1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
18 ///////////////////////////////////////////////////
20 // Reconstructed track
26 ///////////////////////////////////////////////////
28 #include <stdlib.h> // for exit()
30 #include <Riostream.h> // for cout
33 #include <TObjArray.h>
34 #include <TVirtualFitter.h>
36 #include "AliMUONEventReconstructor.h"
37 #include "AliMUONHitForRec.h"
38 #include "AliMUONSegment.h"
39 #include "AliMUONTrack.h"
40 #include "AliMUONTrackHit.h"
41 #include "AliMUONTriggerTrack.h"
42 #include "AliMUONConstants.h"
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);
48 void mnvertLocal(Double_t* a, Int_t l, Int_t m, Int_t n, Int_t& ifail);
50 Double_t MultipleScatteringAngle2(AliMUONTrackHit *TrackHit);
52 ClassImp(AliMUONTrack) // Class implementation in ROOT context
54 TVirtualFitter* AliMUONTrack::fgFitter = NULL;
56 //__________________________________________________________________________
57 AliMUONTrack::AliMUONTrack()
60 // Default constructor
62 fEventReconstructor = 0;
63 fTrackHitsPtr = new TObjArray(10);
64 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
65 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
69 //__________________________________________________________________________
70 AliMUONTrack::AliMUONTrack(AliMUONSegment* BegSegment, AliMUONSegment* EndSegment, AliMUONEventReconstructor* EventReconstructor)
73 // Constructor from two Segment's
74 fEventReconstructor = EventReconstructor; // link back to EventReconstructor
75 // memory allocation for the TObjArray of pointers to reconstructed TrackHit's
76 fTrackHitsPtr = new TObjArray(10);
78 AddSegment(BegSegment); // add hits from BegSegment
79 AddSegment(EndSegment); // add hits from EndSegment
80 fTrackHitsPtr->Sort(); // sort TrackHits according to increasing Z
81 SetTrackParamAtVertex(); // set track parameters at vertex
82 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
83 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
84 // set fit conditions...
89 fMatchTrigger = kFALSE;
90 fChi2MatchTrigger = 0;
95 //__________________________________________________________________________
96 AliMUONTrack::AliMUONTrack(AliMUONSegment* Segment, AliMUONHitForRec* HitForRec, AliMUONEventReconstructor* EventReconstructor)
99 // Constructor from one Segment and one HitForRec
100 fEventReconstructor = EventReconstructor; // link back to EventReconstructor
101 // memory allocation for the TObjArray of pointers to reconstructed TrackHit's
102 fTrackHitsPtr = new TObjArray(10);
104 AddSegment(Segment); // add hits from Segment
105 AddHitForRec(HitForRec); // add HitForRec
106 fTrackHitsPtr->Sort(); // sort TrackHits according to increasing Z
107 SetTrackParamAtVertex(); // set track parameters at vertex
108 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
109 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
110 // set fit conditions...
115 fMatchTrigger = kFALSE;
116 fChi2MatchTrigger = 0;
121 //__________________________________________________________________________
122 AliMUONTrack::~AliMUONTrack()
126 delete fTrackHitsPtr; // delete the TObjArray of pointers to TrackHit's
127 fTrackHitsPtr = NULL;
130 if (fTrackParamAtHit) {
131 // delete the TClonesArray of pointers to TrackParam
132 delete fTrackParamAtHit;
133 fTrackParamAtHit = NULL;
136 if (fHitForRecAtHit) {
137 // delete the TClonesArray of pointers to HitForRec
138 delete fHitForRecAtHit;
139 fHitForRecAtHit = NULL;
143 //__________________________________________________________________________
144 AliMUONTrack::AliMUONTrack (const AliMUONTrack& theMUONTrack)
145 : TObject(theMUONTrack)
147 //fEventReconstructor = new AliMUONEventReconstructor(*MUONTrack.fEventReconstructor);
149 // NO, because it would use dummy copy constructor
150 // and AliMUONTrack is not the owner of its EventReconstructor
151 fEventReconstructor = theMUONTrack.fEventReconstructor;
152 fTrackParamAtVertex = theMUONTrack.fTrackParamAtVertex;
154 // necessary to make a copy of the objects and not only the pointers in TObjArray.
155 fTrackHitsPtr = new TObjArray(10);
156 for (Int_t index = 0; index < (theMUONTrack.fTrackHitsPtr)->GetEntriesFast(); index++) {
157 AliMUONTrackHit *trackHit = new AliMUONTrackHit(*(AliMUONTrackHit*)(theMUONTrack.fTrackHitsPtr)->At(index));
158 fTrackHitsPtr->Add(trackHit);
161 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
162 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
163 for (Int_t index = 0; index < (theMUONTrack.fTrackParamAtHit)->GetEntriesFast(); index++) {
164 {new ((*fTrackParamAtHit)[fTrackParamAtHit->GetEntriesFast()])
165 AliMUONTrackParam(*(AliMUONTrackParam*)(theMUONTrack.fTrackParamAtHit)->At(index));}
168 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
169 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
170 for (Int_t index = 0; index < (theMUONTrack.fHitForRecAtHit)->GetEntriesFast(); index++) {
171 {new ((*fHitForRecAtHit)[fHitForRecAtHit->GetEntriesFast()])
172 AliMUONHitForRec(*(AliMUONHitForRec*)(theMUONTrack.fHitForRecAtHit)->At(index));}
175 fNTrackHits = theMUONTrack.fNTrackHits;
176 fFitMCS = theMUONTrack.fFitMCS;
177 fFitNParam = theMUONTrack.fFitNParam;
178 fFitFMin = theMUONTrack.fFitFMin;
179 fFitStart = theMUONTrack.fFitStart;
180 fMatchTrigger = theMUONTrack.fMatchTrigger;
181 fChi2MatchTrigger = theMUONTrack.fChi2MatchTrigger;
182 fTrackID = theMUONTrack.fTrackID;
185 //__________________________________________________________________________
186 AliMUONTrack & AliMUONTrack::operator=(const AliMUONTrack& theMUONTrack)
189 // check assignement to self
190 if (this == &theMUONTrack)
193 // base class assignement
194 TObject::operator=(theMUONTrack);
196 // fEventReconstructor = new AliMUONEventReconstructor(*MUONTrack.fEventReconstructor); // is it right ?
197 // is it right ? NO because it would use dummy copy constructor
198 fEventReconstructor = theMUONTrack.fEventReconstructor;
199 fTrackParamAtVertex = theMUONTrack.fTrackParamAtVertex;
201 // necessary to make a copy of the objects and not only the pointers in TObjArray.
202 fTrackHitsPtr = new TObjArray(10);
203 for (Int_t index = 0; index < (theMUONTrack.fTrackHitsPtr)->GetEntriesFast(); index++) {
204 AliMUONTrackHit *trackHit = new AliMUONTrackHit(*(AliMUONTrackHit*)(theMUONTrack.fTrackHitsPtr)->At(index));
205 fTrackHitsPtr->Add(trackHit);
208 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
209 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
210 for (Int_t index = 0; index < (theMUONTrack.fTrackParamAtHit)->GetEntriesFast(); index++) {
211 {new ((*fTrackParamAtHit)[fTrackParamAtHit->GetEntriesFast()])
212 AliMUONTrackParam(*(AliMUONTrackParam*)(theMUONTrack.fTrackParamAtHit)->At(index));}
215 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
216 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
217 for (Int_t index = 0; index < (theMUONTrack.fHitForRecAtHit)->GetEntriesFast(); index++) {
218 {new ((*fHitForRecAtHit)[fHitForRecAtHit->GetEntriesFast()])
219 AliMUONHitForRec(*(AliMUONHitForRec*)(theMUONTrack.fHitForRecAtHit)->At(index));}
222 fNTrackHits = theMUONTrack.fNTrackHits;
223 fFitMCS = theMUONTrack.fFitMCS;
224 fFitNParam = theMUONTrack.fFitNParam;
225 fFitFMin = theMUONTrack.fFitFMin;
226 fFitStart = theMUONTrack.fFitStart;
227 fMatchTrigger = theMUONTrack.fMatchTrigger;
228 fChi2MatchTrigger = theMUONTrack.fChi2MatchTrigger;
229 fTrackID = theMUONTrack.fTrackID;
234 //__________________________________________________________________________
235 void AliMUONTrack::Remove()
237 // Remove current track from array of tracks,
238 // and corresponding track hits from array of track hits.
239 // Compress the TClonesArray it belongs to.
240 AliMUONTrackHit *nextTrackHit;
241 AliMUONEventReconstructor *eventRec = this->fEventReconstructor;
242 TClonesArray *trackHitsPtr = eventRec->GetRecTrackHitsPtr();
243 // Loop over all track hits of track
244 AliMUONTrackHit *trackHit = (AliMUONTrackHit*) fTrackHitsPtr->First();
246 nextTrackHit = (AliMUONTrackHit*) fTrackHitsPtr->After(trackHit);
247 // Remove TrackHit from event TClonesArray.
248 // Destructor is called,
249 // hence links between HitForRec's and TrackHit's are updated
250 trackHitsPtr->Remove(trackHit);
251 trackHit = nextTrackHit;
253 // Remove the track from event TClonesArray
254 // Destructor is called,
255 // hence space for TObjArray of pointers to TrackHit's is freed
256 eventRec->GetRecTracksPtr()->Remove(this);
257 // Number of tracks decreased by 1
258 eventRec->SetNRecTracks(eventRec->GetNRecTracks() - 1);
259 // Compress event TClonesArray of Track's:
260 // this is essential to retrieve the TClonesArray afterwards
261 eventRec->GetRecTracksPtr()->Compress();
262 // Compress event TClonesArray of TrackHit's:
263 // this is probably also essential to retrieve the TClonesArray afterwards
264 trackHitsPtr->Compress();
267 //__________________________________________________________________________
268 void AliMUONTrack::SetFitMCS(Int_t FitMCS)
270 // Set multiple Coulomb scattering option for track fit "fFitMCS"
271 // from "FitMCS" argument: 0 without, 1 with
272 if ((FitMCS == 0) || (FitMCS == 1)) fFitMCS = FitMCS;
273 // better implementation with enum(with, without) ????
275 cout << "ERROR in AliMUONTrack::SetFitMCS(FitMCS)" << endl;
276 cout << "FitMCS = " << FitMCS << " is neither 0 nor 1" << endl;
282 //__________________________________________________________________________
283 void AliMUONTrack::SetFitNParam(Int_t FitNParam)
285 // Set number of parameters for track fit "fFitNParam" from "FitNParam":
286 // 3 for momentum, 5 for momentum and position
287 if ((FitNParam == 3) || (FitNParam == 5)) fFitNParam = FitNParam;
289 cout << "ERROR in AliMUONTrack::SetFitNParam(FitNParam)" << endl;
290 cout << "FitNParam = " << FitNParam << " is neither 3 nor 5" << endl;
296 //__________________________________________________________________________
297 void AliMUONTrack::SetFitStart(Int_t FitStart)
299 // Set multiple Coulomb scattering option for track fit "fFitStart"
300 // from "FitStart" argument: 0 without, 1 with
301 if ((FitStart == 0) || (FitStart == 1)) fFitStart = FitStart;
302 // better implementation with enum(vertex, firstHit) ????
304 cout << "ERROR in AliMUONTrack::SetFitStart(FitStart)" << endl;
305 cout << "FitStart = " << FitStart << " is neither 0 nor 1" << endl;
311 //__________________________________________________________________________
312 AliMUONTrackParam* AliMUONTrack::GetTrackParamAtFirstHit(void) const {
313 // Get pointer to TrackParamAtFirstHit
314 return ((AliMUONTrackHit*) (fTrackHitsPtr->First()))->GetTrackParam();}
316 //__________________________________________________________________________
317 void AliMUONTrack::RecursiveDump(void) const
319 // Recursive dump of AliMUONTrack, i.e. with dump of TrackHit's and HitForRec's
320 AliMUONTrackHit *trackHit;
321 AliMUONHitForRec *hitForRec;
322 cout << "Recursive dump of Track: " << this << endl;
325 for (Int_t trackHitIndex = 0; trackHitIndex < fNTrackHits; trackHitIndex++) {
326 trackHit = (AliMUONTrackHit*) ((*fTrackHitsPtr)[trackHitIndex]);
328 cout << "TrackHit: " << trackHit << " (index: " << trackHitIndex << ")" << endl;
330 hitForRec = trackHit->GetHitForRecPtr();
332 cout << "HitForRec: " << hitForRec << endl;
338 //__________________________________________________________________________
339 Bool_t* AliMUONTrack::CompatibleTrack(AliMUONTrack * Track, Double_t Sigma2Cut) const
341 // Return kTRUE/kFALSE for each chamber if hit is compatible or not
342 TClonesArray *hitArray, *thisHitArray;
343 AliMUONHitForRec *hit, *thisHit;
346 Float_t deltaZMax = 1.; // 1 cm
348 Bool_t *nCompHit = new Bool_t[AliMUONConstants::NTrackingCh()];
350 for ( Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) {
351 nCompHit[ch] = kFALSE;
354 thisHitArray = this->GetHitForRecAtHit();
356 hitArray = Track->GetHitForRecAtHit();
358 for (Int_t iHthis = 0; iHthis < thisHitArray->GetEntriesFast(); iHthis++) {
359 thisHit = (AliMUONHitForRec*) thisHitArray->At(iHthis);
360 chamberNumber = thisHit->GetChamberNumber();
361 if (chamberNumber < 0 || chamberNumber > AliMUONConstants::NTrackingCh()) continue;
362 nCompHit[chamberNumber] = kFALSE;
363 for (Int_t iH = 0; iH < hitArray->GetEntriesFast(); iH++) {
364 hit = (AliMUONHitForRec*) hitArray->At(iH);
365 deltaZ = TMath::Abs(thisHit->GetZ() - hit->GetZ());
366 chi2 = thisHit->NormalizedChi2WithHitForRec(hit,Sigma2Cut); // set cut to 4 sigmas
367 if (chi2 < 3. && deltaZ < deltaZMax) {
368 nCompHit[chamberNumber] = kTRUE;
377 //__________________________________________________________________________
378 Int_t AliMUONTrack::HitsInCommon(AliMUONTrack* Track) const
380 // Returns the number of hits in common
381 // between the current track ("this")
382 // and the track pointed to by "Track".
383 Int_t hitsInCommon = 0;
384 AliMUONTrackHit *trackHit1, *trackHit2;
385 // Loop over hits of first track
386 trackHit1 = (AliMUONTrackHit*) this->GetTrackHitsPtr()->First();
388 // Loop over hits of second track
389 trackHit2 = (AliMUONTrackHit*) Track->GetTrackHitsPtr()->First();
391 // Increment "hitsInCommon" if both TrackHits point to the same HitForRec
392 if ( (trackHit1->GetHitForRecPtr()) ==
393 (trackHit2->GetHitForRecPtr()) ) hitsInCommon++;
394 trackHit2 = (AliMUONTrackHit*) Track->GetTrackHitsPtr()->After(trackHit2);
396 trackHit1 = (AliMUONTrackHit*) this->GetTrackHitsPtr()->After(trackHit1);
401 //__________________________________________________________________________
402 void AliMUONTrack::MatchTriggerTrack(TClonesArray *triggerTrackArray)
404 // Match this track with one trigger track if possible
405 AliMUONTrackParam trackParam;
406 AliMUONTriggerTrack *triggerTrack;
407 Double_t xTrack, yTrack, ySlopeTrack, dTrigTrackMin2, dTrigTrack2;
410 Double_t distSigma[3]={1,1,0.02}; // sigma of distributions (trigger-track) X,Y,slopeY
411 Double_t distTriggerTrack[3] = {0,0,0};
413 fMatchTrigger = kFALSE;
414 fChi2MatchTrigger = 0;
416 trackParam = *((AliMUONTrackParam*) fTrackParamAtHit->Last());
417 trackParam.ExtrapToZ(AliMUONConstants::DefaultChamberZ(10)); // extrap to 1st trigger chamber
419 nSigmaCut2 = fEventReconstructor->GetMaxSigma2Distance(); // nb of sigma**2 for cut
420 xTrack = trackParam.GetNonBendingCoor();
421 yTrack = trackParam.GetBendingCoor();
422 ySlopeTrack = trackParam.GetBendingSlope();
423 dTrigTrackMin2 = 999;
425 triggerTrack = (AliMUONTriggerTrack*) triggerTrackArray->First();
427 distTriggerTrack[0] = (triggerTrack->GetX11()-xTrack)/distSigma[0];
428 distTriggerTrack[1] = (triggerTrack->GetY11()-yTrack)/distSigma[1];
429 distTriggerTrack[2] = (TMath::Tan(triggerTrack->GetThetay())-ySlopeTrack)/distSigma[2];
431 for (Int_t iVar = 0; iVar < 3; iVar++)
432 dTrigTrack2 += distTriggerTrack[iVar]*distTriggerTrack[iVar];
433 if (dTrigTrack2 < dTrigTrackMin2 && dTrigTrack2 < nSigmaCut2) {
434 dTrigTrackMin2 = dTrigTrack2;
435 fMatchTrigger = kTRUE;
436 fChi2MatchTrigger = dTrigTrack2/3.; // Normalized Chi2, 3 variables (X,Y,slopeY)
438 triggerTrack = (AliMUONTriggerTrack*) triggerTrackArray->After(triggerTrack);
442 //__________________________________________________________________________
443 void AliMUONTrack::Fit()
445 // Fit the current track ("this"),
446 // with or without multiple Coulomb scattering according to "fFitMCS",
447 // with the number of parameters given by "fFitNParam"
448 // (3 if one keeps X and Y fixed in "TrackParam", 5 if one lets them vary),
449 // starting, according to "fFitStart",
450 // with track parameters at vertex or at the first TrackHit.
451 // "fFitMCS", "fFitNParam" and "fFitStart" have to be set before
452 // by calling the corresponding Set methods.
453 Double_t arg[1], benC, errorParam, invBenP, lower, nonBenC, upper, x, y;
455 AliMUONTrackParam *trackParam;
456 // Check if Minuit is initialized...
457 fgFitter = TVirtualFitter::Fitter(this); // add 3 or 5 for the maximum number of parameters ???
458 fgFitter->Clear(); // necessary ???? probably yes
459 // how to reset the printout number at every fit ????
460 // is there any risk to leave it like that ????
461 // how to go faster ???? choice of Minuit parameters like EDM ????
462 // choice of function to be minimized according to fFitMCS
463 if (fFitMCS == 0) fgFitter->SetFCN(TrackChi2);
464 else fgFitter->SetFCN(TrackChi2MCS);
465 // Switch off printout
467 fgFitter->ExecuteCommand("SET PRINT", arg, 1); // More printing !!!!
469 fgFitter->ExecuteCommand("SET NOW", arg, 0);
470 // Parameters according to "fFitStart"
471 // (should be a function to be used at every place where needed ????)
472 if (fFitStart == 0) trackParam = &fTrackParamAtVertex;
473 else trackParam = this->GetTrackParamAtFirstHit();
474 // set first 3 Minuit parameters
475 // could be tried with no limits for the search (min=max=0) ????
476 fgFitter->SetParameter(0, "InvBenP",
477 trackParam->GetInverseBendingMomentum(),
479 fgFitter->SetParameter(1, "BenS",
480 trackParam->GetBendingSlope(),
482 fgFitter->SetParameter(2, "NonBenS",
483 trackParam->GetNonBendingSlope(),
485 if (fFitNParam == 5) {
486 // set last 2 Minuit parameters
487 // mandatory limits in Bending to avoid NaN values of parameters
488 fgFitter->SetParameter(3, "X",
489 trackParam->GetNonBendingCoor(),
490 0.03, -500.0, 500.0);
491 // mandatory limits in non Bending to avoid NaN values of parameters
492 fgFitter->SetParameter(4, "Y",
493 trackParam->GetBendingCoor(),
494 0.10, -500.0, 500.0);
496 // search without gradient calculation in the function
497 fgFitter->ExecuteCommand("SET NOGRADIENT", arg, 0);
499 fgFitter->ExecuteCommand("MINIMIZE", arg, 0);
501 // fgFitter->ExecuteCommand("EXIT", arg, 0); // necessary ????
502 // get results into "invBenP", "benC", "nonBenC" ("x", "y")
503 fgFitter->GetParameter(0, parName, invBenP, errorParam, lower, upper);
504 fgFitter->GetParameter(1, parName, benC, errorParam, lower, upper);
505 fgFitter->GetParameter(2, parName, nonBenC, errorParam, lower, upper);
506 if (fFitNParam == 5) {
507 fgFitter->GetParameter(3, parName, x, errorParam, lower, upper);
508 fgFitter->GetParameter(4, parName, y, errorParam, lower, upper);
510 // result of the fit into track parameters
511 trackParam->SetInverseBendingMomentum(invBenP);
512 trackParam->SetBendingSlope(benC);
513 trackParam->SetNonBendingSlope(nonBenC);
514 if (fFitNParam == 5) {
515 trackParam->SetNonBendingCoor(x);
516 trackParam->SetBendingCoor(y);
518 // global result of the fit
519 Double_t fedm, errdef;
521 fgFitter->GetStats(fFitFMin, fedm, errdef, npari, nparx);
524 //__________________________________________________________________________
525 void AliMUONTrack::AddSegment(AliMUONSegment* Segment)
527 // Add Segment to the track
528 AddHitForRec(Segment->GetHitForRec1()); // 1st hit
529 AddHitForRec(Segment->GetHitForRec2()); // 2nd hit
532 //__________________________________________________________________________
533 void AliMUONTrack::AddHitForRec(AliMUONHitForRec* HitForRec)
535 // Add HitForRec to the track:
536 // actual TrackHit into TClonesArray of TrackHit's for the event;
537 // pointer to actual TrackHit in TObjArray of pointers to TrackHit's for the track
538 TClonesArray *recTrackHitsPtr = this->fEventReconstructor->GetRecTrackHitsPtr();
539 Int_t eventTrackHits = this->fEventReconstructor->GetNRecTrackHits();
541 AliMUONTrackHit* trackHit =
542 new ((*recTrackHitsPtr)[eventTrackHits]) AliMUONTrackHit(HitForRec);
543 this->fEventReconstructor->SetNRecTrackHits(eventTrackHits + 1);
545 fTrackHitsPtr->Add(trackHit);
549 //__________________________________________________________________________
550 void AliMUONTrack::SetTrackParamAtHit(Int_t indexHit, AliMUONTrackParam *TrackParam) const
552 // Set track parameters at TrackHit with index "indexHit"
553 // from the track parameters pointed to by "TrackParam".
554 //PH AliMUONTrackHit* trackHit = (AliMUONTrackHit*) ((*fTrackHitsPtr)[indexHit]);
555 AliMUONTrackHit* trackHit = (AliMUONTrackHit*) (fTrackHitsPtr->At(indexHit));
556 trackHit->SetTrackParam(TrackParam);
559 //__________________________________________________________________________
560 void AliMUONTrack::SetTrackParamAtVertex()
562 // Set track parameters at vertex.
563 // TrackHit's are assumed to be only in stations(1..) 4 and 5,
564 // and sorted according to increasing Z..
565 // Parameters are calculated from information in HitForRec's
566 // of first and last TrackHit's.
567 AliMUONTrackParam *trackParam =
568 &fTrackParamAtVertex; // pointer to track parameters
569 // Pointer to HitForRec of first TrackHit
570 AliMUONHitForRec *firstHit =
571 ((AliMUONTrackHit*) (fTrackHitsPtr->First()))->GetHitForRecPtr();
572 // Pointer to HitForRec of last TrackHit
573 AliMUONHitForRec *lastHit =
574 ((AliMUONTrackHit*) (fTrackHitsPtr->Last()))->GetHitForRecPtr();
575 // Z difference between first and last hits
576 Double_t deltaZ = firstHit->GetZ() - lastHit->GetZ();
577 // bending slope in stations(1..) 4 and 5
578 Double_t bendingSlope =
579 (firstHit->GetBendingCoor() - lastHit->GetBendingCoor()) / deltaZ;
580 trackParam->SetBendingSlope(bendingSlope);
582 Double_t impactParam =
583 firstHit->GetBendingCoor() - bendingSlope * firstHit->GetZ(); // same if from firstHit and lastHit ????
584 // signed bending momentum
585 Double_t signedBendingMomentum =
586 fEventReconstructor->GetBendingMomentumFromImpactParam(impactParam);
587 trackParam->SetInverseBendingMomentum(1.0 / signedBendingMomentum);
588 // bending slope at vertex
590 SetBendingSlope(bendingSlope +
591 impactParam / fEventReconstructor->GetSimpleBPosition());
593 Double_t nonBendingSlope =
594 (firstHit->GetNonBendingCoor() - lastHit->GetNonBendingCoor()) / deltaZ;
595 trackParam->SetNonBendingSlope(nonBendingSlope);
596 // vertex coordinates at (0,0,0)
597 trackParam->SetZ(0.0);
598 trackParam->SetBendingCoor(0.0);
599 trackParam->SetNonBendingCoor(0.0);
602 //__________________________________________________________________________
603 void TrackChi2(Int_t &NParam, Double_t * /*Gradient*/, Double_t &Chi2, Double_t *Param, Int_t /*Flag*/)
605 // Return the "Chi2" to be minimized with Minuit for track fitting,
606 // with "NParam" parameters
607 // and their current values in array pointed to by "Param".
608 // Assumes that the track hits are sorted according to increasing Z.
609 // Track parameters at each TrackHit are updated accordingly.
610 // Multiple Coulomb scattering is not taken into account
611 AliMUONTrack *trackBeingFitted;
612 AliMUONTrackHit* hit;
613 AliMUONTrackParam param1;
616 Chi2 = 0.0; // initialize Chi2
617 // copy of track parameters to be fitted
618 trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit();
619 if (trackBeingFitted->GetFitStart() == 0)
620 param1 = *(trackBeingFitted->GetTrackParamAtVertex());
621 else param1 = *(trackBeingFitted->GetTrackParamAtFirstHit());
622 // Minuit parameters to be fitted into this copy
623 param1.SetInverseBendingMomentum(Param[0]);
624 param1.SetBendingSlope(Param[1]);
625 param1.SetNonBendingSlope(Param[2]);
627 param1.SetNonBendingCoor(Param[3]);
628 param1.SetBendingCoor(Param[4]);
630 // Follow track through all planes of track hits
631 for (hitNumber = 0; hitNumber < trackBeingFitted->GetNTrackHits(); hitNumber++) {
632 hit = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber];
633 zHit = hit->GetHitForRecPtr()->GetZ();
634 // do something special if 2 hits with same Z ????
635 // security against infinite loop ????
636 (¶m1)->ExtrapToZ(zHit); // extrapolation
637 hit->SetTrackParam(¶m1);
639 // done hit per hit, with hit resolution,
640 // and not with point and angle like in "reco_muon.F" !!!!
641 // Needs to add multiple scattering contribution ????
643 hit->GetHitForRecPtr()->GetNonBendingCoor() - (¶m1)->GetNonBendingCoor();
645 hit->GetHitForRecPtr()->GetBendingCoor() - (¶m1)->GetBendingCoor();
648 dX * dX / hit->GetHitForRecPtr()->GetNonBendingReso2() +
649 dY * dY / hit->GetHitForRecPtr()->GetBendingReso2();
653 //__________________________________________________________________________
654 void TrackChi2MCS(Int_t &NParam, Double_t * /*Gradient*/, Double_t &Chi2, Double_t *Param, Int_t /*Flag*/)
656 // Return the "Chi2" to be minimized with Minuit for track fitting,
657 // with "NParam" parameters
658 // and their current values in array pointed to by "Param".
659 // Assumes that the track hits are sorted according to increasing Z.
660 // Track parameters at each TrackHit are updated accordingly.
661 // Multiple Coulomb scattering is taken into account with covariance matrix.
662 AliMUONTrack *trackBeingFitted;
663 AliMUONTrackParam param1;
664 Chi2 = 0.0; // initialize Chi2
665 // copy of track parameters to be fitted
666 trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit();
667 if (trackBeingFitted->GetFitStart() == 0)
668 param1 = *(trackBeingFitted->GetTrackParamAtVertex());
669 else param1 = *(trackBeingFitted->GetTrackParamAtFirstHit());
670 // Minuit parameters to be fitted into this copy
671 param1.SetInverseBendingMomentum(Param[0]);
672 param1.SetBendingSlope(Param[1]);
673 param1.SetNonBendingSlope(Param[2]);
675 param1.SetNonBendingCoor(Param[3]);
676 param1.SetBendingCoor(Param[4]);
679 AliMUONTrackHit *hit;
680 Int_t chCurrent, chPrev = 0, hitNumber, hitNumber1, hitNumber2, hitNumber3;
681 Double_t z, z1, z2, z3;
682 AliMUONTrackHit *hit1, *hit2, *hit3;
683 Double_t hbc1, hbc2, pbc1, pbc2;
684 Double_t hnbc1, hnbc2, pnbc1, pnbc2;
685 Int_t numberOfHit = trackBeingFitted->GetNTrackHits();
686 TMatrixD *covBending = new TMatrixD(numberOfHit, numberOfHit);
687 TMatrixD *covNonBending = new TMatrixD(numberOfHit, numberOfHit);
688 Double_t *msa2 = new Double_t[numberOfHit];
690 // Predicted coordinates and multiple scattering angles are first calculated
691 for (hitNumber = 0; hitNumber < numberOfHit; hitNumber++) {
692 hit = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber];
693 z = hit->GetHitForRecPtr()->GetZ();
694 // do something special if 2 hits with same Z ????
695 // security against infinite loop ????
696 (¶m1)->ExtrapToZ(z); // extrapolation
697 hit->SetTrackParam(¶m1);
698 // square of multiple scattering angle at current hit, with one chamber
699 msa2[hitNumber] = MultipleScatteringAngle2(hit);
700 // correction for eventual missing hits or multiple hits in a chamber,
701 // according to the number of chambers
702 // between the current hit and the previous one
703 chCurrent = hit->GetHitForRecPtr()->GetChamberNumber();
704 if (hitNumber > 0) msa2[hitNumber] = msa2[hitNumber] * (chCurrent - chPrev);
708 // Calculates the covariance matrix
709 for (hitNumber1 = 0; hitNumber1 < numberOfHit; hitNumber1++) {
710 hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1];
711 z1 = hit1->GetHitForRecPtr()->GetZ();
712 for (hitNumber2 = hitNumber1; hitNumber2 < numberOfHit; hitNumber2++) {
713 hit2 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber2];
714 z2 = hit2->GetHitForRecPtr()->GetZ();
715 // initialization to 0 (diagonal plus upper triangular part)
716 (*covBending)(hitNumber2, hitNumber1) = 0.0;
717 // contribution from multiple scattering in bending plane:
718 // loop over upstream hits
719 for (hitNumber3 = 0; hitNumber3 < hitNumber1; hitNumber3++) {
720 hit3 = (AliMUONTrackHit*)
721 (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber3];
722 z3 = hit3->GetHitForRecPtr()->GetZ();
723 (*covBending)(hitNumber2, hitNumber1) =
724 (*covBending)(hitNumber2, hitNumber1) +
725 ((z1 - z3) * (z2 - z3) * msa2[hitNumber3]);
727 // equal contribution from multiple scattering in non bending plane
728 (*covNonBending)(hitNumber2, hitNumber1) =
729 (*covBending)(hitNumber2, hitNumber1);
730 if (hitNumber1 == hitNumber2) {
731 // Diagonal elements: add contribution from position measurements
733 (*covBending)(hitNumber2, hitNumber1) =
734 (*covBending)(hitNumber2, hitNumber1) +
735 hit1->GetHitForRecPtr()->GetBendingReso2();
736 // and in non bending plane
737 (*covNonBending)(hitNumber2, hitNumber1) =
738 (*covNonBending)(hitNumber2, hitNumber1) +
739 hit1->GetHitForRecPtr()->GetNonBendingReso2();
742 // Non diagonal elements: symmetrization
744 (*covBending)(hitNumber1, hitNumber2) =
745 (*covBending)(hitNumber2, hitNumber1);
746 // and non bending plane
747 (*covNonBending)(hitNumber1, hitNumber2) =
748 (*covNonBending)(hitNumber2, hitNumber1);
750 } // for (hitNumber2 = hitNumber1;...
751 } // for (hitNumber1 = 0;...
753 // Inversion of covariance matrices
754 // with "mnvertLocal", local "mnvert" function of Minuit.
755 // One cannot use directly "mnvert" since "TVirtualFitter" does not know it.
756 // One will have to replace this local function by the right inversion function
757 // from a specialized Root package for symmetric positive definite matrices,
758 // when available!!!!
760 mnvertLocal(&((*covBending)(0,0)), numberOfHit, numberOfHit, numberOfHit,
762 Int_t ifailNonBending;
763 mnvertLocal(&((*covNonBending)(0,0)), numberOfHit, numberOfHit, numberOfHit,
766 // It would be worth trying to calculate the inverse of the covariance matrix
767 // only once per fit, since it cannot change much in principle,
768 // and it would save a lot of computing time !!!!
771 if ((ifailBending == 0) && (ifailNonBending == 0)) {
772 // with Multiple Scattering if inversion correct
773 for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) {
774 hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1];
775 hbc1 = hit1->GetHitForRecPtr()->GetBendingCoor();
776 pbc1 = hit1->GetTrackParam()->GetBendingCoor();
777 hnbc1 = hit1->GetHitForRecPtr()->GetNonBendingCoor();
778 pnbc1 = hit1->GetTrackParam()->GetNonBendingCoor();
779 for (hitNumber2 = 0; hitNumber2 < numberOfHit; hitNumber2++) {
780 hit2 = (AliMUONTrackHit*)
781 (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber2];
782 hbc2 = hit2->GetHitForRecPtr()->GetBendingCoor();
783 pbc2 = hit2->GetTrackParam()->GetBendingCoor();
784 hnbc2 = hit2->GetHitForRecPtr()->GetNonBendingCoor();
785 pnbc2 = hit2->GetTrackParam()->GetNonBendingCoor();
787 ((*covBending)(hitNumber2, hitNumber1) *
788 (hbc1 - pbc1) * (hbc2 - pbc2)) +
789 ((*covNonBending)(hitNumber2, hitNumber1) *
790 (hnbc1 - pnbc1) * (hnbc2 - pnbc2));
794 // without Multiple Scattering if inversion impossible
795 for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) {
796 hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1];
797 hbc1 = hit1->GetHitForRecPtr()->GetBendingCoor();
798 pbc1 = hit1->GetTrackParam()->GetBendingCoor();
799 hnbc1 = hit1->GetHitForRecPtr()->GetNonBendingCoor();
800 pnbc1 = hit1->GetTrackParam()->GetNonBendingCoor();
802 ((hbc1 - pbc1) * (hbc1 - pbc1) /
803 hit1->GetHitForRecPtr()->GetBendingReso2()) +
804 ((hnbc1 - pnbc1) * (hnbc1 - pnbc1) /
805 hit1->GetHitForRecPtr()->GetNonBendingReso2());
810 delete covNonBending;
814 Double_t MultipleScatteringAngle2(AliMUONTrackHit *TrackHit)
816 // Returns square of multiple Coulomb scattering angle
817 // at TrackHit pointed to by "TrackHit"
818 Double_t slopeBending, slopeNonBending, radiationLength, inverseBendingMomentum2, inverseTotalMomentum2;
819 Double_t varMultipleScatteringAngle;
820 AliMUONTrack *trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit();
821 AliMUONTrackParam *param = TrackHit->GetTrackParam();
822 // Better implementation in AliMUONTrack class ????
823 slopeBending = param->GetBendingSlope();
824 slopeNonBending = param->GetNonBendingSlope();
825 // thickness in radiation length for the current track,
826 // taking local angle into account
828 trackBeingFitted->GetEventReconstructor()->GetChamberThicknessInX0() *
830 slopeBending * slopeBending + slopeNonBending * slopeNonBending);
831 inverseBendingMomentum2 =
832 param->GetInverseBendingMomentum() * param->GetInverseBendingMomentum();
833 inverseTotalMomentum2 =
834 inverseBendingMomentum2 * (1.0 + slopeBending * slopeBending) /
835 (1.0 + slopeBending *slopeBending + slopeNonBending * slopeNonBending);
836 varMultipleScatteringAngle = 0.0136 * (1.0 + 0.038 * TMath::Log(radiationLength));
837 // The velocity is assumed to be 1 !!!!
838 varMultipleScatteringAngle = inverseTotalMomentum2 * radiationLength *
839 varMultipleScatteringAngle * varMultipleScatteringAngle;
840 return varMultipleScatteringAngle;
843 //______________________________________________________________________________
844 void mnvertLocal(Double_t *a, Int_t l, Int_t, Int_t n, Int_t &ifail)
846 //*-*-*-*-*-*-*-*-*-*-*-*Inverts a symmetric matrix*-*-*-*-*-*-*-*-*-*-*-*-*
847 //*-* ==========================
848 //*-* inverts a symmetric matrix. matrix is first scaled to
849 //*-* have all ones on the diagonal (equivalent to change of units)
850 //*-* but no pivoting is done since matrix is positive-definite.
851 //*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
853 // taken from TMinuit package of Root (l>=n)
854 // fVERTs, fVERTq and fVERTpp changed to localVERTs, localVERTq and localVERTpp
855 // Double_t localVERTs[n], localVERTq[n], localVERTpp[n];
856 Double_t * localVERTs = new Double_t[n];
857 Double_t * localVERTq = new Double_t[n];
858 Double_t * localVERTpp = new Double_t[n];
859 // fMaxint changed to localMaxint
860 Int_t localMaxint = n;
862 /* System generated locals */
865 /* Local variables */
867 Int_t i, j, k, kp1, km1;
869 /* Parameter adjustments */
875 if (n < 1) goto L100;
876 if (n > localMaxint) goto L100;
877 //*-*- scale matrix by sqrt of diag elements
878 for (i = 1; i <= n; ++i) {
880 if (si <= 0) goto L100;
881 localVERTs[i-1] = 1 / TMath::Sqrt(si);
883 for (i = 1; i <= n; ++i) {
884 for (j = 1; j <= n; ++j) {
885 a[i + j*l] = a[i + j*l]*localVERTs[i-1]*localVERTs[j-1];
888 //*-*- . . . start main loop . . . .
889 for (i = 1; i <= n; ++i) {
891 //*-*- preparation for elimination step1
892 if (a[k + k*l] != 0) localVERTq[k-1] = 1 / a[k + k*l];
894 localVERTpp[k-1] = 1;
898 if (km1 < 0) goto L100;
899 else if (km1 == 0) goto L50;
902 for (j = 1; j <= km1; ++j) {
903 localVERTpp[j-1] = a[j + k*l];
904 localVERTq[j-1] = a[j + k*l]*localVERTq[k-1];
908 if (k - n < 0) goto L51;
909 else if (k - n == 0) goto L60;
912 for (j = kp1; j <= n; ++j) {
913 localVERTpp[j-1] = a[k + j*l];
914 localVERTq[j-1] = -a[k + j*l]*localVERTq[k-1];
917 //*-*- elimination proper
919 for (j = 1; j <= n; ++j) {
920 for (k = j; k <= n; ++k) { a[j + k*l] += localVERTpp[j-1]*localVERTq[k-1]; }
923 //*-*- elements of left diagonal and unscaling
924 for (j = 1; j <= n; ++j) {
925 for (k = 1; k <= j; ++k) {
926 a[k + j*l] = a[k + j*l]*localVERTs[k-1]*localVERTs[j-1];
927 a[j + k*l] = a[k + j*l];
934 //*-*- failure return