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 "AliMUONTrack.h"
30 #include "AliMUONTrackReconstructor.h"
31 #include "AliMUONHitForRec.h"
32 #include "AliMUONSegment.h"
33 #include "AliMUONTrackHit.h"
34 #include "AliMUONTriggerTrack.h"
35 #include "AliMUONConstants.h"
39 #include <Riostream.h> // for cout
42 #include <TObjArray.h>
43 #include <TVirtualFitter.h>
45 #include <stdlib.h> // for exit()
47 // Functions to be minimized with Minuit
48 void TrackChi2(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag);
49 void TrackChi2MCS(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag);
51 void mnvertLocal(Double_t* a, Int_t l, Int_t m, Int_t n, Int_t& ifail);
53 Double_t MultipleScatteringAngle2(AliMUONTrackHit *TrackHit);
55 TVirtualFitter* AliMUONTrack::fgFitter = NULL;
57 ClassImp(AliMUONTrack) // Class implementation in ROOT context
59 //__________________________________________________________________________
60 AliMUONTrack::AliMUONTrack()
63 // Default constructor
65 fTrackReconstructor = 0;
66 fTrackHitsPtr = new TObjArray(10);
67 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
68 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
72 //__________________________________________________________________________
73 AliMUONTrack::AliMUONTrack(AliMUONSegment* BegSegment, AliMUONSegment* EndSegment, AliMUONTrackReconstructor* TrackReconstructor)
76 // Constructor from two Segment's
77 fTrackReconstructor = TrackReconstructor; // link back to TrackReconstructor
78 // memory allocation for the TObjArray of pointers to reconstructed TrackHit's
79 fTrackHitsPtr = new TObjArray(10);
81 AddSegment(BegSegment); // add hits from BegSegment
82 AddSegment(EndSegment); // add hits from EndSegment
83 fTrackHitsPtr->Sort(); // sort TrackHits according to increasing Z
84 SetTrackParamAtVertex(); // set track parameters at vertex
85 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
86 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
87 // set fit conditions...
92 fMatchTrigger = kFALSE;
93 fChi2MatchTrigger = 0;
98 //__________________________________________________________________________
99 AliMUONTrack::AliMUONTrack(AliMUONSegment* Segment, AliMUONHitForRec* HitForRec, AliMUONTrackReconstructor* TrackReconstructor)
102 // Constructor from one Segment and one HitForRec
103 fTrackReconstructor = TrackReconstructor; // link back to TrackReconstructor
104 // memory allocation for the TObjArray of pointers to reconstructed TrackHit's
105 fTrackHitsPtr = new TObjArray(10);
107 AddSegment(Segment); // add hits from Segment
108 AddHitForRec(HitForRec); // add HitForRec
109 fTrackHitsPtr->Sort(); // sort TrackHits according to increasing Z
110 SetTrackParamAtVertex(); // set track parameters at vertex
111 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
112 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
113 // set fit conditions...
118 fMatchTrigger = kFALSE;
119 fChi2MatchTrigger = 0;
124 //__________________________________________________________________________
125 AliMUONTrack::~AliMUONTrack()
129 // delete the TObjArray of pointers to TrackHit's
130 delete fTrackHitsPtr;
131 fTrackHitsPtr = NULL;
134 if (fTrackParamAtHit) {
135 // delete the TClonesArray of pointers to TrackParam
136 delete fTrackParamAtHit;
137 fTrackParamAtHit = NULL;
140 if (fHitForRecAtHit) {
141 // delete the TClonesArray of pointers to HitForRec
142 delete fHitForRecAtHit;
143 fHitForRecAtHit = NULL;
147 //__________________________________________________________________________
148 AliMUONTrack::AliMUONTrack (const AliMUONTrack& theMUONTrack)
149 : TObject(theMUONTrack)
151 //fTrackReconstructor = new AliMUONTrackReconstructor(*MUONTrack.fTrackReconstructor);
153 // NO, because it would use dummy copy constructor
154 // and AliMUONTrack is not the owner of its TrackReconstructor
155 fTrackReconstructor = theMUONTrack.fTrackReconstructor;
156 fTrackParamAtVertex = theMUONTrack.fTrackParamAtVertex;
158 // necessary to make a copy of the objects and not only the pointers in TObjArray.
159 fTrackHitsPtr = new TObjArray(10);
160 for (Int_t index = 0; index < (theMUONTrack.fTrackHitsPtr)->GetEntriesFast(); index++) {
161 AliMUONTrackHit *trackHit = new AliMUONTrackHit(*(AliMUONTrackHit*)(theMUONTrack.fTrackHitsPtr)->At(index));
162 fTrackHitsPtr->Add(trackHit);
164 fTrackHitsPtr->SetOwner(); // nedeed for deleting TClonesArray
166 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
167 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
168 for (Int_t index = 0; index < (theMUONTrack.fTrackParamAtHit)->GetEntriesFast(); index++) {
169 {new ((*fTrackParamAtHit)[fTrackParamAtHit->GetEntriesFast()])
170 AliMUONTrackParam(*(AliMUONTrackParam*)(theMUONTrack.fTrackParamAtHit)->At(index));}
173 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
174 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
175 for (Int_t index = 0; index < (theMUONTrack.fHitForRecAtHit)->GetEntriesFast(); index++) {
176 {new ((*fHitForRecAtHit)[fHitForRecAtHit->GetEntriesFast()])
177 AliMUONHitForRec(*(AliMUONHitForRec*)(theMUONTrack.fHitForRecAtHit)->At(index));}
180 fNTrackHits = theMUONTrack.fNTrackHits;
181 fFitMCS = theMUONTrack.fFitMCS;
182 fFitNParam = theMUONTrack.fFitNParam;
183 fFitFMin = theMUONTrack.fFitFMin;
184 fFitStart = theMUONTrack.fFitStart;
185 fMatchTrigger = theMUONTrack.fMatchTrigger;
186 fChi2MatchTrigger = theMUONTrack.fChi2MatchTrigger;
187 fTrackID = theMUONTrack.fTrackID;
190 //__________________________________________________________________________
191 AliMUONTrack & AliMUONTrack::operator=(const AliMUONTrack& theMUONTrack)
194 // check assignement to self
195 if (this == &theMUONTrack)
198 // base class assignement
199 TObject::operator=(theMUONTrack);
201 // fTrackReconstructor = new AliMUONTrackReconstructor(*MUONTrack.fTrackReconstructor);
203 // is it right ? NO because it would use dummy copy constructor
204 fTrackReconstructor = theMUONTrack.fTrackReconstructor;
205 fTrackParamAtVertex = theMUONTrack.fTrackParamAtVertex;
207 // necessary to make a copy of the objects and not only the pointers in TObjArray.
208 fTrackHitsPtr = new TObjArray(10);
209 for (Int_t index = 0; index < (theMUONTrack.fTrackHitsPtr)->GetEntriesFast(); index++) {
210 AliMUONTrackHit *trackHit = new AliMUONTrackHit(*(AliMUONTrackHit*)(theMUONTrack.fTrackHitsPtr)->At(index));
211 fTrackHitsPtr->Add(trackHit);
213 fTrackHitsPtr->SetOwner(); // nedeed for deleting TClonesArray
215 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
216 fTrackParamAtHit = new TClonesArray("AliMUONTrackParam",10);
217 for (Int_t index = 0; index < (theMUONTrack.fTrackParamAtHit)->GetEntriesFast(); index++) {
218 {new ((*fTrackParamAtHit)[fTrackParamAtHit->GetEntriesFast()])
219 AliMUONTrackParam(*(AliMUONTrackParam*)(theMUONTrack.fTrackParamAtHit)->At(index));}
222 // necessary to make a copy of the objects and not only the pointers in TClonesArray.
223 fHitForRecAtHit = new TClonesArray("AliMUONHitForRec",10);
224 for (Int_t index = 0; index < (theMUONTrack.fHitForRecAtHit)->GetEntriesFast(); index++) {
225 {new ((*fHitForRecAtHit)[fHitForRecAtHit->GetEntriesFast()])
226 AliMUONHitForRec(*(AliMUONHitForRec*)(theMUONTrack.fHitForRecAtHit)->At(index));}
229 fNTrackHits = theMUONTrack.fNTrackHits;
230 fFitMCS = theMUONTrack.fFitMCS;
231 fFitNParam = theMUONTrack.fFitNParam;
232 fFitFMin = theMUONTrack.fFitFMin;
233 fFitStart = theMUONTrack.fFitStart;
234 fMatchTrigger = theMUONTrack.fMatchTrigger;
235 fChi2MatchTrigger = theMUONTrack.fChi2MatchTrigger;
236 fTrackID = theMUONTrack.fTrackID;
241 //__________________________________________________________________________
242 void AliMUONTrack::Remove()
244 // Remove current track from array of tracks,
245 // and corresponding track hits from array of track hits.
246 // Compress the TClonesArray it belongs to.
247 AliMUONTrackHit *nextTrackHit;
248 AliMUONTrackReconstructor *eventRec = this->fTrackReconstructor;
249 TClonesArray *trackHitsPtr = eventRec->GetRecTrackHitsPtr();
250 // Loop over all track hits of track
251 AliMUONTrackHit *trackHit = (AliMUONTrackHit*) fTrackHitsPtr->First();
253 nextTrackHit = (AliMUONTrackHit*) fTrackHitsPtr->After(trackHit);
254 // Remove TrackHit from event TClonesArray.
255 // Destructor is called,
256 // hence links between HitForRec's and TrackHit's are updated
257 trackHitsPtr->Remove(trackHit);
258 trackHit = nextTrackHit;
260 // Remove the track from event TClonesArray
261 // Destructor is called,
262 // hence space for TObjArray of pointers to TrackHit's is freed
263 eventRec->GetRecTracksPtr()->Remove(this);
264 // Number of tracks decreased by 1
265 eventRec->SetNRecTracks(eventRec->GetNRecTracks() - 1);
266 // Compress event TClonesArray of Track's:
267 // this is essential to retrieve the TClonesArray afterwards
268 eventRec->GetRecTracksPtr()->Compress();
269 // Compress event TClonesArray of TrackHit's:
270 // this is probably also essential to retrieve the TClonesArray afterwards
271 trackHitsPtr->Compress();
274 //__________________________________________________________________________
275 void AliMUONTrack::SetFitMCS(Int_t FitMCS)
277 // Set multiple Coulomb scattering option for track fit "fFitMCS"
278 // from "FitMCS" argument: 0 without, 1 with
279 if ((FitMCS == 0) || (FitMCS == 1)) fFitMCS = FitMCS;
280 // better implementation with enum(with, without) ????
282 cout << "ERROR in AliMUONTrack::SetFitMCS(FitMCS)" << endl;
283 cout << "FitMCS = " << FitMCS << " is neither 0 nor 1" << endl;
289 //__________________________________________________________________________
290 void AliMUONTrack::SetFitNParam(Int_t FitNParam)
292 // Set number of parameters for track fit "fFitNParam" from "FitNParam":
293 // 3 for momentum, 5 for momentum and position
294 if ((FitNParam == 3) || (FitNParam == 5)) fFitNParam = FitNParam;
296 cout << "ERROR in AliMUONTrack::SetFitNParam(FitNParam)" << endl;
297 cout << "FitNParam = " << FitNParam << " is neither 3 nor 5" << endl;
303 //__________________________________________________________________________
304 void AliMUONTrack::SetFitStart(Int_t FitStart)
306 // Set multiple Coulomb scattering option for track fit "fFitStart"
307 // from "FitStart" argument: 0 without, 1 with
308 if ((FitStart == 0) || (FitStart == 1)) fFitStart = FitStart;
309 // better implementation with enum(vertex, firstHit) ????
311 cout << "ERROR in AliMUONTrack::SetFitStart(FitStart)" << endl;
312 cout << "FitStart = " << FitStart << " is neither 0 nor 1" << endl;
318 //__________________________________________________________________________
319 AliMUONTrackParam* AliMUONTrack::GetTrackParamAtFirstHit(void) const {
320 // Get pointer to TrackParamAtFirstHit
321 return ((AliMUONTrackHit*) (fTrackHitsPtr->First()))->GetTrackParam();}
323 //__________________________________________________________________________
324 void AliMUONTrack::RecursiveDump(void) const
326 // Recursive dump of AliMUONTrack, i.e. with dump of TrackHit's and HitForRec's
327 AliMUONTrackHit *trackHit;
328 AliMUONHitForRec *hitForRec;
329 cout << "Recursive dump of Track: " << this << endl;
332 for (Int_t trackHitIndex = 0; trackHitIndex < fNTrackHits; trackHitIndex++) {
333 trackHit = (AliMUONTrackHit*) ((*fTrackHitsPtr)[trackHitIndex]);
335 cout << "TrackHit: " << trackHit << " (index: " << trackHitIndex << ")" << endl;
337 hitForRec = trackHit->GetHitForRecPtr();
339 cout << "HitForRec: " << hitForRec << endl;
345 //__________________________________________________________________________
346 Bool_t* AliMUONTrack::CompatibleTrack(AliMUONTrack * Track, Double_t Sigma2Cut) const
348 // Return kTRUE/kFALSE for each chamber if hit is compatible or not
349 TClonesArray *hitArray, *thisHitArray;
350 AliMUONHitForRec *hit, *thisHit;
353 Float_t deltaZMax = 1.; // 1 cm
355 Bool_t *nCompHit = new Bool_t[AliMUONConstants::NTrackingCh()];
357 for ( Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) {
358 nCompHit[ch] = kFALSE;
361 thisHitArray = this->GetHitForRecAtHit();
363 hitArray = Track->GetHitForRecAtHit();
365 for (Int_t iHthis = 0; iHthis < thisHitArray->GetEntriesFast(); iHthis++) {
366 thisHit = (AliMUONHitForRec*) thisHitArray->At(iHthis);
367 chamberNumber = thisHit->GetChamberNumber();
368 if (chamberNumber < 0 || chamberNumber > AliMUONConstants::NTrackingCh()) continue;
369 nCompHit[chamberNumber] = kFALSE;
370 for (Int_t iH = 0; iH < hitArray->GetEntriesFast(); iH++) {
371 hit = (AliMUONHitForRec*) hitArray->At(iH);
372 deltaZ = TMath::Abs(thisHit->GetZ() - hit->GetZ());
373 chi2 = thisHit->NormalizedChi2WithHitForRec(hit,Sigma2Cut); // set cut to 4 sigmas
374 if (chi2 < 3. && deltaZ < deltaZMax) {
375 nCompHit[chamberNumber] = kTRUE;
384 //__________________________________________________________________________
385 Int_t AliMUONTrack::HitsInCommon(AliMUONTrack* Track) const
387 // Returns the number of hits in common
388 // between the current track ("this")
389 // and the track pointed to by "Track".
390 Int_t hitsInCommon = 0;
391 AliMUONTrackHit *trackHit1, *trackHit2;
392 // Loop over hits of first track
393 trackHit1 = (AliMUONTrackHit*) this->GetTrackHitsPtr()->First();
395 // Loop over hits of second track
396 trackHit2 = (AliMUONTrackHit*) Track->GetTrackHitsPtr()->First();
398 // Increment "hitsInCommon" if both TrackHits point to the same HitForRec
399 if ( (trackHit1->GetHitForRecPtr()) ==
400 (trackHit2->GetHitForRecPtr()) ) hitsInCommon++;
401 trackHit2 = (AliMUONTrackHit*) Track->GetTrackHitsPtr()->After(trackHit2);
403 trackHit1 = (AliMUONTrackHit*) this->GetTrackHitsPtr()->After(trackHit1);
408 //__________________________________________________________________________
409 void AliMUONTrack::MatchTriggerTrack(TClonesArray *triggerTrackArray)
411 // Match this track with one trigger track if possible
412 AliMUONTrackParam trackParam;
413 AliMUONTriggerTrack *triggerTrack;
414 Double_t xTrack, yTrack, ySlopeTrack, dTrigTrackMin2, dTrigTrack2;
417 Double_t distSigma[3]={1,1,0.02}; // sigma of distributions (trigger-track) X,Y,slopeY
418 Double_t distTriggerTrack[3] = {0,0,0};
420 fMatchTrigger = kFALSE;
421 fChi2MatchTrigger = 0;
423 trackParam = *((AliMUONTrackParam*) fTrackParamAtHit->Last());
424 trackParam.ExtrapToZ(AliMUONConstants::DefaultChamberZ(10)); // extrap to 1st trigger chamber
426 nSigmaCut2 = fTrackReconstructor->GetMaxSigma2Distance(); // nb of sigma**2 for cut
427 xTrack = trackParam.GetNonBendingCoor();
428 yTrack = trackParam.GetBendingCoor();
429 ySlopeTrack = trackParam.GetBendingSlope();
430 dTrigTrackMin2 = 999;
432 triggerTrack = (AliMUONTriggerTrack*) triggerTrackArray->First();
434 distTriggerTrack[0] = (triggerTrack->GetX11()-xTrack)/distSigma[0];
435 distTriggerTrack[1] = (triggerTrack->GetY11()-yTrack)/distSigma[1];
436 distTriggerTrack[2] = (TMath::Tan(triggerTrack->GetThetay())-ySlopeTrack)/distSigma[2];
438 for (Int_t iVar = 0; iVar < 3; iVar++)
439 dTrigTrack2 += distTriggerTrack[iVar]*distTriggerTrack[iVar];
440 if (dTrigTrack2 < dTrigTrackMin2 && dTrigTrack2 < nSigmaCut2) {
441 dTrigTrackMin2 = dTrigTrack2;
442 fMatchTrigger = kTRUE;
443 fChi2MatchTrigger = dTrigTrack2/3.; // Normalized Chi2, 3 variables (X,Y,slopeY)
445 triggerTrack = (AliMUONTriggerTrack*) triggerTrackArray->After(triggerTrack);
449 //__________________________________________________________________________
450 void AliMUONTrack::Fit()
452 // Fit the current track ("this"),
453 // with or without multiple Coulomb scattering according to "fFitMCS",
454 // with the number of parameters given by "fFitNParam"
455 // (3 if one keeps X and Y fixed in "TrackParam", 5 if one lets them vary),
456 // starting, according to "fFitStart",
457 // with track parameters at vertex or at the first TrackHit.
458 // "fFitMCS", "fFitNParam" and "fFitStart" have to be set before
459 // by calling the corresponding Set methods.
460 Double_t arg[1], benC, errorParam, invBenP, lower, nonBenC, upper, x, y;
462 AliMUONTrackParam *trackParam;
463 // Check if Minuit is initialized...
464 fgFitter = TVirtualFitter::Fitter(this); // add 3 or 5 for the maximum number of parameters ???
465 fgFitter->Clear(); // necessary ???? probably yes
466 // how to reset the printout number at every fit ????
467 // is there any risk to leave it like that ????
468 // how to go faster ???? choice of Minuit parameters like EDM ????
469 // choice of function to be minimized according to fFitMCS
470 if (fFitMCS == 0) fgFitter->SetFCN(TrackChi2);
471 else fgFitter->SetFCN(TrackChi2MCS);
472 // Switch off printout
474 fgFitter->ExecuteCommand("SET PRINT", arg, 1); // More printing !!!!
476 fgFitter->ExecuteCommand("SET NOW", arg, 0);
477 // Parameters according to "fFitStart"
478 // (should be a function to be used at every place where needed ????)
479 if (fFitStart == 0) trackParam = &fTrackParamAtVertex;
480 else trackParam = this->GetTrackParamAtFirstHit();
481 // set first 3 Minuit parameters
482 // could be tried with no limits for the search (min=max=0) ????
483 fgFitter->SetParameter(0, "InvBenP",
484 trackParam->GetInverseBendingMomentum(),
486 fgFitter->SetParameter(1, "BenS",
487 trackParam->GetBendingSlope(),
489 fgFitter->SetParameter(2, "NonBenS",
490 trackParam->GetNonBendingSlope(),
492 if (fFitNParam == 5) {
493 // set last 2 Minuit parameters
494 // mandatory limits in Bending to avoid NaN values of parameters
495 fgFitter->SetParameter(3, "X",
496 trackParam->GetNonBendingCoor(),
497 0.03, -500.0, 500.0);
498 // mandatory limits in non Bending to avoid NaN values of parameters
499 fgFitter->SetParameter(4, "Y",
500 trackParam->GetBendingCoor(),
501 0.10, -500.0, 500.0);
503 // search without gradient calculation in the function
504 fgFitter->ExecuteCommand("SET NOGRADIENT", arg, 0);
506 fgFitter->ExecuteCommand("MINIMIZE", arg, 0);
508 // fgFitter->ExecuteCommand("EXIT", arg, 0); // necessary ????
509 // get results into "invBenP", "benC", "nonBenC" ("x", "y")
510 fgFitter->GetParameter(0, parName, invBenP, errorParam, lower, upper);
511 fgFitter->GetParameter(1, parName, benC, errorParam, lower, upper);
512 fgFitter->GetParameter(2, parName, nonBenC, errorParam, lower, upper);
513 if (fFitNParam == 5) {
514 fgFitter->GetParameter(3, parName, x, errorParam, lower, upper);
515 fgFitter->GetParameter(4, parName, y, errorParam, lower, upper);
517 // result of the fit into track parameters
518 trackParam->SetInverseBendingMomentum(invBenP);
519 trackParam->SetBendingSlope(benC);
520 trackParam->SetNonBendingSlope(nonBenC);
521 if (fFitNParam == 5) {
522 trackParam->SetNonBendingCoor(x);
523 trackParam->SetBendingCoor(y);
525 // global result of the fit
526 Double_t fedm, errdef;
528 fgFitter->GetStats(fFitFMin, fedm, errdef, npari, nparx);
531 //__________________________________________________________________________
532 void AliMUONTrack::AddSegment(AliMUONSegment* Segment)
534 // Add Segment to the track
535 AddHitForRec(Segment->GetHitForRec1()); // 1st hit
536 AddHitForRec(Segment->GetHitForRec2()); // 2nd hit
539 //__________________________________________________________________________
540 void AliMUONTrack::AddHitForRec(AliMUONHitForRec* HitForRec)
542 // Add HitForRec to the track:
543 // actual TrackHit into TClonesArray of TrackHit's for the event;
544 // pointer to actual TrackHit in TObjArray of pointers to TrackHit's for the track
545 TClonesArray *recTrackHitsPtr = this->fTrackReconstructor->GetRecTrackHitsPtr();
546 Int_t eventTrackHits = this->fTrackReconstructor->GetNRecTrackHits();
548 AliMUONTrackHit* trackHit =
549 new ((*recTrackHitsPtr)[eventTrackHits]) AliMUONTrackHit(HitForRec);
550 this->fTrackReconstructor->SetNRecTrackHits(eventTrackHits + 1);
552 if (fTrackHitsPtr->IsOwner()) AliFatal("fTrackHitsPtr is owner");
553 fTrackHitsPtr->Add(trackHit);
557 //__________________________________________________________________________
558 void AliMUONTrack::SetTrackParamAtHit(Int_t indexHit, AliMUONTrackParam *TrackParam) const
560 // Set track parameters at TrackHit with index "indexHit"
561 // from the track parameters pointed to by "TrackParam".
562 //PH AliMUONTrackHit* trackHit = (AliMUONTrackHit*) ((*fTrackHitsPtr)[indexHit]);
563 AliMUONTrackHit* trackHit = (AliMUONTrackHit*) (fTrackHitsPtr->At(indexHit));
564 trackHit->SetTrackParam(TrackParam);
567 //__________________________________________________________________________
568 void AliMUONTrack::SetTrackParamAtVertex()
570 // Set track parameters at vertex.
571 // TrackHit's are assumed to be only in stations(1..) 4 and 5,
572 // and sorted according to increasing Z..
573 // Parameters are calculated from information in HitForRec's
574 // of first and last TrackHit's.
575 AliMUONTrackParam *trackParam =
576 &fTrackParamAtVertex; // pointer to track parameters
577 // Pointer to HitForRec of first TrackHit
578 AliMUONHitForRec *firstHit =
579 ((AliMUONTrackHit*) (fTrackHitsPtr->First()))->GetHitForRecPtr();
580 // Pointer to HitForRec of last TrackHit
581 AliMUONHitForRec *lastHit =
582 ((AliMUONTrackHit*) (fTrackHitsPtr->Last()))->GetHitForRecPtr();
583 // Z difference between first and last hits
584 Double_t deltaZ = firstHit->GetZ() - lastHit->GetZ();
585 // bending slope in stations(1..) 4 and 5
586 Double_t bendingSlope =
587 (firstHit->GetBendingCoor() - lastHit->GetBendingCoor()) / deltaZ;
588 trackParam->SetBendingSlope(bendingSlope);
590 Double_t impactParam =
591 firstHit->GetBendingCoor() - bendingSlope * firstHit->GetZ(); // same if from firstHit and lastHit ????
592 // signed bending momentum
593 Double_t signedBendingMomentum =
594 fTrackReconstructor->GetBendingMomentumFromImpactParam(impactParam);
595 trackParam->SetInverseBendingMomentum(1.0 / signedBendingMomentum);
596 // bending slope at vertex
598 SetBendingSlope(bendingSlope +
599 impactParam / fTrackReconstructor->GetSimpleBPosition());
601 Double_t nonBendingSlope =
602 (firstHit->GetNonBendingCoor() - lastHit->GetNonBendingCoor()) / deltaZ;
603 trackParam->SetNonBendingSlope(nonBendingSlope);
604 // vertex coordinates at (0,0,0)
605 trackParam->SetZ(0.0);
606 trackParam->SetBendingCoor(0.0);
607 trackParam->SetNonBendingCoor(0.0);
610 //__________________________________________________________________________
611 void TrackChi2(Int_t &NParam, Double_t * /*Gradient*/, Double_t &Chi2, Double_t *Param, Int_t /*Flag*/)
613 // Return the "Chi2" to be minimized with Minuit for track fitting,
614 // with "NParam" parameters
615 // and their current values in array pointed to by "Param".
616 // Assumes that the track hits are sorted according to increasing Z.
617 // Track parameters at each TrackHit are updated accordingly.
618 // Multiple Coulomb scattering is not taken into account
619 AliMUONTrack *trackBeingFitted;
620 AliMUONTrackHit* hit;
621 AliMUONTrackParam param1;
624 Chi2 = 0.0; // initialize Chi2
625 // copy of track parameters to be fitted
626 trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit();
627 if (trackBeingFitted->GetFitStart() == 0)
628 param1 = *(trackBeingFitted->GetTrackParamAtVertex());
629 else param1 = *(trackBeingFitted->GetTrackParamAtFirstHit());
630 // Minuit parameters to be fitted into this copy
631 param1.SetInverseBendingMomentum(Param[0]);
632 param1.SetBendingSlope(Param[1]);
633 param1.SetNonBendingSlope(Param[2]);
635 param1.SetNonBendingCoor(Param[3]);
636 param1.SetBendingCoor(Param[4]);
638 // Follow track through all planes of track hits
639 for (hitNumber = 0; hitNumber < trackBeingFitted->GetNTrackHits(); hitNumber++) {
640 hit = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber];
641 zHit = hit->GetHitForRecPtr()->GetZ();
642 // do something special if 2 hits with same Z ????
643 // security against infinite loop ????
644 (¶m1)->ExtrapToZ(zHit); // extrapolation
645 hit->SetTrackParam(¶m1);
647 // done hit per hit, with hit resolution,
648 // and not with point and angle like in "reco_muon.F" !!!!
649 // Needs to add multiple scattering contribution ????
651 hit->GetHitForRecPtr()->GetNonBendingCoor() - (¶m1)->GetNonBendingCoor();
653 hit->GetHitForRecPtr()->GetBendingCoor() - (¶m1)->GetBendingCoor();
656 dX * dX / hit->GetHitForRecPtr()->GetNonBendingReso2() +
657 dY * dY / hit->GetHitForRecPtr()->GetBendingReso2();
661 //__________________________________________________________________________
662 void TrackChi2MCS(Int_t &NParam, Double_t * /*Gradient*/, Double_t &Chi2, Double_t *Param, Int_t /*Flag*/)
664 // Return the "Chi2" to be minimized with Minuit for track fitting,
665 // with "NParam" parameters
666 // and their current values in array pointed to by "Param".
667 // Assumes that the track hits are sorted according to increasing Z.
668 // Track parameters at each TrackHit are updated accordingly.
669 // Multiple Coulomb scattering is taken into account with covariance matrix.
670 AliMUONTrack *trackBeingFitted;
671 AliMUONTrackParam param1;
672 Chi2 = 0.0; // initialize Chi2
673 // copy of track parameters to be fitted
674 trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit();
675 if (trackBeingFitted->GetFitStart() == 0)
676 param1 = *(trackBeingFitted->GetTrackParamAtVertex());
677 else param1 = *(trackBeingFitted->GetTrackParamAtFirstHit());
678 // Minuit parameters to be fitted into this copy
679 param1.SetInverseBendingMomentum(Param[0]);
680 param1.SetBendingSlope(Param[1]);
681 param1.SetNonBendingSlope(Param[2]);
683 param1.SetNonBendingCoor(Param[3]);
684 param1.SetBendingCoor(Param[4]);
687 AliMUONTrackHit *hit;
688 Int_t chCurrent, chPrev = 0, hitNumber, hitNumber1, hitNumber2, hitNumber3;
689 Double_t z, z1, z2, z3;
690 AliMUONTrackHit *hit1, *hit2, *hit3;
691 Double_t hbc1, hbc2, pbc1, pbc2;
692 Double_t hnbc1, hnbc2, pnbc1, pnbc2;
693 Int_t numberOfHit = trackBeingFitted->GetNTrackHits();
694 TMatrixD *covBending = new TMatrixD(numberOfHit, numberOfHit);
695 TMatrixD *covNonBending = new TMatrixD(numberOfHit, numberOfHit);
696 Double_t *msa2 = new Double_t[numberOfHit];
698 // Predicted coordinates and multiple scattering angles are first calculated
699 for (hitNumber = 0; hitNumber < numberOfHit; hitNumber++) {
700 hit = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber];
701 z = hit->GetHitForRecPtr()->GetZ();
702 // do something special if 2 hits with same Z ????
703 // security against infinite loop ????
704 (¶m1)->ExtrapToZ(z); // extrapolation
705 hit->SetTrackParam(¶m1);
706 // square of multiple scattering angle at current hit, with one chamber
707 msa2[hitNumber] = MultipleScatteringAngle2(hit);
708 // correction for eventual missing hits or multiple hits in a chamber,
709 // according to the number of chambers
710 // between the current hit and the previous one
711 chCurrent = hit->GetHitForRecPtr()->GetChamberNumber();
712 if (hitNumber > 0) msa2[hitNumber] = msa2[hitNumber] * (chCurrent - chPrev);
716 // Calculates the covariance matrix
717 for (hitNumber1 = 0; hitNumber1 < numberOfHit; hitNumber1++) {
718 hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1];
719 z1 = hit1->GetHitForRecPtr()->GetZ();
720 for (hitNumber2 = hitNumber1; hitNumber2 < numberOfHit; hitNumber2++) {
721 hit2 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber2];
722 z2 = hit2->GetHitForRecPtr()->GetZ();
723 // initialization to 0 (diagonal plus upper triangular part)
724 (*covBending)(hitNumber2, hitNumber1) = 0.0;
725 // contribution from multiple scattering in bending plane:
726 // loop over upstream hits
727 for (hitNumber3 = 0; hitNumber3 < hitNumber1; hitNumber3++) {
728 hit3 = (AliMUONTrackHit*)
729 (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber3];
730 z3 = hit3->GetHitForRecPtr()->GetZ();
731 (*covBending)(hitNumber2, hitNumber1) =
732 (*covBending)(hitNumber2, hitNumber1) +
733 ((z1 - z3) * (z2 - z3) * msa2[hitNumber3]);
735 // equal contribution from multiple scattering in non bending plane
736 (*covNonBending)(hitNumber2, hitNumber1) =
737 (*covBending)(hitNumber2, hitNumber1);
738 if (hitNumber1 == hitNumber2) {
739 // Diagonal elements: add contribution from position measurements
741 (*covBending)(hitNumber2, hitNumber1) =
742 (*covBending)(hitNumber2, hitNumber1) +
743 hit1->GetHitForRecPtr()->GetBendingReso2();
744 // and in non bending plane
745 (*covNonBending)(hitNumber2, hitNumber1) =
746 (*covNonBending)(hitNumber2, hitNumber1) +
747 hit1->GetHitForRecPtr()->GetNonBendingReso2();
750 // Non diagonal elements: symmetrization
752 (*covBending)(hitNumber1, hitNumber2) =
753 (*covBending)(hitNumber2, hitNumber1);
754 // and non bending plane
755 (*covNonBending)(hitNumber1, hitNumber2) =
756 (*covNonBending)(hitNumber2, hitNumber1);
758 } // for (hitNumber2 = hitNumber1;...
759 } // for (hitNumber1 = 0;...
761 // Inversion of covariance matrices
762 // with "mnvertLocal", local "mnvert" function of Minuit.
763 // One cannot use directly "mnvert" since "TVirtualFitter" does not know it.
764 // One will have to replace this local function by the right inversion function
765 // from a specialized Root package for symmetric positive definite matrices,
766 // when available!!!!
768 mnvertLocal(&((*covBending)(0,0)), numberOfHit, numberOfHit, numberOfHit,
770 Int_t ifailNonBending;
771 mnvertLocal(&((*covNonBending)(0,0)), numberOfHit, numberOfHit, numberOfHit,
774 // It would be worth trying to calculate the inverse of the covariance matrix
775 // only once per fit, since it cannot change much in principle,
776 // and it would save a lot of computing time !!!!
779 if ((ifailBending == 0) && (ifailNonBending == 0)) {
780 // with Multiple Scattering if inversion correct
781 for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) {
782 hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1];
783 hbc1 = hit1->GetHitForRecPtr()->GetBendingCoor();
784 pbc1 = hit1->GetTrackParam()->GetBendingCoor();
785 hnbc1 = hit1->GetHitForRecPtr()->GetNonBendingCoor();
786 pnbc1 = hit1->GetTrackParam()->GetNonBendingCoor();
787 for (hitNumber2 = 0; hitNumber2 < numberOfHit; hitNumber2++) {
788 hit2 = (AliMUONTrackHit*)
789 (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber2];
790 hbc2 = hit2->GetHitForRecPtr()->GetBendingCoor();
791 pbc2 = hit2->GetTrackParam()->GetBendingCoor();
792 hnbc2 = hit2->GetHitForRecPtr()->GetNonBendingCoor();
793 pnbc2 = hit2->GetTrackParam()->GetNonBendingCoor();
795 ((*covBending)(hitNumber2, hitNumber1) *
796 (hbc1 - pbc1) * (hbc2 - pbc2)) +
797 ((*covNonBending)(hitNumber2, hitNumber1) *
798 (hnbc1 - pnbc1) * (hnbc2 - pnbc2));
802 // without Multiple Scattering if inversion impossible
803 for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) {
804 hit1 = (AliMUONTrackHit*) (*(trackBeingFitted->GetTrackHitsPtr()))[hitNumber1];
805 hbc1 = hit1->GetHitForRecPtr()->GetBendingCoor();
806 pbc1 = hit1->GetTrackParam()->GetBendingCoor();
807 hnbc1 = hit1->GetHitForRecPtr()->GetNonBendingCoor();
808 pnbc1 = hit1->GetTrackParam()->GetNonBendingCoor();
810 ((hbc1 - pbc1) * (hbc1 - pbc1) /
811 hit1->GetHitForRecPtr()->GetBendingReso2()) +
812 ((hnbc1 - pnbc1) * (hnbc1 - pnbc1) /
813 hit1->GetHitForRecPtr()->GetNonBendingReso2());
818 delete covNonBending;
822 Double_t MultipleScatteringAngle2(AliMUONTrackHit *TrackHit)
824 // Returns square of multiple Coulomb scattering angle
825 // at TrackHit pointed to by "TrackHit"
826 Double_t slopeBending, slopeNonBending, radiationLength, inverseBendingMomentum2, inverseTotalMomentum2;
827 Double_t varMultipleScatteringAngle;
828 AliMUONTrack *trackBeingFitted = (AliMUONTrack*) AliMUONTrack::Fitter()->GetObjectFit();
829 AliMUONTrackParam *param = TrackHit->GetTrackParam();
830 // Better implementation in AliMUONTrack class ????
831 slopeBending = param->GetBendingSlope();
832 slopeNonBending = param->GetNonBendingSlope();
833 // thickness in radiation length for the current track,
834 // taking local angle into account
836 trackBeingFitted->GetTrackReconstructor()->GetChamberThicknessInX0() *
838 slopeBending * slopeBending + slopeNonBending * slopeNonBending);
839 inverseBendingMomentum2 =
840 param->GetInverseBendingMomentum() * param->GetInverseBendingMomentum();
841 inverseTotalMomentum2 =
842 inverseBendingMomentum2 * (1.0 + slopeBending * slopeBending) /
843 (1.0 + slopeBending *slopeBending + slopeNonBending * slopeNonBending);
844 varMultipleScatteringAngle = 0.0136 * (1.0 + 0.038 * TMath::Log(radiationLength));
845 // The velocity is assumed to be 1 !!!!
846 varMultipleScatteringAngle = inverseTotalMomentum2 * radiationLength *
847 varMultipleScatteringAngle * varMultipleScatteringAngle;
848 return varMultipleScatteringAngle;
851 //______________________________________________________________________________
852 void mnvertLocal(Double_t *a, Int_t l, Int_t, Int_t n, Int_t &ifail)
854 //*-*-*-*-*-*-*-*-*-*-*-*Inverts a symmetric matrix*-*-*-*-*-*-*-*-*-*-*-*-*
855 //*-* ==========================
856 //*-* inverts a symmetric matrix. matrix is first scaled to
857 //*-* have all ones on the diagonal (equivalent to change of units)
858 //*-* but no pivoting is done since matrix is positive-definite.
859 //*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
861 // taken from TMinuit package of Root (l>=n)
862 // fVERTs, fVERTq and fVERTpp changed to localVERTs, localVERTq and localVERTpp
863 // Double_t localVERTs[n], localVERTq[n], localVERTpp[n];
864 Double_t * localVERTs = new Double_t[n];
865 Double_t * localVERTq = new Double_t[n];
866 Double_t * localVERTpp = new Double_t[n];
867 // fMaxint changed to localMaxint
868 Int_t localMaxint = n;
870 /* System generated locals */
873 /* Local variables */
875 Int_t i, j, k, kp1, km1;
877 /* Parameter adjustments */
883 if (n < 1) goto L100;
884 if (n > localMaxint) goto L100;
885 //*-*- scale matrix by sqrt of diag elements
886 for (i = 1; i <= n; ++i) {
888 if (si <= 0) goto L100;
889 localVERTs[i-1] = 1 / TMath::Sqrt(si);
891 for (i = 1; i <= n; ++i) {
892 for (j = 1; j <= n; ++j) {
893 a[i + j*l] = a[i + j*l]*localVERTs[i-1]*localVERTs[j-1];
896 //*-*- . . . start main loop . . . .
897 for (i = 1; i <= n; ++i) {
899 //*-*- preparation for elimination step1
900 if (a[k + k*l] != 0) localVERTq[k-1] = 1 / a[k + k*l];
902 localVERTpp[k-1] = 1;
906 if (km1 < 0) goto L100;
907 else if (km1 == 0) goto L50;
910 for (j = 1; j <= km1; ++j) {
911 localVERTpp[j-1] = a[j + k*l];
912 localVERTq[j-1] = a[j + k*l]*localVERTq[k-1];
916 if (k - n < 0) goto L51;
917 else if (k - n == 0) goto L60;
920 for (j = kp1; j <= n; ++j) {
921 localVERTpp[j-1] = a[k + j*l];
922 localVERTq[j-1] = -a[k + j*l]*localVERTq[k-1];
925 //*-*- elimination proper
927 for (j = 1; j <= n; ++j) {
928 for (k = j; k <= n; ++k) { a[j + k*l] += localVERTpp[j-1]*localVERTq[k-1]; }
931 //*-*- elements of left diagonal and unscaling
932 for (j = 1; j <= n; ++j) {
933 for (k = 1; k <= j; ++k) {
934 a[k + j*l] = a[k + j*l]*localVERTs[k-1]*localVERTs[j-1];
935 a[j + k*l] = a[k + j*l];
938 delete [] localVERTs;
939 delete [] localVERTq;
940 delete [] localVERTpp;
942 //*-*- failure return
944 delete [] localVERTs;
945 delete [] localVERTq;
946 delete [] localVERTpp;