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 fTrackHitsPtr->Clear();
127 delete fTrackHitsPtr; // delete the TObjArray of pointers to TrackHit's
128 fTrackHitsPtr = NULL;
131 if (fTrackParamAtHit) {
132 // delete the TClonesArray of pointers to TrackParam
133 fTrackParamAtHit->Clear();
134 delete fTrackParamAtHit;
135 fTrackParamAtHit = NULL;
138 if (fHitForRecAtHit) {
139 // delete the TClonesArray of pointers to HitForRec
140 fHitForRecAtHit->Clear();
141 delete fHitForRecAtHit;
142 fHitForRecAtHit = NULL;
146 //__________________________________________________________________________
147 AliMUONTrack::AliMUONTrack (const AliMUONTrack& theMUONTrack)
148 : TObject(theMUONTrack)
150 //fEventReconstructor = new AliMUONEventReconstructor(*MUONTrack.fEventReconstructor);
152 // NO, because it would use dummy copy constructor
153 // and AliMUONTrack is not the owner of its EventReconstructor
154 fEventReconstructor = theMUONTrack.fEventReconstructor;
155 fTrackParamAtVertex = theMUONTrack.fTrackParamAtVertex;
157 // necessary to make a copy of the objects and not only the pointers in TObjArray.
158 fTrackHitsPtr = new TObjArray(10);
159 for (Int_t index = 0; index < (theMUONTrack.fTrackHitsPtr)->GetEntriesFast(); index++) {
160 AliMUONTrackHit *trackHit = new AliMUONTrackHit(*(AliMUONTrackHit*)(theMUONTrack.fTrackHitsPtr)->At(index));
161 fTrackHitsPtr->Add(trackHit);
164 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
165 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
166 for (Int_t index = 0; index < (theMUONTrack.fTrackParamAtHit)->GetEntriesFast(); index++) {
167 {new ((*fTrackParamAtHit)[fTrackParamAtHit->GetEntriesFast()])
168 AliMUONTrackParam(*(AliMUONTrackParam*)(theMUONTrack.fTrackParamAtHit)->At(index));}
171 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
172 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
173 for (Int_t index = 0; index < (theMUONTrack.fHitForRecAtHit)->GetEntriesFast(); index++) {
174 {new ((*fHitForRecAtHit)[fHitForRecAtHit->GetEntriesFast()])
175 AliMUONHitForRec(*(AliMUONHitForRec*)(theMUONTrack.fHitForRecAtHit)->At(index));}
178 fNTrackHits = theMUONTrack.fNTrackHits;
179 fFitMCS = theMUONTrack.fFitMCS;
180 fFitNParam = theMUONTrack.fFitNParam;
181 fFitFMin = theMUONTrack.fFitFMin;
182 fFitStart = theMUONTrack.fFitStart;
183 fMatchTrigger = theMUONTrack.fMatchTrigger;
184 fChi2MatchTrigger = theMUONTrack.fChi2MatchTrigger;
185 fTrackID = theMUONTrack.fTrackID;
188 //__________________________________________________________________________
189 AliMUONTrack & AliMUONTrack::operator=(const AliMUONTrack& theMUONTrack)
192 // check assignement to self
193 if (this == &theMUONTrack)
196 // base class assignement
197 TObject::operator=(theMUONTrack);
199 // fEventReconstructor = new AliMUONEventReconstructor(*MUONTrack.fEventReconstructor); // is it right ?
200 // is it right ? NO because it would use dummy copy constructor
201 fEventReconstructor = theMUONTrack.fEventReconstructor;
202 fTrackParamAtVertex = theMUONTrack.fTrackParamAtVertex;
204 // necessary to make a copy of the objects and not only the pointers in TObjArray.
205 fTrackHitsPtr = new TObjArray(10);
206 for (Int_t index = 0; index < (theMUONTrack.fTrackHitsPtr)->GetEntriesFast(); index++) {
207 AliMUONTrackHit *trackHit = new AliMUONTrackHit(*(AliMUONTrackHit*)(theMUONTrack.fTrackHitsPtr)->At(index));
208 fTrackHitsPtr->Add(trackHit);
211 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
212 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
213 for (Int_t index = 0; index < (theMUONTrack.fTrackParamAtHit)->GetEntriesFast(); index++) {
214 {new ((*fTrackParamAtHit)[fTrackParamAtHit->GetEntriesFast()])
215 AliMUONTrackParam(*(AliMUONTrackParam*)(theMUONTrack.fTrackParamAtHit)->At(index));}
218 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
219 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
220 for (Int_t index = 0; index < (theMUONTrack.fHitForRecAtHit)->GetEntriesFast(); index++) {
221 {new ((*fHitForRecAtHit)[fHitForRecAtHit->GetEntriesFast()])
222 AliMUONHitForRec(*(AliMUONHitForRec*)(theMUONTrack.fHitForRecAtHit)->At(index));}
225 fNTrackHits = theMUONTrack.fNTrackHits;
226 fFitMCS = theMUONTrack.fFitMCS;
227 fFitNParam = theMUONTrack.fFitNParam;
228 fFitFMin = theMUONTrack.fFitFMin;
229 fFitStart = theMUONTrack.fFitStart;
230 fMatchTrigger = theMUONTrack.fMatchTrigger;
231 fChi2MatchTrigger = theMUONTrack.fChi2MatchTrigger;
232 fTrackID = theMUONTrack.fTrackID;
237 //__________________________________________________________________________
238 void AliMUONTrack::Remove()
240 // Remove current track from array of tracks,
241 // and corresponding track hits from array of track hits.
242 // Compress the TClonesArray it belongs to.
243 AliMUONTrackHit *nextTrackHit;
244 AliMUONEventReconstructor *eventRec = this->fEventReconstructor;
245 TClonesArray *trackHitsPtr = eventRec->GetRecTrackHitsPtr();
246 // Loop over all track hits of track
247 AliMUONTrackHit *trackHit = (AliMUONTrackHit*) fTrackHitsPtr->First();
249 nextTrackHit = (AliMUONTrackHit*) fTrackHitsPtr->After(trackHit);
250 // Remove TrackHit from event TClonesArray.
251 // Destructor is called,
252 // hence links between HitForRec's and TrackHit's are updated
253 trackHitsPtr->Remove(trackHit);
254 trackHit = nextTrackHit;
256 // Remove the track from event TClonesArray
257 // Destructor is called,
258 // hence space for TObjArray of pointers to TrackHit's is freed
259 eventRec->GetRecTracksPtr()->Remove(this);
260 // Number of tracks decreased by 1
261 eventRec->SetNRecTracks(eventRec->GetNRecTracks() - 1);
262 // Compress event TClonesArray of Track's:
263 // this is essential to retrieve the TClonesArray afterwards
264 eventRec->GetRecTracksPtr()->Compress();
265 // Compress event TClonesArray of TrackHit's:
266 // this is probably also essential to retrieve the TClonesArray afterwards
267 trackHitsPtr->Compress();
270 //__________________________________________________________________________
271 void AliMUONTrack::SetFitMCS(Int_t FitMCS)
273 // Set multiple Coulomb scattering option for track fit "fFitMCS"
274 // from "FitMCS" argument: 0 without, 1 with
275 if ((FitMCS == 0) || (FitMCS == 1)) fFitMCS = FitMCS;
276 // better implementation with enum(with, without) ????
278 cout << "ERROR in AliMUONTrack::SetFitMCS(FitMCS)" << endl;
279 cout << "FitMCS = " << FitMCS << " is neither 0 nor 1" << endl;
285 //__________________________________________________________________________
286 void AliMUONTrack::SetFitNParam(Int_t FitNParam)
288 // Set number of parameters for track fit "fFitNParam" from "FitNParam":
289 // 3 for momentum, 5 for momentum and position
290 if ((FitNParam == 3) || (FitNParam == 5)) fFitNParam = FitNParam;
292 cout << "ERROR in AliMUONTrack::SetFitNParam(FitNParam)" << endl;
293 cout << "FitNParam = " << FitNParam << " is neither 3 nor 5" << endl;
299 //__________________________________________________________________________
300 void AliMUONTrack::SetFitStart(Int_t FitStart)
302 // Set multiple Coulomb scattering option for track fit "fFitStart"
303 // from "FitStart" argument: 0 without, 1 with
304 if ((FitStart == 0) || (FitStart == 1)) fFitStart = FitStart;
305 // better implementation with enum(vertex, firstHit) ????
307 cout << "ERROR in AliMUONTrack::SetFitStart(FitStart)" << endl;
308 cout << "FitStart = " << FitStart << " is neither 0 nor 1" << endl;
314 //__________________________________________________________________________
315 AliMUONTrackParam* AliMUONTrack::GetTrackParamAtFirstHit(void) const {
316 // Get pointer to TrackParamAtFirstHit
317 return ((AliMUONTrackHit*) (fTrackHitsPtr->First()))->GetTrackParam();}
319 //__________________________________________________________________________
320 void AliMUONTrack::RecursiveDump(void) const
322 // Recursive dump of AliMUONTrack, i.e. with dump of TrackHit's and HitForRec's
323 AliMUONTrackHit *trackHit;
324 AliMUONHitForRec *hitForRec;
325 cout << "Recursive dump of Track: " << this << endl;
328 for (Int_t trackHitIndex = 0; trackHitIndex < fNTrackHits; trackHitIndex++) {
329 trackHit = (AliMUONTrackHit*) ((*fTrackHitsPtr)[trackHitIndex]);
331 cout << "TrackHit: " << trackHit << " (index: " << trackHitIndex << ")" << endl;
333 hitForRec = trackHit->GetHitForRecPtr();
335 cout << "HitForRec: " << hitForRec << endl;
341 //__________________________________________________________________________
342 Bool_t* AliMUONTrack::CompatibleTrack(AliMUONTrack * Track, Double_t Sigma2Cut) const
344 // Return kTRUE/kFALSE for each chamber if hit is compatible or not
345 TClonesArray *hitArray, *thisHitArray;
346 AliMUONHitForRec *hit, *thisHit;
349 Float_t deltaZMax = 1.; // 1 cm
351 Bool_t *nCompHit = new Bool_t[AliMUONConstants::NTrackingCh()];
353 for ( Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) {
354 nCompHit[ch] = kFALSE;
357 thisHitArray = this->GetHitForRecAtHit();
359 hitArray = Track->GetHitForRecAtHit();
361 for (Int_t iHthis = 0; iHthis < thisHitArray->GetEntriesFast(); iHthis++) {
362 thisHit = (AliMUONHitForRec*) thisHitArray->At(iHthis);
363 chamberNumber = thisHit->GetChamberNumber();
364 if (chamberNumber < 0 || chamberNumber > AliMUONConstants::NTrackingCh()) continue;
365 nCompHit[chamberNumber] = kFALSE;
366 for (Int_t iH = 0; iH < hitArray->GetEntriesFast(); iH++) {
367 hit = (AliMUONHitForRec*) hitArray->At(iH);
368 deltaZ = TMath::Abs(thisHit->GetZ() - hit->GetZ());
369 chi2 = thisHit->NormalizedChi2WithHitForRec(hit,Sigma2Cut); // set cut to 4 sigmas
370 if (chi2 < 3. && deltaZ < deltaZMax) {
371 nCompHit[chamberNumber] = kTRUE;
380 //__________________________________________________________________________
381 Int_t AliMUONTrack::HitsInCommon(AliMUONTrack* Track) const
383 // Returns the number of hits in common
384 // between the current track ("this")
385 // and the track pointed to by "Track".
386 Int_t hitsInCommon = 0;
387 AliMUONTrackHit *trackHit1, *trackHit2;
388 // Loop over hits of first track
389 trackHit1 = (AliMUONTrackHit*) this->GetTrackHitsPtr()->First();
391 // Loop over hits of second track
392 trackHit2 = (AliMUONTrackHit*) Track->GetTrackHitsPtr()->First();
394 // Increment "hitsInCommon" if both TrackHits point to the same HitForRec
395 if ( (trackHit1->GetHitForRecPtr()) ==
396 (trackHit2->GetHitForRecPtr()) ) hitsInCommon++;
397 trackHit2 = (AliMUONTrackHit*) Track->GetTrackHitsPtr()->After(trackHit2);
399 trackHit1 = (AliMUONTrackHit*) this->GetTrackHitsPtr()->After(trackHit1);
404 //__________________________________________________________________________
405 void AliMUONTrack::MatchTriggerTrack(TClonesArray *triggerTrackArray)
407 // Match this track with one trigger track if possible
408 AliMUONTrackParam trackParam;
409 AliMUONTriggerTrack *triggerTrack;
410 Double_t xTrack, yTrack, ySlopeTrack, dTrigTrackMin2, dTrigTrack2;
413 Double_t distSigma[3]={1,1,0.02}; // sigma of distributions (trigger-track) X,Y,slopeY
414 Double_t distTriggerTrack[3] = {0,0,0};
416 fMatchTrigger = kFALSE;
417 fChi2MatchTrigger = 0;
419 trackParam = *((AliMUONTrackParam*) fTrackParamAtHit->Last());
420 trackParam.ExtrapToZ(AliMUONConstants::DefaultChamberZ(10)); // extrap to 1st trigger chamber
422 nSigmaCut2 = fEventReconstructor->GetMaxSigma2Distance(); // nb of sigma**2 for cut
423 xTrack = trackParam.GetNonBendingCoor();
424 yTrack = trackParam.GetBendingCoor();
425 ySlopeTrack = trackParam.GetBendingSlope();
426 dTrigTrackMin2 = 999;
428 triggerTrack = (AliMUONTriggerTrack*) triggerTrackArray->First();
430 distTriggerTrack[0] = (triggerTrack->GetX11()-xTrack)/distSigma[0];
431 distTriggerTrack[1] = (triggerTrack->GetY11()-yTrack)/distSigma[1];
432 distTriggerTrack[2] = (TMath::Tan(triggerTrack->GetThetay())-ySlopeTrack)/distSigma[2];
434 for (Int_t iVar = 0; iVar < 3; iVar++)
435 dTrigTrack2 += distTriggerTrack[iVar]*distTriggerTrack[iVar];
436 if (dTrigTrack2 < dTrigTrackMin2 && dTrigTrack2 < nSigmaCut2) {
437 dTrigTrackMin2 = dTrigTrack2;
438 fMatchTrigger = kTRUE;
439 fChi2MatchTrigger = dTrigTrack2/3.; // Normalized Chi2, 3 variables (X,Y,slopeY)
441 triggerTrack = (AliMUONTriggerTrack*) triggerTrackArray->After(triggerTrack);
445 //__________________________________________________________________________
446 void AliMUONTrack::Fit()
448 // Fit the current track ("this"),
449 // with or without multiple Coulomb scattering according to "fFitMCS",
450 // with the number of parameters given by "fFitNParam"
451 // (3 if one keeps X and Y fixed in "TrackParam", 5 if one lets them vary),
452 // starting, according to "fFitStart",
453 // with track parameters at vertex or at the first TrackHit.
454 // "fFitMCS", "fFitNParam" and "fFitStart" have to be set before
455 // by calling the corresponding Set methods.
456 Double_t arg[1], benC, errorParam, invBenP, lower, nonBenC, upper, x, y;
458 AliMUONTrackParam *trackParam;
459 // Check if Minuit is initialized...
460 fgFitter = TVirtualFitter::Fitter(this); // add 3 or 5 for the maximum number of parameters ???
461 fgFitter->Clear(); // necessary ???? probably yes
462 // how to reset the printout number at every fit ????
463 // is there any risk to leave it like that ????
464 // how to go faster ???? choice of Minuit parameters like EDM ????
465 // choice of function to be minimized according to fFitMCS
466 if (fFitMCS == 0) fgFitter->SetFCN(TrackChi2);
467 else fgFitter->SetFCN(TrackChi2MCS);
468 // Switch off printout
470 fgFitter->ExecuteCommand("SET PRINT", arg, 1); // More printing !!!!
472 fgFitter->ExecuteCommand("SET NOW", arg, 0);
473 // Parameters according to "fFitStart"
474 // (should be a function to be used at every place where needed ????)
475 if (fFitStart == 0) trackParam = &fTrackParamAtVertex;
476 else trackParam = this->GetTrackParamAtFirstHit();
477 // set first 3 Minuit parameters
478 // could be tried with no limits for the search (min=max=0) ????
479 fgFitter->SetParameter(0, "InvBenP",
480 trackParam->GetInverseBendingMomentum(),
482 fgFitter->SetParameter(1, "BenS",
483 trackParam->GetBendingSlope(),
485 fgFitter->SetParameter(2, "NonBenS",
486 trackParam->GetNonBendingSlope(),
488 if (fFitNParam == 5) {
489 // set last 2 Minuit parameters
490 // mandatory limits in Bending to avoid NaN values of parameters
491 fgFitter->SetParameter(3, "X",
492 trackParam->GetNonBendingCoor(),
493 0.03, -500.0, 500.0);
494 // mandatory limits in non Bending to avoid NaN values of parameters
495 fgFitter->SetParameter(4, "Y",
496 trackParam->GetBendingCoor(),
497 0.10, -500.0, 500.0);
499 // search without gradient calculation in the function
500 fgFitter->ExecuteCommand("SET NOGRADIENT", arg, 0);
502 fgFitter->ExecuteCommand("MINIMIZE", arg, 0);
504 // fgFitter->ExecuteCommand("EXIT", arg, 0); // necessary ????
505 // get results into "invBenP", "benC", "nonBenC" ("x", "y")
506 fgFitter->GetParameter(0, parName, invBenP, errorParam, lower, upper);
507 fgFitter->GetParameter(1, parName, benC, errorParam, lower, upper);
508 fgFitter->GetParameter(2, parName, nonBenC, errorParam, lower, upper);
509 if (fFitNParam == 5) {
510 fgFitter->GetParameter(3, parName, x, errorParam, lower, upper);
511 fgFitter->GetParameter(4, parName, y, errorParam, lower, upper);
513 // result of the fit into track parameters
514 trackParam->SetInverseBendingMomentum(invBenP);
515 trackParam->SetBendingSlope(benC);
516 trackParam->SetNonBendingSlope(nonBenC);
517 if (fFitNParam == 5) {
518 trackParam->SetNonBendingCoor(x);
519 trackParam->SetBendingCoor(y);
521 // global result of the fit
522 Double_t fedm, errdef;
524 fgFitter->GetStats(fFitFMin, fedm, errdef, npari, nparx);
527 //__________________________________________________________________________
528 void AliMUONTrack::AddSegment(AliMUONSegment* Segment)
530 // Add Segment to the track
531 AddHitForRec(Segment->GetHitForRec1()); // 1st hit
532 AddHitForRec(Segment->GetHitForRec2()); // 2nd hit
535 //__________________________________________________________________________
536 void AliMUONTrack::AddHitForRec(AliMUONHitForRec* HitForRec)
538 // Add HitForRec to the track:
539 // actual TrackHit into TClonesArray of TrackHit's for the event;
540 // pointer to actual TrackHit in TObjArray of pointers to TrackHit's for the track
541 TClonesArray *recTrackHitsPtr = this->fEventReconstructor->GetRecTrackHitsPtr();
542 Int_t eventTrackHits = this->fEventReconstructor->GetNRecTrackHits();
544 AliMUONTrackHit* trackHit =
545 new ((*recTrackHitsPtr)[eventTrackHits]) AliMUONTrackHit(HitForRec);
546 this->fEventReconstructor->SetNRecTrackHits(eventTrackHits + 1);
548 fTrackHitsPtr->Add(trackHit);
552 //__________________________________________________________________________
553 void AliMUONTrack::SetTrackParamAtHit(Int_t indexHit, AliMUONTrackParam *TrackParam) const
555 // Set track parameters at TrackHit with index "indexHit"
556 // from the track parameters pointed to by "TrackParam".
557 //PH AliMUONTrackHit* trackHit = (AliMUONTrackHit*) ((*fTrackHitsPtr)[indexHit]);
558 AliMUONTrackHit* trackHit = (AliMUONTrackHit*) (fTrackHitsPtr->At(indexHit));
559 trackHit->SetTrackParam(TrackParam);
562 //__________________________________________________________________________
563 void AliMUONTrack::SetTrackParamAtVertex()
565 // Set track parameters at vertex.
566 // TrackHit's are assumed to be only in stations(1..) 4 and 5,
567 // and sorted according to increasing Z..
568 // Parameters are calculated from information in HitForRec's
569 // of first and last TrackHit's.
570 AliMUONTrackParam *trackParam =
571 &fTrackParamAtVertex; // pointer to track parameters
572 // Pointer to HitForRec of first TrackHit
573 AliMUONHitForRec *firstHit =
574 ((AliMUONTrackHit*) (fTrackHitsPtr->First()))->GetHitForRecPtr();
575 // Pointer to HitForRec of last TrackHit
576 AliMUONHitForRec *lastHit =
577 ((AliMUONTrackHit*) (fTrackHitsPtr->Last()))->GetHitForRecPtr();
578 // Z difference between first and last hits
579 Double_t deltaZ = firstHit->GetZ() - lastHit->GetZ();
580 // bending slope in stations(1..) 4 and 5
581 Double_t bendingSlope =
582 (firstHit->GetBendingCoor() - lastHit->GetBendingCoor()) / deltaZ;
583 trackParam->SetBendingSlope(bendingSlope);
585 Double_t impactParam =
586 firstHit->GetBendingCoor() - bendingSlope * firstHit->GetZ(); // same if from firstHit and lastHit ????
587 // signed bending momentum
588 Double_t signedBendingMomentum =
589 fEventReconstructor->GetBendingMomentumFromImpactParam(impactParam);
590 trackParam->SetInverseBendingMomentum(1.0 / signedBendingMomentum);
591 // bending slope at vertex
593 SetBendingSlope(bendingSlope +
594 impactParam / fEventReconstructor->GetSimpleBPosition());
596 Double_t nonBendingSlope =
597 (firstHit->GetNonBendingCoor() - lastHit->GetNonBendingCoor()) / deltaZ;
598 trackParam->SetNonBendingSlope(nonBendingSlope);
599 // vertex coordinates at (0,0,0)
600 trackParam->SetZ(0.0);
601 trackParam->SetBendingCoor(0.0);
602 trackParam->SetNonBendingCoor(0.0);
605 //__________________________________________________________________________
606 void TrackChi2(Int_t &NParam, Double_t * /*Gradient*/, Double_t &Chi2, Double_t *Param, Int_t /*Flag*/)
608 // Return the "Chi2" to be minimized with Minuit for track fitting,
609 // with "NParam" parameters
610 // and their current values in array pointed to by "Param".
611 // Assumes that the track hits are sorted according to increasing Z.
612 // Track parameters at each TrackHit are updated accordingly.
613 // Multiple Coulomb scattering is not taken into account
614 AliMUONTrack *trackBeingFitted;
615 AliMUONTrackHit* hit;
616 AliMUONTrackParam param1;
619 Chi2 = 0.0; // initialize Chi2
620 // copy of track parameters to be fitted
621 trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit();
622 if (trackBeingFitted->GetFitStart() == 0)
623 param1 = *(trackBeingFitted->GetTrackParamAtVertex());
624 else param1 = *(trackBeingFitted->GetTrackParamAtFirstHit());
625 // Minuit parameters to be fitted into this copy
626 param1.SetInverseBendingMomentum(Param[0]);
627 param1.SetBendingSlope(Param[1]);
628 param1.SetNonBendingSlope(Param[2]);
630 param1.SetNonBendingCoor(Param[3]);
631 param1.SetBendingCoor(Param[4]);
633 // Follow track through all planes of track hits
634 for (hitNumber = 0; hitNumber < trackBeingFitted->GetNTrackHits(); hitNumber++) {
635 hit = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber];
636 zHit = hit->GetHitForRecPtr()->GetZ();
637 // do something special if 2 hits with same Z ????
638 // security against infinite loop ????
639 (¶m1)->ExtrapToZ(zHit); // extrapolation
640 hit->SetTrackParam(¶m1);
642 // done hit per hit, with hit resolution,
643 // and not with point and angle like in "reco_muon.F" !!!!
644 // Needs to add multiple scattering contribution ????
646 hit->GetHitForRecPtr()->GetNonBendingCoor() - (¶m1)->GetNonBendingCoor();
648 hit->GetHitForRecPtr()->GetBendingCoor() - (¶m1)->GetBendingCoor();
651 dX * dX / hit->GetHitForRecPtr()->GetNonBendingReso2() +
652 dY * dY / hit->GetHitForRecPtr()->GetBendingReso2();
656 //__________________________________________________________________________
657 void TrackChi2MCS(Int_t &NParam, Double_t * /*Gradient*/, Double_t &Chi2, Double_t *Param, Int_t /*Flag*/)
659 // Return the "Chi2" to be minimized with Minuit for track fitting,
660 // with "NParam" parameters
661 // and their current values in array pointed to by "Param".
662 // Assumes that the track hits are sorted according to increasing Z.
663 // Track parameters at each TrackHit are updated accordingly.
664 // Multiple Coulomb scattering is taken into account with covariance matrix.
665 AliMUONTrack *trackBeingFitted;
666 AliMUONTrackParam param1;
667 Chi2 = 0.0; // initialize Chi2
668 // copy of track parameters to be fitted
669 trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit();
670 if (trackBeingFitted->GetFitStart() == 0)
671 param1 = *(trackBeingFitted->GetTrackParamAtVertex());
672 else param1 = *(trackBeingFitted->GetTrackParamAtFirstHit());
673 // Minuit parameters to be fitted into this copy
674 param1.SetInverseBendingMomentum(Param[0]);
675 param1.SetBendingSlope(Param[1]);
676 param1.SetNonBendingSlope(Param[2]);
678 param1.SetNonBendingCoor(Param[3]);
679 param1.SetBendingCoor(Param[4]);
682 AliMUONTrackHit *hit;
683 Int_t chCurrent, chPrev = 0, hitNumber, hitNumber1, hitNumber2, hitNumber3;
684 Double_t z, z1, z2, z3;
685 AliMUONTrackHit *hit1, *hit2, *hit3;
686 Double_t hbc1, hbc2, pbc1, pbc2;
687 Double_t hnbc1, hnbc2, pnbc1, pnbc2;
688 Int_t numberOfHit = trackBeingFitted->GetNTrackHits();
689 TMatrixD *covBending = new TMatrixD(numberOfHit, numberOfHit);
690 TMatrixD *covNonBending = new TMatrixD(numberOfHit, numberOfHit);
691 Double_t *msa2 = new Double_t[numberOfHit];
693 // Predicted coordinates and multiple scattering angles are first calculated
694 for (hitNumber = 0; hitNumber < numberOfHit; hitNumber++) {
695 hit = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber];
696 z = hit->GetHitForRecPtr()->GetZ();
697 // do something special if 2 hits with same Z ????
698 // security against infinite loop ????
699 (¶m1)->ExtrapToZ(z); // extrapolation
700 hit->SetTrackParam(¶m1);
701 // square of multiple scattering angle at current hit, with one chamber
702 msa2[hitNumber] = MultipleScatteringAngle2(hit);
703 // correction for eventual missing hits or multiple hits in a chamber,
704 // according to the number of chambers
705 // between the current hit and the previous one
706 chCurrent = hit->GetHitForRecPtr()->GetChamberNumber();
707 if (hitNumber > 0) msa2[hitNumber] = msa2[hitNumber] * (chCurrent - chPrev);
711 // Calculates the covariance matrix
712 for (hitNumber1 = 0; hitNumber1 < numberOfHit; hitNumber1++) {
713 hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1];
714 z1 = hit1->GetHitForRecPtr()->GetZ();
715 for (hitNumber2 = hitNumber1; hitNumber2 < numberOfHit; hitNumber2++) {
716 hit2 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber2];
717 z2 = hit2->GetHitForRecPtr()->GetZ();
718 // initialization to 0 (diagonal plus upper triangular part)
719 (*covBending)(hitNumber2, hitNumber1) = 0.0;
720 // contribution from multiple scattering in bending plane:
721 // loop over upstream hits
722 for (hitNumber3 = 0; hitNumber3 < hitNumber1; hitNumber3++) {
723 hit3 = (AliMUONTrackHit*)
724 (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber3];
725 z3 = hit3->GetHitForRecPtr()->GetZ();
726 (*covBending)(hitNumber2, hitNumber1) =
727 (*covBending)(hitNumber2, hitNumber1) +
728 ((z1 - z3) * (z2 - z3) * msa2[hitNumber3]);
730 // equal contribution from multiple scattering in non bending plane
731 (*covNonBending)(hitNumber2, hitNumber1) =
732 (*covBending)(hitNumber2, hitNumber1);
733 if (hitNumber1 == hitNumber2) {
734 // Diagonal elements: add contribution from position measurements
736 (*covBending)(hitNumber2, hitNumber1) =
737 (*covBending)(hitNumber2, hitNumber1) +
738 hit1->GetHitForRecPtr()->GetBendingReso2();
739 // and in non bending plane
740 (*covNonBending)(hitNumber2, hitNumber1) =
741 (*covNonBending)(hitNumber2, hitNumber1) +
742 hit1->GetHitForRecPtr()->GetNonBendingReso2();
745 // Non diagonal elements: symmetrization
747 (*covBending)(hitNumber1, hitNumber2) =
748 (*covBending)(hitNumber2, hitNumber1);
749 // and non bending plane
750 (*covNonBending)(hitNumber1, hitNumber2) =
751 (*covNonBending)(hitNumber2, hitNumber1);
753 } // for (hitNumber2 = hitNumber1;...
754 } // for (hitNumber1 = 0;...
756 // Inversion of covariance matrices
757 // with "mnvertLocal", local "mnvert" function of Minuit.
758 // One cannot use directly "mnvert" since "TVirtualFitter" does not know it.
759 // One will have to replace this local function by the right inversion function
760 // from a specialized Root package for symmetric positive definite matrices,
761 // when available!!!!
763 mnvertLocal(&((*covBending)(0,0)), numberOfHit, numberOfHit, numberOfHit,
765 Int_t ifailNonBending;
766 mnvertLocal(&((*covNonBending)(0,0)), numberOfHit, numberOfHit, numberOfHit,
769 // It would be worth trying to calculate the inverse of the covariance matrix
770 // only once per fit, since it cannot change much in principle,
771 // and it would save a lot of computing time !!!!
774 if ((ifailBending == 0) && (ifailNonBending == 0)) {
775 // with Multiple Scattering if inversion correct
776 for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) {
777 hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1];
778 hbc1 = hit1->GetHitForRecPtr()->GetBendingCoor();
779 pbc1 = hit1->GetTrackParam()->GetBendingCoor();
780 hnbc1 = hit1->GetHitForRecPtr()->GetNonBendingCoor();
781 pnbc1 = hit1->GetTrackParam()->GetNonBendingCoor();
782 for (hitNumber2 = 0; hitNumber2 < numberOfHit; hitNumber2++) {
783 hit2 = (AliMUONTrackHit*)
784 (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber2];
785 hbc2 = hit2->GetHitForRecPtr()->GetBendingCoor();
786 pbc2 = hit2->GetTrackParam()->GetBendingCoor();
787 hnbc2 = hit2->GetHitForRecPtr()->GetNonBendingCoor();
788 pnbc2 = hit2->GetTrackParam()->GetNonBendingCoor();
790 ((*covBending)(hitNumber2, hitNumber1) *
791 (hbc1 - pbc1) * (hbc2 - pbc2)) +
792 ((*covNonBending)(hitNumber2, hitNumber1) *
793 (hnbc1 - pnbc1) * (hnbc2 - pnbc2));
797 // without Multiple Scattering if inversion impossible
798 for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) {
799 hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1];
800 hbc1 = hit1->GetHitForRecPtr()->GetBendingCoor();
801 pbc1 = hit1->GetTrackParam()->GetBendingCoor();
802 hnbc1 = hit1->GetHitForRecPtr()->GetNonBendingCoor();
803 pnbc1 = hit1->GetTrackParam()->GetNonBendingCoor();
805 ((hbc1 - pbc1) * (hbc1 - pbc1) /
806 hit1->GetHitForRecPtr()->GetBendingReso2()) +
807 ((hnbc1 - pnbc1) * (hnbc1 - pnbc1) /
808 hit1->GetHitForRecPtr()->GetNonBendingReso2());
813 delete covNonBending;
817 Double_t MultipleScatteringAngle2(AliMUONTrackHit *TrackHit)
819 // Returns square of multiple Coulomb scattering angle
820 // at TrackHit pointed to by "TrackHit"
821 Double_t slopeBending, slopeNonBending, radiationLength, inverseBendingMomentum2, inverseTotalMomentum2;
822 Double_t varMultipleScatteringAngle;
823 AliMUONTrack *trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit();
824 AliMUONTrackParam *param = TrackHit->GetTrackParam();
825 // Better implementation in AliMUONTrack class ????
826 slopeBending = param->GetBendingSlope();
827 slopeNonBending = param->GetNonBendingSlope();
828 // thickness in radiation length for the current track,
829 // taking local angle into account
831 trackBeingFitted->GetEventReconstructor()->GetChamberThicknessInX0() *
833 slopeBending * slopeBending + slopeNonBending * slopeNonBending);
834 inverseBendingMomentum2 =
835 param->GetInverseBendingMomentum() * param->GetInverseBendingMomentum();
836 inverseTotalMomentum2 =
837 inverseBendingMomentum2 * (1.0 + slopeBending * slopeBending) /
838 (1.0 + slopeBending *slopeBending + slopeNonBending * slopeNonBending);
839 varMultipleScatteringAngle = 0.0136 * (1.0 + 0.038 * TMath::Log(radiationLength));
840 // The velocity is assumed to be 1 !!!!
841 varMultipleScatteringAngle = inverseTotalMomentum2 * radiationLength *
842 varMultipleScatteringAngle * varMultipleScatteringAngle;
843 return varMultipleScatteringAngle;
846 //______________________________________________________________________________
847 void mnvertLocal(Double_t *a, Int_t l, Int_t, Int_t n, Int_t &ifail)
849 //*-*-*-*-*-*-*-*-*-*-*-*Inverts a symmetric matrix*-*-*-*-*-*-*-*-*-*-*-*-*
850 //*-* ==========================
851 //*-* inverts a symmetric matrix. matrix is first scaled to
852 //*-* have all ones on the diagonal (equivalent to change of units)
853 //*-* but no pivoting is done since matrix is positive-definite.
854 //*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
856 // taken from TMinuit package of Root (l>=n)
857 // fVERTs, fVERTq and fVERTpp changed to localVERTs, localVERTq and localVERTpp
858 // Double_t localVERTs[n], localVERTq[n], localVERTpp[n];
859 Double_t * localVERTs = new Double_t[n];
860 Double_t * localVERTq = new Double_t[n];
861 Double_t * localVERTpp = new Double_t[n];
862 // fMaxint changed to localMaxint
863 Int_t localMaxint = n;
865 /* System generated locals */
868 /* Local variables */
870 Int_t i, j, k, kp1, km1;
872 /* Parameter adjustments */
878 if (n < 1) goto L100;
879 if (n > localMaxint) goto L100;
880 //*-*- scale matrix by sqrt of diag elements
881 for (i = 1; i <= n; ++i) {
883 if (si <= 0) goto L100;
884 localVERTs[i-1] = 1 / TMath::Sqrt(si);
886 for (i = 1; i <= n; ++i) {
887 for (j = 1; j <= n; ++j) {
888 a[i + j*l] = a[i + j*l]*localVERTs[i-1]*localVERTs[j-1];
891 //*-*- . . . start main loop . . . .
892 for (i = 1; i <= n; ++i) {
894 //*-*- preparation for elimination step1
895 if (a[k + k*l] != 0) localVERTq[k-1] = 1 / a[k + k*l];
897 localVERTpp[k-1] = 1;
901 if (km1 < 0) goto L100;
902 else if (km1 == 0) goto L50;
905 for (j = 1; j <= km1; ++j) {
906 localVERTpp[j-1] = a[j + k*l];
907 localVERTq[j-1] = a[j + k*l]*localVERTq[k-1];
911 if (k - n < 0) goto L51;
912 else if (k - n == 0) goto L60;
915 for (j = kp1; j <= n; ++j) {
916 localVERTpp[j-1] = a[k + j*l];
917 localVERTq[j-1] = -a[k + j*l]*localVERTq[k-1];
920 //*-*- elimination proper
922 for (j = 1; j <= n; ++j) {
923 for (k = j; k <= n; ++k) { a[j + k*l] += localVERTpp[j-1]*localVERTq[k-1]; }
926 //*-*- elements of left diagonal and unscaling
927 for (j = 1; j <= n; ++j) {
928 for (k = 1; k <= j; ++k) {
929 a[k + j*l] = a[k + j*l]*localVERTs[k-1]*localVERTs[j-1];
930 a[j + k*l] = a[k + j*l];
933 delete [] localVERTs;
934 delete [] localVERTq;
935 delete [] localVERTpp;
937 //*-*- failure return
939 delete [] localVERTs;
940 delete [] localVERTq;
941 delete [] localVERTpp;