging | |
443 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
444 | cout << "FollowTrackInStation: look for second hits in chamber(1..): " << ch1+1 << endl; | |
445 | } | |
446 | Bool_t foundSecondHit = kFALSE; | |
447 | for (Int_t hit1 = 0; hit1 < fNHitsForRecPerChamber[ch1]; hit1++) { | |
448 | hitForRecCh1 = (AliMUONHitForRec*) fHitsForRecPtr->UncheckedAt(fIndexOfFirstHitForRecPerChamber[ch1]+hit1); | |
449 | chi2WithTwoHitForRec = trackCandidate->TryTwoHitForRec(hitForRecCh2, hitForRecCh1); // order hits like that to save computing time | |
450 | // if good chi2 then create a new track by adding the 2 hitForRec to the "trackCandidate" | |
451 | if (chi2WithTwoHitForRec < maxChi2WithTwoHitForRec) { | |
452 | foundSecondHit = kTRUE; | |
453 | if (fgkTrackAllTracks) { | |
454 | // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new hitForRec's | |
455 | newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(*trackCandidate); | |
456 | fNRecTracks++; | |
457 | AliMUONTrackParam trackParam1(extrapTrackParamSave); | |
458 | AliMUONTrackExtrap::ExtrapToZ(&trackParam1, hitForRecCh1->GetZ()); | |
459 | newTrack->AddTrackParamAtHit(&trackParam1,hitForRecCh1); | |
460 | AliMUONTrackParam trackParam2(extrapTrackParamSave); | |
461 | AliMUONTrackExtrap::ExtrapToZ(&trackParam2, hitForRecCh2->GetZ()); | |
462 | newTrack->AddTrackParamAtHit(&trackParam2,hitForRecCh2); | |
463 | // Sort TrackParamAtHit according to increasing Z | |
464 | newTrack->GetTrackParamAtHit()->Sort(); | |
465 | // Update the chi2 of the new track | |
466 | if (newTrack->GetFitFMin()<0) newTrack->SetFitFMin(chi2WithTwoHitForRec); | |
467 | else newTrack->SetFitFMin(newTrack->GetFitFMin() + chi2WithTwoHitForRec); | |
468 | // Tag hitForRecCh1 as used | |
469 | hitForRecCh1Used[hit1] = kTRUE; | |
470 | // Printout for debuging | |
471 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
472 | cout << "FollowTrackInStation: added two hits in station(1..): " << nextStation+1 | |
473 | << " (Chi2 = " << chi2WithTwoHitForRec << ")" << endl; | |
474 | if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); | |
475 | } | |
476 | } else if (chi2WithTwoHitForRec < bestChi2WithTwoHitForRec) { | |
477 | // keep track of the best couple of hits | |
478 | bestChi2WithTwoHitForRec = chi2WithTwoHitForRec; | |
479 | bestHitForRec1 = hitForRecCh1; | |
480 | bestHitForRec2 = hitForRecCh2; | |
481 | } | |
482 | } | |
483 | } | |
484 | // if no hitForRecCh1 found then consider to add hitForRecCh2 only | |
485 | if (!foundSecondHit) { | |
486 | if (fgkTrackAllTracks) { | |
487 | // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new hitForRec's | |
488 | newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(*trackCandidate); | |
489 | fNRecTracks++; | |
490 | AliMUONTrackParam trackParam1(extrapTrackParamSave); | |
491 | AliMUONTrackExtrap::ExtrapToZ(&trackParam1, hitForRecCh2->GetZ()); | |
492 | newTrack->AddTrackParamAtHit(&trackParam1,hitForRecCh2); | |
493 | // Sort TrackParamAtHit according to increasing Z | |
494 | newTrack->GetTrackParamAtHit()->Sort(); | |
495 | // Update the chi2 of the new track | |
496 | if (newTrack->GetFitFMin()<0) newTrack->SetFitFMin(chi2WithOneHitForRec); | |
497 | else newTrack->SetFitFMin(newTrack->GetFitFMin() + chi2WithOneHitForRec); | |
498 | // Printout for debuging | |
499 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
500 | cout << "FollowTrackInStation: added one hit in chamber(1..): " << ch2+1 | |
501 | << " (Chi2 = " << chi2WithOneHitForRec << ")" << endl; | |
502 | if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); | |
503 | } | |
504 | } if (!bestHitForRec2 && chi2WithOneHitForRec < bestChi2WithOneHitForRec) { | |
505 | // keep track of the best single hitForRec except if a couple | |
506 | // of hits has already been found (i.e. bestHitForRec2!=0x0) | |
507 | bestChi2WithOneHitForRec = chi2WithOneHitForRec; | |
508 | bestHitForRec1 = hitForRecCh2; | |
509 | } | |
510 | } | |
511 | } | |
512 | // reset the extrapolated track parameter for next step | |
513 | trackCandidate->SetExtrapTrackParam(&extrapTrackParamSave); | |
514 | } | |
515 | // | |
516 | // look for candidates in chamber 1 not already attached to a track | |
517 | // if we want to keep all possible tracks or if no good couple of hitForRec has been found | |
518 | if (fgkTrackAllTracks || !bestHitForRec2) { | |
519 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
520 | cout << "FollowTrackInStation: look for single hits in chamber(1..): " << ch1+1 << endl; | |
521 | } | |
522 | for (Int_t hit1 = 0; hit1 < fNHitsForRecPerChamber[ch1]; hit1++) { | |
523 | hitForRecCh1 = (AliMUONHitForRec*) fHitsForRecPtr->UncheckedAt(fIndexOfFirstHitForRecPerChamber[ch1]+hit1); | |
524 | if (hitForRecCh1Used[hit1]) continue; // Skip hitForRec already used | |
525 | chi2WithOneHitForRec = trackCandidate->TryOneHitForRec(hitForRecCh1); | |
526 | // if good chi2 then create a new track by adding the good hitForRec in "ch1" to the "trackCandidate" | |
527 | // We do not try to attach a hitForRec in the other chamber too since it has already been done above | |
528 | if (chi2WithOneHitForRec < maxChi2WithOneHitForRec) { | |
529 | if (fgkTrackAllTracks) { | |
530 | // copy trackCandidate into a new track put at the end of fRecTracksPtr and add the new hitForRec's | |
531 | newTrack = new ((*fRecTracksPtr)[fRecTracksPtr->GetLast()+1]) AliMUONTrack(*trackCandidate); | |
532 | fNRecTracks++; | |
533 | AliMUONTrackParam trackParam1(extrapTrackParamSave); | |
534 | AliMUONTrackExtrap::ExtrapToZ(&trackParam1, hitForRecCh1->GetZ()); | |
535 | newTrack->AddTrackParamAtHit(&trackParam1,hitForRecCh1); | |
536 | // Sort TrackParamAtHit according to increasing Z | |
537 | newTrack->GetTrackParamAtHit()->Sort(); | |
538 | // Update the chi2 of the new track | |
539 | if (newTrack->GetFitFMin()<0) newTrack->SetFitFMin(chi2WithOneHitForRec); | |
540 | else newTrack->SetFitFMin(newTrack->GetFitFMin() + chi2WithOneHitForRec); | |
541 | // Printout for debuging | |
542 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
543 | cout << "FollowTrackInStation: added one hit in chamber(1..): " << ch1+1 | |
544 | << " (Chi2 = " << chi2WithOneHitForRec << ")" << endl; | |
545 | if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); | |
546 | } | |
547 | } if (!bestHitForRec2 && chi2WithOneHitForRec < bestChi2WithOneHitForRec) { | |
548 | // keep track of the best single hitForRec except if a couple | |
549 | // of hits has already been found (i.e. bestHitForRec1!=0x0) | |
550 | bestChi2WithOneHitForRec = chi2WithOneHitForRec; | |
551 | bestHitForRec1 = hitForRecCh1; | |
552 | } | |
553 | } | |
554 | } | |
555 | } | |
556 | // | |
557 | // fill out the best track if required else clean up the fRecTracksPtr array | |
558 | if (!fgkTrackAllTracks && bestHitForRec1) { | |
559 | AliMUONTrackParam trackParam1(extrapTrackParamSave); | |
560 | AliMUONTrackExtrap::ExtrapToZ(&trackParam1, bestHitForRec1->GetZ()); | |
561 | trackCandidate->AddTrackParamAtHit(&trackParam1,bestHitForRec1); | |
562 | if (bestHitForRec2) { | |
563 | AliMUONTrackParam trackParam2(extrapTrackParamSave); | |
564 | AliMUONTrackExtrap::ExtrapToZ(&trackParam2, bestHitForRec2->GetZ()); | |
565 | trackCandidate->AddTrackParamAtHit(&trackParam2,bestHitForRec2); | |
566 | // Sort TrackParamAtHit according to increasing Z | |
567 | trackCandidate->GetTrackParamAtHit()->Sort(); | |
568 | // Update the chi2 of the new track | |
569 | if (trackCandidate->GetFitFMin()<0) trackCandidate->SetFitFMin(bestChi2WithTwoHitForRec); | |
570 | else trackCandidate->SetFitFMin(trackCandidate->GetFitFMin() + bestChi2WithTwoHitForRec); | |
571 | // Printout for debuging | |
572 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
573 | cout << "FollowTrackInStation: added the two best hits in station(1..): " << nextStation+1 | |
574 | << " (Chi2 = " << bestChi2WithTwoHitForRec << ")" << endl; | |
575 | if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); | |
576 | } | |
577 | } else { | |
578 | // Sort TrackParamAtHit according to increasing Z | |
579 | trackCandidate->GetTrackParamAtHit()->Sort(); | |
580 | // Update the chi2 of the new track | |
581 | if (trackCandidate->GetFitFMin()<0) trackCandidate->SetFitFMin(bestChi2WithOneHitForRec); | |
582 | else trackCandidate->SetFitFMin(trackCandidate->GetFitFMin() + bestChi2WithOneHitForRec); | |
583 | // Printout for debuging | |
584 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 1) || (AliLog::GetGlobalDebugLevel() >= 1)) { | |
585 | cout << "FollowTrackInStation: added the best hit in station(1..): " << nextStation+1 | |
586 | << " (Chi2 = " << bestChi2WithOneHitForRec << ")" << endl; | |
587 | if (AliLog::GetGlobalDebugLevel() >= 3) newTrack->RecursiveDump(); | |
588 | } | |
589 | } | |
590 | } else { | |
591 | fRecTracksPtr->Remove(trackCandidate); // obsolete track | |
592 | fNRecTracks--; | |
593 | } | |
594 | ||
595 | } | |
596 | ||
597 | //__________________________________________________________________________ | |
598 | void AliMUONTrackReconstructor::SetVertexForFit(AliMUONTrack* trackCandidate) | |
599 | { | |
600 | /// Add the vertex as a measured hit to constrain the fit of the "trackCandidate" | |
601 | /// Compute the vertex resolution from natural vertex dispersion and | |
602 | /// multiple scattering effets according to trackCandidate path in absorber | |
603 | /// It is necessary to account for multiple scattering effects here instead of during the fit of | |
604 | /// the "trackCandidate" to do not influence the result by changing track resolution at vertex | |
605 | AliDebug(1,"Enter SetVertexForFit"); | |
606 | ||
607 | Double_t nonBendingReso2 = fNonBendingVertexDispersion * fNonBendingVertexDispersion; | |
608 | Double_t bendingReso2 = fBendingVertexDispersion * fBendingVertexDispersion; | |
609 | // add multiple scattering effets | |
610 | AliMUONTrackParam paramAtVertex(*((AliMUONTrackParam*)(trackCandidate->GetTrackParamAtHit()->First()))); | |
611 | paramAtVertex.DeleteCovariances(); // to be sure to account only for multiple scattering | |
612 | AliMUONTrackExtrap::ExtrapToVertexUncorrected(¶mAtVertex,0.); | |
613 | TMatrixD* paramCov = paramAtVertex.GetCovariances(); | |
614 | nonBendingReso2 += (*paramCov)(0,0); | |
615 | bendingReso2 += (*paramCov)(2,2); | |
616 | // Set the vertex | |
617 | AliMUONHitForRec vertex; // Coordinates set to (0.,0.,0.) by default | |
618 | vertex.SetNonBendingReso2(nonBendingReso2); | |
619 | vertex.SetBendingReso2(bendingReso2); | |
620 | trackCandidate->SetVertex(&vertex); | |
621 | } | |
622 | ||
623 | //__________________________________________________________________________ | |
624 | void AliMUONTrackReconstructor::Fit(AliMUONTrack *track, Bool_t includeMCS, Bool_t calcCov) | |
625 | { | |
626 | /// Fit the track "track" with or without multiple Coulomb scattering according to "includeMCS". | |
627 | ||
628 | Double_t benC, errorParam, invBenP, nonBenC, x, y; | |
629 | AliMUONTrackParam *trackParam; | |
630 | Double_t arg[1], fedm, errdef, fitFMin; | |
631 | Int_t npari, nparx; | |
632 | Int_t status, covStatus; | |
633 | ||
634 | // Instantiate gMinuit if not already done | |
635 | if (!gMinuit) gMinuit = new TMinuit(6); | |
636 | // Clear MINUIT parameters | |
637 | gMinuit->mncler(); | |
638 | // Give the fitted track to MINUIT | |
639 | gMinuit->SetObjectFit(track); | |
640 | if ((AliLog::GetDebugLevel("MUON","AliMUONTrackReconstructor") >= 2) || (AliLog::GetGlobalDebugLevel() >= 2)) { | |
641 | // Define print level | |
642 | arg[0] = 1; | |
643 | gMinuit->mnexcm("SET PRI", arg, 1, status); | |
644 | // Print covariance matrix | |
645 | gMinuit->mnexcm("SHO COV", arg, 0, status); | |
646 | } else { | |
647 | arg[0] = -1; | |
648 | gMinuit->mnexcm("SET PRI", arg, 1, status); | |
649 | } | |
650 | // No warnings | |
651 | gMinuit->mnexcm("SET NOW", arg, 0, status); | |
652 | // Define strategy | |
653 | //arg[0] = 2; | |
654 | //gMinuit->mnexcm("SET STR", arg, 1, status); | |
655 | ||
656 | // Switch between available FCN according to "includeMCS" | |
657 | if (includeMCS) gMinuit->SetFCN(TrackChi2MCS); | |
658 | else gMinuit->SetFCN(TrackChi2); | |
659 | ||
660 | // Set fitted parameters (!! The order is very important for the covariance matrix !!) | |
661 | trackParam = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->First()); | |
662 | // could be tried with no limits for the search (min=max=0) ???? | |
663 | // mandatory limits in non Bending to avoid NaN values of parameters | |
664 | gMinuit->mnparm(0, "X", trackParam->GetNonBendingCoor(), 0.03, -500.0, 500.0, status); | |
665 | gMinuit->mnparm(1, "NonBenS", trackParam->GetNonBendingSlope(), 0.001, -0.5, 0.5, status); | |
666 | // mandatory limits in Bending to avoid NaN values of parameters | |
667 | gMinuit->mnparm(2, "Y", trackParam->GetBendingCoor(), 0.10, -500.0, 500.0, status); | |
668 | gMinuit->mnparm(3, "BenS", trackParam->GetBendingSlope(), 0.001, -0.5, 0.5, status); | |
669 | gMinuit->mnparm(4, "InvBenP", trackParam->GetInverseBendingMomentum(), 0.003, -0.4, 0.4, status); | |
670 | ||
671 | // minimization | |
672 | gMinuit->mnexcm("MIGRAD", arg, 0, status); | |
673 | ||
674 | // Calculate the covariance matrix more accurately if required | |
675 | if (calcCov) gMinuit->mnexcm("HESSE", arg, 0, status); | |
676 | ||
677 | // get results into "invBenP", "benC", "nonBenC" ("x", "y") | |
678 | gMinuit->GetParameter(0, x, errorParam); | |
679 | trackParam->SetNonBendingCoor(x); | |
680 | gMinuit->GetParameter(1, nonBenC, errorParam); | |
681 | trackParam->SetNonBendingSlope(nonBenC); | |
682 | gMinuit->GetParameter(2, y, errorParam); | |
683 | trackParam->SetBendingCoor(y); | |
684 | gMinuit->GetParameter(3, benC, errorParam); | |
685 | trackParam->SetBendingSlope(benC); | |
686 | gMinuit->GetParameter(4, invBenP, errorParam); | |
687 | trackParam->SetInverseBendingMomentum(invBenP); | |
688 | ||
689 | // global result of the fit | |
690 | gMinuit->mnstat(fitFMin, fedm, errdef, npari, nparx, covStatus); | |
691 | track->SetFitFMin(fitFMin); | |
692 | ||
693 | // Get the covariance matrix if required | |
694 | if (calcCov) { | |
695 | // Covariance matrix according to HESSE status | |
696 | // If problem then keep only the diagonal terms (variances) | |
697 | Double_t matrix[5][5]; | |
698 | gMinuit->mnemat(&matrix[0][0],5); | |
699 | if (covStatus == 3) trackParam->SetCovariances(matrix); | |
700 | else trackParam->SetVariances(matrix); | |
701 | } else *(trackParam->GetCovariances()) = 0; | |
702 | ||
703 | } | |
704 | ||
705 | //__________________________________________________________________________ | |
706 | void TrackChi2(Int_t & /*NParam*/, Double_t * /*Gradient*/, Double_t &Chi2, Double_t *Param, Int_t /*Flag*/) | |
707 | { | |
708 | /// Return the "Chi2" to be minimized with Minuit for track fitting, | |
709 | /// with "NParam" parameters | |
710 | /// and their current values in array pointed to by "Param". | |
711 | /// Assumes that the track hits are sorted according to increasing Z. | |
712 | /// Track parameters at each TrackHit are updated accordingly. | |
713 | /// Multiple Coulomb scattering is not taken into account | |
714 | ||
715 | AliMUONTrack *trackBeingFitted = (AliMUONTrack*) gMinuit->GetObjectFit(); | |
716 | // AliMUONTrack *trackBeingFitted = (AliMUONTrack*) AliMUONTrackReconstructor::Fitter()->GetObjectFit(); | |
717 | AliMUONTrackParam param1; | |
718 | AliMUONTrackParam* trackParamAtHit; | |
719 | AliMUONHitForRec* hitForRec; | |
720 | Chi2 = 0.0; // initialize Chi2 | |
721 | Double_t dX, dY; | |
722 | ||
723 | // copy of track parameters to be fitted | |
724 | param1 = *((AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->First())); | |
725 | param1.SetNonBendingCoor(Param[0]); | |
726 | param1.SetNonBendingSlope(Param[1]); | |
727 | param1.SetBendingCoor(Param[2]); | |
728 | param1.SetBendingSlope(Param[3]); | |
729 | param1.SetInverseBendingMomentum(Param[4]); | |
730 | ||
731 | // Take the vertex into account in the fit if required | |
732 | if (trackBeingFitted->GetFitWithVertex()) { | |
733 | AliMUONTrackParam paramAtVertex(param1); | |
734 | AliMUONTrackExtrap::ExtrapToZ(¶mAtVertex, 0.); | |
735 | AliMUONHitForRec *vertex = trackBeingFitted->GetVertex(); | |
736 | if (!vertex) { | |
737 | cout<<"Error in TrackChi2: Want to use the vertex in tracking but it has not been created!!"<<endl; | |
738 | exit(-1); | |
739 | } | |
740 | dX = vertex->GetNonBendingCoor() - paramAtVertex.GetNonBendingCoor(); | |
741 | dY = vertex->GetBendingCoor() - paramAtVertex.GetBendingCoor(); | |
742 | Chi2 += dX * dX / vertex->GetNonBendingReso2() + dY * dY / vertex->GetBendingReso2(); | |
743 | } | |
744 | ||
745 | // Follow track through all planes of track hits | |
746 | trackParamAtHit = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->First()); | |
747 | while (trackParamAtHit) { | |
748 | hitForRec = trackParamAtHit->GetHitForRecPtr(); | |
749 | // extrapolation to the plane of the hitForRec attached to the current trackParamAtHit | |
750 | AliMUONTrackExtrap::ExtrapToZ(¶m1, hitForRec->GetZ()); | |
751 | // update track parameters of the current hit | |
752 | trackParamAtHit->SetTrackParam(param1); | |
753 | // Increment Chi2 | |
754 | // done hit per hit, with hit resolution, | |
755 | // and not with point and angle like in "reco_muon.F" !!!! | |
756 | dX = hitForRec->GetNonBendingCoor() - param1.GetNonBendingCoor(); | |
757 | dY = hitForRec->GetBendingCoor() - param1.GetBendingCoor(); | |
758 | Chi2 = Chi2 + dX * dX / hitForRec->GetNonBendingReso2() + dY * dY / hitForRec->GetBendingReso2(); | |
759 | trackParamAtHit = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->After(trackParamAtHit)); | |
760 | } | |
761 | } | |
762 | ||
763 | //__________________________________________________________________________ | |
764 | void TrackChi2MCS(Int_t & /*NParam*/, Double_t * /*Gradient*/, Double_t &Chi2, Double_t *Param, Int_t /*Flag*/) | |
765 | { | |
766 | /// Return the "Chi2" to be minimized with Minuit for track fitting, | |
767 | /// with "NParam" parameters | |
768 | /// and their current values in array pointed to by "Param". | |
769 | /// Assumes that the track hits are sorted according to increasing Z. | |
770 | /// Track parameters at each TrackHit are updated accordingly. | |
771 | /// Multiple Coulomb scattering is taken into account with covariance matrix. | |
772 | ||
773 | AliMUONTrack *trackBeingFitted = (AliMUONTrack*) gMinuit->GetObjectFit(); | |
774 | // AliMUONTrack *trackBeingFitted = (AliMUONTrack*) AliMUONTrackReconstructor::Fitter()->GetObjectFit(); | |
775 | AliMUONTrackParam param1; | |
776 | AliMUONTrackParam* trackParamAtHit; | |
777 | AliMUONHitForRec* hitForRec; | |
778 | Chi2 = 0.0; // initialize Chi2 | |
779 | Int_t chCurrent, chPrev = 0, hitNumber, hitNumber1, hitNumber2, hitNumber3; | |
780 | Double_t z1, z2, z3; | |
781 | AliMUONTrackParam *trackParamAtHit1, *trackParamAtHit2, *trackParamAtHit3; | |
782 | AliMUONHitForRec *hitForRec1, *hitForRec2; | |
783 | Double_t hbc1, hbc2, pbc1, pbc2; | |
784 | Double_t hnbc1, hnbc2, pnbc1, pnbc2; | |
785 | Int_t numberOfHit = trackBeingFitted->GetNTrackHits(); | |
786 | TMatrixD *covBending = new TMatrixD(numberOfHit, numberOfHit); | |
787 | TMatrixD *covNonBending = new TMatrixD(numberOfHit, numberOfHit); | |
788 | Double_t *msa2 = new Double_t[numberOfHit]; | |
789 | ||
790 | // copy of track parameters to be fitted | |
791 | param1 = *((AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->First())); | |
792 | param1.SetNonBendingCoor(Param[0]); | |
793 | param1.SetNonBendingSlope(Param[1]); | |
794 | param1.SetBendingCoor(Param[2]); | |
795 | param1.SetBendingSlope(Param[3]); | |
796 | param1.SetInverseBendingMomentum(Param[4]); | |
797 | ||
798 | // Take the vertex into account in the fit if required | |
799 | if (trackBeingFitted->GetFitWithVertex()) { | |
800 | AliMUONTrackParam paramAtVertex(param1); | |
801 | AliMUONTrackExtrap::ExtrapToZ(¶mAtVertex, 0.); | |
802 | AliMUONHitForRec *vertex = trackBeingFitted->GetVertex(); | |
803 | if (!vertex) { | |
804 | cout<<"Error in TrackChi2MCS: Want to use the vertex in tracking but it has not been created!!"<<endl; | |
805 | exit(-1); | |
806 | } | |
807 | Double_t dX = vertex->GetNonBendingCoor() - paramAtVertex.GetNonBendingCoor(); | |
808 | Double_t dY = vertex->GetBendingCoor() - paramAtVertex.GetBendingCoor(); | |
809 | Chi2 += dX * dX / vertex->GetNonBendingReso2() + dY * dY / vertex->GetBendingReso2(); | |
810 | } | |
811 | ||
812 | // Predicted coordinates and multiple scattering angles are first calculated | |
813 | for (hitNumber = 0; hitNumber < numberOfHit; hitNumber++) { | |
814 | trackParamAtHit = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber)); | |
815 | hitForRec = trackParamAtHit->GetHitForRecPtr(); | |
816 | // extrapolation to the plane of the hitForRec attached to the current trackParamAtHit | |
817 | AliMUONTrackExtrap::ExtrapToZ(¶m1, hitForRec->GetZ()); | |
818 | // update track parameters of the current hit | |
819 | trackParamAtHit->SetTrackParam(param1); | |
820 | // square of multiple scattering angle at current hit, with one chamber | |
821 | msa2[hitNumber] = MultipleScatteringAngle2(¶m1); | |
822 | // correction for eventual missing hits or multiple hits in a chamber, | |
823 | // according to the number of chambers | |
824 | // between the current hit and the previous one | |
825 | chCurrent = hitForRec->GetChamberNumber(); | |
826 | if (hitNumber > 0) msa2[hitNumber] = msa2[hitNumber] * (chCurrent - chPrev); | |
827 | chPrev = chCurrent; | |
828 | } | |
829 | ||
830 | // Calculates the covariance matrix | |
831 | for (hitNumber1 = 0; hitNumber1 < numberOfHit; hitNumber1++) { | |
832 | trackParamAtHit1 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber1)); | |
833 | hitForRec1 = trackParamAtHit1->GetHitForRecPtr(); | |
834 | z1 = hitForRec1->GetZ(); | |
835 | for (hitNumber2 = hitNumber1; hitNumber2 < numberOfHit; hitNumber2++) { | |
836 | trackParamAtHit2 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber2)); | |
837 | z2 = trackParamAtHit2->GetHitForRecPtr()->GetZ(); | |
838 | // initialization to 0 (diagonal plus upper triangular part) | |
839 | (*covBending)(hitNumber2, hitNumber1) = 0.0; | |
840 | // contribution from multiple scattering in bending plane: | |
841 | // loop over upstream hits | |
842 | for (hitNumber3 = 0; hitNumber3 < hitNumber1; hitNumber3++) { | |
843 | trackParamAtHit3 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber3)); | |
844 | z3 = trackParamAtHit3->GetHitForRecPtr()->GetZ(); | |
845 | (*covBending)(hitNumber2, hitNumber1) = (*covBending)(hitNumber2, hitNumber1) + ((z1 - z3) * (z2 - z3) * msa2[hitNumber3]); | |
846 | } | |
847 | // equal contribution from multiple scattering in non bending plane | |
848 | (*covNonBending)(hitNumber2, hitNumber1) = (*covBending)(hitNumber2, hitNumber1); | |
849 | if (hitNumber1 == hitNumber2) { | |
850 | // Diagonal elements: add contribution from position measurements | |
851 | // in bending plane | |
852 | (*covBending)(hitNumber2, hitNumber1) = (*covBending)(hitNumber2, hitNumber1) + hitForRec1->GetBendingReso2(); | |
853 | // and in non bending plane | |
854 | (*covNonBending)(hitNumber2, hitNumber1) = (*covNonBending)(hitNumber2, hitNumber1) + hitForRec1->GetNonBendingReso2(); | |
855 | } else { | |
856 | // Non diagonal elements: symmetrization | |
857 | // for bending plane | |
858 | (*covBending)(hitNumber1, hitNumber2) = (*covBending)(hitNumber2, hitNumber1); | |
859 | // and non bending plane | |
860 | (*covNonBending)(hitNumber1, hitNumber2) = (*covNonBending)(hitNumber2, hitNumber1); | |
861 | } | |
862 | } // for (hitNumber2 = hitNumber1;... | |
863 | } // for (hitNumber1 = 0;... | |
864 | ||
865 | // Inversion of covariance matrices | |
866 | Int_t ifailBending; | |
867 | gMinuit->mnvert(&((*covBending)(0,0)), numberOfHit, numberOfHit, numberOfHit, ifailBending); | |
868 | Int_t ifailNonBending; | |
869 | gMinuit->mnvert(&((*covNonBending)(0,0)), numberOfHit, numberOfHit, numberOfHit, ifailNonBending); | |
870 | ||
871 | // It would be worth trying to calculate the inverse of the covariance matrix | |
872 | // only once per fit, since it cannot change much in principle, | |
873 | // and it would save a lot of computing time !!!! | |
874 | ||
875 | // Calculates Chi2 | |
876 | if ((ifailBending == 0) && (ifailNonBending == 0)) { | |
877 | // with Multiple Scattering if inversion correct | |
878 | for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) { | |
879 | trackParamAtHit1 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber1)); | |
880 | hitForRec1 = trackParamAtHit1->GetHitForRecPtr(); | |
881 | hbc1 = hitForRec1->GetBendingCoor(); | |
882 | pbc1 = trackParamAtHit1->GetBendingCoor(); | |
883 | hnbc1 = hitForRec1->GetNonBendingCoor(); | |
884 | pnbc1 = trackParamAtHit1->GetNonBendingCoor(); | |
885 | for (hitNumber2 = 0; hitNumber2 < numberOfHit; hitNumber2++) { | |
886 | trackParamAtHit2 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber2)); | |
887 | hitForRec2 = trackParamAtHit2->GetHitForRecPtr(); | |
888 | hbc2 = hitForRec2->GetBendingCoor(); | |
889 | pbc2 = trackParamAtHit2->GetBendingCoor(); | |
890 | hnbc2 = hitForRec2->GetNonBendingCoor(); | |
891 | pnbc2 = trackParamAtHit2->GetNonBendingCoor(); | |
892 | Chi2 += ((*covBending)(hitNumber2, hitNumber1) * (hbc1 - pbc1) * (hbc2 - pbc2)) + | |
893 | ((*covNonBending)(hitNumber2, hitNumber1) * (hnbc1 - pnbc1) * (hnbc2 - pnbc2)); | |
894 | } | |
895 | } | |
896 | } else { | |
897 | // without Multiple Scattering if inversion impossible | |
898 | for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) { | |
899 | trackParamAtHit1 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber1)); | |
900 | hitForRec1 = trackParamAtHit1->GetHitForRecPtr(); | |
901 | hbc1 = hitForRec1->GetBendingCoor(); | |
902 | pbc1 = trackParamAtHit1->GetBendingCoor(); | |
903 | hnbc1 = hitForRec1->GetNonBendingCoor(); | |
904 | pnbc1 = trackParamAtHit1->GetNonBendingCoor(); | |
905 | Chi2 += ((hbc1 - pbc1) * (hbc1 - pbc1) / hitForRec1->GetBendingReso2()) + | |
906 | ((hnbc1 - pnbc1) * (hnbc1 - pnbc1) / hitForRec1->GetNonBendingReso2()); | |
907 | } | |
908 | } | |
909 | ||
910 | delete covBending; | |
911 | delete covNonBending; | |
912 | delete [] msa2; | |
913 | } | |
914 | ||
915 | //__________________________________________________________________________ | |
916 | Double_t MultipleScatteringAngle2(AliMUONTrackParam *param) | |
917 | { | |
918 | /// Returns square of multiple Coulomb scattering angle | |
919 | /// from TrackParamAtHit pointed to by "param" | |
920 | Double_t slopeBending, slopeNonBending, radiationLength, inverseBendingMomentum2, inverseTotalMomentum2; | |
921 | Double_t varMultipleScatteringAngle; | |
922 | slopeBending = param->GetBendingSlope(); | |
923 | slopeNonBending = param->GetNonBendingSlope(); | |
924 | // thickness in radiation length for the current track, | |
925 | // taking local angle into account | |
926 | radiationLength = AliMUONConstants::ChamberThicknessInX0() * | |
927 | TMath::Sqrt(1.0 + slopeBending*slopeBending + slopeNonBending*slopeNonBending); | |
928 | inverseBendingMomentum2 = param->GetInverseBendingMomentum() * param->GetInverseBendingMomentum(); | |
929 | inverseTotalMomentum2 = inverseBendingMomentum2 * (1.0 + slopeBending * slopeBending) / | |
930 | (1.0 + slopeBending *slopeBending + slopeNonBending * slopeNonBending); | |
931 | varMultipleScatteringAngle = 0.0136 * (1.0 + 0.038 * TMath::Log(radiationLength)); | |
932 | // The velocity is assumed to be 1 !!!! | |
933 | varMultipleScatteringAngle = inverseTotalMomentum2 * radiationLength * varMultipleScatteringAngle * varMultipleScatteringAngle; | |
934 | return varMultipleScatteringAngle; | |
935 | } | |
936 | ||
937 | //__________________________________________________________________________ | |
938 | void AliMUONTrackReconstructor::FillMUONTrack(void) | |
939 | { | |
940 | /// Fill fHitForRecAtHit of AliMUONTrack's | |
941 | AliMUONTrack *track; | |
942 | AliMUONTrackParam *trackParamAtHit; | |
943 | track = (AliMUONTrack*) fRecTracksPtr->First(); | |
944 | while (track) { | |
945 | trackParamAtHit = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->First()); | |
946 | while (trackParamAtHit) { | |
947 | track->AddHitForRecAtHit(trackParamAtHit->GetHitForRecPtr()); | |
948 | trackParamAtHit = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->After(trackParamAtHit)); | |
949 | } | |
950 | track = (AliMUONTrack*) fRecTracksPtr->After(track); | |
951 | } | |
952 | return; | |
953 | } | |
954 | ||
955 | //__________________________________________________________________________ | |
956 | void AliMUONTrackReconstructor::EventDump(void) | |
957 | { | |
958 | /// Dump reconstructed event (track parameters at vertex and at first hit), | |
959 | /// and the particle parameters | |
960 | AliMUONTrack *track; | |
961 | AliMUONTrackParam trackParam, *trackParam1; | |
962 | Double_t bendingSlope, nonBendingSlope, pYZ; | |
963 | Double_t pX, pY, pZ, x, y, z, c; | |
964 | Int_t trackIndex, nTrackHits; | |
965 | ||
966 | AliDebug(1,"****** enter EventDump ******"); | |
967 | AliDebug(1, Form("Number of Reconstructed tracks : %d", fNRecTracks)); | |
968 | ||
969 | fRecTracksPtr->Compress(); // for simple loop without "Next" since no hole | |
970 | // Loop over reconstructed tracks | |
971 | for (trackIndex = 0; trackIndex < fNRecTracks; trackIndex++) { | |
972 | AliDebug(1, Form("track number: %d", trackIndex)); | |
973 | // function for each track for modularity ???? | |
974 | track = (AliMUONTrack*) ((*fRecTracksPtr)[trackIndex]); | |
975 | nTrackHits = track->GetNTrackHits(); | |
976 | AliDebug(1, Form("Number of track hits: %d ", nTrackHits)); | |
977 | // track parameters at Vertex | |
978 | trackParam = (*((AliMUONTrackParam*) track->GetTrackParamAtHit()->First())); | |
979 | AliMUONTrackExtrap::ExtrapToVertex(&trackParam,0.,0.,0.); | |
980 | x = trackParam.GetNonBendingCoor(); | |
981 | y = trackParam.GetBendingCoor(); | |
982 | z = trackParam.GetZ(); | |
983 | bendingSlope = trackParam.GetBendingSlope(); | |
984 | nonBendingSlope = trackParam.GetNonBendingSlope(); | |
985 | pYZ = 1/TMath::Abs(trackParam.GetInverseBendingMomentum()); | |
986 | pZ = pYZ/TMath::Sqrt(1+bendingSlope*bendingSlope); | |
987 | pX = pZ * nonBendingSlope; | |
988 | pY = pZ * bendingSlope; | |
989 | c = TMath::Sign(1.0, trackParam.GetInverseBendingMomentum()); | |
990 | AliDebug(1, Form("Track parameters at Vertex z= %f: X= %f Y= %f pX= %f pY= %f pZ= %f c= %f\n", | |
991 | z, x, y, pX, pY, pZ, c)); | |
992 | ||
993 | // track parameters at first hit | |
994 | trackParam1 = (AliMUONTrackParam*) track->GetTrackParamAtHit()->First(); | |
995 | x = trackParam1->GetNonBendingCoor(); | |
996 | y = trackParam1->GetBendingCoor(); | |
997 | z = trackParam1->GetZ(); | |
998 | bendingSlope = trackParam1->GetBendingSlope(); | |
999 | nonBendingSlope = trackParam1->GetNonBendingSlope(); | |
1000 | pYZ = 1/TMath::Abs(trackParam1->GetInverseBendingMomentum()); | |
1001 | pZ = pYZ/TMath::Sqrt(1.0 + bendingSlope * bendingSlope); | |
1002 | pX = pZ * nonBendingSlope; | |
1003 | pY = pZ * bendingSlope; | |
1004 | c = TMath::Sign(1.0, trackParam1->GetInverseBendingMomentum()); | |
1005 | AliDebug(1, Form("track parameters at z= %f: X= %f Y= %f pX= %f pY= %f pZ= %f c= %f\n", | |
1006 | z, x, y, pX, pY, pZ, c)); | |
1007 | } | |
1008 | // informations about generated particles NO !!!!!!!! | |
1009 | ||
1010 | // for (Int_t iPart = 0; iPart < np; iPart++) { | |
1011 | // p = gAlice->Particle(iPart); | |
1012 | // printf(" particle %d: type= %d px= %f py= %f pz= %f pdg= %d\n", | |
1013 | // iPart, p->GetPdgCode(), p->Px(), p->Py(), p->Pz(), p->GetPdgCode()); | |
1014 | // } | |
1015 | return; | |
1016 | } | |
1017 | ||
1018 |