Conding conventions violation and Doxygen comments (Philippe Pillot)
[u/mrichter/AliRoot.git] / MUON / AliMUONTrackReconstructor.cxx
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a9e2aefa 1/**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
3 * *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
6 * *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
15
cc87ebcd 16/* $Id$ */
17
3831f268 18////////////////////////////////////
a9e2aefa 19//
2457f726 20// MUON track reconstructor using the original method
a9e2aefa 21//
22// This class contains as data:
29f1b13a 23// * the parameters for the track reconstruction
a9e2aefa 24//
25// It contains as methods, among others:
a9e2aefa 26// * MakeTracks to build the tracks
3831f268 27//
28////////////////////////////////////
a9e2aefa 29
ae17f568 30#include <stdlib.h>
30178c30 31#include <Riostream.h>
cc87ebcd 32#include <TMatrixD.h>
a9e2aefa 33
2457f726 34#include "AliMUONVTrackReconstructor.h"
29f1b13a 35#include "AliMUONTrackReconstructor.h"
5e671e06 36#include "AliMUONData.h"
29fc2c86 37#include "AliMUONConstants.h"
a9e2aefa 38#include "AliMUONRawCluster.h"
2457f726 39#include "AliMUONHitForRec.h"
3831f268 40#include "AliMUONSegment.h"
a9e2aefa 41#include "AliMUONTrack.h"
8c343c7c 42#include "AliLog.h"
de2cd600 43#include <TVirtualFitter.h>
a9e2aefa 44
de2cd600 45// Functions to be minimized with Minuit
46void TrackChi2(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag);
47void TrackChi2MCS(Int_t &NParam, Double_t *Gradient, Double_t &Chi2, Double_t *Param, Int_t Flag);
48
49void mnvertLocal(Double_t* a, Int_t l, Int_t m, Int_t n, Int_t& ifail);
50
51Double_t MultipleScatteringAngle2(AliMUONTrackParam *param);
52
29f1b13a 53ClassImp(AliMUONTrackReconstructor) // Class implementation in ROOT context
a9e2aefa 54
2457f726 55//************* Defaults parameters for reconstruction
56const Double_t AliMUONTrackReconstructor::fgkDefaultMaxChi2 = 100.0;
57
58TVirtualFitter* AliMUONTrackReconstructor::fgFitter = 0x0;
59
3bc8b580 60//__________________________________________________________________________
cc9e7528 61AliMUONTrackReconstructor::AliMUONTrackReconstructor(AliMUONData* data)
2457f726 62 : AliMUONVTrackReconstructor(data),
63 fMaxChi2(fgkDefaultMaxChi2)
a9e2aefa 64{
2457f726 65 /// Constructor for class AliMUONTrackReconstructor
de2cd600 66
a9e2aefa 67 // Memory allocation for the TClonesArray of reconstructed tracks
a9e2aefa 68 fRecTracksPtr = new TClonesArray("AliMUONTrack", 10);
a9e2aefa 69}
9cbdf048 70
a9e2aefa 71 //__________________________________________________________________________
29f1b13a 72AliMUONTrackReconstructor::~AliMUONTrackReconstructor(void)
a9e2aefa 73{
2457f726 74 /// Destructor for class AliMUONTrackReconstructor
de2cd600 75 delete fRecTracksPtr;
a9e2aefa 76}
a9e2aefa 77
78 //__________________________________________________________________________
2457f726 79void AliMUONTrackReconstructor::AddHitsForRecFromRawClusters()
a9e2aefa 80{
2457f726 81 /// To add to the list of hits for reconstruction all the raw clusters
82 TTree *TR = fMUONData->TreeR();
a9e2aefa 83 AliMUONHitForRec *hitForRec;
84 AliMUONRawCluster *clus;
f69d51b5 85 Int_t iclus, nclus, nTRentries;
a9e2aefa 86 TClonesArray *rawclusters;
b840996b 87 AliDebug(1,"Enter AddHitsForRecFromRawClusters");
2457f726 88
89 fMUONData->SetTreeAddress("RC");
90 nTRentries = Int_t(TR->GetEntries());
91 if (nTRentries != 1) {
92 AliError(Form("nTRentries = %d not equal to 1 ",nTRentries));
93 exit(0);
f69d51b5 94 }
2457f726 95 fMUONData->GetRawClusters(); // only one entry
96
a9e2aefa 97 // Loop over tracking chambers
190f97ea 98 for (Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) {
a9e2aefa 99 // number of HitsForRec to 0 for the chamber
100 fNHitsForRecPerChamber[ch] = 0;
101 // index of first HitForRec for the chamber
102 if (ch == 0) fIndexOfFirstHitForRecPerChamber[ch] = 0;
103 else fIndexOfFirstHitForRecPerChamber[ch] = fNHitsForRec;
52c9bc11 104 rawclusters =fMUONData->RawClusters(ch);
a9e2aefa 105 nclus = (Int_t) (rawclusters->GetEntries());
106 // Loop over (cathode correlated) raw clusters
107 for (iclus = 0; iclus < nclus; iclus++) {
108 clus = (AliMUONRawCluster*) rawclusters->UncheckedAt(iclus);
109 // new AliMUONHitForRec from raw cluster
110 // and increment number of AliMUONHitForRec's (total and in chamber)
111 hitForRec = new ((*fHitsForRecPtr)[fNHitsForRec]) AliMUONHitForRec(clus);
112 fNHitsForRec++;
113 (fNHitsForRecPerChamber[ch])++;
114 // more information into HitForRec
fff097e0 115 hitForRec->SetBendingReso2(clus->GetErrY() * clus->GetErrY());
116 hitForRec->SetNonBendingReso2(clus->GetErrX() * clus->GetErrX());
a9e2aefa 117 // original raw cluster
118 hitForRec->SetChamberNumber(ch);
119 hitForRec->SetHitNumber(iclus);
ba5b68db 120 // Z coordinate of the raw cluster (cm)
ba12c242 121 hitForRec->SetZ(clus->GetZ(0));
80e33fc5 122
123 StdoutToAliDebug(3,
124 cout << "Chamber " << ch <<
125 " raw cluster " << iclus << " : " << endl;
126 clus->Print("full");
127 cout << "AliMUONHitForRec number (1...): " << fNHitsForRec << endl;
128 hitForRec->Print("full");
129 );
a9e2aefa 130 } // end of cluster loop
131 } // end of chamber loop
cc87ebcd 132 SortHitsForRecWithIncreasingChamber();
2457f726 133
134 AliDebug(1,"End of AddHitsForRecFromRawClusters");
135 if (AliLog::GetGlobalDebugLevel() > 0) {
136 AliDebug(1, Form("NHitsForRec: %d",fNHitsForRec));
137 for (Int_t ch = 0; ch < AliMUONConstants::NTrackingCh(); ch++) {
138 AliDebug(1, Form("Chamber(0...): %d",ch));
139 AliDebug(1, Form("NHitsForRec: %d", fNHitsForRecPerChamber[ch]));
140 AliDebug(1, Form("Index(first HitForRec): %d", fIndexOfFirstHitForRecPerChamber[ch]));
141 for (Int_t hit = fIndexOfFirstHitForRecPerChamber[ch];
142 hit < fIndexOfFirstHitForRecPerChamber[ch] + fNHitsForRecPerChamber[ch];
143 hit++) {
144 AliDebug(1, Form("HitForRec index(0...): %d",hit));
145 ((*fHitsForRecPtr)[hit])->Dump();
146 }
147 }
148 }
149
a9e2aefa 150 return;
151}
152
153 //__________________________________________________________________________
29f1b13a 154void AliMUONTrackReconstructor::MakeSegments(void)
a9e2aefa 155{
2457f726 156 /// To make the list of segments in all stations,
157 /// from the list of hits to be reconstructed
b840996b 158 AliDebug(1,"Enter MakeSegments");
a9e2aefa 159 // Loop over stations
2457f726 160 for (Int_t st = 0; st < AliMUONConstants::NTrackingCh()/2; st++) MakeSegmentsPerStation(st);
80e33fc5 161
162 StdoutToAliDebug(3,
a9e2aefa 163 cout << "end of MakeSegments" << endl;
80e33fc5 164 for (Int_t st = 0; st < AliMUONConstants::NTrackingCh()/2; st++)
165 {
166 cout << "station " << st
167 << " has " << fNSegments[st] << " segments:"
168 << endl;
169 for (Int_t seg = 0; seg < fNSegments[st]; seg++)
170 {
171 ((*fSegmentsPtr[st])[seg])->Print();
a9e2aefa 172 }
173 }
80e33fc5 174 );
a9e2aefa 175 return;
176}
177
178 //__________________________________________________________________________
29f1b13a 179void AliMUONTrackReconstructor::MakeTracks(void)
a9e2aefa 180{
2457f726 181 /// To make the tracks from the list of segments and points in all stations
b840996b 182 AliDebug(1,"Enter MakeTracks");
2457f726 183 // Look for candidates from at least 3 aligned points in stations(1..) 4 and 5
184 MakeTrackCandidates();
185 // Follow tracks in stations(1..) 3, 2 and 1
186 FollowTracks();
187 // Remove double tracks
188 RemoveDoubleTracks();
189 UpdateHitForRecAtHit();
276c44b7 190}
191
de2cd600 192 //__________________________________________________________________________
193void AliMUONTrackReconstructor::MakeTrackCandidates(void)
194{
2457f726 195 /// To make track candidates
196 /// with at least 3 aligned points in stations(1..) 4 and 5
197 /// (two Segment's or one Segment and one HitForRec)
de2cd600 198 Int_t begStation, iBegSegment, nbCan1Seg1Hit, nbCan2Seg;
199 AliMUONSegment *begSegment;
200 AliDebug(1,"Enter MakeTrackCandidates");
201 // Loop over stations(1..) 5 and 4 for the beginning segment
202 for (begStation = 4; begStation > 2; begStation--) {
203 // Loop over segments in the beginning station
204 for (iBegSegment = 0; iBegSegment < fNSegments[begStation]; iBegSegment++) {
205 // pointer to segment
206 begSegment = (AliMUONSegment*) ((*fSegmentsPtr[begStation])[iBegSegment]);
207 AliDebug(2,Form("Look for TrackCandidate's with Segment %d in Station(0..) %d", iBegSegment, begStation));
208 // Look for track candidates with two segments,
209 // "begSegment" and all compatible segments in other station.
210 // Only for beginning station(1..) 5
211 // because candidates with 2 segments have to looked for only once.
212 if (begStation == 4)
213 nbCan2Seg = MakeTrackCandidatesWithTwoSegments(begSegment);
214 // Look for track candidates with one segment and one point,
215 // "begSegment" and all compatible HitForRec's in other station.
216 // Only if "begSegment" does not belong already to a track candidate.
217 // Is that a too strong condition ????
218 if (!(begSegment->GetInTrack()))
219 nbCan1Seg1Hit = MakeTrackCandidatesWithOneSegmentAndOnePoint(begSegment);
220 } // for (iBegSegment = 0;...
221 } // for (begStation = 4;...
222 return;
223}
224
a9e2aefa 225 //__________________________________________________________________________
29f1b13a 226Int_t AliMUONTrackReconstructor::MakeTrackCandidatesWithTwoSegments(AliMUONSegment *BegSegment)
a9e2aefa 227{
2457f726 228 /// To make track candidates with two segments in stations(1..) 4 and 5,
229 /// the first segment being pointed to by "BegSegment".
230 /// Returns the number of such track candidates.
a9e2aefa 231 Int_t endStation, iEndSegment, nbCan2Seg;
e516b01d 232 AliMUONSegment *endSegment;
233 AliMUONSegment *extrapSegment = NULL;
a9e2aefa 234 AliMUONTrack *recTrack;
235 Double_t mcsFactor;
b840996b 236 AliDebug(1,"Enter MakeTrackCandidatesWithTwoSegments");
a9e2aefa 237 // Station for the end segment
238 endStation = 7 - (BegSegment->GetHitForRec1())->GetChamberNumber() / 2;
239 // multiple scattering factor corresponding to one chamber
240 mcsFactor = 0.0136 /
241 GetBendingMomentumFromImpactParam(BegSegment->GetBendingImpact());
242 mcsFactor = fChamberThicknessInX0 * mcsFactor * mcsFactor;
243 // linear extrapolation to end station
a9e2aefa 244 // number of candidates with 2 segments to 0
245 nbCan2Seg = 0;
246 // Loop over segments in the end station
247 for (iEndSegment = 0; iEndSegment < fNSegments[endStation]; iEndSegment++) {
248 // pointer to segment
249 endSegment = (AliMUONSegment*) ((*fSegmentsPtr[endStation])[iEndSegment]);
250 // test compatibility between current segment and "extrapSegment"
04b5ea16 251 // 4 because 4 quantities in chi2
e516b01d 252 extrapSegment =
253 BegSegment->CreateSegmentFromLinearExtrapToStation(endSegment->GetZ(), mcsFactor);
a9e2aefa 254 if ((endSegment->
255 NormalizedChi2WithSegment(extrapSegment,
256 fMaxSigma2Distance)) <= 4.0) {
257 // both segments compatible:
258 // make track candidate from "begSegment" and "endSegment"
b840996b 259 AliDebug(2,Form("TrackCandidate with Segment %d in Station(0..) %d", iEndSegment, endStation));
a9e2aefa 260 // flag for both segments in one track:
261 // to be done in track constructor ????
262 BegSegment->SetInTrack(kTRUE);
263 endSegment->SetInTrack(kTRUE);
de2cd600 264 recTrack = new ((*fRecTracksPtr)[fNRecTracks]) AliMUONTrack(BegSegment, endSegment);
265 // Set track parameters at vertex from last stations 4 & 5
266 CalcTrackParamAtVertex(recTrack);
a9e2aefa 267 fNRecTracks++;
b840996b 268 if (AliLog::GetGlobalDebugLevel() > 1) recTrack->RecursiveDump();
a9e2aefa 269 // increment number of track candidates with 2 segments
270 nbCan2Seg++;
271 }
ddf8948c 272 delete extrapSegment; // should not delete HitForRec's it points to !!!!
a9e2aefa 273 } // for (iEndSegment = 0;...
a9e2aefa 274 return nbCan2Seg;
275}
276
277 //__________________________________________________________________________
29f1b13a 278Int_t AliMUONTrackReconstructor::MakeTrackCandidatesWithOneSegmentAndOnePoint(AliMUONSegment *BegSegment)
a9e2aefa 279{
2457f726 280 /// To make track candidates with one segment and one point
281 /// in stations(1..) 4 and 5,
282 /// the segment being pointed to by "BegSegment".
a9e2aefa 283 Int_t ch, ch1, ch2, endStation, iHit, iHitMax, iHitMin, nbCan1Seg1Hit;
e516b01d 284 AliMUONHitForRec *extrapHitForRec= NULL;
285 AliMUONHitForRec *hit;
a9e2aefa 286 AliMUONTrack *recTrack;
287 Double_t mcsFactor;
b840996b 288 AliDebug(1,"Enter MakeTrackCandidatesWithOneSegmentAndOnePoint");
a9e2aefa 289 // station for the end point
290 endStation = 7 - (BegSegment->GetHitForRec1())->GetChamberNumber() / 2;
291 // multiple scattering factor corresponding to one chamber
292 mcsFactor = 0.0136 /
293 GetBendingMomentumFromImpactParam(BegSegment->GetBendingImpact());
294 mcsFactor = fChamberThicknessInX0 * mcsFactor * mcsFactor;
295 // first and second chambers(0..) in the end station
296 ch1 = 2 * endStation;
297 ch2 = ch1 + 1;
298 // number of candidates to 0
299 nbCan1Seg1Hit = 0;
300 // Loop over chambers of the end station
301 for (ch = ch2; ch >= ch1; ch--) {
a9e2aefa 302 // limits for the hit index in the loop
303 iHitMin = fIndexOfFirstHitForRecPerChamber[ch];
304 iHitMax = iHitMin + fNHitsForRecPerChamber[ch];
305 // Loop over HitForRec's in the chamber
306 for (iHit = iHitMin; iHit < iHitMax; iHit++) {
307 // pointer to HitForRec
308 hit = (AliMUONHitForRec*) ((*fHitsForRecPtr)[iHit]);
309 // test compatibility between current HitForRec and "extrapHitForRec"
04b5ea16 310 // 2 because 2 quantities in chi2
e516b01d 311 // linear extrapolation to chamber
312 extrapHitForRec =
313 BegSegment->CreateHitForRecFromLinearExtrapToChamber( hit->GetZ(), mcsFactor);
a9e2aefa 314 if ((hit->
315 NormalizedChi2WithHitForRec(extrapHitForRec,
316 fMaxSigma2Distance)) <= 2.0) {
317 // both HitForRec's compatible:
318 // make track candidate from begSegment and current HitForRec
b840996b 319 AliDebug(2, Form("TrackCandidate with HitForRec %d in Chamber(0..) %d", iHit, ch));
a9e2aefa 320 // flag for beginning segments in one track:
321 // to be done in track constructor ????
322 BegSegment->SetInTrack(kTRUE);
de2cd600 323 recTrack = new ((*fRecTracksPtr)[fNRecTracks]) AliMUONTrack(BegSegment, hit);
324 // Set track parameters at vertex from last stations 4 & 5
325 CalcTrackParamAtVertex(recTrack);
a9e2aefa 326 // the right place to eliminate "double counting" ???? how ????
327 fNRecTracks++;
b840996b 328 if (AliLog::GetGlobalDebugLevel() > 1) recTrack->RecursiveDump();
a9e2aefa 329 // increment number of track candidates
330 nbCan1Seg1Hit++;
331 }
ddf8948c 332 delete extrapHitForRec;
a9e2aefa 333 } // for (iHit = iHitMin;...
a9e2aefa 334 } // for (ch = ch2;...
335 return nbCan1Seg1Hit;
336}
337
338 //__________________________________________________________________________
2457f726 339void AliMUONTrackReconstructor::CalcTrackParamAtVertex(AliMUONTrack *Track) const
a9e2aefa 340{
2457f726 341 /// Set track parameters at vertex.
342 /// TrackHit's are assumed to be only in stations(1..) 4 and 5,
343 /// and sorted according to increasing Z.
344 /// Parameters are calculated from information in HitForRec's
345 /// of first and last TrackHit's.
de2cd600 346 AliMUONTrackParam *trackParamVertex = Track->GetTrackParamAtVertex(); // pointer to track parameters at vertex
347 // Pointer to HitForRec attached to first TrackParamAtHit
348 AliMUONHitForRec *firstHit = ((AliMUONTrackParam*) (Track->GetTrackParamAtHit()->First()))->GetHitForRecPtr();
349 // Pointer to HitForRec attached to last TrackParamAtHit
350 AliMUONHitForRec *lastHit = ((AliMUONTrackParam*) (Track->GetTrackParamAtHit()->Last()))->GetHitForRecPtr();
351 // Z difference between first and last hits
352 Double_t deltaZ = firstHit->GetZ() - lastHit->GetZ();
353 // bending slope in stations(1..) 4 and 5
354 Double_t bendingSlope = (firstHit->GetBendingCoor() - lastHit->GetBendingCoor()) / deltaZ;
355 trackParamVertex->SetBendingSlope(bendingSlope);
356 // impact parameter
357 Double_t impactParam = firstHit->GetBendingCoor() - bendingSlope * firstHit->GetZ();
358 // signed bending momentum
359 trackParamVertex->SetInverseBendingMomentum(1.0 / GetBendingMomentumFromImpactParam(impactParam));
360 // bending slope at vertex
2457f726 361 trackParamVertex->SetBendingSlope(bendingSlope + impactParam / fSimpleBPosition);
de2cd600 362 // non bending slope
363 trackParamVertex->SetNonBendingSlope((firstHit->GetNonBendingCoor() - lastHit->GetNonBendingCoor()) / deltaZ);
364 // vertex coordinates at (0,0,0)
365 trackParamVertex->SetZ(0.0);
366 trackParamVertex->SetBendingCoor(0.0);
367 trackParamVertex->SetNonBendingCoor(0.0);
a9e2aefa 368}
369
370 //__________________________________________________________________________
29f1b13a 371void AliMUONTrackReconstructor::FollowTracks(void)
a9e2aefa 372{
2457f726 373 /// Follow tracks in stations(1..) 3, 2 and 1
04b5ea16 374 // too long: should be made more modular !!!!
e516b01d 375 AliMUONHitForRec *bestHit, *extrapHit, *hit;
376 AliMUONSegment *bestSegment, *extrapSegment, *segment;
04b5ea16 377 AliMUONTrack *track, *nextTrack;
378 AliMUONTrackParam *trackParam1, trackParam[2], trackParamVertex;
ecfa008b 379 // -1 to avoid compilation warnings
380 Int_t ch = -1, chInStation, chBestHit = -1, iHit, iSegment, station, trackIndex;
04b5ea16 381 Double_t bestChi2, chi2, dZ1, dZ2, dZ3, maxSigma2Distance, mcsFactor;
d0bfce8d 382 Double_t bendingMomentum, chi2Norm = 0.;
cc87ebcd 383
1a38e749 384
04b5ea16 385 // local maxSigma2Distance, for easy increase in testing
386 maxSigma2Distance = fMaxSigma2Distance;
b840996b 387 AliDebug(2,"Enter FollowTracks");
a9e2aefa 388 // Loop over track candidates
04b5ea16 389 track = (AliMUONTrack*) fRecTracksPtr->First();
390 trackIndex = -1;
391 while (track) {
04b5ea16 392 trackIndex++;
393 nextTrack = (AliMUONTrack*) fRecTracksPtr->After(track); // prepare next track
b840996b 394 AliDebug(2,Form("FollowTracks: track candidate(0..): %d", trackIndex));
de2cd600 395 // Fit track candidate from parameters at vertex
396 // -> with 3 parameters (X_vertex and Y_vertex are fixed)
397 // without multiple Coulomb scattering
398 Fit(track,0,0);
b840996b 399 if (AliLog::GetGlobalDebugLevel()> 2) {
a9e2aefa 400 cout << "FollowTracks: track candidate(0..): " << trackIndex
956019b6 401 << " after fit in stations(0..) 3 and 4" << endl;
a9e2aefa 402 track->RecursiveDump();
403 }
404 // Loop over stations(1..) 3, 2 and 1
04b5ea16 405 // something SPECIAL for stations 2 and 1 for majority 3 coincidence ????
406 // otherwise: majority coincidence 2 !!!!
a9e2aefa 407 for (station = 2; station >= 0; station--) {
408 // Track parameters at first track hit (smallest Z)
de2cd600 409 trackParam1 = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->First());
a9e2aefa 410 // extrapolation to station
411 trackParam1->ExtrapToStation(station, trackParam);
79e1e601 412 extrapSegment = new AliMUONSegment(); // empty segment
a9e2aefa 413 // multiple scattering factor corresponding to one chamber
414 // and momentum in bending plane (not total)
415 mcsFactor = 0.0136 * trackParam1->GetInverseBendingMomentum();
416 mcsFactor = fChamberThicknessInX0 * mcsFactor * mcsFactor;
417 // Z difference from previous station
f93b9bd8 418 dZ1 = AliMUONConstants::DefaultChamberZ(2 * station) -
419 AliMUONConstants::DefaultChamberZ(2 * station + 2);
a9e2aefa 420 // Z difference between the two previous stations
f93b9bd8 421 dZ2 = AliMUONConstants::DefaultChamberZ(2 * station + 2) -
422 AliMUONConstants::DefaultChamberZ(2 * station + 4);
04b5ea16 423 // Z difference between the two chambers in the previous station
f93b9bd8 424 dZ3 = AliMUONConstants::DefaultChamberZ(2 * station) -
425 AliMUONConstants::DefaultChamberZ(2 * station + 1);
04b5ea16 426 extrapSegment->SetBendingCoorReso2(fBendingResolution * fBendingResolution);
de2cd600 427 extrapSegment->SetNonBendingCoorReso2(fNonBendingResolution * fNonBendingResolution);
428 extrapSegment->UpdateFromStationTrackParam(trackParam, mcsFactor, dZ1, dZ2, dZ3, station,
429 trackParam1->GetInverseBendingMomentum());
a9e2aefa 430 bestChi2 = 5.0;
431 bestSegment = NULL;
b840996b 432 if (AliLog::GetGlobalDebugLevel() > 2) {
a9e2aefa 433 cout << "FollowTracks: track candidate(0..): " << trackIndex
434 << " Look for segment in station(0..): " << station << endl;
435 }
1a38e749 436
a9e2aefa 437 // Loop over segments in station
438 for (iSegment = 0; iSegment < fNSegments[station]; iSegment++) {
439 // Look for best compatible Segment in station
440 // should consider all possibilities ????
441 // multiple scattering ????
442 // separation in 2 functions: Segment and HitForRec ????
443 segment = (AliMUONSegment*) ((*fSegmentsPtr[station])[iSegment]);
d0bfce8d 444 // correction of corrected segment (fBendingCoor and fNonBendingCoor)
445 // according to real Z value of "segment" and slopes of "extrapSegment"
de2cd600 446 trackParam[0].ExtrapToZ(segment->GetZ());
447 trackParam[1].ExtrapToZ(segment->GetZ()); // now same as trackParam[0] !?!?!?!?!?!
e516b01d 448 extrapSegment->SetBendingCoor((&(trackParam[0]))->GetBendingCoor());
449 extrapSegment->SetNonBendingCoor((&(trackParam[0]))->GetNonBendingCoor());
450 extrapSegment->SetBendingSlope((&(trackParam[0]))->GetBendingSlope());
451 extrapSegment->SetNonBendingSlope((&(trackParam[0]))->GetNonBendingSlope());
de2cd600 452 chi2 = segment->NormalizedChi2WithSegment(extrapSegment, maxSigma2Distance);
a9e2aefa 453 if (chi2 < bestChi2) {
454 // update best Chi2 and Segment if better found
455 bestSegment = segment;
456 bestChi2 = chi2;
457 }
458 }
459 if (bestSegment) {
460 // best segment found: add it to track candidate
de2cd600 461 trackParam[0].ExtrapToZ(bestSegment->GetZ());
462 track->AddTrackParamAtHit(&(trackParam[0]),bestSegment->GetHitForRec1());
463 trackParam[1].ExtrapToZ(bestSegment->GetZ()); // now same as trackParam[0] !?!?!?!?!?!
464 track->AddTrackParamAtHit(&(trackParam[1]),bestSegment->GetHitForRec2());
b840996b 465 AliDebug(3, Form("FollowTracks: track candidate(0..): %d Added segment in station(0..): %d", trackIndex, station));
466 if (AliLog::GetGlobalDebugLevel()>2) track->RecursiveDump();
de2cd600 467 } else {
a9e2aefa 468 // No best segment found:
469 // Look for best compatible HitForRec in station:
470 // should consider all possibilities ????
471 // multiple scattering ???? do about like for extrapSegment !!!!
79e1e601 472 extrapHit = new AliMUONHitForRec(); // empty hit
a9e2aefa 473 bestChi2 = 3.0;
474 bestHit = NULL;
b840996b 475 AliDebug(3, Form("FollowTracks: track candidate(0..): %d Segment not found, look for hit in station(0..): %d ",
476 trackIndex, station));
477
a9e2aefa 478 // Loop over chambers of the station
d82671a0 479 for (chInStation = 0; chInStation < 2; chInStation++) {
956019b6 480 ch = 2 * station + chInStation;
de2cd600 481 for (iHit = fIndexOfFirstHitForRecPerChamber[ch]; iHit < fIndexOfFirstHitForRecPerChamber[ch]+fNHitsForRecPerChamber[ch]; iHit++) {
a9e2aefa 482 hit = (AliMUONHitForRec*) ((*fHitsForRecPtr)[iHit]);
e516b01d 483 // coordinates of extrapolated hit
de2cd600 484 trackParam[chInStation].ExtrapToZ(hit->GetZ());
485 extrapHit->SetBendingCoor((&(trackParam[chInStation]))->GetBendingCoor());
486 extrapHit->SetNonBendingCoor((&(trackParam[chInStation]))->GetNonBendingCoor());
e516b01d 487 // resolutions from "extrapSegment"
488 extrapHit->SetBendingReso2(extrapSegment->GetBendingCoorReso2());
489 extrapHit->SetNonBendingReso2(extrapSegment->GetNonBendingCoorReso2());
490 // Loop over hits in the chamber
a9e2aefa 491 // condition for hit not already in segment ????
492 chi2 = hit->NormalizedChi2WithHitForRec(extrapHit, maxSigma2Distance);
493 if (chi2 < bestChi2) {
494 // update best Chi2 and HitForRec if better found
495 bestHit = hit;
496 bestChi2 = chi2;
d82671a0 497 chBestHit = chInStation;
a9e2aefa 498 }
499 }
500 }
501 if (bestHit) {
502 // best hit found: add it to track candidate
de2cd600 503 trackParam[chBestHit].ExtrapToZ(bestHit->GetZ());
504 track->AddTrackParamAtHit(&(trackParam[chBestHit]),bestHit);
b840996b 505 if (AliLog::GetGlobalDebugLevel() > 2) {
a9e2aefa 506 cout << "FollowTracks: track candidate(0..): " << trackIndex
507 << " Added hit in station(0..): " << station << endl;
508 track->RecursiveDump();
509 }
de2cd600 510 } else {
8429a5e4 511 // Remove current track candidate
512 // and corresponding TrackHit's, ...
de2cd600 513 fRecTracksPtr->Remove(track);
514 fNRecTracks--;
04b5ea16 515 delete extrapSegment;
d0bfce8d 516 delete extrapHit;
a9e2aefa 517 break; // stop the search for this candidate:
518 // exit from the loop over station
519 }
d0bfce8d 520 delete extrapHit;
a9e2aefa 521 }
04b5ea16 522 delete extrapSegment;
de2cd600 523 // Sort TrackParamAtHit according to increasing Z
524 track->GetTrackParamAtHit()->Sort();
a9e2aefa 525 // Update track parameters at first track hit (smallest Z)
de2cd600 526 trackParam1 = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->First());
d0bfce8d 527 bendingMomentum = 0.;
528 if (TMath::Abs(trackParam1->GetInverseBendingMomentum()) > 0.)
529 bendingMomentum = TMath::Abs(1/(trackParam1->GetInverseBendingMomentum()));
530 // Track removed if bendingMomentum not in window [min, max]
531 if ((bendingMomentum < fMinBendingMomentum) || (bendingMomentum > fMaxBendingMomentum)) {
de2cd600 532 fRecTracksPtr->Remove(track);
533 fNRecTracks--;
d0bfce8d 534 break; // stop the search for this candidate:
535 // exit from the loop over station
536 }
de2cd600 537 // Track fit from parameters at first hit
538 // -> with 5 parameters (momentum and position)
04b5ea16 539 // with multiple Coulomb scattering if all stations
de2cd600 540 if (station == 0) Fit(track,1,1);
956019b6 541 // without multiple Coulomb scattering if not all stations
de2cd600 542 else Fit(track,1,0);
d0bfce8d 543 Double_t numberOfDegFree = (2.0 * track->GetNTrackHits() - 5);
544 if (numberOfDegFree > 0) {
545 chi2Norm = track->GetFitFMin() / numberOfDegFree;
546 } else {
547 chi2Norm = 1.e10;
548 }
549 // Track removed if normalized chi2 too high
550 if (chi2Norm > fMaxChi2) {
de2cd600 551 fRecTracksPtr->Remove(track);
552 fNRecTracks--;
d0bfce8d 553 break; // stop the search for this candidate:
554 // exit from the loop over station
555 }
b840996b 556 if (AliLog::GetGlobalDebugLevel() > 2) {
a9e2aefa 557 cout << "FollowTracks: track candidate(0..): " << trackIndex
558 << " after fit from station(0..): " << station << " to 4" << endl;
559 track->RecursiveDump();
560 }
04b5ea16 561 // Track extrapolation to the vertex through the absorber (Branson)
956019b6 562 // after going through the first station
04b5ea16 563 if (station == 0) {
de2cd600 564 trackParamVertex = *((AliMUONTrackParam*) (track->GetTrackParamAtHit()->First()));
889a0215 565 (&trackParamVertex)->ExtrapToVertex(0.,0.,0.);
04b5ea16 566 track->SetTrackParamAtVertex(&trackParamVertex);
b840996b 567 if (AliLog::GetGlobalDebugLevel() > 0) {
6ae236ee 568 cout << "FollowTracks: track candidate(0..): " << trackIndex
569 << " after extrapolation to vertex" << endl;
570 track->RecursiveDump();
571 }
04b5ea16 572 }
a9e2aefa 573 } // for (station = 2;...
04b5ea16 574 // go really to next track
575 track = nextTrack;
576 } // while (track)
de2cd600 577 // Compression of track array (necessary after Remove)
04b5ea16 578 fRecTracksPtr->Compress();
579 return;
580}
581
de2cd600 582 //__________________________________________________________________________
583void AliMUONTrackReconstructor::Fit(AliMUONTrack *Track, Int_t FitStart, Int_t FitMCS)
584{
2457f726 585 /// Fit the track "Track",
586 /// with or without multiple Coulomb scattering according to "FitMCS",
587 /// starting, according to "FitStart",
588 /// with track parameters at vertex or at the first TrackHit.
de2cd600 589
590 if ((FitStart != 0) && (FitStart != 1)) {
591 cout << "ERROR in AliMUONTrackReconstructor::Fit(...)" << endl;
592 cout << "FitStart = " << FitStart << " is neither 0 nor 1" << endl;
593 exit(0);
594 }
595 if ((FitMCS != 0) && (FitMCS != 1)) {
596 cout << "ERROR in AliMUONTrackReconstructor::Fit(...)" << endl;
597 cout << "FitMCS = " << FitMCS << " is neither 0 nor 1" << endl;
598 exit(0);
599 }
600
601 Double_t arg[1], benC, errorParam, invBenP, lower, nonBenC, upper, x, y;
602 char parName[50];
603 AliMUONTrackParam *trackParam;
604 // Check if Minuit is initialized...
605 fgFitter = TVirtualFitter::Fitter(Track,5);
606 fgFitter->Clear(); // necessary ???? probably yes
607 // how to reset the printout number at every fit ????
608 // is there any risk to leave it like that ????
609 // how to go faster ???? choice of Minuit parameters like EDM ????
610 // choice of function to be minimized according to fFitMCS
611 if (FitMCS == 0) fgFitter->SetFCN(TrackChi2);
612 else fgFitter->SetFCN(TrackChi2MCS);
613 // Switch off printout
614 arg[0] = -1;
615 fgFitter->ExecuteCommand("SET PRINT", arg, 1); // More printing !!!!
616 // No warnings
617 fgFitter->ExecuteCommand("SET NOW", arg, 0);
618 // Parameters according to "fFitStart"
619 // (should be a function to be used at every place where needed ????)
620 if (FitStart == 0) trackParam = Track->GetTrackParamAtVertex();
621 else trackParam = (AliMUONTrackParam*) (Track->GetTrackParamAtHit()->First());
622 // set first 3 Minuit parameters
623 // could be tried with no limits for the search (min=max=0) ????
624 fgFitter->SetParameter(0, "InvBenP",
625 trackParam->GetInverseBendingMomentum(),
626 0.003, -0.4, 0.4);
627 fgFitter->SetParameter(1, "BenS",
628 trackParam->GetBendingSlope(),
629 0.001, -0.5, 0.5);
630 fgFitter->SetParameter(2, "NonBenS",
631 trackParam->GetNonBendingSlope(),
632 0.001, -0.5, 0.5);
633 if (FitStart == 1) {
634 // set last 2 Minuit parameters when we start from first track hit
635 // mandatory limits in Bending to avoid NaN values of parameters
636 fgFitter->SetParameter(3, "X",
637 trackParam->GetNonBendingCoor(),
638 0.03, -500.0, 500.0);
639 // mandatory limits in non Bending to avoid NaN values of parameters
640 fgFitter->SetParameter(4, "Y",
641 trackParam->GetBendingCoor(),
642 0.10, -500.0, 500.0);
643 }
644 // search without gradient calculation in the function
645 fgFitter->ExecuteCommand("SET NOGRADIENT", arg, 0);
646 // minimization
647 fgFitter->ExecuteCommand("MINIMIZE", arg, 0);
648 // exit from Minuit
649 // fgFitter->ExecuteCommand("EXIT", arg, 0); // necessary ????
650 // get results into "invBenP", "benC", "nonBenC" ("x", "y")
651 fgFitter->GetParameter(0, parName, invBenP, errorParam, lower, upper);
652 trackParam->SetInverseBendingMomentum(invBenP);
653 fgFitter->GetParameter(1, parName, benC, errorParam, lower, upper);
654 trackParam->SetBendingSlope(benC);
655 fgFitter->GetParameter(2, parName, nonBenC, errorParam, lower, upper);
656 trackParam->SetNonBendingSlope(nonBenC);
657 if (FitStart == 1) {
658 fgFitter->GetParameter(3, parName, x, errorParam, lower, upper);
659 trackParam->SetNonBendingCoor(x);
660 fgFitter->GetParameter(4, parName, y, errorParam, lower, upper);
661 trackParam->SetBendingCoor(y);
662 }
663 // global result of the fit
2457f726 664 Double_t fedm, errdef, fitFMin;
de2cd600 665 Int_t npari, nparx;
2457f726 666 fgFitter->GetStats(fitFMin, fedm, errdef, npari, nparx);
667 Track->SetFitFMin(fitFMin);
de2cd600 668}
669
670 //__________________________________________________________________________
671void TrackChi2(Int_t &NParam, Double_t * /*Gradient*/, Double_t &Chi2, Double_t *Param, Int_t /*Flag*/)
672{
2457f726 673 /// Return the "Chi2" to be minimized with Minuit for track fitting,
674 /// with "NParam" parameters
675 /// and their current values in array pointed to by "Param".
676 /// Assumes that the track hits are sorted according to increasing Z.
677 /// Track parameters at each TrackHit are updated accordingly.
678 /// Multiple Coulomb scattering is not taken into account
de2cd600 679 AliMUONTrack *trackBeingFitted;
680 AliMUONTrackParam param1;
2457f726 681 AliMUONTrackParam* trackParamAtHit;
682 AliMUONHitForRec* hitForRec;
de2cd600 683 Chi2 = 0.0; // initialize Chi2
684 // copy of track parameters to be fitted
685 trackBeingFitted = (AliMUONTrack*) AliMUONTrackReconstructor::Fitter()->GetObjectFit();
686 // 3 parameters means fit track candidate from parameters at vertex (X_vertex and Y_vertex are fixed)
687 if (NParam == 3) param1 = *(trackBeingFitted->GetTrackParamAtVertex());
688 else param1 = *((AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->First()));
689 // Minuit parameters to be fitted into this copy
690 param1.SetInverseBendingMomentum(Param[0]);
691 param1.SetBendingSlope(Param[1]);
692 param1.SetNonBendingSlope(Param[2]);
693 if (NParam == 5) {
694 param1.SetNonBendingCoor(Param[3]);
695 param1.SetBendingCoor(Param[4]);
696 }
697 // Follow track through all planes of track hits
2457f726 698 trackParamAtHit = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->First());
699 while (trackParamAtHit) {
700 hitForRec = trackParamAtHit->GetHitForRecPtr();
701 // extrapolation to the plane of the hitForRec attached to the current trackParamAtHit
702 param1.ExtrapToZ(hitForRec->GetZ());
de2cd600 703 // update track parameters of the current hit
2457f726 704 trackParamAtHit->SetTrackParam(param1);
de2cd600 705 // Increment Chi2
706 // done hit per hit, with hit resolution,
707 // and not with point and angle like in "reco_muon.F" !!!!
708 // Needs to add multiple scattering contribution ????
2457f726 709 Double_t dX = hitForRec->GetNonBendingCoor() - param1.GetNonBendingCoor();
710 Double_t dY = hitForRec->GetBendingCoor() - param1.GetBendingCoor();
711 Chi2 = Chi2 + dX * dX / hitForRec->GetNonBendingReso2() + dY * dY / hitForRec->GetBendingReso2();
712 trackParamAtHit = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->After(trackParamAtHit));
de2cd600 713 }
714}
715
716 //__________________________________________________________________________
717void TrackChi2MCS(Int_t &NParam, Double_t * /*Gradient*/, Double_t &Chi2, Double_t *Param, Int_t /*Flag*/)
718{
2457f726 719 /// Return the "Chi2" to be minimized with Minuit for track fitting,
720 /// with "NParam" parameters
721 /// and their current values in array pointed to by "Param".
722 /// Assumes that the track hits are sorted according to increasing Z.
723 /// Track parameters at each TrackHit are updated accordingly.
724 /// Multiple Coulomb scattering is taken into account with covariance matrix.
de2cd600 725 AliMUONTrack *trackBeingFitted;
726 AliMUONTrackParam param1;
2457f726 727 AliMUONTrackParam* trackParamAtHit;
728 AliMUONHitForRec* hitForRec;
de2cd600 729 Chi2 = 0.0; // initialize Chi2
730 // copy of track parameters to be fitted
731 trackBeingFitted = (AliMUONTrack*) AliMUONTrackReconstructor::Fitter()->GetObjectFit();
732 // 3 parameters means fit track candidate from parameters at vertex (X_vertex and Y_vertex are fixed)
733 if (NParam == 3) param1 = *(trackBeingFitted->GetTrackParamAtVertex());
734 else param1 = *((AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->First()));
735 // Minuit parameters to be fitted into this copy
736 param1.SetInverseBendingMomentum(Param[0]);
737 param1.SetBendingSlope(Param[1]);
738 param1.SetNonBendingSlope(Param[2]);
739 if (NParam == 5) {
740 param1.SetNonBendingCoor(Param[3]);
741 param1.SetBendingCoor(Param[4]);
742 }
743
744 Int_t chCurrent, chPrev = 0, hitNumber, hitNumber1, hitNumber2, hitNumber3;
745 Double_t z1, z2, z3;
2457f726 746 AliMUONTrackParam *trackParamAtHit1, *trackParamAtHit2, *trackParamAtHit3;
747 AliMUONHitForRec *hitForRec1, *hitForRec2;
de2cd600 748 Double_t hbc1, hbc2, pbc1, pbc2;
749 Double_t hnbc1, hnbc2, pnbc1, pnbc2;
750 Int_t numberOfHit = trackBeingFitted->GetNTrackHits();
751 TMatrixD *covBending = new TMatrixD(numberOfHit, numberOfHit);
752 TMatrixD *covNonBending = new TMatrixD(numberOfHit, numberOfHit);
753 Double_t *msa2 = new Double_t[numberOfHit];
754
755 // Predicted coordinates and multiple scattering angles are first calculated
756 for (hitNumber = 0; hitNumber < numberOfHit; hitNumber++) {
2457f726 757 trackParamAtHit = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber));
758 hitForRec = trackParamAtHit->GetHitForRecPtr();
759 // extrapolation to the plane of the hitForRec attached to the current trackParamAtHit
760 param1.ExtrapToZ(hitForRec->GetZ());
de2cd600 761 // update track parameters of the current hit
2457f726 762 trackParamAtHit->SetTrackParam(param1);
de2cd600 763 // square of multiple scattering angle at current hit, with one chamber
764 msa2[hitNumber] = MultipleScatteringAngle2(&param1);
765 // correction for eventual missing hits or multiple hits in a chamber,
766 // according to the number of chambers
767 // between the current hit and the previous one
2457f726 768 chCurrent = hitForRec->GetChamberNumber();
de2cd600 769 if (hitNumber > 0) msa2[hitNumber] = msa2[hitNumber] * (chCurrent - chPrev);
770 chPrev = chCurrent;
771 }
772
773 // Calculates the covariance matrix
774 for (hitNumber1 = 0; hitNumber1 < numberOfHit; hitNumber1++) {
2457f726 775 trackParamAtHit1 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber1));
776 hitForRec1 = trackParamAtHit1->GetHitForRecPtr();
777 z1 = hitForRec1->GetZ();
de2cd600 778 for (hitNumber2 = hitNumber1; hitNumber2 < numberOfHit; hitNumber2++) {
2457f726 779 trackParamAtHit2 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber2));
780 z2 = trackParamAtHit2->GetHitForRecPtr()->GetZ();
de2cd600 781 // initialization to 0 (diagonal plus upper triangular part)
782 (*covBending)(hitNumber2, hitNumber1) = 0.0;
783 // contribution from multiple scattering in bending plane:
784 // loop over upstream hits
785 for (hitNumber3 = 0; hitNumber3 < hitNumber1; hitNumber3++) {
2457f726 786 trackParamAtHit3 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber3));
787 z3 = trackParamAtHit3->GetHitForRecPtr()->GetZ();
de2cd600 788 (*covBending)(hitNumber2, hitNumber1) = (*covBending)(hitNumber2, hitNumber1) + ((z1 - z3) * (z2 - z3) * msa2[hitNumber3]);
789 }
790 // equal contribution from multiple scattering in non bending plane
791 (*covNonBending)(hitNumber2, hitNumber1) = (*covBending)(hitNumber2, hitNumber1);
792 if (hitNumber1 == hitNumber2) {
793 // Diagonal elements: add contribution from position measurements
794 // in bending plane
2457f726 795 (*covBending)(hitNumber2, hitNumber1) = (*covBending)(hitNumber2, hitNumber1) + hitForRec1->GetBendingReso2();
de2cd600 796 // and in non bending plane
2457f726 797 (*covNonBending)(hitNumber2, hitNumber1) = (*covNonBending)(hitNumber2, hitNumber1) + hitForRec1->GetNonBendingReso2();
de2cd600 798 } else {
799 // Non diagonal elements: symmetrization
800 // for bending plane
801 (*covBending)(hitNumber1, hitNumber2) = (*covBending)(hitNumber2, hitNumber1);
802 // and non bending plane
803 (*covNonBending)(hitNumber1, hitNumber2) = (*covNonBending)(hitNumber2, hitNumber1);
804 }
805 } // for (hitNumber2 = hitNumber1;...
806 } // for (hitNumber1 = 0;...
807
808 // Inversion of covariance matrices
809 // with "mnvertLocal", local "mnvert" function of Minuit.
810 // One cannot use directly "mnvert" since "TVirtualFitter" does not know it.
811 // One will have to replace this local function by the right inversion function
812 // from a specialized Root package for symmetric positive definite matrices,
813 // when available!!!!
814 Int_t ifailBending;
815 mnvertLocal(&((*covBending)(0,0)), numberOfHit, numberOfHit, numberOfHit, ifailBending);
816 Int_t ifailNonBending;
817 mnvertLocal(&((*covNonBending)(0,0)), numberOfHit, numberOfHit, numberOfHit, ifailNonBending);
818
819 // It would be worth trying to calculate the inverse of the covariance matrix
820 // only once per fit, since it cannot change much in principle,
821 // and it would save a lot of computing time !!!!
822
823 // Calculates Chi2
824 if ((ifailBending == 0) && (ifailNonBending == 0)) {
825 // with Multiple Scattering if inversion correct
826 for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) {
2457f726 827 trackParamAtHit1 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber1));
828 hitForRec1 = trackParamAtHit1->GetHitForRecPtr();
829 hbc1 = hitForRec1->GetBendingCoor();
830 pbc1 = trackParamAtHit1->GetBendingCoor();
831 hnbc1 = hitForRec1->GetNonBendingCoor();
832 pnbc1 = trackParamAtHit1->GetNonBendingCoor();
de2cd600 833 for (hitNumber2 = 0; hitNumber2 < numberOfHit; hitNumber2++) {
2457f726 834 trackParamAtHit2 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber2));
835 hitForRec2 = trackParamAtHit2->GetHitForRecPtr();
836 hbc2 = hitForRec2->GetBendingCoor();
837 pbc2 = trackParamAtHit2->GetBendingCoor();
838 hnbc2 = hitForRec2->GetNonBendingCoor();
839 pnbc2 = trackParamAtHit2->GetNonBendingCoor();
de2cd600 840 Chi2 += ((*covBending)(hitNumber2, hitNumber1) * (hbc1 - pbc1) * (hbc2 - pbc2)) +
841 ((*covNonBending)(hitNumber2, hitNumber1) * (hnbc1 - pnbc1) * (hnbc2 - pnbc2));
842 }
843 }
844 } else {
845 // without Multiple Scattering if inversion impossible
846 for (hitNumber1 = 0; hitNumber1 < numberOfHit ; hitNumber1++) {
2457f726 847 trackParamAtHit1 = (AliMUONTrackParam*) (trackBeingFitted->GetTrackParamAtHit()->UncheckedAt(hitNumber1));
848 hitForRec1 = trackParamAtHit1->GetHitForRecPtr();
849 hbc1 = hitForRec1->GetBendingCoor();
850 pbc1 = trackParamAtHit1->GetBendingCoor();
851 hnbc1 = hitForRec1->GetNonBendingCoor();
852 pnbc1 = trackParamAtHit1->GetNonBendingCoor();
853 Chi2 += ((hbc1 - pbc1) * (hbc1 - pbc1) / hitForRec1->GetBendingReso2()) +
854 ((hnbc1 - pnbc1) * (hnbc1 - pnbc1) / hitForRec1->GetNonBendingReso2());
de2cd600 855 }
856 }
857
858 delete covBending;
859 delete covNonBending;
860 delete [] msa2;
861}
862
863Double_t MultipleScatteringAngle2(AliMUONTrackParam *param)
864{
2457f726 865 /// Returns square of multiple Coulomb scattering angle
866 /// from TrackParamAtHit pointed to by "param"
de2cd600 867 Double_t slopeBending, slopeNonBending, radiationLength, inverseBendingMomentum2, inverseTotalMomentum2;
868 Double_t varMultipleScatteringAngle;
869 // Better implementation in AliMUONTrack class ????
870 slopeBending = param->GetBendingSlope();
871 slopeNonBending = param->GetNonBendingSlope();
872 // thickness in radiation length for the current track,
873 // taking local angle into account
874 radiationLength = AliMUONConstants::DefaultChamberThicknessInX0() *
875 TMath::Sqrt(1.0 + slopeBending*slopeBending + slopeNonBending*slopeNonBending);
876 inverseBendingMomentum2 = param->GetInverseBendingMomentum() * param->GetInverseBendingMomentum();
877 inverseTotalMomentum2 = inverseBendingMomentum2 * (1.0 + slopeBending * slopeBending) /
878 (1.0 + slopeBending *slopeBending + slopeNonBending * slopeNonBending);
879 varMultipleScatteringAngle = 0.0136 * (1.0 + 0.038 * TMath::Log(radiationLength));
880 // The velocity is assumed to be 1 !!!!
881 varMultipleScatteringAngle = inverseTotalMomentum2 * radiationLength * varMultipleScatteringAngle * varMultipleScatteringAngle;
882 return varMultipleScatteringAngle;
883}
884
885//______________________________________________________________________________
886 void mnvertLocal(Double_t *a, Int_t l, Int_t, Int_t n, Int_t &ifail)
887{
2457f726 888///*-*-*-*-*-*-*-*-*-*-*-*Inverts a symmetric matrix*-*-*-*-*-*-*-*-*-*-*-*-*
889///*-* ==========================
890///*-* inverts a symmetric matrix. matrix is first scaled to
891///*-* have all ones on the diagonal (equivalent to change of units)
892///*-* but no pivoting is done since matrix is positive-definite.
893///*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
de2cd600 894
895 // taken from TMinuit package of Root (l>=n)
896 // fVERTs, fVERTq and fVERTpp changed to localVERTs, localVERTq and localVERTpp
897 // Double_t localVERTs[n], localVERTq[n], localVERTpp[n];
898 Double_t * localVERTs = new Double_t[n];
899 Double_t * localVERTq = new Double_t[n];
900 Double_t * localVERTpp = new Double_t[n];
901 // fMaxint changed to localMaxint
902 Int_t localMaxint = n;
903
904 /* System generated locals */
905 Int_t aOffset;
906
907 /* Local variables */
908 Double_t si;
909 Int_t i, j, k, kp1, km1;
910
911 /* Parameter adjustments */
912 aOffset = l + 1;
913 a -= aOffset;
914
915 /* Function Body */
916 ifail = 0;
917 if (n < 1) goto L100;
918 if (n > localMaxint) goto L100;
919//*-*- scale matrix by sqrt of diag elements
920 for (i = 1; i <= n; ++i) {
921 si = a[i + i*l];
922 if (si <= 0) goto L100;
923 localVERTs[i-1] = 1 / TMath::Sqrt(si);
924 }
925 for (i = 1; i <= n; ++i) {
926 for (j = 1; j <= n; ++j) {
927 a[i + j*l] = a[i + j*l]*localVERTs[i-1]*localVERTs[j-1];
928 }
929 }
930//*-*- . . . start main loop . . . .
931 for (i = 1; i <= n; ++i) {
932 k = i;
933//*-*- preparation for elimination step1
934 if (a[k + k*l] != 0) localVERTq[k-1] = 1 / a[k + k*l];
935 else goto L100;
936 localVERTpp[k-1] = 1;
937 a[k + k*l] = 0;
938 kp1 = k + 1;
939 km1 = k - 1;
940 if (km1 < 0) goto L100;
941 else if (km1 == 0) goto L50;
942 else goto L40;
943L40:
944 for (j = 1; j <= km1; ++j) {
945 localVERTpp[j-1] = a[j + k*l];
946 localVERTq[j-1] = a[j + k*l]*localVERTq[k-1];
947 a[j + k*l] = 0;
948 }
949L50:
950 if (k - n < 0) goto L51;
951 else if (k - n == 0) goto L60;
952 else goto L100;
953L51:
954 for (j = kp1; j <= n; ++j) {
955 localVERTpp[j-1] = a[k + j*l];
956 localVERTq[j-1] = -a[k + j*l]*localVERTq[k-1];
957 a[k + j*l] = 0;
958 }
959//*-*- elimination proper
960L60:
961 for (j = 1; j <= n; ++j) {
962 for (k = j; k <= n; ++k) { a[j + k*l] += localVERTpp[j-1]*localVERTq[k-1]; }
963 }
964 }
965//*-*- elements of left diagonal and unscaling
966 for (j = 1; j <= n; ++j) {
967 for (k = 1; k <= j; ++k) {
968 a[k + j*l] = a[k + j*l]*localVERTs[k-1]*localVERTs[j-1];
969 a[j + k*l] = a[k + j*l];
970 }
971 }
972 delete [] localVERTs;
973 delete [] localVERTq;
974 delete [] localVERTpp;
975 return;
976//*-*- failure return
977L100:
978 delete [] localVERTs;
979 delete [] localVERTq;
980 delete [] localVERTpp;
981 ifail = 1;
982} /* mnvertLocal */
983
04b5ea16 984 //__________________________________________________________________________
29f1b13a 985void AliMUONTrackReconstructor::RemoveDoubleTracks(void)
8429a5e4 986{
2457f726 987 /// To remove double tracks.
988 /// Tracks are considered identical
989 /// if they have at least half of their hits in common.
990 /// Among two identical tracks, one keeps the track with the larger number of hits
991 /// or, if these numbers are equal, the track with the minimum Chi2.
8429a5e4 992 AliMUONTrack *track1, *track2, *trackToRemove;
8429a5e4 993 Int_t hitsInCommon, nHits1, nHits2;
de2cd600 994 Bool_t removedTrack1;
995 // Loop over first track of the pair
996 track1 = (AliMUONTrack*) fRecTracksPtr->First();
997 while (track1) {
998 removedTrack1 = kFALSE;
999 nHits1 = track1->GetNTrackHits();
1000 // Loop over second track of the pair
1001 track2 = (AliMUONTrack*) fRecTracksPtr->After(track1);
1002 while (track2) {
1003 nHits2 = track2->GetNTrackHits();
1004 // number of hits in common between two tracks
1005 hitsInCommon = track1->HitsInCommon(track2);
1006 // check for identical tracks
1007 if ((4 * hitsInCommon) >= (nHits1 + nHits2)) {
1008 // decide which track to remove
1009 if ((nHits1 > nHits2) || ((nHits1 == nHits2) && (track1->GetFitFMin() < track2->GetFitFMin()))) {
1010 // remove track2 and continue the second loop with the track next to track2
1011 trackToRemove = track2;
1012 track2 = (AliMUONTrack*) fRecTracksPtr->After(track2);
1013 fRecTracksPtr->Remove(trackToRemove);
1014 fNRecTracks--;
1015 fRecTracksPtr->Compress(); // this is essential to retrieve the TClonesArray afterwards
1016 } else {
1017 // else remove track1 and continue the first loop with the track next to track1
1018 trackToRemove = track1;
1019 track1 = (AliMUONTrack*) fRecTracksPtr->After(track1);
1020 fRecTracksPtr->Remove(trackToRemove);
1021 fNRecTracks--;
1022 fRecTracksPtr->Compress(); // this is essential to retrieve the TClonesArray afterwards
1023 removedTrack1 = kTRUE;
1024 break;
1025 }
1026 } else track2 = (AliMUONTrack*) fRecTracksPtr->After(track2);
1027 } // track2
1028 if (removedTrack1) continue;
1029 track1 = (AliMUONTrack*) fRecTracksPtr->After(track1);
1030 } // track1
d837040f 1031 return;
1032}
1033
b8dc484b 1034 //__________________________________________________________________________
29f1b13a 1035void AliMUONTrackReconstructor::UpdateHitForRecAtHit()
b8dc484b 1036{
2457f726 1037 /// Set cluster parameters after track fitting. Fill fHitForRecAtHit of AliMUONTrack's
b8dc484b 1038 AliMUONTrack *track;
de2cd600 1039 AliMUONTrackParam *trackParamAtHit;
b8dc484b 1040 track = (AliMUONTrack*) fRecTracksPtr->First();
1041 while (track) {
de2cd600 1042 trackParamAtHit = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->First());
1043 while (trackParamAtHit) {
1044 track->AddHitForRecAtHit(trackParamAtHit->GetHitForRecPtr());
1045 trackParamAtHit = (AliMUONTrackParam*) (track->GetTrackParamAtHit()->After(trackParamAtHit));
1046 }
b8dc484b 1047 track = (AliMUONTrack*) fRecTracksPtr->After(track);
de2cd600 1048 }
b8dc484b 1049 return;
1050}
1051
8429a5e4 1052 //__________________________________________________________________________
29f1b13a 1053void AliMUONTrackReconstructor::EventDump(void)
04b5ea16 1054{
2457f726 1055 /// Dump reconstructed event (track parameters at vertex and at first hit),
1056 /// and the particle parameters
04b5ea16 1057 AliMUONTrack *track;
1058 AliMUONTrackParam *trackParam, *trackParam1;
04b5ea16 1059 Double_t bendingSlope, nonBendingSlope, pYZ;
1060 Double_t pX, pY, pZ, x, y, z, c;
5e671e06 1061 Int_t trackIndex, nTrackHits;
04b5ea16 1062
b840996b 1063 AliDebug(1,"****** enter EventDump ******");
1064 AliDebug(1, Form("Number of Reconstructed tracks : %d", fNRecTracks));
1065
04b5ea16 1066 fRecTracksPtr->Compress(); // for simple loop without "Next" since no hole
1067 // Loop over reconstructed tracks
1068 for (trackIndex = 0; trackIndex < fNRecTracks; trackIndex++) {
b840996b 1069 AliDebug(1, Form("track number: %d", trackIndex));
04b5ea16 1070 // function for each track for modularity ????
1071 track = (AliMUONTrack*) ((*fRecTracksPtr)[trackIndex]);
1072 nTrackHits = track->GetNTrackHits();
b840996b 1073 AliDebug(1, Form("Number of track hits: %d ", nTrackHits));
04b5ea16 1074 // track parameters at Vertex
1075 trackParam = track->GetTrackParamAtVertex();
1076 x = trackParam->GetNonBendingCoor();
1077 y = trackParam->GetBendingCoor();
1078 z = trackParam->GetZ();
1079 bendingSlope = trackParam->GetBendingSlope();
1080 nonBendingSlope = trackParam->GetNonBendingSlope();
1081 pYZ = 1/TMath::Abs(trackParam->GetInverseBendingMomentum());
1082 pZ = pYZ/TMath::Sqrt(1+bendingSlope*bendingSlope);
1083 pX = pZ * nonBendingSlope;
1084 pY = pZ * bendingSlope;
1085 c = TMath::Sign(1.0, trackParam->GetInverseBendingMomentum());
b840996b 1086 AliDebug(1, Form("Track parameters at Vertex z= %f: X= %f Y= %f pX= %f pY= %f pZ= %f c= %f\n",
1087 z, x, y, pX, pY, pZ, c));
04b5ea16 1088
1089 // track parameters at first hit
de2cd600 1090 trackParam1 = (AliMUONTrackParam*) track->GetTrackParamAtHit()->First();
04b5ea16 1091 x = trackParam1->GetNonBendingCoor();
1092 y = trackParam1->GetBendingCoor();
1093 z = trackParam1->GetZ();
1094 bendingSlope = trackParam1->GetBendingSlope();
1095 nonBendingSlope = trackParam1->GetNonBendingSlope();
1096 pYZ = 1/TMath::Abs(trackParam1->GetInverseBendingMomentum());
1097 pZ = pYZ/TMath::Sqrt(1.0 + bendingSlope * bendingSlope);
1098 pX = pZ * nonBendingSlope;
1099 pY = pZ * bendingSlope;
1100 c = TMath::Sign(1.0, trackParam1->GetInverseBendingMomentum());
b840996b 1101 AliDebug(1, Form("track parameters at z= %f: X= %f Y= %f pX= %f pY= %f pZ= %f c= %f\n",
1102 z, x, y, pX, pY, pZ, c));
04b5ea16 1103 }
8f373020 1104 // informations about generated particles NO !!!!!!!!
04b5ea16 1105
88cb7938 1106// for (Int_t iPart = 0; iPart < np; iPart++) {
1107// p = gAlice->Particle(iPart);
1108// printf(" particle %d: type= %d px= %f py= %f pz= %f pdg= %d\n",
1109// iPart, p->GetPdgCode(), p->Px(), p->Py(), p->Pz(), p->GetPdgCode());
1110// }
a9e2aefa 1111 return;
1112}
1113
276c44b7 1114