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a9e2aefa | 1 | /************************************************************************** |
2 | * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. * | |
3 | * * | |
4 | * Author: The ALICE Off-line Project. * | |
5 | * Contributors are mentioned in the code where appropriate. * | |
6 | * * | |
7 | * Permission to use, copy, modify and distribute this software and its * | |
8 | * documentation strictly for non-commercial purposes is hereby granted * | |
9 | * without fee, provided that the above copyright notice appears in all * | |
10 | * copies and that both the copyright notice and this permission notice * | |
11 | * appear in the supporting documentation. The authors make no claims * | |
12 | * about the suitability of this software for any purpose. It is * | |
13 | * provided "as is" without express or implied warranty. * | |
14 | **************************************************************************/ | |
15 | ||
16 | /* | |
17 | $Log$ | |
d0bfce8d | 18 | Revision 1.7 2000/09/19 15:50:46 gosset |
19 | TrackChi2MCS function: covariance matrix better calculated, | |
20 | taking into account missing planes... | |
21 | ||
eb9c9dab | 22 | Revision 1.6 2000/07/20 12:45:27 gosset |
23 | New "EventReconstructor..." structure, | |
24 | hopefully more adapted to tree/streamer. | |
25 | "AliMUONEventReconstructor::RemoveDoubleTracks" | |
26 | to keep only one track among similar ones. | |
27 | ||
8429a5e4 | 28 | Revision 1.5 2000/07/18 16:04:06 gosset |
29 | AliMUONEventReconstructor package: | |
30 | * a few minor modifications and more comments | |
31 | * a few corrections | |
32 | * right sign for Z of raw clusters | |
33 | * right loop over chambers inside station | |
34 | * symmetrized covariance matrix for measurements (TrackChi2MCS) | |
35 | * right sign of charge in extrapolation (ExtrapToZ) | |
36 | * right zEndAbsorber for Branson correction below 3 degrees | |
37 | * use of TVirtualFitter instead of TMinuit for AliMUONTrack::Fit | |
38 | * no parameter for AliMUONTrack::Fit() but more fit parameters in Track object | |
39 | ||
956019b6 | 40 | Revision 1.4 2000/06/30 10:15:48 gosset |
41 | Changes to EventReconstructor...: | |
42 | precision fit with multiple Coulomb scattering; | |
43 | extrapolation to vertex with Branson correction in absorber (JPC) | |
44 | ||
04b5ea16 | 45 | Revision 1.3 2000/06/25 13:23:28 hristov |
46 | stdlib.h needed for non-Linux compilation | |
47 | ||
f6e92cf4 | 48 | Revision 1.2 2000/06/15 07:58:48 morsch |
49 | Code from MUON-dev joined | |
50 | ||
a9e2aefa | 51 | Revision 1.1.2.3 2000/06/12 10:11:34 morsch |
52 | Dummy copy constructor and assignment operator added | |
53 | ||
54 | Revision 1.1.2.2 2000/06/09 12:58:05 gosset | |
55 | Removed comment beginnings in Log sections of .cxx files | |
56 | Suppressed most violations of coding rules | |
57 | ||
58 | Revision 1.1.2.1 2000/06/07 14:44:53 gosset | |
59 | Addition of files for track reconstruction in C++ | |
60 | */ | |
61 | ||
62 | //__________________________________________________________________________ | |
63 | // | |
64 | // Reconstructed track in ALICE dimuon spectrometer | |
65 | //__________________________________________________________________________ | |
66 | ||
67 | #include "AliMUONTrack.h" | |
68 | ||
69 | #include <iostream.h> | |
70 | ||
71 | #include <TClonesArray.h> | |
04b5ea16 | 72 | #include <TMath.h> |
d0bfce8d | 73 | #include <TMatrixD.h> |
8429a5e4 | 74 | #include <TObjArray.h> |
956019b6 | 75 | #include <TVirtualFitter.h> |
a9e2aefa | 76 | |
77 | #include "AliMUONEventReconstructor.h" | |
78 | #include "AliMUONHitForRec.h" | |
79 | #include "AliMUONSegment.h" | |
80 | #include "AliMUONTrackHit.h" | |
81 | ||
f6e92cf4 | 82 | #include <stdlib.h> |
83 | ||
04b5ea16 | 84 | // Functions to be minimized with Minuit |
a9e2aefa | 85 | void TrackChi2(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag); |
04b5ea16 | 86 | void TrackChi2MCS(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag); |
87 | ||
88 | Double_t MultipleScatteringAngle2(AliMUONTrackHit *TrackHit); | |
a9e2aefa | 89 | |
90 | ClassImp(AliMUONTrack) // Class implementation in ROOT context | |
91 | ||
956019b6 | 92 | TVirtualFitter* AliMUONTrack::fgFitter = NULL; |
93 | ||
a9e2aefa | 94 | //__________________________________________________________________________ |
95 | AliMUONTrack::AliMUONTrack(AliMUONSegment* BegSegment, AliMUONSegment* EndSegment, AliMUONEventReconstructor* EventReconstructor) | |
96 | { | |
97 | // Constructor from two Segment's | |
98 | fEventReconstructor = EventReconstructor; // link back to EventReconstructor | |
8429a5e4 | 99 | // memory allocation for the TObjArray of pointers to reconstructed TrackHit's |
100 | fTrackHitsPtr = new TObjArray(10); | |
a9e2aefa | 101 | fNTrackHits = 0; |
102 | AddSegment(BegSegment); // add hits from BegSegment | |
103 | AddSegment(EndSegment); // add hits from EndSegment | |
104 | fTrackHitsPtr->Sort(); // sort TrackHits according to increasing Z | |
105 | SetTrackParamAtVertex(); // set track parameters at vertex | |
8429a5e4 | 106 | // set fit conditions... |
04b5ea16 | 107 | fFitMCS = 0; |
956019b6 | 108 | fFitNParam = 3; |
109 | fFitStart = 1; | |
8429a5e4 | 110 | fFitFMin = -1.0; |
a9e2aefa | 111 | return; |
112 | } | |
113 | ||
114 | //__________________________________________________________________________ | |
115 | AliMUONTrack::AliMUONTrack(AliMUONSegment* Segment, AliMUONHitForRec* HitForRec, AliMUONEventReconstructor* EventReconstructor) | |
116 | { | |
117 | // Constructor from one Segment and one HitForRec | |
118 | fEventReconstructor = EventReconstructor; // link back to EventReconstructor | |
8429a5e4 | 119 | // memory allocation for the TObjArray of pointers to reconstructed TrackHit's |
120 | fTrackHitsPtr = new TObjArray(10); | |
a9e2aefa | 121 | fNTrackHits = 0; |
122 | AddSegment(Segment); // add hits from Segment | |
123 | AddHitForRec(HitForRec); // add HitForRec | |
124 | fTrackHitsPtr->Sort(); // sort TrackHits according to increasing Z | |
125 | SetTrackParamAtVertex(); // set track parameters at vertex | |
8429a5e4 | 126 | // set fit conditions... |
04b5ea16 | 127 | fFitMCS = 0; |
956019b6 | 128 | fFitNParam = 3; |
129 | fFitStart = 1; | |
8429a5e4 | 130 | fFitFMin = -1.0; |
a9e2aefa | 131 | return; |
132 | } | |
133 | ||
8429a5e4 | 134 | //__________________________________________________________________________ |
135 | AliMUONTrack::~AliMUONTrack() | |
136 | { | |
137 | // Destructor | |
138 | if (fTrackHitsPtr) { | |
139 | delete fTrackHitsPtr; // delete the TObjArray of pointers to TrackHit's | |
140 | fTrackHitsPtr = NULL; | |
141 | } | |
142 | } | |
143 | ||
956019b6 | 144 | //__________________________________________________________________________ |
a9e2aefa | 145 | AliMUONTrack::AliMUONTrack (const AliMUONTrack& MUONTrack) |
146 | { | |
147 | // Dummy copy constructor | |
148 | } | |
149 | ||
956019b6 | 150 | //__________________________________________________________________________ |
a9e2aefa | 151 | AliMUONTrack & AliMUONTrack::operator=(const AliMUONTrack& MUONTrack) |
152 | { | |
153 | // Dummy assignment operator | |
154 | return *this; | |
155 | } | |
156 | ||
8429a5e4 | 157 | //__________________________________________________________________________ |
158 | void AliMUONTrack::Remove() | |
159 | { | |
160 | // Remove current track from array of tracks, | |
161 | // and corresponding track hits from array of track hits. | |
162 | // Compress the TClonesArray it belongs to. | |
163 | AliMUONTrackHit *nextTrackHit; | |
164 | AliMUONEventReconstructor *eventRec = this->fEventReconstructor; | |
165 | TClonesArray *trackHitsPtr = eventRec->GetRecTrackHitsPtr(); | |
166 | // Loop over all track hits of track | |
167 | AliMUONTrackHit *trackHit = (AliMUONTrackHit*) fTrackHitsPtr->First(); | |
168 | while (trackHit) { | |
169 | nextTrackHit = (AliMUONTrackHit*) fTrackHitsPtr->After(trackHit); | |
170 | // Remove TrackHit from event TClonesArray. | |
171 | // Destructor is called, | |
172 | // hence links between HitForRec's and TrackHit's are updated | |
173 | trackHitsPtr->Remove(trackHit); | |
174 | trackHit = nextTrackHit; | |
175 | } | |
176 | // Remove the track from event TClonesArray | |
177 | // Destructor is called, | |
178 | // hence space for TObjArray of pointers to TrackHit's is freed | |
179 | eventRec->GetRecTracksPtr()->Remove(this); | |
180 | // Number of tracks decreased by 1 | |
181 | eventRec->SetNRecTracks(eventRec->GetNRecTracks() - 1); | |
182 | // Compress event TClonesArray of Track's: | |
183 | // this is essential to retrieve the TClonesArray afterwards | |
184 | eventRec->GetRecTracksPtr()->Compress(); | |
185 | // Compress event TClonesArray of TrackHit's: | |
186 | // this is probably also essential to retrieve the TClonesArray afterwards | |
187 | trackHitsPtr->Compress(); | |
188 | } | |
189 | ||
04b5ea16 | 190 | //__________________________________________________________________________ |
191 | void AliMUONTrack::SetFitMCS(Int_t FitMCS) | |
192 | { | |
956019b6 | 193 | // Set multiple Coulomb scattering option for track fit "fFitMCS" |
04b5ea16 | 194 | // from "FitMCS" argument: 0 without, 1 with |
956019b6 | 195 | if ((FitMCS == 0) || (FitMCS == 1)) fFitMCS = FitMCS; |
04b5ea16 | 196 | // better implementation with enum(with, without) ???? |
956019b6 | 197 | else { |
198 | cout << "ERROR in AliMUONTrack::SetFitMCS(FitMCS)" << endl; | |
199 | cout << "FitMCS = " << FitMCS << " is neither 0 nor 1" << endl; | |
200 | exit(0); | |
201 | } | |
202 | return; | |
203 | } | |
204 | ||
205 | //__________________________________________________________________________ | |
206 | void AliMUONTrack::SetFitNParam(Int_t FitNParam) | |
207 | { | |
208 | // Set number of parameters for track fit "fFitNParam" from "FitNParam": | |
209 | // 3 for momentum, 5 for momentum and position | |
210 | if ((FitNParam == 3) || (FitNParam == 5)) fFitNParam = FitNParam; | |
211 | else { | |
212 | cout << "ERROR in AliMUONTrack::SetFitNParam(FitNParam)" << endl; | |
213 | cout << "FitNParam = " << FitNParam << " is neither 3 nor 5" << endl; | |
214 | exit(0); | |
215 | } | |
216 | return; | |
217 | } | |
218 | ||
219 | //__________________________________________________________________________ | |
220 | void AliMUONTrack::SetFitStart(Int_t FitStart) | |
221 | { | |
222 | // Set multiple Coulomb scattering option for track fit "fFitStart" | |
223 | // from "FitStart" argument: 0 without, 1 with | |
224 | if ((FitStart == 0) || (FitStart == 1)) fFitStart = FitStart; | |
225 | // better implementation with enum(vertex, firstHit) ???? | |
226 | else { | |
227 | cout << "ERROR in AliMUONTrack::SetFitStart(FitStart)" << endl; | |
228 | cout << "FitStart = " << FitStart << " is neither 0 nor 1" << endl; | |
229 | exit(0); | |
230 | } | |
04b5ea16 | 231 | return; |
232 | } | |
233 | ||
956019b6 | 234 | //__________________________________________________________________________ |
a9e2aefa | 235 | AliMUONTrackParam* AliMUONTrack::GetTrackParamAtFirstHit(void) { |
236 | // Get pointer to TrackParamAtFirstHit | |
237 | return ((AliMUONTrackHit*) (fTrackHitsPtr->First()))->GetTrackParam();} | |
a9e2aefa | 238 | |
239 | //__________________________________________________________________________ | |
240 | void AliMUONTrack::RecursiveDump(void) | |
241 | { | |
242 | // Recursive dump of AliMUONTrack, i.e. with dump of TrackHit's and HitForRec's | |
243 | AliMUONTrackHit *trackHit; | |
244 | AliMUONHitForRec *hitForRec; | |
245 | cout << "Recursive dump of Track: " << this << endl; | |
246 | // Track | |
247 | this->Dump(); | |
248 | for (Int_t trackHitIndex = 0; trackHitIndex < fNTrackHits; trackHitIndex++) { | |
249 | trackHit = (AliMUONTrackHit*) ((*fTrackHitsPtr)[trackHitIndex]); | |
250 | // TrackHit | |
251 | cout << "TrackHit: " << trackHit << " (index: " << trackHitIndex << ")" << endl; | |
252 | trackHit->Dump(); | |
253 | hitForRec = trackHit->GetHitForRecPtr(); | |
254 | // HitForRec | |
255 | cout << "HitForRec: " << hitForRec << endl; | |
256 | hitForRec->Dump(); | |
257 | } | |
258 | return; | |
259 | } | |
260 | ||
8429a5e4 | 261 | //__________________________________________________________________________ |
262 | Int_t AliMUONTrack::HitsInCommon(AliMUONTrack* Track) | |
263 | { | |
264 | // Returns the number of hits in common | |
265 | // between the current track ("this") | |
266 | // and the track pointed to by "Track". | |
267 | Int_t hitsInCommon = 0; | |
268 | AliMUONTrackHit *trackHit1, *trackHit2; | |
269 | // Loop over hits of first track | |
270 | trackHit1 = (AliMUONTrackHit*) this->GetTrackHitsPtr()->First(); | |
271 | while (trackHit1) { | |
272 | // Loop over hits of second track | |
273 | trackHit2 = (AliMUONTrackHit*) Track->GetTrackHitsPtr()->First(); | |
274 | while (trackHit2) { | |
275 | // Increment "hitsInCommon" if both TrackHits point to the same HitForRec | |
276 | if ( (trackHit1->GetHitForRecPtr()) == | |
277 | (trackHit2->GetHitForRecPtr()) ) hitsInCommon++; | |
278 | trackHit2 = (AliMUONTrackHit*) Track->GetTrackHitsPtr()->After(trackHit2); | |
279 | } // trackHit2 | |
280 | trackHit1 = (AliMUONTrackHit*) this->GetTrackHitsPtr()->After(trackHit1); | |
281 | } // trackHit1 | |
282 | return hitsInCommon; | |
283 | } | |
284 | ||
a9e2aefa | 285 | //__________________________________________________________________________ |
956019b6 | 286 | void AliMUONTrack::Fit() |
a9e2aefa | 287 | { |
288 | // Fit the current track ("this"), | |
956019b6 | 289 | // with or without multiple Coulomb scattering according to "fFitMCS", |
290 | // with the number of parameters given by "fFitNParam" | |
291 | // (3 if one keeps X and Y fixed in "TrackParam", 5 if one lets them vary), | |
292 | // starting, according to "fFitStart", | |
293 | // with track parameters at vertex or at the first TrackHit. | |
294 | // "fFitMCS", "fFitNParam" and "fFitStart" have to be set before | |
295 | // by calling the corresponding Set methods. | |
a9e2aefa | 296 | Double_t arg[1], benC, errorParam, invBenP, lower, nonBenC, upper, x, y; |
956019b6 | 297 | char parName[50]; |
298 | AliMUONTrackParam *trackParam; | |
299 | // Check if Minuit is initialized... | |
300 | fgFitter = TVirtualFitter::Fitter(this); // add 3 or 5 for the maximum number of parameters ??? | |
301 | fgFitter->Clear(); // necessary ???? probably yes | |
302 | // how to reset the printout number at every fit ???? | |
303 | // is there any risk to leave it like that ???? | |
a9e2aefa | 304 | // how to go faster ???? choice of Minuit parameters like EDM ???? |
04b5ea16 | 305 | // choice of function to be minimized according to fFitMCS |
956019b6 | 306 | if (fFitMCS == 0) fgFitter->SetFCN(TrackChi2); |
307 | else fgFitter->SetFCN(TrackChi2MCS); | |
d0bfce8d | 308 | arg[0] = -1; |
956019b6 | 309 | fgFitter->ExecuteCommand("SET PRINT", arg, 1); // More printing !!!! |
310 | // Parameters according to "fFitStart" | |
311 | // (should be a function to be used at every place where needed ????) | |
312 | if (fFitStart == 0) trackParam = &fTrackParamAtVertex; | |
313 | else trackParam = this->GetTrackParamAtFirstHit(); | |
314 | // set first 3 Minuit parameters | |
04b5ea16 | 315 | // could be tried with no limits for the search (min=max=0) ???? |
956019b6 | 316 | fgFitter->SetParameter(0, "InvBenP", |
317 | trackParam->GetInverseBendingMomentum(), | |
318 | 0.003, -0.4, 0.4); | |
319 | fgFitter->SetParameter(1, "BenS", | |
320 | trackParam->GetBendingSlope(), | |
321 | 0.001, -0.5, 0.5); | |
322 | fgFitter->SetParameter(2, "NonBenS", | |
323 | trackParam->GetNonBendingSlope(), | |
324 | 0.001, -0.5, 0.5); | |
325 | if (fFitNParam == 5) { | |
d0bfce8d | 326 | // set last 2 Minuit parameters |
327 | // mandatory limits in Bending to avoid NaN values of parameters | |
956019b6 | 328 | fgFitter->SetParameter(3, "X", |
329 | trackParam->GetNonBendingCoor(), | |
d0bfce8d | 330 | 0.03, -500.0, 500.0); |
331 | // mandatory limits in non Bending to avoid NaN values of parameters | |
956019b6 | 332 | fgFitter->SetParameter(4, "Y", |
333 | trackParam->GetBendingCoor(), | |
d0bfce8d | 334 | 0.10, -500.0, 500.0); |
a9e2aefa | 335 | } |
336 | // search without gradient calculation in the function | |
956019b6 | 337 | fgFitter->ExecuteCommand("SET NOGRADIENT", arg, 0); |
a9e2aefa | 338 | // minimization |
956019b6 | 339 | fgFitter->ExecuteCommand("MINIMIZE", arg, 0); |
a9e2aefa | 340 | // exit from Minuit |
956019b6 | 341 | fgFitter->ExecuteCommand("EXIT", arg, 0); // necessary ???? |
342 | // get results into "invBenP", "benC", "nonBenC" ("x", "y") | |
343 | fgFitter->GetParameter(0, parName, invBenP, errorParam, lower, upper); | |
344 | fgFitter->GetParameter(1, parName, benC, errorParam, lower, upper); | |
345 | fgFitter->GetParameter(2, parName, nonBenC, errorParam, lower, upper); | |
346 | if (fFitNParam == 5) { | |
347 | fgFitter->GetParameter(3, parName, x, errorParam, lower, upper); | |
348 | fgFitter->GetParameter(4, parName, y, errorParam, lower, upper); | |
a9e2aefa | 349 | } |
350 | // result of the fit into track parameters | |
956019b6 | 351 | trackParam->SetInverseBendingMomentum(invBenP); |
352 | trackParam->SetBendingSlope(benC); | |
353 | trackParam->SetNonBendingSlope(nonBenC); | |
354 | if (fFitNParam == 5) { | |
355 | trackParam->SetNonBendingCoor(x); | |
356 | trackParam->SetBendingCoor(y); | |
a9e2aefa | 357 | } |
8429a5e4 | 358 | // global result of the fit |
359 | Double_t fedm, errdef; | |
360 | Int_t npari, nparx; | |
361 | fgFitter->GetStats(fFitFMin, fedm, errdef, npari, nparx); | |
a9e2aefa | 362 | } |
363 | ||
364 | //__________________________________________________________________________ | |
365 | void AliMUONTrack::AddSegment(AliMUONSegment* Segment) | |
366 | { | |
8429a5e4 | 367 | // Add Segment to the track |
a9e2aefa | 368 | AddHitForRec(Segment->GetHitForRec1()); // 1st hit |
369 | AddHitForRec(Segment->GetHitForRec2()); // 2nd hit | |
370 | } | |
371 | ||
372 | //__________________________________________________________________________ | |
373 | void AliMUONTrack::AddHitForRec(AliMUONHitForRec* HitForRec) | |
374 | { | |
8429a5e4 | 375 | // Add HitForRec to the track: |
376 | // actual TrackHit into TClonesArray of TrackHit's for the event; | |
377 | // pointer to actual TrackHit in TObjArray of pointers to TrackHit's for the track | |
378 | TClonesArray *recTrackHitsPtr = this->fEventReconstructor->GetRecTrackHitsPtr(); | |
379 | Int_t eventTrackHits = this->fEventReconstructor->GetNRecTrackHits(); | |
380 | // event | |
381 | AliMUONTrackHit* trackHit = | |
382 | new ((*recTrackHitsPtr)[eventTrackHits]) AliMUONTrackHit(HitForRec); | |
383 | this->fEventReconstructor->SetNRecTrackHits(eventTrackHits + 1); | |
384 | // track | |
385 | fTrackHitsPtr->Add(trackHit); | |
a9e2aefa | 386 | fNTrackHits++; |
387 | } | |
388 | ||
389 | //__________________________________________________________________________ | |
390 | void AliMUONTrack::SetTrackParamAtHit(Int_t indexHit, AliMUONTrackParam *TrackParam) | |
391 | { | |
392 | // Set track parameters at TrackHit with index "indexHit" | |
393 | // from the track parameters pointed to by "TrackParam". | |
394 | AliMUONTrackHit* trackHit = (AliMUONTrackHit*) ((*fTrackHitsPtr)[indexHit]); | |
395 | trackHit->SetTrackParam(TrackParam); | |
396 | } | |
397 | ||
398 | //__________________________________________________________________________ | |
399 | void AliMUONTrack::SetTrackParamAtVertex() | |
400 | { | |
401 | // Set track parameters at vertex. | |
402 | // TrackHit's are assumed to be only in stations(1..) 4 and 5, | |
403 | // and sorted according to increasing Z.. | |
404 | // Parameters are calculated from information in HitForRec's | |
405 | // of first and last TrackHit's. | |
406 | AliMUONTrackParam *trackParam = | |
407 | &fTrackParamAtVertex; // pointer to track parameters | |
408 | // Pointer to HitForRec of first TrackHit | |
409 | AliMUONHitForRec *firstHit = | |
410 | ((AliMUONTrackHit*) (fTrackHitsPtr->First()))->GetHitForRecPtr(); | |
411 | // Pointer to HitForRec of last TrackHit | |
412 | AliMUONHitForRec *lastHit = | |
413 | ((AliMUONTrackHit*) (fTrackHitsPtr->Last()))->GetHitForRecPtr(); | |
414 | // Z difference between first and last hits | |
415 | Double_t deltaZ = firstHit->GetZ() - lastHit->GetZ(); | |
416 | // bending slope in stations(1..) 4 and 5 | |
417 | Double_t bendingSlope = | |
418 | (firstHit->GetBendingCoor() - lastHit->GetBendingCoor()) / deltaZ; | |
419 | trackParam->SetBendingSlope(bendingSlope); | |
420 | // impact parameter | |
421 | Double_t impactParam = | |
422 | firstHit->GetBendingCoor() - bendingSlope * firstHit->GetZ(); // same if from firstHit and lastHit ???? | |
423 | // signed bending momentum | |
424 | Double_t signedBendingMomentum = | |
425 | fEventReconstructor->GetBendingMomentumFromImpactParam(impactParam); | |
426 | trackParam->SetInverseBendingMomentum(1.0 / signedBendingMomentum); | |
427 | // bending slope at vertex | |
428 | trackParam-> | |
429 | SetBendingSlope(bendingSlope + | |
430 | impactParam / fEventReconstructor->GetSimpleBPosition()); | |
431 | // non bending slope | |
432 | Double_t nonBendingSlope = | |
433 | (firstHit->GetNonBendingCoor() - lastHit->GetNonBendingCoor()) / deltaZ; | |
434 | trackParam->SetNonBendingSlope(nonBendingSlope); | |
435 | // vertex coordinates at (0,0,0) | |
436 | trackParam->SetZ(0.0); | |
437 | trackParam->SetBendingCoor(0.0); | |
438 | trackParam->SetNonBendingCoor(0.0); | |
439 | } | |
440 | ||
441 | //__________________________________________________________________________ | |
442 | void TrackChi2(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag) | |
443 | { | |
444 | // Return the "Chi2" to be minimized with Minuit for track fitting, | |
445 | // with "NParam" parameters | |
446 | // and their current values in array pointed to by "Param". | |
447 | // Assumes that the track hits are sorted according to increasing Z. | |
448 | // Track parameters at each TrackHit are updated accordingly. | |
04b5ea16 | 449 | // Multiple Coulomb scattering is not taken into account |
956019b6 | 450 | AliMUONTrack *trackBeingFitted; |
a9e2aefa | 451 | AliMUONTrackHit* hit; |
452 | AliMUONTrackParam param1; | |
453 | Int_t hitNumber; | |
454 | Double_t zHit; | |
455 | Chi2 = 0.0; // initialize Chi2 | |
456 | // copy of track parameters to be fitted | |
956019b6 | 457 | trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit(); |
458 | if (trackBeingFitted->GetFitStart() == 0) | |
459 | param1 = *(trackBeingFitted->GetTrackParamAtVertex()); | |
460 | else param1 = *(trackBeingFitted->GetTrackParamAtFirstHit()); | |
a9e2aefa | 461 | // Minuit parameters to be fitted into this copy |
462 | param1.SetInverseBendingMomentum(Param[0]); | |
463 | param1.SetBendingSlope(Param[1]); | |
464 | param1.SetNonBendingSlope(Param[2]); | |
465 | if (NParam == 5) { | |
466 | param1.SetNonBendingCoor(Param[3]); | |
467 | param1.SetBendingCoor(Param[4]); | |
468 | } | |
469 | // Follow track through all planes of track hits | |
470 | for (hitNumber = 0; hitNumber < trackBeingFitted->GetNTrackHits(); hitNumber++) { | |
471 | hit = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber]; | |
472 | zHit = hit->GetHitForRecPtr()->GetZ(); | |
473 | // do something special if 2 hits with same Z ???? | |
474 | // security against infinite loop ???? | |
475 | (¶m1)->ExtrapToZ(zHit); // extrapolation | |
476 | hit->SetTrackParam(¶m1); | |
477 | // Increment Chi2 | |
478 | // done hit per hit, with hit resolution, | |
479 | // and not with point and angle like in "reco_muon.F" !!!! | |
480 | // Needs to add multiple scattering contribution ???? | |
481 | Double_t dX = | |
482 | hit->GetHitForRecPtr()->GetNonBendingCoor() - (¶m1)->GetNonBendingCoor(); | |
483 | Double_t dY = | |
484 | hit->GetHitForRecPtr()->GetBendingCoor() - (¶m1)->GetBendingCoor(); | |
485 | Chi2 = | |
486 | Chi2 + | |
487 | dX * dX / hit->GetHitForRecPtr()->GetNonBendingReso2() + | |
488 | dY * dY / hit->GetHitForRecPtr()->GetBendingReso2(); | |
489 | } | |
490 | } | |
04b5ea16 | 491 | |
492 | //__________________________________________________________________________ | |
493 | void TrackChi2MCS(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag) | |
494 | { | |
495 | // Return the "Chi2" to be minimized with Minuit for track fitting, | |
496 | // with "NParam" parameters | |
497 | // and their current values in array pointed to by "Param". | |
498 | // Assumes that the track hits are sorted according to increasing Z. | |
499 | // Track parameters at each TrackHit are updated accordingly. | |
500 | // Multiple Coulomb scattering is taken into account with covariance matrix. | |
956019b6 | 501 | AliMUONTrack *trackBeingFitted; |
04b5ea16 | 502 | AliMUONTrackParam param1; |
503 | Chi2 = 0.0; // initialize Chi2 | |
504 | // copy of track parameters to be fitted | |
956019b6 | 505 | trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit(); |
506 | if (trackBeingFitted->GetFitStart() == 0) | |
507 | param1 = *(trackBeingFitted->GetTrackParamAtVertex()); | |
508 | else param1 = *(trackBeingFitted->GetTrackParamAtFirstHit()); | |
04b5ea16 | 509 | // Minuit parameters to be fitted into this copy |
510 | param1.SetInverseBendingMomentum(Param[0]); | |
511 | param1.SetBendingSlope(Param[1]); | |
512 | param1.SetNonBendingSlope(Param[2]); | |
513 | if (NParam == 5) { | |
514 | param1.SetNonBendingCoor(Param[3]); | |
515 | param1.SetBendingCoor(Param[4]); | |
516 | } | |
517 | ||
956019b6 | 518 | AliMUONTrackHit *hit; |
519 | Bool_t goodDeterminant; | |
eb9c9dab | 520 | Int_t chCurrent, chPrev, hitNumber, hitNumber1, hitNumber2, hitNumber3; |
521 | Double_t z, z1, z2, z3; | |
522 | AliMUONTrackHit *hit1, *hit2, *hit3; | |
523 | Double_t hbc1, hbc2, pbc1, pbc2; | |
524 | Double_t hnbc1, hnbc2, pnbc1, pnbc2; | |
525 | Int_t numberOfHit = trackBeingFitted->GetNTrackHits(); | |
d0bfce8d | 526 | TMatrixD *covBending = new TMatrixD(numberOfHit, numberOfHit); |
527 | TMatrixD *covNonBending = new TMatrixD(numberOfHit, numberOfHit); | |
eb9c9dab | 528 | Double_t *msa2 = new Double_t[numberOfHit]; |
04b5ea16 | 529 | |
530 | // Predicted coordinates and multiple scattering angles are first calculated | |
531 | for (hitNumber = 0; hitNumber < numberOfHit; hitNumber++) { | |
532 | hit = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber]; | |
eb9c9dab | 533 | z = hit->GetHitForRecPtr()->GetZ(); |
04b5ea16 | 534 | // do something special if 2 hits with same Z ???? |
535 | // security against infinite loop ???? | |
eb9c9dab | 536 | (¶m1)->ExtrapToZ(z); // extrapolation |
04b5ea16 | 537 | hit->SetTrackParam(¶m1); |
eb9c9dab | 538 | // square of multiple scattering angle at current hit, with one chamber |
539 | msa2[hitNumber] = MultipleScatteringAngle2(hit); | |
540 | // correction for eventual missing hits or multiple hits in a chamber, | |
541 | // according to the number of chambers | |
542 | // between the current hit and the previous one | |
543 | chCurrent = hit->GetHitForRecPtr()->GetChamberNumber(); | |
544 | if (hitNumber > 0) msa2[hitNumber] = msa2[hitNumber] * (chCurrent - chPrev); | |
545 | chPrev = chCurrent; | |
04b5ea16 | 546 | } |
547 | ||
548 | // Calculates the covariance matrix | |
eb9c9dab | 549 | for (hitNumber1 = 0; hitNumber1 < numberOfHit; hitNumber1++) { |
550 | hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1]; | |
551 | z1 = hit1->GetHitForRecPtr()->GetZ(); | |
04b5ea16 | 552 | for (hitNumber2 = hitNumber1; hitNumber2 < numberOfHit; hitNumber2++) { |
eb9c9dab | 553 | hit2 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber2]; |
554 | z2 = hit2->GetHitForRecPtr()->GetZ(); | |
956019b6 | 555 | // initialization to 0 (diagonal plus upper triangular part) |
556 | (*covBending)(hitNumber2, hitNumber1) = 0.0; | |
557 | // contribution from multiple scattering in bending plane: | |
558 | // loop over upstream hits | |
559 | for (hitNumber3 = 0; hitNumber3 < hitNumber1; hitNumber3++) { | |
eb9c9dab | 560 | hit3 = (AliMUONTrackHit*) |
561 | (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber3]; | |
562 | z3 = hit3->GetHitForRecPtr()->GetZ(); | |
04b5ea16 | 563 | (*covBending)(hitNumber2, hitNumber1) = |
564 | (*covBending)(hitNumber2, hitNumber1) + | |
eb9c9dab | 565 | ((z1 - z3) * (z2 - z3) * msa2[hitNumber3]); |
956019b6 | 566 | } |
567 | // equal contribution from multiple scattering in non bending plane | |
04b5ea16 | 568 | (*covNonBending)(hitNumber2, hitNumber1) = |
569 | (*covBending)(hitNumber2, hitNumber1); | |
956019b6 | 570 | if (hitNumber1 == hitNumber2) { |
571 | // Diagonal elements: add contribution from position measurements | |
572 | // in bending plane | |
573 | (*covBending)(hitNumber2, hitNumber1) = | |
eb9c9dab | 574 | (*covBending)(hitNumber2, hitNumber1) + |
575 | hit1->GetHitForRecPtr()->GetBendingReso2(); | |
956019b6 | 576 | // and in non bending plane |
04b5ea16 | 577 | (*covNonBending)(hitNumber2, hitNumber1) = |
eb9c9dab | 578 | (*covNonBending)(hitNumber2, hitNumber1) + |
579 | hit1->GetHitForRecPtr()->GetNonBendingReso2(); | |
956019b6 | 580 | } |
581 | else { | |
582 | // Non diagonal elements: symmetrization | |
583 | // for bending plane | |
584 | (*covBending)(hitNumber1, hitNumber2) = | |
585 | (*covBending)(hitNumber2, hitNumber1); | |
586 | // and non bending plane | |
587 | (*covNonBending)(hitNumber1, hitNumber2) = | |
588 | (*covNonBending)(hitNumber2, hitNumber1); | |
589 | } | |
590 | } // for (hitNumber2 = hitNumber1;... | |
591 | } // for (hitNumber1 = 0;... | |
d0bfce8d | 592 | // Normalization of covariance matrices |
593 | Double_t normCovBending2 = covBending->E2Norm(); | |
594 | Double_t normCovNonBending2 = covNonBending->E2Norm(); | |
595 | (*covBending) *= 1/normCovBending2; | |
596 | (*covNonBending) *= 1/normCovNonBending2; | |
597 | // if (covBending->Determinant() < 1.e-33) { | |
598 | // printf(" *** covBending *** \n"); | |
599 | // covBending->Print(); | |
600 | // printf(" *** covNonBending *** \n"); | |
601 | // covNonBending->Print(); | |
602 | // cout << " number of hits " << numberOfHit << endl; | |
603 | // cout << "Momentum = " << 1/Param[0] <<endl; | |
604 | // cout << "normCovBending = " << normCovBending2 << endl; | |
605 | // cout << "normCovNonBending = " << normCovNonBending2 << endl; | |
606 | // exit(0); | |
607 | ||
608 | // } | |
04b5ea16 | 609 | // Inverts covariance matrix |
956019b6 | 610 | goodDeterminant = kTRUE; |
611 | // check whether the Invert method returns flag if matrix cannot be inverted, | |
612 | // and do not calculate the Determinant in that case !!!! | |
04b5ea16 | 613 | if (covBending->Determinant() != 0) { |
614 | covBending->Invert(); | |
615 | } else { | |
956019b6 | 616 | goodDeterminant = kFALSE; |
04b5ea16 | 617 | cout << "Warning in ChiMCS Determinant Bending=0: " << endl; |
618 | } | |
956019b6 | 619 | if (covNonBending->Determinant() != 0) { |
04b5ea16 | 620 | covNonBending->Invert(); |
621 | } else { | |
956019b6 | 622 | goodDeterminant = kFALSE; |
04b5ea16 | 623 | cout << "Warning in ChiMCS Determinant non Bending=0: " << endl; |
624 | } | |
956019b6 | 625 | |
626 | // It would be worth trying to calculate the inverse of the covariance matrix | |
627 | // only once per fit, since it cannot change much in principle, | |
628 | // and it would save a lot of computing time !!!! | |
04b5ea16 | 629 | |
630 | // Calculates Chi2 | |
eb9c9dab | 631 | if (goodDeterminant) { |
632 | // with Multiple Scattering if inversion correct | |
d0bfce8d | 633 | // Inverse matrices without normalization |
634 | (*covBending) *= 1/normCovBending2; | |
635 | (*covNonBending) *= 1/normCovNonBending2; | |
eb9c9dab | 636 | for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) { |
637 | hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1]; | |
638 | hbc1 = hit1->GetHitForRecPtr()->GetBendingCoor(); | |
639 | pbc1 = hit1->GetTrackParam()->GetBendingCoor(); | |
640 | hnbc1 = hit1->GetHitForRecPtr()->GetNonBendingCoor(); | |
641 | pnbc1 = hit1->GetTrackParam()->GetNonBendingCoor(); | |
642 | for (hitNumber2 = 0; hitNumber2 < numberOfHit; hitNumber2++) { | |
643 | hit2 = (AliMUONTrackHit*) | |
644 | (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber2]; | |
645 | hbc2 = hit2->GetHitForRecPtr()->GetBendingCoor(); | |
646 | pbc2 = hit2->GetTrackParam()->GetBendingCoor(); | |
647 | hnbc2 = hit2->GetHitForRecPtr()->GetNonBendingCoor(); | |
648 | pnbc2 = hit2->GetTrackParam()->GetNonBendingCoor(); | |
04b5ea16 | 649 | Chi2 = Chi2 + |
eb9c9dab | 650 | ((*covBending)(hitNumber2, hitNumber1) * |
651 | (hbc1 - pbc1) * (hbc2 - pbc2)) + | |
04b5ea16 | 652 | ((*covNonBending)(hitNumber2, hitNumber1) * |
eb9c9dab | 653 | (hnbc1 - pnbc1) * (hnbc2 - pnbc2)); |
04b5ea16 | 654 | } |
655 | } | |
eb9c9dab | 656 | } else { |
657 | // without Multiple Scattering if inversion impossible | |
658 | for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) { | |
659 | hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1]; | |
660 | hbc1 = hit1->GetHitForRecPtr()->GetBendingCoor(); | |
661 | pbc1 = hit1->GetTrackParam()->GetBendingCoor(); | |
662 | hnbc1 = hit1->GetHitForRecPtr()->GetNonBendingCoor(); | |
663 | pnbc1 = hit1->GetTrackParam()->GetNonBendingCoor(); | |
664 | Chi2 = Chi2 + | |
665 | ((hbc1 - pbc1) * (hbc1 - pbc1) / | |
666 | hit1->GetHitForRecPtr()->GetBendingReso2()) + | |
667 | ((hnbc1 - pnbc1) * (hnbc1 - pnbc1) / | |
668 | hit1->GetHitForRecPtr()->GetNonBendingReso2()); | |
04b5ea16 | 669 | } |
670 | } | |
671 | ||
672 | delete covBending; | |
673 | delete covNonBending; | |
eb9c9dab | 674 | delete [] msa2; |
04b5ea16 | 675 | } |
676 | ||
677 | Double_t MultipleScatteringAngle2(AliMUONTrackHit *TrackHit) | |
678 | { | |
679 | // Returns square of multiple Coulomb scattering angle | |
680 | // at TrackHit pointed to by "TrackHit" | |
681 | Double_t slopeBending, slopeNonBending, radiationLength, inverseBendingMomentum2, inverseTotalMomentum2; | |
682 | Double_t varMultipleScatteringAngle; | |
956019b6 | 683 | AliMUONTrack *trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit(); |
04b5ea16 | 684 | AliMUONTrackParam *param = TrackHit->GetTrackParam(); |
956019b6 | 685 | // Better implementation in AliMUONTrack class ???? |
04b5ea16 | 686 | slopeBending = param->GetBendingSlope(); |
687 | slopeNonBending = param->GetNonBendingSlope(); | |
688 | // thickness in radiation length for the current track, | |
689 | // taking local angle into account | |
690 | radiationLength = | |
691 | trackBeingFitted->GetEventReconstructor()->GetChamberThicknessInX0() * | |
692 | TMath::Sqrt(1.0 + | |
693 | slopeBending * slopeBending + slopeNonBending * slopeNonBending); | |
694 | inverseBendingMomentum2 = | |
695 | param->GetInverseBendingMomentum() * param->GetInverseBendingMomentum(); | |
696 | inverseTotalMomentum2 = | |
956019b6 | 697 | inverseBendingMomentum2 * (1.0 + slopeBending * slopeBending) / |
04b5ea16 | 698 | (1.0 + slopeBending *slopeBending + slopeNonBending * slopeNonBending); |
699 | varMultipleScatteringAngle = 0.0136 * (1.0 + 0.038 * TMath::Log(radiationLength)); | |
956019b6 | 700 | // The velocity is assumed to be 1 !!!! |
04b5ea16 | 701 | varMultipleScatteringAngle = inverseTotalMomentum2 * radiationLength * |
702 | varMultipleScatteringAngle * varMultipleScatteringAngle; | |
703 | return varMultipleScatteringAngle; | |
704 | } |