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>
38 #include "AliMUONTrackReconstructor.h"
39 #include "AliMUONHitForRec.h"
40 #include "AliMUONSegment.h"
41 #include "AliMUONTrack.h"
42 #include "AliMUONTrackHit.h"
43 #include "AliMUONTriggerTrack.h"
44 #include "AliMUONConstants.h"
46 // Functions to be minimized with Minuit
47 void TrackChi2(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag);
48 void TrackChi2MCS(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag);
50 void mnvertLocal(Double_t* a, Int_t l, Int_t m, Int_t n, Int_t& ifail);
52 Double_t MultipleScatteringAngle2(AliMUONTrackHit *TrackHit);
54 ClassImp(AliMUONTrack) // Class implementation in ROOT context
56 TVirtualFitter* AliMUONTrack::fgFitter = NULL;
58 //__________________________________________________________________________
59 AliMUONTrack::AliMUONTrack()
62 // Default constructor
64 fTrackReconstructor = 0;
65 fTrackHitsPtr = new TObjArray(10);
66 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
67 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
71 //__________________________________________________________________________
72 AliMUONTrack::AliMUONTrack(AliMUONSegment* BegSegment, AliMUONSegment* EndSegment, AliMUONTrackReconstructor* TrackReconstructor)
75 // Constructor from two Segment's
76 fTrackReconstructor = TrackReconstructor; // link back to TrackReconstructor
77 // memory allocation for the TObjArray of pointers to reconstructed TrackHit's
78 fTrackHitsPtr = new TObjArray(10);
80 AddSegment(BegSegment); // add hits from BegSegment
81 AddSegment(EndSegment); // add hits from EndSegment
82 fTrackHitsPtr->Sort(); // sort TrackHits according to increasing Z
83 SetTrackParamAtVertex(); // set track parameters at vertex
84 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
85 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
86 // set fit conditions...
91 fMatchTrigger = kFALSE;
92 fChi2MatchTrigger = 0;
97 //__________________________________________________________________________
98 AliMUONTrack::AliMUONTrack(AliMUONSegment* Segment, AliMUONHitForRec* HitForRec, AliMUONTrackReconstructor* TrackReconstructor)
101 // Constructor from one Segment and one HitForRec
102 fTrackReconstructor = TrackReconstructor; // link back to TrackReconstructor
103 // memory allocation for the TObjArray of pointers to reconstructed TrackHit's
104 fTrackHitsPtr = new TObjArray(10);
106 AddSegment(Segment); // add hits from Segment
107 AddHitForRec(HitForRec); // add HitForRec
108 fTrackHitsPtr->Sort(); // sort TrackHits according to increasing Z
109 SetTrackParamAtVertex(); // set track parameters at vertex
110 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
111 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
112 // set fit conditions...
117 fMatchTrigger = kFALSE;
118 fChi2MatchTrigger = 0;
123 //__________________________________________________________________________
124 AliMUONTrack::~AliMUONTrack()
128 // delete the TObjArray of pointers to TrackHit's
129 delete fTrackHitsPtr;
130 fTrackHitsPtr = NULL;
133 if (fTrackParamAtHit) {
134 // delete the TClonesArray of pointers to TrackParam
135 delete fTrackParamAtHit;
136 fTrackParamAtHit = NULL;
139 if (fHitForRecAtHit) {
140 // delete the TClonesArray of pointers to HitForRec
141 delete fHitForRecAtHit;
142 fHitForRecAtHit = NULL;
146 //__________________________________________________________________________
147 AliMUONTrack::AliMUONTrack (const AliMUONTrack& theMUONTrack)
148 : TObject(theMUONTrack)
150 //fTrackReconstructor = new AliMUONTrackReconstructor(*MUONTrack.fTrackReconstructor);
152 // NO, because it would use dummy copy constructor
153 // and AliMUONTrack is not the owner of its TrackReconstructor
154 fTrackReconstructor = theMUONTrack.fTrackReconstructor;
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);
163 fTrackHitsPtr->SetOwner(); // nedeed for deleting TClonesArray
165 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
166 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
167 for (Int_t index = 0; index < (theMUONTrack.fTrackParamAtHit)->GetEntriesFast(); index++) {
168 {new ((*fTrackParamAtHit)[fTrackParamAtHit->GetEntriesFast()])
169 AliMUONTrackParam(*(AliMUONTrackParam*)(theMUONTrack.fTrackParamAtHit)->At(index));}
172 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
173 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
174 for (Int_t index = 0; index < (theMUONTrack.fHitForRecAtHit)->GetEntriesFast(); index++) {
175 {new ((*fHitForRecAtHit)[fHitForRecAtHit->GetEntriesFast()])
176 AliMUONHitForRec(*(AliMUONHitForRec*)(theMUONTrack.fHitForRecAtHit)->At(index));}
179 fNTrackHits = theMUONTrack.fNTrackHits;
180 fFitMCS = theMUONTrack.fFitMCS;
181 fFitNParam = theMUONTrack.fFitNParam;
182 fFitFMin = theMUONTrack.fFitFMin;
183 fFitStart = theMUONTrack.fFitStart;
184 fMatchTrigger = theMUONTrack.fMatchTrigger;
185 fChi2MatchTrigger = theMUONTrack.fChi2MatchTrigger;
186 fTrackID = theMUONTrack.fTrackID;
189 //__________________________________________________________________________
190 AliMUONTrack & AliMUONTrack::operator=(const AliMUONTrack& theMUONTrack)
193 // check assignement to self
194 if (this == &theMUONTrack)
197 // base class assignement
198 TObject::operator=(theMUONTrack);
200 // fTrackReconstructor = new AliMUONTrackReconstructor(*MUONTrack.fTrackReconstructor);
202 // is it right ? NO because it would use dummy copy constructor
203 fTrackReconstructor = theMUONTrack.fTrackReconstructor;
204 fTrackParamAtVertex = theMUONTrack.fTrackParamAtVertex;
206 // necessary to make a copy of the objects and not only the pointers in TObjArray.
207 fTrackHitsPtr = new TObjArray(10);
208 for (Int_t index = 0; index < (theMUONTrack.fTrackHitsPtr)->GetEntriesFast(); index++) {
209 AliMUONTrackHit *trackHit = new AliMUONTrackHit(*(AliMUONTrackHit*)(theMUONTrack.fTrackHitsPtr)->At(index));
210 fTrackHitsPtr->Add(trackHit);
212 fTrackHitsPtr->SetOwner(); // nedeed for deleting TClonesArray
214 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
215 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
216 for (Int_t index = 0; index < (theMUONTrack.fTrackParamAtHit)->GetEntriesFast(); index++) {
217 {new ((*fTrackParamAtHit)[fTrackParamAtHit->GetEntriesFast()])
218 AliMUONTrackParam(*(AliMUONTrackParam*)(theMUONTrack.fTrackParamAtHit)->At(index));}
221 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
222 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
223 for (Int_t index = 0; index < (theMUONTrack.fHitForRecAtHit)->GetEntriesFast(); index++) {
224 {new ((*fHitForRecAtHit)[fHitForRecAtHit->GetEntriesFast()])
225 AliMUONHitForRec(*(AliMUONHitForRec*)(theMUONTrack.fHitForRecAtHit)->At(index));}
228 fNTrackHits = theMUONTrack.fNTrackHits;
229 fFitMCS = theMUONTrack.fFitMCS;
230 fFitNParam = theMUONTrack.fFitNParam;
231 fFitFMin = theMUONTrack.fFitFMin;
232 fFitStart = theMUONTrack.fFitStart;
233 fMatchTrigger = theMUONTrack.fMatchTrigger;
234 fChi2MatchTrigger = theMUONTrack.fChi2MatchTrigger;
235 fTrackID = theMUONTrack.fTrackID;
240 //__________________________________________________________________________
241 void AliMUONTrack::Remove()
243 // Remove current track from array of tracks,
244 // and corresponding track hits from array of track hits.
245 // Compress the TClonesArray it belongs to.
246 AliMUONTrackHit *nextTrackHit;
247 AliMUONTrackReconstructor *eventRec = this->fTrackReconstructor;
248 TClonesArray *trackHitsPtr = eventRec->GetRecTrackHitsPtr();
249 // Loop over all track hits of track
250 AliMUONTrackHit *trackHit = (AliMUONTrackHit*) fTrackHitsPtr->First();
252 nextTrackHit = (AliMUONTrackHit*) fTrackHitsPtr->After(trackHit);
253 // Remove TrackHit from event TClonesArray.
254 // Destructor is called,
255 // hence links between HitForRec's and TrackHit's are updated
256 trackHitsPtr->Remove(trackHit);
257 trackHit = nextTrackHit;
259 // Remove the track from event TClonesArray
260 // Destructor is called,
261 // hence space for TObjArray of pointers to TrackHit's is freed
262 eventRec->GetRecTracksPtr()->Remove(this);
263 // Number of tracks decreased by 1
264 eventRec->SetNRecTracks(eventRec->GetNRecTracks() - 1);
265 // Compress event TClonesArray of Track's:
266 // this is essential to retrieve the TClonesArray afterwards
267 eventRec->GetRecTracksPtr()->Compress();
268 // Compress event TClonesArray of TrackHit's:
269 // this is probably also essential to retrieve the TClonesArray afterwards
270 trackHitsPtr->Compress();
273 //__________________________________________________________________________
274 void AliMUONTrack::SetFitMCS(Int_t FitMCS)
276 // Set multiple Coulomb scattering option for track fit "fFitMCS"
277 // from "FitMCS" argument: 0 without, 1 with
278 if ((FitMCS == 0) || (FitMCS == 1)) fFitMCS = FitMCS;
279 // better implementation with enum(with, without) ????
281 cout << "ERROR in AliMUONTrack::SetFitMCS(FitMCS)" << endl;
282 cout << "FitMCS = " << FitMCS << " is neither 0 nor 1" << endl;
288 //__________________________________________________________________________
289 void AliMUONTrack::SetFitNParam(Int_t FitNParam)
291 // Set number of parameters for track fit "fFitNParam" from "FitNParam":
292 // 3 for momentum, 5 for momentum and position
293 if ((FitNParam == 3) || (FitNParam == 5)) fFitNParam = FitNParam;
295 cout << "ERROR in AliMUONTrack::SetFitNParam(FitNParam)" << endl;
296 cout << "FitNParam = " << FitNParam << " is neither 3 nor 5" << endl;
302 //__________________________________________________________________________
303 void AliMUONTrack::SetFitStart(Int_t FitStart)
305 // Set multiple Coulomb scattering option for track fit "fFitStart"
306 // from "FitStart" argument: 0 without, 1 with
307 if ((FitStart == 0) || (FitStart == 1)) fFitStart = FitStart;
308 // better implementation with enum(vertex, firstHit) ????
310 cout << "ERROR in AliMUONTrack::SetFitStart(FitStart)" << endl;
311 cout << "FitStart = " << FitStart << " is neither 0 nor 1" << endl;
317 //__________________________________________________________________________
318 AliMUONTrackParam* AliMUONTrack::GetTrackParamAtFirstHit(void) const {
319 // Get pointer to TrackParamAtFirstHit
320 return ((AliMUONTrackHit*) (fTrackHitsPtr->First()))->GetTrackParam();}
322 //__________________________________________________________________________
323 void AliMUONTrack::RecursiveDump(void) const
325 // Recursive dump of AliMUONTrack, i.e. with dump of TrackHit's and HitForRec's
326 AliMUONTrackHit *trackHit;
327 AliMUONHitForRec *hitForRec;
328 cout << "Recursive dump of Track: " << this << endl;
331 for (Int_t trackHitIndex = 0; trackHitIndex < fNTrackHits; trackHitIndex++) {
332 trackHit = (AliMUONTrackHit*) ((*fTrackHitsPtr)[trackHitIndex]);
334 cout << "TrackHit: " << trackHit << " (index: " << trackHitIndex << ")" << endl;
336 hitForRec = trackHit->GetHitForRecPtr();
338 cout << "HitForRec: " << hitForRec << endl;
344 //__________________________________________________________________________
345 Bool_t* AliMUONTrack::CompatibleTrack(AliMUONTrack * Track, Double_t Sigma2Cut) const
347 // Return kTRUE/kFALSE for each chamber if hit is compatible or not
348 TClonesArray *hitArray, *thisHitArray;
349 AliMUONHitForRec *hit, *thisHit;
352 Float_t deltaZMax = 1.; // 1 cm
354 Bool_t *nCompHit = new Bool_t[AliMUONConstants::NTrackingCh()];
356 for ( Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) {
357 nCompHit[ch] = kFALSE;
360 thisHitArray = this->GetHitForRecAtHit();
362 hitArray = Track->GetHitForRecAtHit();
364 for (Int_t iHthis = 0; iHthis < thisHitArray->GetEntriesFast(); iHthis++) {
365 thisHit = (AliMUONHitForRec*) thisHitArray->At(iHthis);
366 chamberNumber = thisHit->GetChamberNumber();
367 if (chamberNumber < 0 || chamberNumber > AliMUONConstants::NTrackingCh()) continue;
368 nCompHit[chamberNumber] = kFALSE;
369 for (Int_t iH = 0; iH < hitArray->GetEntriesFast(); iH++) {
370 hit = (AliMUONHitForRec*) hitArray->At(iH);
371 deltaZ = TMath::Abs(thisHit->GetZ() - hit->GetZ());
372 chi2 = thisHit->NormalizedChi2WithHitForRec(hit,Sigma2Cut); // set cut to 4 sigmas
373 if (chi2 < 3. && deltaZ < deltaZMax) {
374 nCompHit[chamberNumber] = kTRUE;
383 //__________________________________________________________________________
384 Int_t AliMUONTrack::HitsInCommon(AliMUONTrack* Track) const
386 // Returns the number of hits in common
387 // between the current track ("this")
388 // and the track pointed to by "Track".
389 Int_t hitsInCommon = 0;
390 AliMUONTrackHit *trackHit1, *trackHit2;
391 // Loop over hits of first track
392 trackHit1 = (AliMUONTrackHit*) this->GetTrackHitsPtr()->First();
394 // Loop over hits of second track
395 trackHit2 = (AliMUONTrackHit*) Track->GetTrackHitsPtr()->First();
397 // Increment "hitsInCommon" if both TrackHits point to the same HitForRec
398 if ( (trackHit1->GetHitForRecPtr()) ==
399 (trackHit2->GetHitForRecPtr()) ) hitsInCommon++;
400 trackHit2 = (AliMUONTrackHit*) Track->GetTrackHitsPtr()->After(trackHit2);
402 trackHit1 = (AliMUONTrackHit*) this->GetTrackHitsPtr()->After(trackHit1);
407 //__________________________________________________________________________
408 void AliMUONTrack::MatchTriggerTrack(TClonesArray *triggerTrackArray)
410 // Match this track with one trigger track if possible
411 AliMUONTrackParam trackParam;
412 AliMUONTriggerTrack *triggerTrack;
413 Double_t xTrack, yTrack, ySlopeTrack, dTrigTrackMin2, dTrigTrack2;
416 Double_t distSigma[3]={1,1,0.02}; // sigma of distributions (trigger-track) X,Y,slopeY
417 Double_t distTriggerTrack[3] = {0,0,0};
419 fMatchTrigger = kFALSE;
420 fChi2MatchTrigger = 0;
422 trackParam = *((AliMUONTrackParam*) fTrackParamAtHit->Last());
423 trackParam.ExtrapToZ(AliMUONConstants::DefaultChamberZ(10)); // extrap to 1st trigger chamber
425 nSigmaCut2 = fTrackReconstructor->GetMaxSigma2Distance(); // nb of sigma**2 for cut
426 xTrack = trackParam.GetNonBendingCoor();
427 yTrack = trackParam.GetBendingCoor();
428 ySlopeTrack = trackParam.GetBendingSlope();
429 dTrigTrackMin2 = 999;
431 triggerTrack = (AliMUONTriggerTrack*) triggerTrackArray->First();
433 distTriggerTrack[0] = (triggerTrack->GetX11()-xTrack)/distSigma[0];
434 distTriggerTrack[1] = (triggerTrack->GetY11()-yTrack)/distSigma[1];
435 distTriggerTrack[2] = (TMath::Tan(triggerTrack->GetThetay())-ySlopeTrack)/distSigma[2];
437 for (Int_t iVar = 0; iVar < 3; iVar++)
438 dTrigTrack2 += distTriggerTrack[iVar]*distTriggerTrack[iVar];
439 if (dTrigTrack2 < dTrigTrackMin2 && dTrigTrack2 < nSigmaCut2) {
440 dTrigTrackMin2 = dTrigTrack2;
441 fMatchTrigger = kTRUE;
442 fChi2MatchTrigger = dTrigTrack2/3.; // Normalized Chi2, 3 variables (X,Y,slopeY)
444 triggerTrack = (AliMUONTriggerTrack*) triggerTrackArray->After(triggerTrack);
448 //__________________________________________________________________________
449 void AliMUONTrack::Fit()
451 // Fit the current track ("this"),
452 // with or without multiple Coulomb scattering according to "fFitMCS",
453 // with the number of parameters given by "fFitNParam"
454 // (3 if one keeps X and Y fixed in "TrackParam", 5 if one lets them vary),
455 // starting, according to "fFitStart",
456 // with track parameters at vertex or at the first TrackHit.
457 // "fFitMCS", "fFitNParam" and "fFitStart" have to be set before
458 // by calling the corresponding Set methods.
459 Double_t arg[1], benC, errorParam, invBenP, lower, nonBenC, upper, x, y;
461 AliMUONTrackParam *trackParam;
462 // Check if Minuit is initialized...
463 fgFitter = TVirtualFitter::Fitter(this); // add 3 or 5 for the maximum number of parameters ???
464 fgFitter->Clear(); // necessary ???? probably yes
465 // how to reset the printout number at every fit ????
466 // is there any risk to leave it like that ????
467 // how to go faster ???? choice of Minuit parameters like EDM ????
468 // choice of function to be minimized according to fFitMCS
469 if (fFitMCS == 0) fgFitter->SetFCN(TrackChi2);
470 else fgFitter->SetFCN(TrackChi2MCS);
471 // Switch off printout
473 fgFitter->ExecuteCommand("SET PRINT", arg, 1); // More printing !!!!
475 fgFitter->ExecuteCommand("SET NOW", arg, 0);
476 // Parameters according to "fFitStart"
477 // (should be a function to be used at every place where needed ????)
478 if (fFitStart == 0) trackParam = &fTrackParamAtVertex;
479 else trackParam = this->GetTrackParamAtFirstHit();
480 // set first 3 Minuit parameters
481 // could be tried with no limits for the search (min=max=0) ????
482 fgFitter->SetParameter(0, "InvBenP",
483 trackParam->GetInverseBendingMomentum(),
485 fgFitter->SetParameter(1, "BenS",
486 trackParam->GetBendingSlope(),
488 fgFitter->SetParameter(2, "NonBenS",
489 trackParam->GetNonBendingSlope(),
491 if (fFitNParam == 5) {
492 // set last 2 Minuit parameters
493 // mandatory limits in Bending to avoid NaN values of parameters
494 fgFitter->SetParameter(3, "X",
495 trackParam->GetNonBendingCoor(),
496 0.03, -500.0, 500.0);
497 // mandatory limits in non Bending to avoid NaN values of parameters
498 fgFitter->SetParameter(4, "Y",
499 trackParam->GetBendingCoor(),
500 0.10, -500.0, 500.0);
502 // search without gradient calculation in the function
503 fgFitter->ExecuteCommand("SET NOGRADIENT", arg, 0);
505 fgFitter->ExecuteCommand("MINIMIZE", arg, 0);
507 // fgFitter->ExecuteCommand("EXIT", arg, 0); // necessary ????
508 // get results into "invBenP", "benC", "nonBenC" ("x", "y")
509 fgFitter->GetParameter(0, parName, invBenP, errorParam, lower, upper);
510 fgFitter->GetParameter(1, parName, benC, errorParam, lower, upper);
511 fgFitter->GetParameter(2, parName, nonBenC, errorParam, lower, upper);
512 if (fFitNParam == 5) {
513 fgFitter->GetParameter(3, parName, x, errorParam, lower, upper);
514 fgFitter->GetParameter(4, parName, y, errorParam, lower, upper);
516 // result of the fit into track parameters
517 trackParam->SetInverseBendingMomentum(invBenP);
518 trackParam->SetBendingSlope(benC);
519 trackParam->SetNonBendingSlope(nonBenC);
520 if (fFitNParam == 5) {
521 trackParam->SetNonBendingCoor(x);
522 trackParam->SetBendingCoor(y);
524 // global result of the fit
525 Double_t fedm, errdef;
527 fgFitter->GetStats(fFitFMin, fedm, errdef, npari, nparx);
530 //__________________________________________________________________________
531 void AliMUONTrack::AddSegment(AliMUONSegment* Segment)
533 // Add Segment to the track
534 AddHitForRec(Segment->GetHitForRec1()); // 1st hit
535 AddHitForRec(Segment->GetHitForRec2()); // 2nd hit
538 //__________________________________________________________________________
539 void AliMUONTrack::AddHitForRec(AliMUONHitForRec* HitForRec)
541 // Add HitForRec to the track:
542 // actual TrackHit into TClonesArray of TrackHit's for the event;
543 // pointer to actual TrackHit in TObjArray of pointers to TrackHit's for the track
544 TClonesArray *recTrackHitsPtr = this->fTrackReconstructor->GetRecTrackHitsPtr();
545 Int_t eventTrackHits = this->fTrackReconstructor->GetNRecTrackHits();
547 AliMUONTrackHit* trackHit =
548 new ((*recTrackHitsPtr)[eventTrackHits]) AliMUONTrackHit(HitForRec);
549 this->fTrackReconstructor->SetNRecTrackHits(eventTrackHits + 1);
551 if (fTrackHitsPtr->IsOwner()) AliFatal("fTrackHitsPtr is owner");
552 fTrackHitsPtr->Add(trackHit);
556 //__________________________________________________________________________
557 void AliMUONTrack::SetTrackParamAtHit(Int_t indexHit, AliMUONTrackParam *TrackParam) const
559 // Set track parameters at TrackHit with index "indexHit"
560 // from the track parameters pointed to by "TrackParam".
561 //PH AliMUONTrackHit* trackHit = (AliMUONTrackHit*) ((*fTrackHitsPtr)[indexHit]);
562 AliMUONTrackHit* trackHit = (AliMUONTrackHit*) (fTrackHitsPtr->At(indexHit));
563 trackHit->SetTrackParam(TrackParam);
566 //__________________________________________________________________________
567 void AliMUONTrack::SetTrackParamAtVertex()
569 // Set track parameters at vertex.
570 // TrackHit's are assumed to be only in stations(1..) 4 and 5,
571 // and sorted according to increasing Z..
572 // Parameters are calculated from information in HitForRec's
573 // of first and last TrackHit's.
574 AliMUONTrackParam *trackParam =
575 &fTrackParamAtVertex; // pointer to track parameters
576 // Pointer to HitForRec of first TrackHit
577 AliMUONHitForRec *firstHit =
578 ((AliMUONTrackHit*) (fTrackHitsPtr->First()))->GetHitForRecPtr();
579 // Pointer to HitForRec of last TrackHit
580 AliMUONHitForRec *lastHit =
581 ((AliMUONTrackHit*) (fTrackHitsPtr->Last()))->GetHitForRecPtr();
582 // Z difference between first and last hits
583 Double_t deltaZ = firstHit->GetZ() - lastHit->GetZ();
584 // bending slope in stations(1..) 4 and 5
585 Double_t bendingSlope =
586 (firstHit->GetBendingCoor() - lastHit->GetBendingCoor()) / deltaZ;
587 trackParam->SetBendingSlope(bendingSlope);
589 Double_t impactParam =
590 firstHit->GetBendingCoor() - bendingSlope * firstHit->GetZ(); // same if from firstHit and lastHit ????
591 // signed bending momentum
592 Double_t signedBendingMomentum =
593 fTrackReconstructor->GetBendingMomentumFromImpactParam(impactParam);
594 trackParam->SetInverseBendingMomentum(1.0 / signedBendingMomentum);
595 // bending slope at vertex
597 SetBendingSlope(bendingSlope +
598 impactParam / fTrackReconstructor->GetSimpleBPosition());
600 Double_t nonBendingSlope =
601 (firstHit->GetNonBendingCoor() - lastHit->GetNonBendingCoor()) / deltaZ;
602 trackParam->SetNonBendingSlope(nonBendingSlope);
603 // vertex coordinates at (0,0,0)
604 trackParam->SetZ(0.0);
605 trackParam->SetBendingCoor(0.0);
606 trackParam->SetNonBendingCoor(0.0);
609 //__________________________________________________________________________
610 void TrackChi2(Int_t &NParam, Double_t * /*Gradient*/, Double_t &Chi2, Double_t *Param, Int_t /*Flag*/)
612 // Return the "Chi2" to be minimized with Minuit for track fitting,
613 // with "NParam" parameters
614 // and their current values in array pointed to by "Param".
615 // Assumes that the track hits are sorted according to increasing Z.
616 // Track parameters at each TrackHit are updated accordingly.
617 // Multiple Coulomb scattering is not taken into account
618 AliMUONTrack *trackBeingFitted;
619 AliMUONTrackHit* hit;
620 AliMUONTrackParam param1;
623 Chi2 = 0.0; // initialize Chi2
624 // copy of track parameters to be fitted
625 trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit();
626 if (trackBeingFitted->GetFitStart() == 0)
627 param1 = *(trackBeingFitted->GetTrackParamAtVertex());
628 else param1 = *(trackBeingFitted->GetTrackParamAtFirstHit());
629 // Minuit parameters to be fitted into this copy
630 param1.SetInverseBendingMomentum(Param[0]);
631 param1.SetBendingSlope(Param[1]);
632 param1.SetNonBendingSlope(Param[2]);
634 param1.SetNonBendingCoor(Param[3]);
635 param1.SetBendingCoor(Param[4]);
637 // Follow track through all planes of track hits
638 for (hitNumber = 0; hitNumber < trackBeingFitted->GetNTrackHits(); hitNumber++) {
639 hit = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber];
640 zHit = hit->GetHitForRecPtr()->GetZ();
641 // do something special if 2 hits with same Z ????
642 // security against infinite loop ????
643 (¶m1)->ExtrapToZ(zHit); // extrapolation
644 hit->SetTrackParam(¶m1);
646 // done hit per hit, with hit resolution,
647 // and not with point and angle like in "reco_muon.F" !!!!
648 // Needs to add multiple scattering contribution ????
650 hit->GetHitForRecPtr()->GetNonBendingCoor() - (¶m1)->GetNonBendingCoor();
652 hit->GetHitForRecPtr()->GetBendingCoor() - (¶m1)->GetBendingCoor();
655 dX * dX / hit->GetHitForRecPtr()->GetNonBendingReso2() +
656 dY * dY / hit->GetHitForRecPtr()->GetBendingReso2();
660 //__________________________________________________________________________
661 void TrackChi2MCS(Int_t &NParam, Double_t * /*Gradient*/, Double_t &Chi2, Double_t *Param, Int_t /*Flag*/)
663 // Return the "Chi2" to be minimized with Minuit for track fitting,
664 // with "NParam" parameters
665 // and their current values in array pointed to by "Param".
666 // Assumes that the track hits are sorted according to increasing Z.
667 // Track parameters at each TrackHit are updated accordingly.
668 // Multiple Coulomb scattering is taken into account with covariance matrix.
669 AliMUONTrack *trackBeingFitted;
670 AliMUONTrackParam param1;
671 Chi2 = 0.0; // initialize Chi2
672 // copy of track parameters to be fitted
673 trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit();
674 if (trackBeingFitted->GetFitStart() == 0)
675 param1 = *(trackBeingFitted->GetTrackParamAtVertex());
676 else param1 = *(trackBeingFitted->GetTrackParamAtFirstHit());
677 // Minuit parameters to be fitted into this copy
678 param1.SetInverseBendingMomentum(Param[0]);
679 param1.SetBendingSlope(Param[1]);
680 param1.SetNonBendingSlope(Param[2]);
682 param1.SetNonBendingCoor(Param[3]);
683 param1.SetBendingCoor(Param[4]);
686 AliMUONTrackHit *hit;
687 Int_t chCurrent, chPrev = 0, hitNumber, hitNumber1, hitNumber2, hitNumber3;
688 Double_t z, z1, z2, z3;
689 AliMUONTrackHit *hit1, *hit2, *hit3;
690 Double_t hbc1, hbc2, pbc1, pbc2;
691 Double_t hnbc1, hnbc2, pnbc1, pnbc2;
692 Int_t numberOfHit = trackBeingFitted->GetNTrackHits();
693 TMatrixD *covBending = new TMatrixD(numberOfHit, numberOfHit);
694 TMatrixD *covNonBending = new TMatrixD(numberOfHit, numberOfHit);
695 Double_t *msa2 = new Double_t[numberOfHit];
697 // Predicted coordinates and multiple scattering angles are first calculated
698 for (hitNumber = 0; hitNumber < numberOfHit; hitNumber++) {
699 hit = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber];
700 z = hit->GetHitForRecPtr()->GetZ();
701 // do something special if 2 hits with same Z ????
702 // security against infinite loop ????
703 (¶m1)->ExtrapToZ(z); // extrapolation
704 hit->SetTrackParam(¶m1);
705 // square of multiple scattering angle at current hit, with one chamber
706 msa2[hitNumber] = MultipleScatteringAngle2(hit);
707 // correction for eventual missing hits or multiple hits in a chamber,
708 // according to the number of chambers
709 // between the current hit and the previous one
710 chCurrent = hit->GetHitForRecPtr()->GetChamberNumber();
711 if (hitNumber > 0) msa2[hitNumber] = msa2[hitNumber] * (chCurrent - chPrev);
715 // Calculates the covariance matrix
716 for (hitNumber1 = 0; hitNumber1 < numberOfHit; hitNumber1++) {
717 hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1];
718 z1 = hit1->GetHitForRecPtr()->GetZ();
719 for (hitNumber2 = hitNumber1; hitNumber2 < numberOfHit; hitNumber2++) {
720 hit2 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber2];
721 z2 = hit2->GetHitForRecPtr()->GetZ();
722 // initialization to 0 (diagonal plus upper triangular part)
723 (*covBending)(hitNumber2, hitNumber1) = 0.0;
724 // contribution from multiple scattering in bending plane:
725 // loop over upstream hits
726 for (hitNumber3 = 0; hitNumber3 < hitNumber1; hitNumber3++) {
727 hit3 = (AliMUONTrackHit*)
728 (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber3];
729 z3 = hit3->GetHitForRecPtr()->GetZ();
730 (*covBending)(hitNumber2, hitNumber1) =
731 (*covBending)(hitNumber2, hitNumber1) +
732 ((z1 - z3) * (z2 - z3) * msa2[hitNumber3]);
734 // equal contribution from multiple scattering in non bending plane
735 (*covNonBending)(hitNumber2, hitNumber1) =
736 (*covBending)(hitNumber2, hitNumber1);
737 if (hitNumber1 == hitNumber2) {
738 // Diagonal elements: add contribution from position measurements
740 (*covBending)(hitNumber2, hitNumber1) =
741 (*covBending)(hitNumber2, hitNumber1) +
742 hit1->GetHitForRecPtr()->GetBendingReso2();
743 // and in non bending plane
744 (*covNonBending)(hitNumber2, hitNumber1) =
745 (*covNonBending)(hitNumber2, hitNumber1) +
746 hit1->GetHitForRecPtr()->GetNonBendingReso2();
749 // Non diagonal elements: symmetrization
751 (*covBending)(hitNumber1, hitNumber2) =
752 (*covBending)(hitNumber2, hitNumber1);
753 // and non bending plane
754 (*covNonBending)(hitNumber1, hitNumber2) =
755 (*covNonBending)(hitNumber2, hitNumber1);
757 } // for (hitNumber2 = hitNumber1;...
758 } // for (hitNumber1 = 0;...
760 // Inversion of covariance matrices
761 // with "mnvertLocal", local "mnvert" function of Minuit.
762 // One cannot use directly "mnvert" since "TVirtualFitter" does not know it.
763 // One will have to replace this local function by the right inversion function
764 // from a specialized Root package for symmetric positive definite matrices,
765 // when available!!!!
767 mnvertLocal(&((*covBending)(0,0)), numberOfHit, numberOfHit, numberOfHit,
769 Int_t ifailNonBending;
770 mnvertLocal(&((*covNonBending)(0,0)), numberOfHit, numberOfHit, numberOfHit,
773 // It would be worth trying to calculate the inverse of the covariance matrix
774 // only once per fit, since it cannot change much in principle,
775 // and it would save a lot of computing time !!!!
778 if ((ifailBending == 0) && (ifailNonBending == 0)) {
779 // with Multiple Scattering if inversion correct
780 for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) {
781 hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1];
782 hbc1 = hit1->GetHitForRecPtr()->GetBendingCoor();
783 pbc1 = hit1->GetTrackParam()->GetBendingCoor();
784 hnbc1 = hit1->GetHitForRecPtr()->GetNonBendingCoor();
785 pnbc1 = hit1->GetTrackParam()->GetNonBendingCoor();
786 for (hitNumber2 = 0; hitNumber2 < numberOfHit; hitNumber2++) {
787 hit2 = (AliMUONTrackHit*)
788 (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber2];
789 hbc2 = hit2->GetHitForRecPtr()->GetBendingCoor();
790 pbc2 = hit2->GetTrackParam()->GetBendingCoor();
791 hnbc2 = hit2->GetHitForRecPtr()->GetNonBendingCoor();
792 pnbc2 = hit2->GetTrackParam()->GetNonBendingCoor();
794 ((*covBending)(hitNumber2, hitNumber1) *
795 (hbc1 - pbc1) * (hbc2 - pbc2)) +
796 ((*covNonBending)(hitNumber2, hitNumber1) *
797 (hnbc1 - pnbc1) * (hnbc2 - pnbc2));
801 // without Multiple Scattering if inversion impossible
802 for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) {
803 hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1];
804 hbc1 = hit1->GetHitForRecPtr()->GetBendingCoor();
805 pbc1 = hit1->GetTrackParam()->GetBendingCoor();
806 hnbc1 = hit1->GetHitForRecPtr()->GetNonBendingCoor();
807 pnbc1 = hit1->GetTrackParam()->GetNonBendingCoor();
809 ((hbc1 - pbc1) * (hbc1 - pbc1) /
810 hit1->GetHitForRecPtr()->GetBendingReso2()) +
811 ((hnbc1 - pnbc1) * (hnbc1 - pnbc1) /
812 hit1->GetHitForRecPtr()->GetNonBendingReso2());
817 delete covNonBending;
821 Double_t MultipleScatteringAngle2(AliMUONTrackHit *TrackHit)
823 // Returns square of multiple Coulomb scattering angle
824 // at TrackHit pointed to by "TrackHit"
825 Double_t slopeBending, slopeNonBending, radiationLength, inverseBendingMomentum2, inverseTotalMomentum2;
826 Double_t varMultipleScatteringAngle;
827 AliMUONTrack *trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit();
828 AliMUONTrackParam *param = TrackHit->GetTrackParam();
829 // Better implementation in AliMUONTrack class ????
830 slopeBending = param->GetBendingSlope();
831 slopeNonBending = param->GetNonBendingSlope();
832 // thickness in radiation length for the current track,
833 // taking local angle into account
835 trackBeingFitted->GetTrackReconstructor()->GetChamberThicknessInX0() *
837 slopeBending * slopeBending + slopeNonBending * slopeNonBending);
838 inverseBendingMomentum2 =
839 param->GetInverseBendingMomentum() * param->GetInverseBendingMomentum();
840 inverseTotalMomentum2 =
841 inverseBendingMomentum2 * (1.0 + slopeBending * slopeBending) /
842 (1.0 + slopeBending *slopeBending + slopeNonBending * slopeNonBending);
843 varMultipleScatteringAngle = 0.0136 * (1.0 + 0.038 * TMath::Log(radiationLength));
844 // The velocity is assumed to be 1 !!!!
845 varMultipleScatteringAngle = inverseTotalMomentum2 * radiationLength *
846 varMultipleScatteringAngle * varMultipleScatteringAngle;
847 return varMultipleScatteringAngle;
850 //______________________________________________________________________________
851 void mnvertLocal(Double_t *a, Int_t l, Int_t, Int_t n, Int_t &ifail)
853 //*-*-*-*-*-*-*-*-*-*-*-*Inverts a symmetric matrix*-*-*-*-*-*-*-*-*-*-*-*-*
854 //*-* ==========================
855 //*-* inverts a symmetric matrix. matrix is first scaled to
856 //*-* have all ones on the diagonal (equivalent to change of units)
857 //*-* but no pivoting is done since matrix is positive-definite.
858 //*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
860 // taken from TMinuit package of Root (l>=n)
861 // fVERTs, fVERTq and fVERTpp changed to localVERTs, localVERTq and localVERTpp
862 // Double_t localVERTs[n], localVERTq[n], localVERTpp[n];
863 Double_t * localVERTs = new Double_t[n];
864 Double_t * localVERTq = new Double_t[n];
865 Double_t * localVERTpp = new Double_t[n];
866 // fMaxint changed to localMaxint
867 Int_t localMaxint = n;
869 /* System generated locals */
872 /* Local variables */
874 Int_t i, j, k, kp1, km1;
876 /* Parameter adjustments */
882 if (n < 1) goto L100;
883 if (n > localMaxint) goto L100;
884 //*-*- scale matrix by sqrt of diag elements
885 for (i = 1; i <= n; ++i) {
887 if (si <= 0) goto L100;
888 localVERTs[i-1] = 1 / TMath::Sqrt(si);
890 for (i = 1; i <= n; ++i) {
891 for (j = 1; j <= n; ++j) {
892 a[i + j*l] = a[i + j*l]*localVERTs[i-1]*localVERTs[j-1];
895 //*-*- . . . start main loop . . . .
896 for (i = 1; i <= n; ++i) {
898 //*-*- preparation for elimination step1
899 if (a[k + k*l] != 0) localVERTq[k-1] = 1 / a[k + k*l];
901 localVERTpp[k-1] = 1;
905 if (km1 < 0) goto L100;
906 else if (km1 == 0) goto L50;
909 for (j = 1; j <= km1; ++j) {
910 localVERTpp[j-1] = a[j + k*l];
911 localVERTq[j-1] = a[j + k*l]*localVERTq[k-1];
915 if (k - n < 0) goto L51;
916 else if (k - n == 0) goto L60;
919 for (j = kp1; j <= n; ++j) {
920 localVERTpp[j-1] = a[k + j*l];
921 localVERTq[j-1] = -a[k + j*l]*localVERTq[k-1];
924 //*-*- elimination proper
926 for (j = 1; j <= n; ++j) {
927 for (k = j; k <= n; ++k) { a[j + k*l] += localVERTpp[j-1]*localVERTq[k-1]; }
930 //*-*- elements of left diagonal and unscaling
931 for (j = 1; j <= n; ++j) {
932 for (k = 1; k <= j; ++k) {
933 a[k + j*l] = a[k + j*l]*localVERTs[k-1]*localVERTs[j-1];
934 a[j + k*l] = a[k + j*l];
937 delete [] localVERTs;
938 delete [] localVERTq;
939 delete [] localVERTpp;
941 //*-*- failure return
943 delete [] localVERTs;
944 delete [] localVERTq;
945 delete [] localVERTpp;