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 ///////////////////////////////////////////////////////////////////////////////
23 // Alex Bercuci <A.Bercuci@gsi.de> //
24 // Markus Fasel <M.Fasel@gsi.de> //
26 ///////////////////////////////////////////////////////////////////////////////
29 #include <TDirectory.h>
30 #include <TLinearFitter.h>
32 #include <TClonesArray.h>
33 #include <TTreeStream.h>
34 #include <TGeoMatrix.h>
35 #include <TGeoManager.h>
38 #include "AliMathBase.h"
39 #include "AliESDEvent.h"
40 #include "AliGeomManager.h"
41 #include "AliRieman.h"
42 #include "AliTrackPointArray.h"
44 #include "AliTRDgeometry.h"
45 #include "AliTRDpadPlane.h"
46 #include "AliTRDcalibDB.h"
47 #include "AliTRDReconstructor.h"
48 #include "AliTRDCalibraFillHisto.h"
49 #include "AliTRDrecoParam.h"
51 #include "AliTRDcluster.h"
52 #include "AliTRDseedV1.h"
53 #include "AliTRDtrackV1.h"
54 #include "AliTRDtrackerV1.h"
55 #include "AliTRDtrackerDebug.h"
56 #include "AliTRDtrackingChamber.h"
57 #include "AliTRDchamberTimeBin.h"
59 ClassImp(AliTRDtrackerV1)
61 const Float_t AliTRDtrackerV1::fgkMinClustersInTrack = 0.5; //
62 const Float_t AliTRDtrackerV1::fgkLabelFraction = 0.8; //
63 const Double_t AliTRDtrackerV1::fgkMaxChi2 = 12.0; //
64 const Double_t AliTRDtrackerV1::fgkMaxSnp = 0.95; // Maximum local sine of the azimuthal angle
65 const Double_t AliTRDtrackerV1::fgkMaxStep = 2.0; // Maximal step size in propagation
66 Double_t AliTRDtrackerV1::fgTopologicQA[kNConfigs] = {
67 0.5112, 0.5112, 0.5112, 0.0786, 0.0786,
68 0.0786, 0.0786, 0.0579, 0.0579, 0.0474,
69 0.0474, 0.0408, 0.0335, 0.0335, 0.0335
71 const Double_t AliTRDtrackerV1::fgkX0[kNPlanes] = {
72 300.2, 312.8, 325.4, 338.0, 350.6, 363.2};
73 Int_t AliTRDtrackerV1::fgNTimeBins = 0;
74 AliRieman* AliTRDtrackerV1::fgRieman = NULL;
75 TLinearFitter* AliTRDtrackerV1::fgTiltedRieman = NULL;
76 TLinearFitter* AliTRDtrackerV1::fgTiltedRiemanConstrained = NULL;
78 //____________________________________________________________________
79 AliTRDtrackerV1::AliTRDtrackerV1(AliTRDReconstructor *rec)
81 ,fkReconstructor(NULL)
89 // Default constructor.
92 SetReconstructor(rec); // initialize reconstructor
94 // initialize geometry
95 if(!AliGeomManager::GetGeometry()){
96 AliFatal("Could not get geometry.");
98 fGeom = new AliTRDgeometry();
99 fGeom->CreateClusterMatrixArray();
100 TGeoHMatrix *matrix = NULL;
101 Double_t loc[] = {0., 0., 0.};
102 Double_t glb[] = {0., 0., 0.};
103 for(Int_t ily=kNPlanes; ily--;){
105 while(!(matrix = fGeom->GetClusterMatrix(AliTRDgeometry::GetDetector(ily, 2, ism)))) ism++;
107 AliError(Form("Could not get transformation matrix for layer %d. Use default.", ily));
108 fR[ily] = fgkX0[ily];
111 matrix->LocalToMaster(loc, glb);
112 fR[ily] = glb[0]+ AliTRDgeometry::AnodePos()-.5*AliTRDgeometry::AmThick() - AliTRDgeometry::DrThick();
115 // initialize calibration values
116 AliTRDcalibDB *trd = NULL;
117 if (!(trd = AliTRDcalibDB::Instance())) {
118 AliFatal("Could not get calibration.");
120 if(!fgNTimeBins) fgNTimeBins = trd->GetNumberOfTimeBins();
122 // initialize cluster containers
123 for (Int_t isector = 0; isector < AliTRDgeometry::kNsector; isector++) new(&fTrSec[isector]) AliTRDtrackingSector(fGeom, isector);
126 memset(fTrackQuality, 0, kMaxTracksStack*sizeof(Double_t));
127 memset(fSeedLayer, 0, kMaxTracksStack*sizeof(Int_t));
128 memset(fSeedTB, 0, kNSeedPlanes*sizeof(AliTRDchamberTimeBin*));
131 //____________________________________________________________________
132 AliTRDtrackerV1::~AliTRDtrackerV1()
138 if(fgRieman) delete fgRieman; fgRieman = NULL;
139 if(fgTiltedRieman) delete fgTiltedRieman; fgTiltedRieman = NULL;
140 if(fgTiltedRiemanConstrained) delete fgTiltedRiemanConstrained; fgTiltedRiemanConstrained = NULL;
141 for(Int_t isl =0; isl<kNSeedPlanes; isl++) if(fSeedTB[isl]) delete fSeedTB[isl];
142 if(fTracks) {fTracks->Delete(); delete fTracks;}
143 if(fTracklets) {fTracklets->Delete(); delete fTracklets;}
145 fClusters->Delete(); delete fClusters;
147 if(fGeom) delete fGeom;
150 //____________________________________________________________________
151 Int_t AliTRDtrackerV1::Clusters2Tracks(AliESDEvent *esd)
154 // Steering stand alone tracking for full TRD detector
157 // esd : The ESD event. On output it contains
158 // the ESD tracks found in TRD.
161 // Number of tracks found in the TRD detector.
163 // Detailed description
164 // 1. Launch individual SM trackers.
165 // See AliTRDtrackerV1::Clusters2TracksSM() for details.
168 if(!fkReconstructor->GetRecoParam() ){
169 AliError("Reconstruction configuration not initialized. Call first AliTRDReconstructor::SetRecoParam().");
173 //AliInfo("Start Track Finder ...");
175 for(int ism=0; ism<AliTRDgeometry::kNsector; ism++){
176 // for(int ism=1; ism<2; ism++){
177 //AliInfo(Form("Processing supermodule %i ...", ism));
178 ntracks += Clusters2TracksSM(ism, esd);
180 AliInfo(Form("Number of found tracks : %d", ntracks));
185 //_____________________________________________________________________________
186 Bool_t AliTRDtrackerV1::GetTrackPoint(Int_t index, AliTrackPoint &p) const
188 //AliInfo(Form("Asking for tracklet %d", index));
190 // reset position of the point before using it
191 p.SetXYZ(0., 0., 0.);
192 AliTRDseedV1 *tracklet = GetTracklet(index);
193 if (!tracklet) return kFALSE;
195 // get detector for this tracklet
196 Int_t det = tracklet->GetDetector();
197 Int_t sec = fGeom->GetSector(det);
198 Double_t alpha = (sec+.5)*AliTRDgeometry::GetAlpha(),
199 sinA = TMath::Sin(alpha),
200 cosA = TMath::Cos(alpha);
202 local[0] = tracklet->GetX();
203 local[1] = tracklet->GetY();
204 local[2] = tracklet->GetZ();
206 fGeom->RotateBack(det, local, global);
208 Double_t cov2D[3]; Float_t cov[6];
209 tracklet->GetCovAt(local[0], cov2D);
210 cov[0] = cov2D[0]*sinA*sinA;
211 cov[1] =-cov2D[0]*sinA*cosA;
212 cov[2] =-cov2D[1]*sinA;
213 cov[3] = cov2D[0]*cosA*cosA;
214 cov[4] = cov2D[1]*cosA;
216 // store the global position of the tracklet and its covariance matrix in the track point
217 p.SetXYZ(global[0],global[1],global[2], cov);
220 AliGeomManager::ELayerID iLayer = AliGeomManager::ELayerID(AliGeomManager::kTRD1+fGeom->GetLayer(det));
221 Int_t modId = fGeom->GetSector(det) * AliTRDgeometry::kNstack + fGeom->GetStack(det);
222 UShort_t volid = AliGeomManager::LayerToVolUID(iLayer, modId);
223 p.SetVolumeID(volid);
228 //____________________________________________________________________
229 TLinearFitter* AliTRDtrackerV1::GetTiltedRiemanFitter()
231 if(!fgTiltedRieman) fgTiltedRieman = new TLinearFitter(4, "hyp4");
232 return fgTiltedRieman;
235 //____________________________________________________________________
236 TLinearFitter* AliTRDtrackerV1::GetTiltedRiemanFitterConstraint()
238 if(!fgTiltedRiemanConstrained) fgTiltedRiemanConstrained = new TLinearFitter(2, "hyp2");
239 return fgTiltedRiemanConstrained;
242 //____________________________________________________________________
243 AliRieman* AliTRDtrackerV1::GetRiemanFitter()
245 if(!fgRieman) fgRieman = new AliRieman(AliTRDseedV1::kNtb * AliTRDgeometry::kNlayer);
249 //_____________________________________________________________________________
250 Int_t AliTRDtrackerV1::PropagateBack(AliESDEvent *event)
252 // Propagation of ESD tracks from TPC to TOF detectors and building of the TRD track. For building
253 // a TRD track an ESD track is used as seed. The informations obtained on the TRD track (measured points,
254 // covariance, PID, etc.) are than used to update the corresponding ESD track.
255 // Each track seed is first propagated to the geometrical limit of the TRD detector.
256 // Its prolongation is searched in the TRD and if corresponding clusters are found tracklets are
257 // constructed out of them (see AliTRDseedV1::AttachClusters()) and the track is updated.
258 // Otherwise the ESD track is left unchanged.
260 // The following steps are performed:
261 // 1. Selection of tracks based on the variance in the y-z plane.
262 // 2. Propagation to the geometrical limit of the TRD volume. If track propagation fails the AliESDtrack::kTRDStop is set.
263 // 3. Prolongation inside the fiducial volume (see AliTRDtrackerV1::FollowBackProlongation()) and marking
264 // the following status bits:
265 // - AliESDtrack::kTRDin - if the tracks enters the TRD fiducial volume
266 // - AliESDtrack::kTRDStop - if the tracks fails propagation
267 // - AliESDtrack::kTRDbackup - if the tracks fulfills chi2 conditions and qualify for refitting
268 // 4. Writting to friends, PID, MC label, quality etc. Setting status bit AliESDtrack::kTRDout.
269 // 5. Propagation to TOF. If track propagation fails the AliESDtrack::kTRDStop is set.
272 AliTRDCalibraFillHisto *calibra = AliTRDCalibraFillHisto::Instance(); // Calibration monitor
273 if (!calibra) AliInfo("Could not get Calibra instance\n");
276 Int_t nFound = 0, // number of tracks found
277 nSeeds = 0, // total number of ESD seeds
278 nTRDseeds= 0, // number of seeds in the TRD acceptance
279 nTPCseeds= 0; // number of TPC seeds
280 Float_t foundMin = 20.0;
282 Float_t *quality = NULL;
284 nSeeds = event->GetNumberOfTracks();
285 // Sort tracks according to quality
286 // (covariance in the yz plane)
288 quality = new Float_t[nSeeds];
289 index = new Int_t[nSeeds];
290 for (Int_t iSeed = nSeeds; iSeed--;) {
291 AliESDtrack *seed = event->GetTrack(iSeed);
292 Double_t covariance[15];
293 seed->GetExternalCovariance(covariance);
294 quality[iSeed] = covariance[0] + covariance[2];
296 TMath::Sort(nSeeds, quality, index,kFALSE);
299 // Propagate all seeds
302 for (Int_t iSeed = 0; iSeed < nSeeds; iSeed++) {
304 // Get the seeds in sorted sequence
305 AliESDtrack *seed = event->GetTrack(index[iSeed]);
306 Float_t p4 = seed->GetC(seed->GetBz());
308 // Check the seed status
309 ULong_t status = seed->GetStatus();
310 if ((status & AliESDtrack::kTPCout) == 0) continue;
311 if ((status & AliESDtrack::kTRDout) != 0) continue;
313 // Propagate to the entrance in the TRD mother volume
314 new(&track) AliTRDtrackV1(*seed);
315 if(AliTRDgeometry::GetXtrdBeg() > (fgkMaxStep + track.GetX()) && !PropagateToX(track, AliTRDgeometry::GetXtrdBeg(), fgkMaxStep)){
316 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
319 if(!AdjustSector(&track)){
320 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
323 if(TMath::Abs(track.GetSnp()) > fgkMaxSnp) {
324 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
330 // store track status at TRD entrance
331 seed->UpdateTrackParams(&track, AliESDtrack::kTRDbackup);
333 // prepare track and do propagation in the TRD
334 track.SetReconstructor(fkReconstructor);
335 track.SetKink(Bool_t(seed->GetKinkIndex(0)));
336 expectedClr = FollowBackProlongation(track);
337 // check if track entered the TRD fiducial volume
338 if(track.GetTrackLow()){
339 seed->UpdateTrackParams(&track, AliESDtrack::kTRDin);
342 // check if track was stopped in the TRD
344 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
350 // computes PID for track
352 // update calibration references using this track
353 if(calibra->GetHisto2d()) calibra->UpdateHistogramsV1(&track);
354 // save calibration object
355 if (fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) > 0){
356 AliTRDtrackV1 *calibTrack = new AliTRDtrackV1(track);
357 calibTrack->SetOwner();
358 seed->AddCalibObject(calibTrack);
361 if ((track.GetNumberOfClusters() > 15) && (track.GetNumberOfClusters() > 0.5*expectedClr)) {
362 seed->UpdateTrackParams(&track, AliESDtrack::kTRDout);
363 track.UpdateESDtrack(seed);
367 if ((TMath::Abs(track.GetC(track.GetBz()) - p4) / TMath::Abs(p4) < 0.2) ||(track.Pt() > 0.8)) {
369 // Make backup for back propagation
370 Int_t foundClr = track.GetNumberOfClusters();
371 if (foundClr >= foundMin) {
372 track.CookLabel(1. - fgkLabelFraction);
373 //if(track.GetBackupTrack()) UseClusters(track.GetBackupTrack());
375 // Sign only gold tracks
376 if (track.GetChi2() / track.GetNumberOfClusters() < 4) {
377 //if ((seed->GetKinkIndex(0) == 0) && (track.Pt() < 1.5)) UseClusters(&track);
379 Bool_t isGold = kFALSE;
382 if (track.GetChi2() / track.GetNumberOfClusters() < 5) {
383 if (track.GetBackupTrack()) seed->UpdateTrackParams(track.GetBackupTrack(),AliESDtrack::kTRDbackup);
389 if ((!isGold) && (track.GetNCross() == 0) && (track.GetChi2() / track.GetNumberOfClusters() < 7)) {
390 //seed->UpdateTrackParams(track, AliESDtrack::kTRDbackup);
391 if (track.GetBackupTrack()) seed->UpdateTrackParams(track.GetBackupTrack(),AliESDtrack::kTRDbackup);
396 if ((!isGold) && (track.GetBackupTrack())) {
397 if ((track.GetBackupTrack()->GetNumberOfClusters() > foundMin) && ((track.GetBackupTrack()->GetChi2()/(track.GetBackupTrack()->GetNumberOfClusters()+1)) < 7)) {
398 seed->UpdateTrackParams(track.GetBackupTrack(),AliESDtrack::kTRDbackup);
405 // Propagation to the TOF
406 if(!(seed->GetStatus()&AliESDtrack::kTRDStop)) {
407 Int_t sm = track.GetSector();
408 // default value in case we have problems with the geometry.
409 Double_t xtof = 371.;
410 //Calculate radial position of the beginning of the TOF
411 //mother volume. In order to avoid mixing of the TRD
412 //and TOF modules some hard values are needed. This are:
413 //1. The path to the TOF module.
414 //2. The width of the TOF (29.05 cm)
415 //(with the help of Annalisa de Caro Mar-17-2009)
417 gGeoManager->cd(Form("/ALIC_1/B077_1/BSEGMO%d_1/BTOF%d_1", sm, sm));
418 TGeoHMatrix *m = NULL;
419 Double_t loc[]={0., 0., -.5*29.05}, glob[3];
421 if((m=gGeoManager->GetCurrentMatrix())){
422 m->LocalToMaster(loc, glob);
423 xtof = TMath::Sqrt(glob[0]*glob[0]+glob[1]*glob[1]);
426 if(xtof > (fgkMaxStep + track.GetX()) && !PropagateToX(track, xtof, fgkMaxStep)){
427 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
430 if(!AdjustSector(&track)){
431 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
434 if(TMath::Abs(track.GetSnp()) > fgkMaxSnp){
435 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
438 seed->UpdateTrackParams(&track, AliESDtrack::kTRDout);
439 // TODO obsolete - delete
440 seed->SetTRDQuality(track.StatusForTOF());
442 seed->SetTRDBudget(track.GetBudget(0));
444 if(index) delete [] index;
445 if(quality) delete [] quality;
447 AliInfo(Form("Number of seeds: TPCout[%d] TRDin[%d]", nTPCseeds, nTRDseeds));
448 AliInfo(Form("Number of tracks: TRDout[%d]", nFound));
450 // run stand alone tracking
451 if (fkReconstructor->IsSeeding()) Clusters2Tracks(event);
457 //____________________________________________________________________
458 Int_t AliTRDtrackerV1::RefitInward(AliESDEvent *event)
461 // Refits tracks within the TRD. The ESD event is expected to contain seeds
462 // at the outer part of the TRD.
463 // The tracks are propagated to the innermost time bin
464 // of the TRD and the ESD event is updated
465 // Origin: Thomas KUHR (Thomas.Kuhr@cern.ch)
468 Int_t nseed = 0; // contor for loaded seeds
469 Int_t found = 0; // contor for updated TRD tracks
473 for (Int_t itrack = 0; itrack < event->GetNumberOfTracks(); itrack++) {
474 AliESDtrack *seed = event->GetTrack(itrack);
475 new(&track) AliTRDtrackV1(*seed);
477 if (track.GetX() < 270.0) {
478 seed->UpdateTrackParams(&track, AliESDtrack::kTRDbackup);
482 // reject tracks which failed propagation in the TRD or
483 // are produced by the TRD stand alone tracker
484 ULong_t status = seed->GetStatus();
485 if(!(status & AliESDtrack::kTRDout)) continue;
486 if(!(status & AliESDtrack::kTRDin)) continue;
489 track.ResetCovariance(50.0);
491 // do the propagation and processing
492 Bool_t kUPDATE = kFALSE;
493 Double_t xTPC = 250.0;
494 if(FollowProlongation(track)){
496 if (PropagateToX(track, xTPC, fgkMaxStep)) { // -with update
497 seed->UpdateTrackParams(&track, AliESDtrack::kTRDrefit);
502 // Update the friend track
503 if (fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) > 0){
504 TObject *o = NULL; Int_t ic = 0;
505 AliTRDtrackV1 *calibTrack = NULL;
506 while((o = seed->GetCalibObject(ic++))){
507 if(!(calibTrack = dynamic_cast<AliTRDtrackV1*>(o))) continue;
508 calibTrack->SetTrackHigh(track.GetTrackHigh());
513 // Prolongate to TPC without update
515 AliTRDtrackV1 tt(*seed);
516 if (PropagateToX(tt, xTPC, fgkMaxStep)) seed->UpdateTrackParams(&tt, AliESDtrack::kTRDbackup);
519 AliInfo(Form("Number of loaded seeds: %d",nseed));
520 AliInfo(Form("Number of found tracks from loaded seeds: %d",found));
525 //____________________________________________________________________
526 Int_t AliTRDtrackerV1::FollowProlongation(AliTRDtrackV1 &t)
528 // Extrapolates the TRD track in the TPC direction.
531 // t : the TRD track which has to be extrapolated
534 // number of clusters attached to the track
536 // Detailed description
538 // Starting from current radial position of track <t> this function
539 // extrapolates the track through the 6 TRD layers. The following steps
540 // are being performed for each plane:
542 // a. get plane limits in the local x direction
543 // b. check crossing sectors
544 // c. check track inclination
545 // 2. search tracklet in the tracker list (see GetTracklet() for details)
546 // 3. evaluate material budget using the geo manager
547 // 4. propagate and update track using the tracklet information.
552 Bool_t kStoreIn = kTRUE;
553 Int_t nClustersExpected = 0;
554 for (Int_t iplane = kNPlanes; iplane--;) {
556 AliTRDseedV1 *tracklet = GetTracklet(&t, iplane, index);
557 if(!tracklet) continue;
558 if(!tracklet->IsOK()) AliWarning("tracklet not OK");
560 Double_t x = tracklet->GetX();//GetX0();
561 // reject tracklets which are not considered for inward refit
562 if(x > t.GetX()+fgkMaxStep) continue;
564 // append tracklet to track
565 t.SetTracklet(tracklet, index);
567 if (x < (t.GetX()-fgkMaxStep) && !PropagateToX(t, x+fgkMaxStep, fgkMaxStep)) break;
568 if (!AdjustSector(&t)) break;
570 // Start global position
574 // End global position
575 Double_t alpha = t.GetAlpha(), y, z;
576 if (!t.GetProlongation(x,y,z)) break;
578 xyz1[0] = x * TMath::Cos(alpha) - y * TMath::Sin(alpha);
579 xyz1[1] = x * TMath::Sin(alpha) + y * TMath::Cos(alpha);
582 Double_t length = TMath::Sqrt(
583 (xyz0[0]-xyz1[0])*(xyz0[0]-xyz1[0]) +
584 (xyz0[1]-xyz1[1])*(xyz0[1]-xyz1[1]) +
585 (xyz0[2]-xyz1[2])*(xyz0[2]-xyz1[2])
588 // Get material budget
590 if(AliTracker::MeanMaterialBudget(xyz0, xyz1, param)<=0.) break;
591 Double_t xrho= param[0]*param[4];
592 Double_t xx0 = param[1]; // Get mean propagation parameters
594 // Propagate and update
595 t.PropagateTo(x, xx0, xrho);
596 if (!AdjustSector(&t)) break;
603 Double_t cov[3]; tracklet->GetCovAt(x, cov);
604 Double_t p[2] = { tracklet->GetY(), tracklet->GetZ()};
605 Double_t chi2 = ((AliExternalTrackParam)t).GetPredictedChi2(p, cov);
606 if (chi2 < 1e+10 && t.Update(p, cov, chi2)){
607 nClustersExpected += tracklet->GetN();
611 if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) > 1){
613 for(int iplane=0; iplane<AliTRDgeometry::kNlayer; iplane++){
614 AliTRDseedV1 *tracklet = GetTracklet(&t, iplane, index);
615 if(!tracklet) continue;
616 t.SetTracklet(tracklet, index);
619 if(fkReconstructor->IsDebugStreaming()){
620 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
621 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
622 AliTRDtrackV1 track(t);
624 cstreamer << "FollowProlongation"
625 << "EventNumber=" << eventNumber
626 << "ncl=" << nClustersExpected
627 << "track.=" << &track
631 return nClustersExpected;
635 //_____________________________________________________________________________
636 Int_t AliTRDtrackerV1::FollowBackProlongation(AliTRDtrackV1 &t)
638 // Extrapolates/Build the TRD track in the TOF direction.
641 // t : the TRD track which has to be extrapolated
644 // number of clusters attached to the track
646 // Starting from current radial position of track <t> this function
647 // extrapolates the track through the 6 TRD layers. The following steps
648 // are being performed for each plane:
649 // 1. Propagate track to the entrance of the next chamber:
650 // - get chamber limits in the radial direction
651 // - check crossing sectors
652 // - check track inclination
653 // - check track prolongation against boundary conditions (see exclusion boundaries on AliTRDgeometry::IsOnBoundary())
654 // 2. Build tracklet (see AliTRDseed::AttachClusters() for details) for this layer if needed. If only
655 // Kalman filter is needed and tracklets are already linked to the track this step is skipped.
656 // 3. Fit tracklet using the information from the Kalman filter.
657 // 4. Propagate and update track at reference radial position of the tracklet.
658 // 5. Register tracklet with the tracker and track; update pulls monitoring.
661 // 1. During the propagation a bit map is filled detailing the status of the track in each TRD chamber. The following errors are being registered for each tracklet:
662 // - AliTRDtrackV1::kProlongation : track prolongation failed
663 // - AliTRDtrackV1::kPropagation : track prolongation failed
664 // - AliTRDtrackV1::kAdjustSector : failed during sector crossing
665 // - AliTRDtrackV1::kSnp : too large bending
666 // - AliTRDtrackV1::kTrackletInit : fail to initialize tracklet
667 // - AliTRDtrackV1::kUpdate : fail to attach clusters or fit the tracklet
668 // - AliTRDtrackV1::kUnknown : anything which is not covered before
669 // 2. By default the status of the track before first TRD update is saved.
674 // Alexandru Bercuci <A.Bercuci@gsi.de>
678 Double_t driftLength = .5*AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick();
679 AliTRDtrackingChamber *chamber = NULL;
681 Int_t debugLevel = fkReconstructor->IsDebugStreaming() ? fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) : 0;
682 TTreeSRedirector *cstreamer = fkReconstructor->IsDebugStreaming() ? fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker) : 0x0;
684 AliTRDseedV1 tracklet, *ptrTracklet = NULL;
685 // in case of stand alone tracking we store all the pointers to the tracklets in a temporary array
686 AliTRDseedV1 *tracklets[kNPlanes];
687 memset(tracklets, 0, sizeof(AliTRDseedV1 *) * kNPlanes);
688 for(Int_t ip = 0; ip < kNPlanes; ip++){
689 tracklets[ip] = t.GetTracklet(ip);
692 Bool_t kStoreIn = kTRUE, kPropagateIn = kTRUE;
694 // Loop through the TRD layers
695 TGeoHMatrix *matrix = NULL;
697 for (Int_t ily=0, sm=-1, stk=-1, det=-1; ily < AliTRDgeometry::kNlayer; ily++) {
698 // rough estimate of the entry point
699 if (!t.GetProlongation(fR[ily], y, z)){
701 t.SetStatus(AliTRDtrackV1::kProlongation);
705 // find sector / stack / detector
707 // TODO cross check with y value !
708 stk = fGeom->GetStack(z, ily);
709 det = stk>=0 ? AliTRDgeometry::GetDetector(ily, stk, sm) : -1;
710 matrix = det>=0 ? fGeom->GetClusterMatrix(det) : NULL;
712 // check if supermodule/chamber is installed
713 if( !fGeom->GetSMstatus(sm) ||
715 fGeom->IsHole(ily, stk, sm) ||
717 // propagate to the default radial position
718 if(fR[ily] > (fgkMaxStep + t.GetX()) && !PropagateToX(t, fR[ily], fgkMaxStep)){
720 t.SetStatus(AliTRDtrackV1::kPropagation);
723 if(!AdjustSector(&t)){
725 t.SetStatus(AliTRDtrackV1::kAdjustSector);
728 if(TMath::Abs(t.GetSnp()) > fgkMaxSnp){
730 t.SetStatus(AliTRDtrackV1::kSnp);
733 t.SetStatus(AliTRDtrackV1::kGeometry, ily);
737 // retrieve rotation matrix for the current chamber
738 Double_t loc[] = {AliTRDgeometry::AnodePos()- driftLength, 0., 0.};
739 Double_t glb[] = {0., 0., 0.};
740 matrix->LocalToMaster(loc, glb);
742 // Propagate to the radial distance of the current layer
743 x = glb[0] - fgkMaxStep;
744 if(x > (fgkMaxStep + t.GetX()) && !PropagateToX(t, x, fgkMaxStep)){
746 t.SetStatus(AliTRDtrackV1::kPropagation);
749 if(!AdjustSector(&t)){
751 t.SetStatus(AliTRDtrackV1::kAdjustSector);
754 if(TMath::Abs(t.GetSnp()) > fgkMaxSnp) {
756 t.SetStatus(AliTRDtrackV1::kSnp);
759 Bool_t doRecalculate = kFALSE;
760 if(sm != t.GetSector()){
762 doRecalculate = kTRUE;
764 if(stk != fGeom->GetStack(z, ily)){
765 stk = fGeom->GetStack(z, ily);
766 doRecalculate = kTRUE;
769 det = AliTRDgeometry::GetDetector(ily, stk, sm);
770 if(!(matrix = fGeom->GetClusterMatrix(det))){
771 t.SetStatus(AliTRDtrackV1::kGeometry, ily);
774 matrix->LocalToMaster(loc, glb);
775 x = glb[0] - fgkMaxStep;
778 // check if track is well inside fiducial volume
779 if (!t.GetProlongation(x+fgkMaxStep, y, z)) {
781 t.SetStatus(AliTRDtrackV1::kProlongation);
784 if(fGeom->IsOnBoundary(det, y, z, .5)){
785 t.SetStatus(AliTRDtrackV1::kBoundary, ily);
788 // mark track as entering the FIDUCIAL volume of TRD
794 ptrTracklet = tracklets[ily];
795 if(!ptrTracklet){ // BUILD TRACKLET
796 // check data in supermodule
797 if(!fTrSec[sm].GetNChambers()){
798 t.SetStatus(AliTRDtrackV1::kNoClusters, ily);
801 if(fTrSec[sm].GetX(ily) < 1.){
802 t.SetStatus(AliTRDtrackV1::kNoClusters, ily);
806 // check data in chamber
807 if(!(chamber = fTrSec[sm].GetChamber(stk, ily))){
808 t.SetStatus(AliTRDtrackV1::kNoClusters, ily);
811 if(chamber->GetNClusters() < fgNTimeBins*fkReconstructor->GetRecoParam() ->GetFindableClusters()){
812 t.SetStatus(AliTRDtrackV1::kNoClusters, ily);
816 ptrTracklet = new(&tracklet) AliTRDseedV1(det);
817 ptrTracklet->SetReconstructor(fkReconstructor);
818 ptrTracklet->SetKink(t.IsKink());
819 ptrTracklet->SetPadPlane(fGeom->GetPadPlane(ily, stk));
820 ptrTracklet->SetX0(glb[0]+driftLength);
821 if(!tracklet.Init(&t)){
823 t.SetStatus(AliTRDtrackV1::kTrackletInit);
826 if(!tracklet.AttachClusters(chamber, kTRUE)){
827 t.SetStatus(AliTRDtrackV1::kNoAttach, ily);
829 AliTRDseedV1 trackletCp(*ptrTracklet);
830 UChar_t status(t.GetStatusTRD(ily));
831 (*cstreamer) << "FollowBackProlongation2"
832 <<"status=" << status
833 <<"tracklet.=" << &trackletCp
838 if(tracklet.GetN() < fgNTimeBins*fkReconstructor->GetRecoParam() ->GetFindableClusters()){
839 t.SetStatus(AliTRDtrackV1::kNoClustersTracklet, ily);
841 AliTRDseedV1 trackletCp(*ptrTracklet);
842 UChar_t status(t.GetStatusTRD(ily));
843 (*cstreamer) << "FollowBackProlongation2"
844 <<"status=" << status
845 <<"tracklet.=" << &trackletCp
850 ptrTracklet->UpdateUsed();
852 // propagate track to the radial position of the tracklet
853 ptrTracklet->UseClusters(); // TODO ? do we need this here ?
854 // fit tracklet no tilt correction
855 if(!ptrTracklet->Fit(kFALSE)){
856 t.SetStatus(AliTRDtrackV1::kNoFit, ily);
859 x = ptrTracklet->GetX(); //GetX0();
860 if(x > (fgkMaxStep + t.GetX()) && !PropagateToX(t, x, fgkMaxStep)) {
862 t.SetStatus(AliTRDtrackV1::kPropagation);
865 if(!AdjustSector(&t)) {
867 t.SetStatus(AliTRDtrackV1::kAdjustSector);
870 if(TMath::Abs(t.GetSnp()) > fgkMaxSnp) {
872 t.SetStatus(AliTRDtrackV1::kSnp);
877 kPropagateIn = kFALSE;
879 Double_t cov[3]; ptrTracklet->GetCovAt(x, cov);
880 Double_t p[2] = { ptrTracklet->GetY(), ptrTracklet->GetZ()};
881 Double_t chi2 = ((AliExternalTrackParam)t).GetPredictedChi2(p, cov);
882 // update Kalman with the TRD measurement
883 if(chi2>1e+10){ // TODO
884 t.SetStatus(AliTRDtrackV1::kChi2, ily);
886 UChar_t status(t.GetStatusTRD());
887 AliTRDseedV1 trackletCp(*ptrTracklet);
888 AliTRDtrackV1 trackCp(t);
890 (*cstreamer) << "FollowBackProlongation1"
891 << "status=" << status
892 << "tracklet.=" << &trackletCp
893 << "track.=" << &trackCp
898 if(!t.Update(p, cov, chi2)) {
900 t.SetStatus(AliTRDtrackV1::kUpdate);
902 UChar_t status(t.GetStatusTRD());
903 AliTRDseedV1 trackletCp(*ptrTracklet);
904 AliTRDtrackV1 trackCp(t);
906 (*cstreamer) << "FollowBackProlongation1"
907 << "status=" << status
908 << "tracklet.=" << &trackletCp
909 << "track.=" << &trackCp
915 AliTracker::FillResiduals(&t, p, cov, ptrTracklet->GetVolumeId());
918 // load tracklet to the tracker
919 ptrTracklet->Update(&t);
920 ptrTracklet = SetTracklet(ptrTracklet);
921 t.SetTracklet(ptrTracklet, fTracklets->GetEntriesFast()-1);
922 n += ptrTracklet->GetN();
924 // Reset material budget if 2 consecutive gold
925 // if(ilayer>0 && t.GetTracklet(ilayer-1) && ptrTracklet->GetN() + t.GetTracklet(ilayer-1)->GetN() > 20) t.SetBudget(2, 0.);
927 // Make backup of the track until is gold
928 // TO DO update quality check of the track.
929 // consider comparison with fTimeBinsRange
930 Float_t ratio0 = ptrTracklet->GetN() / Float_t(fgNTimeBins);
931 //Float_t ratio1 = Float_t(t.GetNumberOfClusters()+1) / Float_t(t.GetNExpected()+1);
936 //(ratio0+ratio1 > 1.5) &&
937 (t.GetNCross() == 0) &&
938 (TMath::Abs(t.GetSnp()) < 0.85) &&
939 (t.GetNumberOfClusters() > 20)){
943 //printf("clusters[%d] chi2[%f] x[%f] status[%d ", n, t.GetChi2(), t.GetX(), t.GetStatusTRD());
944 //for(int i=0; i<6; i++) printf("%d ", t.GetStatusTRD(i)); printf("]\n");
947 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
948 AliTRDtrackV1 track(t);
950 (*cstreamer) << "FollowBackProlongation0"
951 << "EventNumber=" << eventNumber
953 << "track.=" << &track
960 //_________________________________________________________________________
961 Float_t AliTRDtrackerV1::FitRieman(AliTRDseedV1 *tracklets, Double_t *chi2, Int_t *const planes){
963 // Fits a Riemann-circle to the given points without tilting pad correction.
964 // The fit is performed using an instance of the class AliRieman (equations
965 // and transformations see documentation of this class)
966 // Afterwards all the tracklets are Updated
968 // Parameters: - Array of tracklets (AliTRDseedV1)
969 // - Storage for the chi2 values (beginning with direction z)
970 // - Seeding configuration
971 // Output: - The curvature
973 AliRieman *fitter = AliTRDtrackerV1::GetRiemanFitter();
975 Int_t allplanes[] = {0, 1, 2, 3, 4, 5};
976 Int_t *ppl = &allplanes[0];
982 for(Int_t il = 0; il < maxLayers; il++){
983 if(!tracklets[ppl[il]].IsOK()) continue;
984 fitter->AddPoint(tracklets[ppl[il]].GetX0(), tracklets[ppl[il]].GetYfit(0), tracklets[ppl[il]].GetZfit(0),1,10);
987 // Set the reference position of the fit and calculate the chi2 values
988 memset(chi2, 0, sizeof(Double_t) * 2);
989 for(Int_t il = 0; il < maxLayers; il++){
990 // Reference positions
991 tracklets[ppl[il]].Init(fitter);
994 if((!tracklets[ppl[il]].IsOK()) && (!planes)) continue;
995 chi2[0] += tracklets[ppl[il]].GetChi2Y();
996 chi2[1] += tracklets[ppl[il]].GetChi2Z();
998 return fitter->GetC();
1001 //_________________________________________________________________________
1002 void AliTRDtrackerV1::FitRieman(AliTRDcluster **seedcl, Double_t chi2[2])
1005 // Performs a Riemann helix fit using the seedclusters as spacepoints
1006 // Afterwards the chi2 values are calculated and the seeds are updated
1008 // Parameters: - The four seedclusters
1009 // - The tracklet array (AliTRDseedV1)
1010 // - The seeding configuration
1015 AliRieman *fitter = AliTRDtrackerV1::GetRiemanFitter();
1017 for(Int_t i = 0; i < 4; i++){
1018 fitter->AddPoint(seedcl[i]->GetX(), seedcl[i]->GetY(), seedcl[i]->GetZ(), 1., 10.);
1023 // Update the seed and calculated the chi2 value
1024 chi2[0] = 0; chi2[1] = 0;
1025 for(Int_t ipl = 0; ipl < kNSeedPlanes; ipl++){
1027 chi2[0] += (seedcl[ipl]->GetZ() - fitter->GetZat(seedcl[ipl]->GetX())) * (seedcl[ipl]->GetZ() - fitter->GetZat(seedcl[ipl]->GetX()));
1028 chi2[1] += (seedcl[ipl]->GetY() - fitter->GetYat(seedcl[ipl]->GetX())) * (seedcl[ipl]->GetY() - fitter->GetYat(seedcl[ipl]->GetX()));
1033 //_________________________________________________________________________
1034 Float_t AliTRDtrackerV1::FitTiltedRiemanConstraint(AliTRDseedV1 *tracklets, Double_t zVertex)
1037 // Fits a helix to the clusters. Pad tilting is considered. As constraint it is
1038 // assumed that the vertex position is set to 0.
1039 // This method is very usefull for high-pt particles
1040 // Basis for the fit: (x - x0)^2 + (y - y0)^2 - R^2 = 0
1041 // x0, y0: Center of the circle
1042 // Measured y-position: ymeas = y - tan(phiT)(zc - zt)
1043 // zc: center of the pad row
1044 // Equation which has to be fitted (after transformation):
1045 // a + b * u + e * v + 2*(ymeas + tan(phiT)(z - zVertex))*t = 0
1047 // t = 1/(x^2 + y^2)
1049 // v = 2 * x * tan(phiT) * t
1050 // Parameters in the equation:
1051 // a = -1/y0, b = x0/y0, e = dz/dx
1053 // The Curvature is calculated by the following equation:
1054 // - curv = a/Sqrt(b^2 + 1) = 1/R
1055 // Parameters: - the 6 tracklets
1056 // - the Vertex constraint
1057 // Output: - the Chi2 value of the track
1062 TLinearFitter *fitter = GetTiltedRiemanFitterConstraint();
1063 fitter->StoreData(kTRUE);
1064 fitter->ClearPoints();
1065 AliTRDcluster *cl = NULL;
1067 Float_t x, y, z, w, t, error, tilt;
1070 for(Int_t ilr = 0; ilr < AliTRDgeometry::kNlayer; ilr++){
1071 if(!tracklets[ilr].IsOK()) continue;
1072 for(Int_t itb = 0; itb < AliTRDseedV1::kNclusters; itb++){
1073 if(!tracklets[ilr].IsUsable(itb)) continue;
1074 cl = tracklets[ilr].GetClusters(itb);
1075 if(!cl->IsInChamber()) continue;
1079 tilt = tracklets[ilr].GetTilt();
1081 t = 1./(x * x + y * y);
1082 uvt[0] = 2. * x * t;
1083 uvt[1] = 2. * x * t * tilt ;
1084 w = 2. * (y + tilt * (z - zVertex)) * t;
1085 error = 2. * TMath::Sqrt(cl->GetSigmaY2()+tilt*tilt*cl->GetSigmaZ2()) * t;
1086 fitter->AddPoint(uvt, w, error);
1092 // Calculate curvature
1093 Double_t a = fitter->GetParameter(0);
1094 Double_t b = fitter->GetParameter(1);
1095 Double_t curvature = a/TMath::Sqrt(b*b + 1);
1097 Float_t chi2track = fitter->GetChisquare()/Double_t(nPoints);
1098 for(Int_t ip = 0; ip < AliTRDtrackerV1::kNPlanes; ip++)
1099 tracklets[ip].SetC(curvature);
1101 /* if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker()) >= 5){
1102 //Linear Model on z-direction
1103 Double_t xref = CalculateReferenceX(tracklets); // Relative to the middle of the stack
1104 Double_t slope = fitter->GetParameter(2);
1105 Double_t zref = slope * xref;
1106 Float_t chi2Z = CalculateChi2Z(tracklets, zref, slope, xref);
1107 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
1108 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
1109 TTreeSRedirector &treeStreamer = *fkReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
1110 treeStreamer << "FitTiltedRiemanConstraint"
1111 << "EventNumber=" << eventNumber
1112 << "CandidateNumber=" << candidateNumber
1113 << "Curvature=" << curvature
1114 << "Chi2Track=" << chi2track
1115 << "Chi2Z=" << chi2Z
1122 //_________________________________________________________________________
1123 Float_t AliTRDtrackerV1::FitTiltedRieman(AliTRDseedV1 *tracklets, Bool_t sigError)
1126 // Performs a Riemann fit taking tilting pad correction into account
1127 // The equation of a Riemann circle, where the y position is substituted by the
1128 // measured y-position taking pad tilting into account, has to be transformed
1129 // into a 4-dimensional hyperplane equation
1130 // Riemann circle: (x-x0)^2 + (y-y0)^2 -R^2 = 0
1131 // Measured y-Position: ymeas = y - tan(phiT)(zc - zt)
1132 // zc: center of the pad row
1133 // zt: z-position of the track
1134 // The z-position of the track is assumed to be linear dependent on the x-position
1135 // Transformed equation: a + b * u + c * t + d * v + e * w - 2 * (ymeas + tan(phiT) * zc) * t = 0
1136 // Transformation: u = 2 * x * t
1137 // v = 2 * tan(phiT) * t
1138 // w = 2 * tan(phiT) * (x - xref) * t
1139 // t = 1 / (x^2 + ymeas^2)
1140 // Parameters: a = -1/y0
1142 // c = (R^2 -x0^2 - y0^2)/y0
1145 // If the offset respectively the slope in z-position is impossible, the parameters are fixed using
1146 // results from the simple riemann fit. Afterwards the fit is redone.
1147 // The curvature is calculated according to the formula:
1148 // curv = a/(1 + b^2 + c*a) = 1/R
1150 // Paramters: - Array of tracklets (connected to the track candidate)
1151 // - Flag selecting the error definition
1152 // Output: - Chi2 values of the track (in Parameter list)
1154 TLinearFitter *fitter = GetTiltedRiemanFitter();
1155 fitter->StoreData(kTRUE);
1156 fitter->ClearPoints();
1157 AliTRDLeastSquare zfitter;
1158 AliTRDcluster *cl = NULL;
1160 Double_t xref = CalculateReferenceX(tracklets);
1161 Double_t x, y, z, t, tilt, dx, w, we, erry, errz;
1162 Double_t uvt[4], sumPolY[5], sumPolZ[3];
1163 memset(sumPolY, 0, sizeof(Double_t) * 5);
1164 memset(sumPolZ, 0, sizeof(Double_t) * 3);
1166 // Containers for Least-square fitter
1167 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1168 if(!tracklets[ipl].IsOK()) continue;
1169 tilt = tracklets[ipl].GetTilt();
1170 for(Int_t itb = 0; itb < AliTRDseedV1::kNclusters; itb++){
1171 if(!(cl = tracklets[ipl].GetClusters(itb))) continue;
1172 if(!cl->IsInChamber()) continue;
1173 if (!tracklets[ipl].IsUsable(itb)) continue;
1180 uvt[0] = 2. * x * t;
1182 uvt[2] = 2. * tilt * t;
1183 uvt[3] = 2. * tilt * dx * t;
1184 w = 2. * (y + tilt*z) * t;
1185 // error definition changes for the different calls
1187 we *= sigError ? TMath::Sqrt(cl->GetSigmaY2()+tilt*tilt*cl->GetSigmaZ2()) : 0.2;
1188 fitter->AddPoint(uvt, w, we);
1189 zfitter.AddPoint(&x, z, static_cast<Double_t>(TMath::Sqrt(cl->GetSigmaZ2())));
1190 // adding points for covariance matrix estimation
1191 erry = 1./(TMath::Sqrt(cl->GetSigmaY2()) + 0.1); // 0.1 is a systematic error (due to misalignment and miscalibration)
1193 errz = 1./cl->GetSigmaZ2();
1194 for(Int_t ipol = 0; ipol < 5; ipol++){
1195 sumPolY[ipol] += erry;
1198 sumPolZ[ipol] += errz;
1208 Double_t offset = fitter->GetParameter(3);
1209 Double_t slope = fitter->GetParameter(4);
1211 // Linear fitter - not possible to make boundaries
1212 // Do not accept non possible z and dzdx combinations
1213 Bool_t acceptablez = kTRUE;
1214 Double_t zref = 0.0;
1215 for (Int_t iLayer = 0; iLayer < kNPlanes; iLayer++) {
1216 if(!tracklets[iLayer].IsOK()) continue;
1217 zref = offset + slope * (tracklets[iLayer].GetX0() - xref);
1218 if (TMath::Abs(tracklets[iLayer].GetZfit(0) - zref) > tracklets[iLayer].GetPadLength() * 0.5 + 1.0)
1219 acceptablez = kFALSE;
1222 Double_t dzmf = zfitter.GetFunctionParameter(1);
1223 Double_t zmf = zfitter.GetFunctionValue(&xref);
1224 fgTiltedRieman->FixParameter(3, zmf);
1225 fgTiltedRieman->FixParameter(4, dzmf);
1227 fitter->ReleaseParameter(3);
1228 fitter->ReleaseParameter(4);
1229 offset = fitter->GetParameter(3);
1230 slope = fitter->GetParameter(4);
1233 // Calculate Curvarture
1234 Double_t a = fitter->GetParameter(0);
1235 Double_t b = fitter->GetParameter(1);
1236 Double_t c = fitter->GetParameter(2);
1237 Double_t curvature = 1.0 + b*b - c*a;
1238 if (curvature > 0.0)
1239 curvature = a / TMath::Sqrt(curvature);
1241 Double_t chi2track = fitter->GetChisquare()/Double_t(nPoints);
1243 // Prepare error calculation
1244 TMatrixD covarPolY(3,3);
1245 covarPolY(0,0) = sumPolY[0]; covarPolY(1,1) = sumPolY[2]; covarPolY(2,2) = sumPolY[4];
1246 covarPolY(0,1) = covarPolY(1,0) = sumPolY[1];
1247 covarPolY(0,2) = covarPolY(2,0) = sumPolY[2];
1248 covarPolY(2,1) = covarPolY(1,2) = sumPolY[3];
1250 TMatrixD covarPolZ(2,2);
1251 covarPolZ(0,0) = sumPolZ[0]; covarPolZ(1,1) = sumPolZ[2];
1252 covarPolZ(1,0) = covarPolZ(0,1) = sumPolZ[1];
1255 // Update the tracklets
1256 Double_t x1, dy, dz;
1258 memset(cov, 0, sizeof(Double_t) * 15);
1259 for(Int_t iLayer = 0; iLayer < AliTRDtrackerV1::kNPlanes; iLayer++) {
1261 x = tracklets[iLayer].GetX0();
1267 memset(cov, 0, sizeof(Double_t) * 3);
1268 TMatrixD transform(3,3);
1271 transform(0,2) = x*x;
1275 TMatrixD covariance(transform, TMatrixD::kMult, covarPolY);
1276 covariance *= transform.T();
1277 TMatrixD transformZ(2,2);
1278 transformZ(0,0) = transformZ(1,1) = 1;
1279 transformZ(0,1) = x;
1280 TMatrixD covarZ(transformZ, TMatrixD::kMult, covarPolZ);
1281 covarZ *= transformZ.T();
1282 // y: R^2 = (x - x0)^2 + (y - y0)^2
1283 // => y = y0 +/- Sqrt(R^2 - (x - x0)^2)
1284 // R = Sqrt() = 1/Curvature
1285 // => y = y0 +/- Sqrt(1/Curvature^2 - (x - x0)^2)
1286 Double_t res = (x * a + b); // = (x - x0)/y0
1288 res = 1.0 - c * a + b * b - res; // = (R^2 - (x - x0)^2)/y0^2
1290 res = TMath::Sqrt(res);
1291 y = (1.0 - res) / a;
1293 cov[0] = covariance(0,0);
1294 cov[2] = covarZ(0,0);
1297 // dy: R^2 = (x - x0)^2 + (y - y0)^2
1298 // => y = +/- Sqrt(R^2 - (x - x0)^2) + y0
1299 // => dy/dx = (x - x0)/Sqrt(R^2 - (x - x0)^2)
1300 // Curvature: cr = 1/R = a/Sqrt(1 + b^2 - c*a)
1301 // => dy/dx = (x - x0)/(1/(cr^2) - (x - x0)^2)
1302 Double_t x0 = -b / a;
1303 if (-c * a + b * b + 1 > 0) {
1304 if (1.0/(curvature * curvature) - (x - x0) * (x - x0) > 0.0) {
1305 Double_t yderiv = (x - x0) / TMath::Sqrt(1.0/(curvature * curvature) - (x - x0) * (x - x0));
1306 if (a < 0) yderiv *= -1.0;
1310 z = offset + slope * (x - xref);
1312 tracklets[iLayer].SetYref(0, y);
1313 tracklets[iLayer].SetYref(1, dy);
1314 tracklets[iLayer].SetZref(0, z);
1315 tracklets[iLayer].SetZref(1, dz);
1316 tracklets[iLayer].SetC(curvature);
1317 tracklets[iLayer].SetCovRef(cov);
1318 tracklets[iLayer].SetChi2(chi2track);
1321 /* if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) >=5){
1322 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
1323 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
1324 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
1325 Double_t chi2z = CalculateChi2Z(tracklets, offset, slope, xref);
1326 cstreamer << "FitTiltedRieman0"
1327 << "EventNumber=" << eventNumber
1328 << "CandidateNumber=" << candidateNumber
1330 << "Chi2Z=" << chi2z
1337 //____________________________________________________________________
1338 Double_t AliTRDtrackerV1::FitLine(const AliTRDtrackV1 *track, AliTRDseedV1 *tracklets, Bool_t err, Int_t np, AliTrackPoint *points)
1341 // Fit track with a staight line
1342 // Fills an AliTrackPoint array with np points
1343 // Function should be used to refit tracks when no magnetic field was on
1345 AliTRDLeastSquare yfitter, zfitter;
1346 AliTRDcluster *cl = NULL;
1348 AliTRDseedV1 work[kNPlanes], *tracklet = NULL;
1350 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1351 if(!(tracklet = track->GetTracklet(ipl))) continue;
1352 if(!tracklet->IsOK()) continue;
1353 new(&work[ipl]) AliTRDseedV1(*tracklet);
1355 tracklets = &work[0];
1358 Double_t xref = CalculateReferenceX(tracklets);
1359 Double_t x, y, z, dx, ye, yr, tilt;
1360 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1361 if(!tracklets[ipl].IsOK()) continue;
1362 for(Int_t itb = 0; itb < fgNTimeBins; itb++){
1363 if(!(cl = tracklets[ipl].GetClusters(itb))) continue;
1364 if (!tracklets[ipl].IsUsable(itb)) continue;
1368 zfitter.AddPoint(&dx, z, static_cast<Double_t>(TMath::Sqrt(cl->GetSigmaZ2())));
1372 Double_t z0 = zfitter.GetFunctionParameter(0);
1373 Double_t dzdx = zfitter.GetFunctionParameter(1);
1374 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1375 if(!tracklets[ipl].IsOK()) continue;
1376 for(Int_t itb = 0; itb < fgNTimeBins; itb++){
1377 if(!(cl = tracklets[ipl].GetClusters(itb))) continue;
1378 if (!tracklets[ipl].IsUsable(itb)) continue;
1382 tilt = tracklets[ipl].GetTilt();
1384 yr = y + tilt*(z - z0 - dzdx*dx);
1385 // error definition changes for the different calls
1386 ye = tilt*TMath::Sqrt(cl->GetSigmaZ2());
1387 ye += err ? tracklets[ipl].GetSigmaY() : 0.2;
1388 yfitter.AddPoint(&dx, yr, ye);
1392 Double_t y0 = yfitter.GetFunctionParameter(0);
1393 Double_t dydx = yfitter.GetFunctionParameter(1);
1394 Double_t chi2 = 0.;//yfitter.GetChisquare()/Double_t(nPoints);
1396 //update track points array
1399 for(int ip=0; ip<np; ip++){
1400 points[ip].GetXYZ(xyz);
1401 xyz[1] = y0 + dydx * (xyz[0] - xref);
1402 xyz[2] = z0 + dzdx * (xyz[0] - xref);
1403 points[ip].SetXYZ(xyz);
1410 //_________________________________________________________________________
1411 Double_t AliTRDtrackerV1::FitRiemanTilt(const AliTRDtrackV1 *track, AliTRDseedV1 *tracklets, Bool_t sigError, Int_t np, AliTrackPoint *points)
1414 // Performs a Riemann fit taking tilting pad correction into account
1416 // Paramters: - Array of tracklets (connected to the track candidate)
1417 // - Flag selecting the error definition
1418 // Output: - Chi2 values of the track (in Parameter list)
1420 // The equations which has to be solved simultaneously are:
1422 // R^{2} = (x-x_{0})^{2} + (y^{*}-y_{0})^{2}
1423 // y^{*} = y - tg(h)(z - z_{t})
1424 // z_{t} = z_{0}+dzdx*(x-x_{r})
1426 // with (x, y, z) the coordinate of the cluster, (x_0, y_0, z_0) the coordinate of the center of the Riemann circle,
1427 // R its radius, x_r a constant refrence radial position in the middle of the TRD stack and dzdx the slope of the
1428 // track in the x-z plane. Using the following transformations
1430 // t = 1 / (x^{2} + y^{2})
1432 // v = 2 * tan(h) * t
1433 // w = 2 * tan(h) * (x - x_{r}) * t
1435 // One gets the following linear equation
1437 // a + b * u + c * t + d * v + e * w = 2 * (y + tg(h) * z) * t
1439 // where the coefficients have the following meaning
1443 // c = (R^{2} -x_{0}^{2} - y_{0}^{2})/y_{0}
1447 // The error calculation for the free term is thus
1449 // #sigma = 2 * #sqrt{#sigma^{2}_{y} + (tilt corr ...) + tg^{2}(h) * #sigma^{2}_{z}} * t
1452 // From this simple model one can compute chi^2 estimates and a rough approximation of pt from the curvature according
1455 // C = 1/R = a/(1 + b^{2} + c*a)
1459 // M.Ivanov <M.Ivanov@gsi.de>
1460 // A.Bercuci <A.Bercuci@gsi.de>
1461 // M.Fasel <M.Fasel@gsi.de>
1463 TLinearFitter *fitter = GetTiltedRiemanFitter();
1464 fitter->StoreData(kTRUE);
1465 fitter->ClearPoints();
1466 AliTRDLeastSquare zfitter;
1467 AliTRDcluster *cl = NULL;
1469 AliTRDseedV1 work[kNPlanes], *tracklet = NULL;
1471 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1472 if(!(tracklet = track->GetTracklet(ipl))) continue;
1473 if(!tracklet->IsOK()) continue;
1474 new(&work[ipl]) AliTRDseedV1(*tracklet);
1476 tracklets = &work[0];
1479 Double_t xref = CalculateReferenceX(tracklets);
1480 Double_t x, y, z, t, tilt, dx, w, we;
1483 // Containers for Least-square fitter
1484 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1485 if(!tracklets[ipl].IsOK()) continue;
1486 for(Int_t itb = 0; itb < AliTRDseedV1::kNclusters; itb++){
1487 if(!(cl = tracklets[ipl].GetClusters(itb))) continue;
1488 if (!tracklets[ipl].IsUsable(itb)) continue;
1492 tilt = tracklets[ipl].GetTilt();
1496 uvt[0] = 2. * x * t;
1498 uvt[2] = 2. * tilt * t;
1499 uvt[3] = 2. * tilt * dx * t;
1500 w = 2. * (y + tilt*z) * t;
1501 // error definition changes for the different calls
1503 we *= sigError ? TMath::Sqrt(cl->GetSigmaY2()) : 0.2;
1504 fitter->AddPoint(uvt, w, we);
1505 zfitter.AddPoint(&x, z, static_cast<Double_t>(TMath::Sqrt(cl->GetSigmaZ2())));
1509 if(fitter->Eval()) return 1.E10;
1511 Double_t z0 = fitter->GetParameter(3);
1512 Double_t dzdx = fitter->GetParameter(4);
1515 // Linear fitter - not possible to make boundaries
1516 // Do not accept non possible z and dzdx combinations
1517 Bool_t accept = kTRUE;
1518 Double_t zref = 0.0;
1519 for (Int_t iLayer = 0; iLayer < kNPlanes; iLayer++) {
1520 if(!tracklets[iLayer].IsOK()) continue;
1521 zref = z0 + dzdx * (tracklets[iLayer].GetX0() - xref);
1522 if (TMath::Abs(tracklets[iLayer].GetZfit(0) - zref) > tracklets[iLayer].GetPadLength() * 0.5 + 1.0)
1527 Double_t dzmf = zfitter.GetFunctionParameter(1);
1528 Double_t zmf = zfitter.GetFunctionValue(&xref);
1529 fitter->FixParameter(3, zmf);
1530 fitter->FixParameter(4, dzmf);
1532 fitter->ReleaseParameter(3);
1533 fitter->ReleaseParameter(4);
1534 z0 = fitter->GetParameter(3); // = zmf ?
1535 dzdx = fitter->GetParameter(4); // = dzmf ?
1538 // Calculate Curvature
1539 Double_t a = fitter->GetParameter(0);
1540 Double_t b = fitter->GetParameter(1);
1541 Double_t c = fitter->GetParameter(2);
1542 Double_t y0 = 1. / a;
1543 Double_t x0 = -b * y0;
1544 Double_t tmp = y0*y0 + x0*x0 - c*y0;
1545 if(tmp<=0.) return 1.E10;
1546 Double_t radius = TMath::Sqrt(tmp);
1547 Double_t curvature = 1.0 + b*b - c*a;
1548 if (curvature > 0.0) curvature = a / TMath::Sqrt(curvature);
1550 // Calculate chi2 of the fit
1551 Double_t chi2 = fitter->GetChisquare()/Double_t(nPoints);
1553 // Update the tracklets
1555 for(Int_t ip = 0; ip < kNPlanes; ip++) {
1556 x = tracklets[ip].GetX0();
1557 tmp = radius*radius-(x-x0)*(x-x0);
1558 if(tmp <= 0.) continue;
1559 tmp = TMath::Sqrt(tmp);
1561 // y: R^2 = (x - x0)^2 + (y - y0)^2
1562 // => y = y0 +/- Sqrt(R^2 - (x - x0)^2)
1563 tracklets[ip].SetYref(0, y0 - (y0>0.?1.:-1)*tmp);
1564 // => dy/dx = (x - x0)/Sqrt(R^2 - (x - x0)^2)
1565 tracklets[ip].SetYref(1, (x - x0) / tmp);
1566 tracklets[ip].SetZref(0, z0 + dzdx * (x - xref));
1567 tracklets[ip].SetZref(1, dzdx);
1568 tracklets[ip].SetC(curvature);
1569 tracklets[ip].SetChi2(chi2);
1572 //update track points array
1575 for(int ip=0; ip<np; ip++){
1576 points[ip].GetXYZ(xyz);
1577 xyz[1] = TMath::Abs(xyz[0] - x0) > radius ? 100. : y0 - (y0>0.?1.:-1.)*TMath::Sqrt((radius-(xyz[0]-x0))*(radius+(xyz[0]-x0)));
1578 xyz[2] = z0 + dzdx * (xyz[0] - xref);
1579 points[ip].SetXYZ(xyz);
1587 //____________________________________________________________________
1588 Double_t AliTRDtrackerV1::FitKalman(AliTRDtrackV1 *track, AliTRDseedV1 * const tracklets, Bool_t up, Int_t np, AliTrackPoint *points)
1590 // Kalman filter implementation for the TRD.
1591 // It returns the positions of the fit in the array "points"
1593 // Author : A.Bercuci@gsi.de
1595 // printf("Start track @ x[%f]\n", track->GetX());
1597 //prepare marker points along the track
1598 Int_t ip = np ? 0 : 1;
1600 if((up?-1:1) * (track->GetX() - points[ip].GetX()) > 0.) break;
1601 //printf("AliTRDtrackerV1::FitKalman() : Skip track marker x[%d] = %7.3f. Before track start ( %7.3f ).\n", ip, points[ip].GetX(), track->GetX());
1604 //if(points) printf("First marker point @ x[%d] = %f\n", ip, points[ip].GetX());
1607 AliTRDseedV1 tracklet, *ptrTracklet = NULL;
1609 //Loop through the TRD planes
1610 for (Int_t jplane = 0; jplane < kNPlanes; jplane++) {
1611 // GET TRACKLET OR BUILT IT
1612 Int_t iplane = up ? jplane : kNPlanes - 1 - jplane;
1614 if(!(ptrTracklet = &tracklets[iplane])) continue;
1616 if(!(ptrTracklet = track->GetTracklet(iplane))){
1617 /*AliTRDtrackerV1 *tracker = NULL;
1618 if(!(tracker = dynamic_cast<AliTRDtrackerV1*>( AliTRDrecoParam:Tracker()))) continue;
1619 ptrTracklet = new(&tracklet) AliTRDseedV1(iplane);
1620 if(!tracker->MakeTracklet(ptrTracklet, track)) */
1624 if(!ptrTracklet->IsOK()) continue;
1626 Double_t x = ptrTracklet->GetX0();
1629 //don't do anything if next marker is after next update point.
1630 if((up?-1:1) * (points[ip].GetX() - x) - fgkMaxStep < 0) break;
1631 if(((up?-1:1) * (points[ip].GetX() - track->GetX()) < 0) && !PropagateToX(*track, points[ip].GetX(), fgkMaxStep)) return -1.;
1633 Double_t xyz[3]; // should also get the covariance
1635 track->Global2LocalPosition(xyz, track->GetAlpha());
1636 points[ip].SetXYZ(xyz[0], xyz[1], xyz[2]);
1639 // printf("plane[%d] tracklet[%p] x[%f]\n", iplane, ptrTracklet, x);
1641 // Propagate closer to the next update point
1642 if(((up?-1:1) * (x - track->GetX()) + fgkMaxStep < 0) && !PropagateToX(*track, x + (up?-1:1)*fgkMaxStep, fgkMaxStep)) return -1.;
1644 if(!AdjustSector(track)) return -1;
1645 if(TMath::Abs(track->GetSnp()) > fgkMaxSnp) return -1;
1647 //load tracklet to the tracker and the track
1649 if((index = FindTracklet(ptrTracklet)) < 0){
1650 ptrTracklet = SetTracklet(&tracklet);
1651 index = fTracklets->GetEntriesFast()-1;
1653 track->SetTracklet(ptrTracklet, index);*/
1656 // register tracklet to track with tracklet creation !!
1657 // PropagateBack : loaded tracklet to the tracker and update index
1658 // RefitInward : update index
1659 // MakeTrack : loaded tracklet to the tracker and update index
1660 if(!tracklets) track->SetTracklet(ptrTracklet, -1);
1663 //Calculate the mean material budget along the path inside the chamber
1664 Double_t xyz0[3]; track->GetXYZ(xyz0);
1665 Double_t alpha = track->GetAlpha();
1666 Double_t xyz1[3], y, z;
1667 if(!track->GetProlongation(x, y, z)) return -1;
1668 xyz1[0] = x * TMath::Cos(alpha) - y * TMath::Sin(alpha);
1669 xyz1[1] = +x * TMath::Sin(alpha) + y * TMath::Cos(alpha);
1671 if((xyz0[0] - xyz1[9] < 1e-3) && (xyz0[0] - xyz1[9] < 1e-3)) continue; // check wheter we are at the same global x position
1673 if(AliTracker::MeanMaterialBudget(xyz0, xyz1, param) <=0.) break;
1674 Double_t xrho = param[0]*param[4]; // density*length
1675 Double_t xx0 = param[1]; // radiation length
1677 //Propagate the track
1678 track->PropagateTo(x, xx0, xrho);
1679 if (!AdjustSector(track)) break;
1682 Double_t cov[3]; ptrTracklet->GetCovAt(x, cov);
1683 Double_t p[2] = { ptrTracklet->GetY(), ptrTracklet->GetZ()};
1684 Double_t chi2 = ((AliExternalTrackParam*)track)->GetPredictedChi2(p, cov);
1685 if(chi2<1e+10) track->Update(p, cov, chi2);
1688 //Reset material budget if 2 consecutive gold
1689 if(iplane>0 && track->GetTracklet(iplane-1) && ptrTracklet->GetN() + track->GetTracklet(iplane-1)->GetN() > 20) track->SetBudget(2, 0.);
1690 } // end planes loop
1694 if(((up?-1:1) * (points[ip].GetX() - track->GetX()) < 0) && !PropagateToX(*track, points[ip].GetX(), fgkMaxStep)) return -1.;
1696 Double_t xyz[3]; // should also get the covariance
1698 track->Global2LocalPosition(xyz, track->GetAlpha());
1699 points[ip].SetXYZ(xyz[0], xyz[1], xyz[2]);
1703 return track->GetChi2();
1706 //_________________________________________________________________________
1707 Float_t AliTRDtrackerV1::CalculateChi2Z(AliTRDseedV1 *tracklets, Double_t offset, Double_t slope, Double_t xref)
1710 // Calculates the chi2-value of the track in z-Direction including tilting pad correction.
1711 // A linear dependence on the x-value serves as a model.
1712 // The parameters are related to the tilted Riemann fit.
1713 // Parameters: - Array of tracklets (AliTRDseedV1) related to the track candidate
1714 // - the offset for the reference x
1716 // - the reference x position
1717 // Output: - The Chi2 value of the track in z-Direction
1719 Float_t chi2Z = 0, nLayers = 0;
1720 for (Int_t iLayer = 0; iLayer < AliTRDgeometry::kNlayer; iLayer++) {
1721 if(!tracklets[iLayer].IsOK()) continue;
1722 Double_t z = offset + slope * (tracklets[iLayer].GetX0() - xref);
1723 chi2Z += TMath::Abs(tracklets[iLayer].GetZfit(0) - z);
1726 chi2Z /= TMath::Max((nLayers - 3.0),1.0);
1730 //_____________________________________________________________________________
1731 Int_t AliTRDtrackerV1::PropagateToX(AliTRDtrackV1 &t, Double_t xToGo, Double_t maxStep)
1734 // Starting from current X-position of track <t> this function
1735 // extrapolates the track up to radial position <xToGo>.
1736 // Returns 1 if track reaches the plane, and 0 otherwise
1739 const Double_t kEpsilon = 0.00001;
1741 // Current track X-position
1742 Double_t xpos = t.GetX();
1744 // Direction: inward or outward
1745 Double_t dir = (xpos < xToGo) ? 1.0 : -1.0;
1747 while (((xToGo - xpos) * dir) > kEpsilon) {
1756 // The next step size
1757 Double_t step = dir * TMath::Min(TMath::Abs(xToGo-xpos),maxStep);
1759 // Get the global position of the starting point
1762 // X-position after next step
1765 // Get local Y and Z at the X-position of the next step
1766 if(t.GetProlongation(x,y,z)<0) return 0; // No prolongation possible
1768 // The global position of the end point of this prolongation step
1769 xyz1[0] = x * TMath::Cos(t.GetAlpha()) - y * TMath::Sin(t.GetAlpha());
1770 xyz1[1] = +x * TMath::Sin(t.GetAlpha()) + y * TMath::Cos(t.GetAlpha());
1773 // Calculate the mean material budget between start and
1774 // end point of this prolongation step
1775 if(AliTracker::MeanMaterialBudget(xyz0, xyz1, param)<=0.) return 0;
1777 // Propagate the track to the X-position after the next step
1778 if (!t.PropagateTo(x, param[1], param[0]*param[4])) return 0;
1780 // Rotate the track if necessary
1783 // New track X-position
1793 //_____________________________________________________________________________
1794 Int_t AliTRDtrackerV1::ReadClusters(TClonesArray* &array, TTree *clusterTree) const
1797 // Reads AliTRDclusters from the file.
1798 // The names of the cluster tree and branches
1799 // should match the ones used in AliTRDclusterizer::WriteClusters()
1802 Int_t nsize = Int_t(clusterTree->GetTotBytes() / (sizeof(AliTRDcluster)));
1803 TObjArray *clusterArray = new TObjArray(nsize+1000);
1805 TBranch *branch = clusterTree->GetBranch("TRDcluster");
1807 AliError("Can't get the branch !");
1810 branch->SetAddress(&clusterArray);
1813 Float_t nclusters = fkReconstructor->GetRecoParam()->GetNClusters();
1814 if(fkReconstructor->IsHLT()) nclusters /= AliTRDgeometry::kNsector;
1815 array = new TClonesArray("AliTRDcluster", Int_t(nclusters));
1816 array->SetOwner(kTRUE);
1819 // Loop through all entries in the tree
1820 Int_t nEntries = (Int_t) clusterTree->GetEntries();
1823 AliTRDcluster *c = NULL;
1824 for (Int_t iEntry = 0; iEntry < nEntries; iEntry++) {
1826 nbytes += clusterTree->GetEvent(iEntry);
1828 // Get the number of points in the detector
1829 Int_t nCluster = clusterArray->GetEntriesFast();
1830 for (Int_t iCluster = 0; iCluster < nCluster; iCluster++) {
1831 if(!(c = (AliTRDcluster *) clusterArray->UncheckedAt(iCluster))) continue;
1832 new((*fClusters)[ncl++]) AliTRDcluster(*c);
1833 delete (clusterArray->RemoveAt(iCluster));
1837 delete clusterArray;
1842 //_____________________________________________________________________________
1843 Int_t AliTRDtrackerV1::LoadClusters(TTree *cTree)
1846 // Fills clusters into TRD tracking sectors
1849 if(!fkReconstructor->IsWritingClusters()){
1850 fClusters = AliTRDReconstructor::GetClusters();
1852 if (ReadClusters(fClusters, cTree)) {
1853 AliError("Problem with reading the clusters !");
1859 if(!fClusters || !fClusters->GetEntriesFast()){
1860 AliInfo("No TRD clusters");
1865 BuildTrackingContainers();
1867 //Int_t ncl = fClusters->GetEntriesFast();
1868 //AliInfo(Form("Clusters %d [%6.2f %% in the active volume]", ncl, 100.*float(nin)/ncl));
1873 //_____________________________________________________________________________
1874 Int_t AliTRDtrackerV1::LoadClusters(TClonesArray * const clusters)
1877 // Fills clusters into TRD tracking sectors
1878 // Function for use in the HLT
1880 if(!clusters || !clusters->GetEntriesFast()){
1881 AliInfo("No TRD clusters");
1885 fClusters = clusters;
1889 BuildTrackingContainers();
1891 //Int_t ncl = fClusters->GetEntriesFast();
1892 //AliInfo(Form("Clusters %d [%6.2f %% in the active volume]", ncl, 100.*float(nin)/ncl));
1898 //____________________________________________________________________
1899 Int_t AliTRDtrackerV1::BuildTrackingContainers()
1901 // Building tracking containers for clusters
1903 Int_t nin =0, icl = fClusters->GetEntriesFast();
1905 AliTRDcluster *c = (AliTRDcluster *) fClusters->UncheckedAt(icl);
1906 if(c->IsInChamber()) nin++;
1907 Int_t detector = c->GetDetector();
1908 Int_t sector = fGeom->GetSector(detector);
1909 Int_t stack = fGeom->GetStack(detector);
1910 Int_t layer = fGeom->GetLayer(detector);
1912 fTrSec[sector].GetChamber(stack, layer, kTRUE)->InsertCluster(c, icl);
1915 const AliTRDCalDet *cal = AliTRDcalibDB::Instance()->GetT0Det();
1916 for(int isector =0; isector<AliTRDgeometry::kNsector; isector++){
1917 if(!fTrSec[isector].GetNChambers()) continue;
1918 fTrSec[isector].Init(fkReconstructor, cal);
1926 //____________________________________________________________________
1927 void AliTRDtrackerV1::UnloadClusters()
1930 // Clears the arrays of clusters and tracks. Resets sectors and timebins
1931 // If option "force" is also set the containers are also deleted. This is useful
1936 if(HasRemoveContainers()){delete fTracks; fTracks = NULL;}
1939 fTracklets->Delete();
1940 if(HasRemoveContainers()){delete fTracklets; fTracklets = NULL;}
1943 if(IsClustersOwner()) fClusters->Delete();
1945 // save clusters array in the reconstructor for further use.
1946 if(!fkReconstructor->IsWritingClusters()){
1947 AliTRDReconstructor::SetClusters(fClusters);
1948 SetClustersOwner(kFALSE);
1949 } else AliTRDReconstructor::SetClusters(NULL);
1952 for (int i = 0; i < AliTRDgeometry::kNsector; i++) fTrSec[i].Clear();
1954 // Increment the Event Number
1955 AliTRDtrackerDebug::SetEventNumber(AliTRDtrackerDebug::GetEventNumber() + 1);
1958 // //____________________________________________________________________
1959 // void AliTRDtrackerV1::UseClusters(const AliKalmanTrack *t, Int_t) const
1961 // const AliTRDtrackV1 *track = dynamic_cast<const AliTRDtrackV1*>(t);
1962 // if(!track) return;
1964 // AliTRDseedV1 *tracklet = NULL;
1965 // for(Int_t ily=AliTRDgeometry::kNlayer; ily--;){
1966 // if(!(tracklet = track->GetTracklet(ily))) continue;
1967 // AliTRDcluster *c = NULL;
1968 // for(Int_t ic=AliTRDseed::kNclusters; ic--;){
1969 // if(!(c=tracklet->GetClusters(ic))) continue;
1976 //_____________________________________________________________________________
1977 Bool_t AliTRDtrackerV1::AdjustSector(AliTRDtrackV1 *const track)
1980 // Rotates the track when necessary
1983 Double_t alpha = AliTRDgeometry::GetAlpha();
1984 Double_t y = track->GetY();
1985 Double_t ymax = track->GetX()*TMath::Tan(0.5*alpha);
1988 if (!track->Rotate( alpha)) {
1992 else if (y < -ymax) {
1993 if (!track->Rotate(-alpha)) {
2003 //____________________________________________________________________
2004 AliTRDseedV1* AliTRDtrackerV1::GetTracklet(AliTRDtrackV1 *const track, Int_t p, Int_t &idx)
2006 // Find tracklet for TRD track <track>
2015 // Detailed description
2017 idx = track->GetTrackletIndex(p);
2018 AliTRDseedV1 *tracklet = (idx==0xffff) ? NULL : (AliTRDseedV1*)fTracklets->UncheckedAt(idx);
2023 //____________________________________________________________________
2024 AliTRDseedV1* AliTRDtrackerV1::SetTracklet(const AliTRDseedV1 * const tracklet)
2026 // Add this tracklet to the list of tracklets stored in the tracker
2029 // - tracklet : pointer to the tracklet to be added to the list
2032 // - the index of the new tracklet in the tracker tracklets list
2034 // Detailed description
2035 // Build the tracklets list if it is not yet created (late initialization)
2036 // and adds the new tracklet to the list.
2039 fTracklets = new TClonesArray("AliTRDseedV1", AliTRDgeometry::Nsector()*kMaxTracksStack);
2040 fTracklets->SetOwner(kTRUE);
2042 Int_t nentries = fTracklets->GetEntriesFast();
2043 return new ((*fTracklets)[nentries]) AliTRDseedV1(*tracklet);
2046 //____________________________________________________________________
2047 AliTRDtrackV1* AliTRDtrackerV1::SetTrack(const AliTRDtrackV1 * const track)
2049 // Add this track to the list of tracks stored in the tracker
2052 // - track : pointer to the track to be added to the list
2055 // - the pointer added
2057 // Detailed description
2058 // Build the tracks list if it is not yet created (late initialization)
2059 // and adds the new track to the list.
2062 fTracks = new TClonesArray("AliTRDtrackV1", AliTRDgeometry::Nsector()*kMaxTracksStack);
2063 fTracks->SetOwner(kTRUE);
2065 Int_t nentries = fTracks->GetEntriesFast();
2066 return new ((*fTracks)[nentries]) AliTRDtrackV1(*track);
2071 //____________________________________________________________________
2072 Int_t AliTRDtrackerV1::Clusters2TracksSM(Int_t sector, AliESDEvent *esd)
2075 // Steer tracking for one SM.
2078 // sector : Array of (SM) propagation layers containing clusters
2079 // esd : The current ESD event. On output it contains the also
2080 // the ESD (TRD) tracks found in this SM.
2083 // Number of tracks found in this TRD supermodule.
2085 // Detailed description
2087 // 1. Unpack AliTRDpropagationLayers objects for each stack.
2088 // 2. Launch stack tracking.
2089 // See AliTRDtrackerV1::Clusters2TracksStack() for details.
2090 // 3. Pack results in the ESD event.
2093 // allocate space for esd tracks in this SM
2094 TClonesArray esdTrackList("AliESDtrack", 2*kMaxTracksStack);
2095 esdTrackList.SetOwner();
2098 Int_t nChambers = 0;
2099 AliTRDtrackingChamber **stack = NULL, *chamber = NULL;
2100 for(int istack = 0; istack<AliTRDgeometry::kNstack; istack++){
2101 if(!(stack = fTrSec[sector].GetStack(istack))) continue;
2103 for(int ilayer=0; ilayer<AliTRDgeometry::kNlayer; ilayer++){
2104 if(!(chamber = stack[ilayer])) continue;
2105 if(chamber->GetNClusters() < fgNTimeBins * fkReconstructor->GetRecoParam() ->GetFindableClusters()) continue;
2107 //AliInfo(Form("sector %d stack %d layer %d clusters %d", sector, istack, ilayer, chamber->GetNClusters()));
2109 if(nChambers < 4) continue;
2110 //AliInfo(Form("Doing stack %d", istack));
2111 nTracks += Clusters2TracksStack(stack, &esdTrackList);
2113 //AliInfo(Form("Found %d tracks in SM %d [%d]\n", nTracks, sector, esd->GetNumberOfTracks()));
2115 for(int itrack=0; itrack<nTracks; itrack++)
2116 esd->AddTrack((AliESDtrack*)esdTrackList[itrack]);
2118 // Reset Track and Candidate Number
2119 AliTRDtrackerDebug::SetCandidateNumber(0);
2120 AliTRDtrackerDebug::SetTrackNumber(0);
2124 //____________________________________________________________________
2125 Int_t AliTRDtrackerV1::Clusters2TracksStack(AliTRDtrackingChamber **stack, TClonesArray * const esdTrackList)
2128 // Make tracks in one TRD stack.
2131 // layer : Array of stack propagation layers containing clusters
2132 // esdTrackList : Array of ESD tracks found by the stand alone tracker.
2133 // On exit the tracks found in this stack are appended.
2136 // Number of tracks found in this stack.
2138 // Detailed description
2140 // 1. Find the 3 most useful seeding chambers. See BuildSeedingConfigs() for details.
2141 // 2. Steer AliTRDtrackerV1::MakeSeeds() for 3 seeding layer configurations.
2142 // See AliTRDtrackerV1::MakeSeeds() for more details.
2143 // 3. Arrange track candidates in decreasing order of their quality
2144 // 4. Classify tracks in 5 categories according to:
2145 // a) number of layers crossed
2147 // 5. Sign clusters by tracks in decreasing order of track quality
2148 // 6. Build AliTRDtrack out of seeding tracklets
2150 // 8. Build ESD track and register it to the output list
2153 const AliTRDCalDet *cal = AliTRDcalibDB::Instance()->GetT0Det();
2154 AliTRDtrackingChamber *chamber = NULL;
2155 AliTRDtrackingChamber **ci = NULL;
2156 AliTRDseedV1 sseed[kMaxTracksStack*6]; // to be initialized
2157 Int_t pars[4]; // MakeSeeds parameters
2159 //Double_t alpha = AliTRDgeometry::GetAlpha();
2160 //Double_t shift = .5 * alpha;
2161 Int_t configs[kNConfigs];
2163 // Purge used clusters from the containers
2165 for(Int_t ic = kNPlanes; ic--; ci++){
2166 if(!(*ci)) continue;
2170 // Build initial seeding configurations
2171 Double_t quality = BuildSeedingConfigs(stack, configs);
2172 if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) > 10){
2173 AliInfo(Form("Plane config %d %d %d Quality %f"
2174 , configs[0], configs[1], configs[2], quality));
2178 // Initialize contors
2179 Int_t ntracks, // number of TRD track candidates
2180 ntracks1, // number of registered TRD tracks/iter
2181 ntracks2 = 0; // number of all registered TRD tracks in stack
2185 Int_t ic = 0; ci = &stack[0];
2186 while(ic<kNPlanes && !(*ci)){ic++; ci++;}
2187 if(!(*ci)) return ntracks2;
2188 Int_t istack = fGeom->GetStack((*ci)->GetDetector());
2191 // Loop over seeding configurations
2192 ntracks = 0; ntracks1 = 0;
2193 for (Int_t iconf = 0; iconf<3; iconf++) {
2194 pars[0] = configs[iconf];
2197 ntracks = MakeSeeds(stack, &sseed[6*ntracks], pars);
2198 //AliInfo(Form("Number of Tracks after iteration step %d: %d\n", iconf, ntracks));
2199 if(ntracks == kMaxTracksStack) break;
2201 if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) > 1) AliInfo(Form("Candidate TRD tracks %d in iteration %d.", ntracks, fSieveSeeding));
2205 // Sort the seeds according to their quality
2206 Int_t sort[kMaxTracksStack];
2207 TMath::Sort(ntracks, fTrackQuality, sort, kTRUE);
2209 // Initialize number of tracks so far and logic switches
2210 Int_t ntracks0 = esdTrackList->GetEntriesFast();
2211 Bool_t signedTrack[kMaxTracksStack];
2212 Bool_t fakeTrack[kMaxTracksStack];
2213 for (Int_t i=0; i<ntracks; i++){
2214 signedTrack[i] = kFALSE;
2215 fakeTrack[i] = kFALSE;
2217 //AliInfo("Selecting track candidates ...");
2219 // Sieve clusters in decreasing order of track quality
2220 Double_t trackParams[7];
2221 // AliTRDseedV1 *lseed = NULL;
2222 Int_t jSieve = 0, candidates;
2224 //AliInfo(Form("\t\tITER = %i ", jSieve));
2226 // Check track candidates
2228 for (Int_t itrack = 0; itrack < ntracks; itrack++) {
2229 Int_t trackIndex = sort[itrack];
2230 if (signedTrack[trackIndex] || fakeTrack[trackIndex]) continue;
2233 // Calculate track parameters from tracklets seeds
2238 for (Int_t jLayer = 0; jLayer < kNPlanes; jLayer++) {
2239 Int_t jseed = kNPlanes*trackIndex+jLayer;
2240 if(!sseed[jseed].IsOK()) continue;
2241 if (TMath::Abs(sseed[jseed].GetYref(0) / sseed[jseed].GetX0()) < 0.158) findable++;
2242 // TODO here we get a sig fault which should never happen !
2243 sseed[jseed].UpdateUsed();
2244 ncl += sseed[jseed].GetN2();
2245 nused += sseed[jseed].GetNUsed();
2249 // Filter duplicated tracks
2251 //printf("Skip %d nused %d\n", trackIndex, nused);
2252 fakeTrack[trackIndex] = kTRUE;
2255 if (Float_t(nused)/ncl >= .25){
2256 //printf("Skip %d nused/ncl >= .25\n", trackIndex);
2257 fakeTrack[trackIndex] = kTRUE;
2262 Bool_t skip = kFALSE;
2265 if(nlayers < 6) {skip = kTRUE; break;}
2266 if(TMath::Log(1.E-9+fTrackQuality[trackIndex]) < -5.){skip = kTRUE; break;}
2270 if(nlayers < findable){skip = kTRUE; break;}
2271 if(TMath::Log(1.E-9+fTrackQuality[trackIndex]) < -4.){skip = kTRUE; break;}
2275 if ((nlayers == findable) || (nlayers == 6)) { skip = kTRUE; break;}
2276 if (TMath::Log(1.E-9+fTrackQuality[trackIndex]) < -6.0){skip = kTRUE; break;}
2280 if (TMath::Log(1.E-9+fTrackQuality[trackIndex]) < -5.){skip = kTRUE; break;}
2284 if (nlayers == 3){skip = kTRUE; break;}
2285 //if (TMath::Log(1.E-9+fTrackQuality[trackIndex]) - nused/(nlayers-3.0) < -15.0){skip = kTRUE; break;}
2290 //printf("REJECTED : %d [%d] nlayers %d trackQuality = %e nused %d\n", itrack, trackIndex, nlayers, fTrackQuality[trackIndex], nused);
2293 signedTrack[trackIndex] = kTRUE;
2295 // Build track parameters
2296 AliTRDseedV1 *lseed =&sseed[trackIndex*6];
2298 while(idx<3 && !lseed->IsOK()) {
2302 Double_t x = lseed->GetX0();// - 3.5;
2303 trackParams[0] = x; //NEW AB
2304 trackParams[1] = lseed->GetYref(0); // lseed->GetYat(x);
2305 trackParams[2] = lseed->GetZref(0); // lseed->GetZat(x);
2306 trackParams[3] = TMath::Sin(TMath::ATan(lseed->GetYref(1)));
2307 trackParams[4] = lseed->GetZref(1) / TMath::Sqrt(1. + lseed->GetYref(1) * lseed->GetYref(1));
2308 trackParams[5] = lseed->GetC();
2309 Int_t ich = 0; while(!(chamber = stack[ich])) ich++;
2310 trackParams[6] = fGeom->GetSector(chamber->GetDetector());/* *alpha+shift; // Supermodule*/
2312 if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) > 1 && fkReconstructor->IsDebugStreaming()){
2313 //AliInfo(Form("Track %d [%d] nlayers %d trackQuality = %e nused %d, yref = %3.3f", itrack, trackIndex, nlayers, fTrackQuality[trackIndex], nused, trackParams[1]));
2315 AliTRDseedV1 *dseed[6];
2316 for(Int_t iseed = AliTRDgeometry::kNlayer; iseed--;) dseed[iseed] = new AliTRDseedV1(lseed[iseed]);
2318 //Int_t eventNrInFile = esd->GetEventNumberInFile();
2319 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2320 Int_t trackNumber = AliTRDtrackerDebug::GetTrackNumber();
2321 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2322 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
2323 cstreamer << "Clusters2TracksStack"
2324 << "EventNumber=" << eventNumber
2325 << "TrackNumber=" << trackNumber
2326 << "CandidateNumber=" << candidateNumber
2327 << "Iter=" << fSieveSeeding
2328 << "Like=" << fTrackQuality[trackIndex]
2329 << "S0.=" << dseed[0]
2330 << "S1.=" << dseed[1]
2331 << "S2.=" << dseed[2]
2332 << "S3.=" << dseed[3]
2333 << "S4.=" << dseed[4]
2334 << "S5.=" << dseed[5]
2335 << "p0=" << trackParams[0]
2336 << "p1=" << trackParams[1]
2337 << "p2=" << trackParams[2]
2338 << "p3=" << trackParams[3]
2339 << "p4=" << trackParams[4]
2340 << "p5=" << trackParams[5]
2341 << "p6=" << trackParams[6]
2343 << "NLayers=" << nlayers
2344 << "Findable=" << findable
2345 << "NUsed=" << nused
2349 AliTRDtrackV1 *track = MakeTrack(&sseed[trackIndex*kNPlanes], trackParams);
2351 AliWarning("Fail to build a TRD Track.");
2355 //AliInfo("End of MakeTrack()");
2356 AliESDtrack *esdTrack = new ((*esdTrackList)[ntracks0++]) AliESDtrack();
2357 esdTrack->UpdateTrackParams(track, AliESDtrack::kTRDout);
2358 esdTrack->SetLabel(track->GetLabel());
2359 track->UpdateESDtrack(esdTrack);
2360 // write ESD-friends if neccessary
2361 if (fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) > 0){
2362 AliTRDtrackV1 *calibTrack = new AliTRDtrackV1(*track);
2363 calibTrack->SetOwner();
2364 esdTrack->AddCalibObject(calibTrack);
2367 AliTRDtrackerDebug::SetTrackNumber(AliTRDtrackerDebug::GetTrackNumber() + 1);
2371 } while(jSieve<5 && candidates); // end track candidates sieve
2372 if(!ntracks1) break;
2374 // increment counters
2375 ntracks2 += ntracks1;
2377 if(fkReconstructor->IsHLT()) break;
2380 // Rebuild plane configurations and indices taking only unused clusters into account
2381 quality = BuildSeedingConfigs(stack, configs);
2382 if(quality < 1.E-7) break; //fkReconstructor->GetRecoParam() ->GetPlaneQualityThreshold()) break;
2384 for(Int_t ip = 0; ip < kNPlanes; ip++){
2385 if(!(chamber = stack[ip])) continue;
2386 chamber->Build(fGeom, cal);//Indices(fSieveSeeding);
2389 if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) > 10){
2390 AliInfo(Form("Sieve level %d Plane config %d %d %d Quality %f", fSieveSeeding, configs[0], configs[1], configs[2], quality));
2392 } while(fSieveSeeding<10); // end stack clusters sieve
2396 //AliInfo(Form("Registered TRD tracks %d in stack %d.", ntracks2, pars[1]));
2401 //___________________________________________________________________
2402 Double_t AliTRDtrackerV1::BuildSeedingConfigs(AliTRDtrackingChamber **stack, Int_t *configs)
2405 // Assign probabilities to chambers according to their
2406 // capability of producing seeds.
2410 // layers : Array of stack propagation layers for all 6 chambers in one stack
2411 // configs : On exit array of configuration indexes (see GetSeedingConfig()
2412 // for details) in the decreasing order of their seeding probabilities.
2416 // Return top configuration quality
2418 // Detailed description:
2420 // To each chamber seeding configuration (see GetSeedingConfig() for
2421 // the list of all configurations) one defines 2 quality factors:
2422 // - an apriori topological quality (see GetSeedingConfig() for details) and
2423 // - a data quality based on the uniformity of the distribution of
2424 // clusters over the x range (time bins population). See CookChamberQA() for details.
2425 // The overall chamber quality is given by the product of this 2 contributions.
2428 Double_t chamberQ[kNPlanes];memset(chamberQ, 0, kNPlanes*sizeof(Double_t));
2429 AliTRDtrackingChamber *chamber = NULL;
2430 for(int iplane=0; iplane<kNPlanes; iplane++){
2431 if(!(chamber = stack[iplane])) continue;
2432 chamberQ[iplane] = (chamber = stack[iplane]) ? chamber->GetQuality() : 0.;
2435 Double_t tconfig[kNConfigs];memset(tconfig, 0, kNConfigs*sizeof(Double_t));
2436 Int_t planes[] = {0, 0, 0, 0};
2437 for(int iconf=0; iconf<kNConfigs; iconf++){
2438 GetSeedingConfig(iconf, planes);
2439 tconfig[iconf] = fgTopologicQA[iconf];
2440 for(int iplane=0; iplane<4; iplane++) tconfig[iconf] *= chamberQ[planes[iplane]];
2443 TMath::Sort((Int_t)kNConfigs, tconfig, configs, kTRUE);
2444 // AliInfo(Form("q[%d] = %f", configs[0], tconfig[configs[0]]));
2445 // AliInfo(Form("q[%d] = %f", configs[1], tconfig[configs[1]]));
2446 // AliInfo(Form("q[%d] = %f", configs[2], tconfig[configs[2]]));
2448 return tconfig[configs[0]];
2451 //____________________________________________________________________
2452 Int_t AliTRDtrackerV1::MakeSeeds(AliTRDtrackingChamber **stack, AliTRDseedV1 * const sseed, const Int_t * const ipar)
2455 // Seed tracklets and build candidate TRD tracks. The procedure is used during barrel tracking to account for tracks which are
2456 // either missed by TPC prolongation or conversions inside the TRD volume.
2457 // For stand alone tracking the procedure is used to estimate all tracks measured by TRD.
2460 // layers : Array of stack propagation layers containing clusters
2461 // sseed : Array of empty tracklet seeds. On exit they are filled.
2462 // ipar : Control parameters:
2463 // ipar[0] -> seeding chambers configuration
2464 // ipar[1] -> stack index
2465 // ipar[2] -> number of track candidates found so far
2468 // Number of tracks candidates found.
2470 // The following steps are performed:
2471 // 1. Build seeding layers by collapsing all time bins from each of the four seeding chambers along the
2472 // radial coordinate. See AliTRDtrackingChamber::GetSeedingLayer() for details. The chambers selection for seeding
2473 // is described in AliTRDtrackerV1::Clusters2TracksStack().
2474 // 2. Using the seeding clusters from the seeding layer (step 1) build combinatorics using the following algorithm:
2475 // - for each seeding cluster in the lower seeding layer find
2476 // - all seeding clusters in the upper seeding layer inside a road defined by a given phi angle. The angle
2477 // is calculated on the minimum pt of tracks from vertex accesible to the stand alone tracker.
2478 // - for each pair of two extreme seeding clusters select middle upper cluster using roads defined externally by the
2480 // - select last seeding cluster as the nearest to the linear approximation of the track described by the first three
2481 // seeding clusters.
2482 // The implementation of road calculation and cluster selection can be found in the functions AliTRDchamberTimeBin::BuildCond()
2483 // and AliTRDchamberTimeBin::GetClusters().
2484 // 3. Helix fit of the seeding clusters set. (see AliTRDtrackerFitter::FitRieman(AliTRDcluster**)). No tilt correction is
2485 // performed at this level
2486 // 4. Initialize seeding tracklets in the seeding chambers.
2487 // 5. *Filter 0* Chi2 cut on the Y and Z directions. The threshold is set externally by the reco params.
2488 // 6. Attach (true) clusters to seeding tracklets (see AliTRDseedV1::AttachClusters()) and fit tracklet (see
2489 // AliTRDseedV1::Fit()). The number of used clusters used by current seeds should not exceed ... (25).
2490 // 7. *Filter 1* Check if all 4 seeding tracklets are correctly constructed.
2491 // 8. Helix fit of the clusters from the seeding tracklets with tilt correction. Refit tracklets using the new
2492 // approximation of the track.
2493 // 9. *Filter 2* Calculate likelihood of the track. (See AliTRDtrackerV1::CookLikelihood()). The following quantities are
2494 // checked against the Riemann fit:
2495 // - position resolution in y
2496 // - angular resolution in the bending plane
2497 // - likelihood of the number of clusters attached to the tracklet
2498 // 10. Extrapolation of the helix fit to the other 2 chambers *non seeding* chambers:
2499 // - Initialization of extrapolation tracklets with the fit parameters
2500 // - Attach clusters to extrapolated tracklets
2501 // - Helix fit of tracklets
2502 // 11. Improve seeding tracklets quality by reassigning clusters based on the last parameters of the track
2503 // See AliTRDtrackerV1::ImproveSeedQuality() for details.
2504 // 12. Helix fit of all 6 seeding tracklets and chi2 calculation
2505 // 13. Hyperplane fit and track quality calculation. See AliTRDtrackerFitter::FitHyperplane() for details.
2506 // 14. Cooking labels for tracklets. Should be done only for MC
2507 // 15. Register seeds.
2510 // Marian Ivanov <M.Ivanov@gsi.de>
2511 // Alexandru Bercuci <A.Bercuci@gsi.de>
2512 // Markus Fasel <M.Fasel@gsi.de>
2514 AliTRDtrackingChamber *chamber = NULL;
2515 AliTRDcluster *c[kNSeedPlanes] = {NULL, NULL, NULL, NULL}; // initilize seeding clusters
2516 AliTRDseedV1 *cseed = &sseed[0]; // initialize tracklets for first track
2517 Int_t ncl, mcl; // working variable for looping over clusters
2518 Int_t index[AliTRDchamberTimeBin::kMaxClustersLayer], jndex[AliTRDchamberTimeBin::kMaxClustersLayer];
2520 // chi2[0] = tracklet chi2 on the Z direction
2521 // chi2[1] = tracklet chi2 on the R direction
2524 // this should be data member of AliTRDtrack TODO
2525 Double_t seedQuality[kMaxTracksStack];
2527 // unpack control parameters
2528 Int_t config = ipar[0];
2529 Int_t ntracks = ipar[1];
2530 Int_t istack = ipar[2];
2531 Int_t planes[kNSeedPlanes]; GetSeedingConfig(config, planes);
2532 Int_t planesExt[kNPlanes-kNSeedPlanes]; GetExtrapolationConfig(config, planesExt);
2535 // Init chambers geometry
2536 Double_t hL[kNPlanes]; // Tilting angle
2537 Float_t padlength[kNPlanes]; // pad lenghts
2538 Float_t padwidth[kNPlanes]; // pad widths
2539 AliTRDpadPlane *pp = NULL;
2540 for(int iplane=0; iplane<kNPlanes; iplane++){
2541 pp = fGeom->GetPadPlane(iplane, istack);
2542 hL[iplane] = TMath::Tan(TMath::DegToRad()*pp->GetTiltingAngle());
2543 padlength[iplane] = pp->GetLengthIPad();
2544 padwidth[iplane] = pp->GetWidthIPad();
2547 // Init anode wire position for chambers
2548 Double_t x0[kNPlanes], // anode wire position
2549 driftLength = .5*AliTRDgeometry::AmThick() - AliTRDgeometry::DrThick(); // drift length
2550 TGeoHMatrix *matrix = NULL;
2551 Double_t loc[] = {AliTRDgeometry::AnodePos(), 0., 0.};
2552 Double_t glb[] = {0., 0., 0.};
2553 AliTRDtrackingChamber **cIter = &stack[0];
2554 for(int iLayer=0; iLayer<kNPlanes; iLayer++,cIter++){
2555 if(!(*cIter)) continue;
2556 if(!(matrix = fGeom->GetClusterMatrix((*cIter)->GetDetector()))){
2558 x0[iLayer] = fgkX0[iLayer];
2560 matrix->LocalToMaster(loc, glb);
2561 x0[iLayer] = glb[0];
2564 if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) > 2){
2565 AliInfo(Form("Making seeds Stack[%d] Config[%d] Tracks[%d]...", istack, config, ntracks));
2568 // Build seeding layers
2571 for(int isl=0; isl<kNSeedPlanes; isl++){
2572 if(!(chamber = stack[planes[isl]])) continue;
2573 if(!chamber->GetSeedingLayer(fSeedTB[isl], fGeom, fkReconstructor)) continue;
2576 if(nlayers < kNSeedPlanes) return ntracks;
2579 // Start finding seeds
2580 Double_t cond0[4], cond1[4], cond2[4];
2582 while((c[3] = (*fSeedTB[3])[icl++])){
2584 fSeedTB[0]->BuildCond(c[3], cond0, 0);
2585 fSeedTB[0]->GetClusters(cond0, index, ncl);
2586 //printf("Found c[3] candidates 0 %d\n", ncl);
2589 c[0] = (*fSeedTB[0])[index[jcl++]];
2591 Double_t dx = c[3]->GetX() - c[0]->GetX();
2592 Double_t dzdx = (c[3]->GetZ() - c[0]->GetZ())/dx;
2593 Double_t dydx = (c[3]->GetY() - c[0]->GetY())/dx;
2594 fSeedTB[1]->BuildCond(c[0], cond1, 1, dzdx, dydx);
2595 fSeedTB[1]->GetClusters(cond1, jndex, mcl);
2596 //printf("Found c[0] candidates 1 %d\n", mcl);
2600 c[1] = (*fSeedTB[1])[jndex[kcl++]];
2602 fSeedTB[2]->BuildCond(c[1], cond2, 2, dzdx, dydx);
2603 c[2] = fSeedTB[2]->GetNearestCluster(cond2);
2604 //printf("Found c[1] candidate 2 %p\n", c[2]);
2607 //AliInfo("Seeding clusters found. Building seeds ...");
2608 //for(Int_t i = 0; i < kNSeedPlanes; i++) printf("%i. coordinates: x = %6.3f, y = %6.3f, z = %6.3f\n", i, c[i]->GetX(), c[i]->GetY(), c[i]->GetZ());
2610 for (Int_t il = 0; il < kNPlanes; il++) cseed[il].Reset();
2614 AliTRDseedV1 *tseed = &cseed[0];
2616 for(int iLayer=0; iLayer<kNPlanes; iLayer++, tseed++, cIter++){
2617 Int_t det = (*cIter) ? (*cIter)->GetDetector() : -1;
2618 tseed->SetDetector(det);
2619 tseed->SetTilt(hL[iLayer]);
2620 tseed->SetPadLength(padlength[iLayer]);
2621 tseed->SetPadWidth(padwidth[iLayer]);
2622 tseed->SetReconstructor(fkReconstructor);
2623 tseed->SetX0(det<0 ? fR[iLayer]+driftLength : x0[iLayer]);
2624 tseed->Init(GetRiemanFitter());
2625 tseed->SetStandAlone(kTRUE);
2628 Bool_t isFake = kFALSE;
2629 if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) >= 2 && fkReconstructor->IsDebugStreaming()){
2630 if (c[0]->GetLabel(0) != c[3]->GetLabel(0)) isFake = kTRUE;
2631 if (c[1]->GetLabel(0) != c[3]->GetLabel(0)) isFake = kTRUE;
2632 if (c[2]->GetLabel(0) != c[3]->GetLabel(0)) isFake = kTRUE;
2635 for(Int_t l = 0; l < kNSeedPlanes; l++) xpos[l] = fSeedTB[l]->GetX();
2637 for(int il=0; il<4; il++) yref[il] = cseed[planes[il]].GetYref(0);
2638 Int_t ll = c[3]->GetLabel(0);
2639 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2640 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2641 AliRieman *rim = GetRiemanFitter();
2642 TTreeSRedirector &cs0 = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
2644 <<"EventNumber=" << eventNumber
2645 <<"CandidateNumber=" << candidateNumber
2646 <<"isFake=" << isFake
2647 <<"config=" << config
2649 <<"chi2z=" << chi2[0]
2650 <<"chi2y=" << chi2[1]
2651 <<"Y2exp=" << cond2[0]
2652 <<"Z2exp=" << cond2[1]
2653 <<"X0=" << xpos[0] //layer[sLayer]->GetX()
2654 <<"X1=" << xpos[1] //layer[sLayer + 1]->GetX()
2655 <<"X2=" << xpos[2] //layer[sLayer + 2]->GetX()
2656 <<"X3=" << xpos[3] //layer[sLayer + 3]->GetX()
2657 <<"yref0=" << yref[0]
2658 <<"yref1=" << yref[1]
2659 <<"yref2=" << yref[2]
2660 <<"yref3=" << yref[3]
2665 <<"Seed0.=" << &cseed[planes[0]]
2666 <<"Seed1.=" << &cseed[planes[1]]
2667 <<"Seed2.=" << &cseed[planes[2]]
2668 <<"Seed3.=" << &cseed[planes[3]]
2669 <<"RiemanFitter.=" << rim
2672 if(chi2[0] > fkReconstructor->GetRecoParam() ->GetChi2Z()/*7./(3. - sLayer)*//*iter*/){
2673 //AliInfo(Form("Failed chi2 filter on chi2Z [%f].", chi2[0]));
2674 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2677 if(chi2[1] > fkReconstructor->GetRecoParam() ->GetChi2Y()/*1./(3. - sLayer)*//*iter*/){
2678 //AliInfo(Form("Failed chi2 filter on chi2Y [%f].", chi2[1]));
2679 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2682 //AliInfo("Passed chi2 filter.");
2684 // try attaching clusters to tracklets
2686 AliTRDcluster *cl = NULL;
2687 for(int iLayer=0; iLayer<kNSeedPlanes; iLayer++){
2688 Int_t jLayer = planes[iLayer];
2689 Int_t nNotInChamber = 0;
2690 if(!cseed[jLayer].AttachClusters(stack[jLayer], kTRUE)) continue;
2691 if(/*fkReconstructor->IsHLT()*/kFALSE){
2692 cseed[jLayer].UpdateUsed();
2693 if(!cseed[jLayer].IsOK()) continue;
2695 cseed[jLayer].Fit();
2696 cseed[jLayer].UpdateUsed();
2697 cseed[jLayer].ResetClusterIter();
2698 while((cl = cseed[jLayer].NextCluster())){
2699 if(!cl->IsInChamber()) nNotInChamber++;
2701 //printf("clusters[%d], used[%d], not in chamber[%d]\n", cseed[jLayer].GetN(), cseed[jLayer].GetNUsed(), nNotInChamber);
2702 if(cseed[jLayer].GetN() - (cseed[jLayer].GetNUsed() + nNotInChamber) < 5) continue; // checking for Cluster which are not in chamber is a much stronger restriction on real data
2707 if(mlayers < kNSeedPlanes){
2708 //AliInfo(Form("Failed updating all seeds %d [%d].", mlayers, kNSeedPlanes));
2709 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2713 // temporary exit door for the HLT
2714 if(fkReconstructor->IsHLT()){
2715 // attach clusters to extrapolation chambers
2716 for(int iLayer=0; iLayer<kNPlanes-kNSeedPlanes; iLayer++){
2717 Int_t jLayer = planesExt[iLayer];
2718 if(!(chamber = stack[jLayer])) continue;
2719 cseed[jLayer].AttachClusters(chamber, kTRUE);
2720 cseed[jLayer].Fit();
2722 fTrackQuality[ntracks] = 1.; // dummy value
2724 if(ntracks == kMaxTracksStack) return ntracks;
2730 // Update Seeds and calculate Likelihood
2731 // fit tracklets and cook likelihood
2732 FitTiltedRieman(&cseed[0], kTRUE);
2733 for(int iLayer=0; iLayer<kNSeedPlanes; iLayer++){
2734 Int_t jLayer = planes[iLayer];
2735 cseed[jLayer].Fit(kTRUE);
2737 Double_t like = CookLikelihood(&cseed[0], planes); // to be checked
2739 if (TMath::Log(1.E-9 + like) < fkReconstructor->GetRecoParam() ->GetTrackLikelihood()){
2740 //AliInfo(Form("Failed likelihood %f[%e].", TMath::Log(1.E-9 + like), like));
2741 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2744 //AliInfo(Form("Passed likelihood %f[%e].", TMath::Log(1.E-9 + like), like));
2746 // book preliminary results
2747 seedQuality[ntracks] = like;
2748 fSeedLayer[ntracks] = config;/*sLayer;*/
2750 // attach clusters to the extrapolation seeds
2751 for(int iLayer=0; iLayer<kNPlanes-kNSeedPlanes; iLayer++){
2752 Int_t jLayer = planesExt[iLayer];
2753 if(!(chamber = stack[jLayer])) continue;
2755 // fit extrapolated seed
2756 if ((jLayer == 0) && !(cseed[1].IsOK())) continue;
2757 if ((jLayer == 5) && !(cseed[4].IsOK())) continue;
2758 AliTRDseedV1 pseed = cseed[jLayer];
2759 if(!pseed.AttachClusters(chamber, kTRUE)) continue;
2761 cseed[jLayer] = pseed;
2762 FitTiltedRieman(cseed, kTRUE);
2763 cseed[jLayer].Fit(kTRUE);
2766 // AliInfo("Extrapolation done.");
2767 // Debug Stream containing all the 6 tracklets
2768 if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) >= 2 && fkReconstructor->IsDebugStreaming()){
2769 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
2770 TLinearFitter *tiltedRieman = GetTiltedRiemanFitter();
2771 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2772 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2773 cstreamer << "MakeSeeds1"
2774 << "EventNumber=" << eventNumber
2775 << "CandidateNumber=" << candidateNumber
2776 << "S0.=" << &cseed[0]
2777 << "S1.=" << &cseed[1]
2778 << "S2.=" << &cseed[2]
2779 << "S3.=" << &cseed[3]
2780 << "S4.=" << &cseed[4]
2781 << "S5.=" << &cseed[5]
2782 << "FitterT.=" << tiltedRieman
2786 if(fkReconstructor->GetRecoParam()->HasImproveTracklets() && ImproveSeedQuality(stack, cseed) < 4){
2787 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2790 //AliInfo("Improve seed quality done.");
2792 // fit full track and cook likelihoods
2793 // Double_t curv = FitRieman(&cseed[0], chi2);
2794 // Double_t chi2ZF = chi2[0] / TMath::Max((mlayers - 3.), 1.);
2795 // Double_t chi2RF = chi2[1] / TMath::Max((mlayers - 3.), 1.);
2797 // do the final track fitting (Once with vertex constraint and once without vertex constraint)
2798 Double_t chi2Vals[3];
2799 chi2Vals[0] = FitTiltedRieman(&cseed[0], kTRUE);
2800 if(fkReconstructor->GetRecoParam()->IsVertexConstrained())
2801 chi2Vals[1] = FitTiltedRiemanConstraint(&cseed[0], GetZ()); // Do Vertex Constrained fit if desired
2804 chi2Vals[2] = GetChi2Z(&cseed[0]) / TMath::Max((mlayers - 3.), 1.);
2805 // Chi2 definitions in testing stage
2806 //chi2Vals[2] = GetChi2ZTest(&cseed[0]);
2807 fTrackQuality[ntracks] = CalculateTrackLikelihood(&cseed[0], &chi2Vals[0]);
2808 //AliInfo("Hyperplane fit done\n");
2810 if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) >= 2 && fkReconstructor->IsDebugStreaming()){
2811 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
2812 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2813 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2814 TLinearFitter *fitterTC = GetTiltedRiemanFitterConstraint();
2815 TLinearFitter *fitterT = GetTiltedRiemanFitter();
2817 for(Int_t iseed = 0; iseed < kNPlanes; iseed++){
2818 ncls += cseed[iseed].IsOK() ? cseed[iseed].GetN2() : 0;
2820 cstreamer << "MakeSeeds2"
2821 << "EventNumber=" << eventNumber
2822 << "CandidateNumber=" << candidateNumber
2823 << "Chi2TR=" << chi2Vals[0]
2824 << "Chi2TC=" << chi2Vals[1]
2825 << "Nlayers=" << mlayers
2826 << "NClusters=" << ncls
2828 << "S0.=" << &cseed[0]
2829 << "S1.=" << &cseed[1]
2830 << "S2.=" << &cseed[2]
2831 << "S3.=" << &cseed[3]
2832 << "S4.=" << &cseed[4]
2833 << "S5.=" << &cseed[5]
2834 << "FitterT.=" << fitterT
2835 << "FitterTC.=" << fitterTC
2840 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2841 if(ntracks == kMaxTracksStack){
2842 AliWarning(Form("Number of seeds reached maximum allowed (%d) in stack.", kMaxTracksStack));
2853 //_____________________________________________________________________________
2854 AliTRDtrackV1* AliTRDtrackerV1::MakeTrack(AliTRDseedV1 * const seeds, Double_t *params)
2857 // Build a TRD track out of tracklet candidates
2860 // seeds : array of tracklets
2861 // params : array of track parameters as they are estimated by stand alone tracker. 7 elements.
2862 // [0] - radial position of the track at reference point
2863 // [1] - y position of the fit at [0]
2864 // [2] - z position of the fit at [0]
2865 // [3] - snp of the first tracklet
2866 // [4] - tgl of the first tracklet
2867 // [5] - curvature of the Riemann fit - 1/pt
2868 // [6] - sector rotation angle
2873 // Initialize the TRD track based on the parameters of the fit and a parametric covariance matrix
2874 // (diagonal with constant variance terms TODO - correct parameterization)
2876 // In case of HLT just register the tracklets in the tracker and return values of the Riemann fit. For the
2877 // offline case perform a full Kalman filter on the already found tracklets (see AliTRDtrackerV1::FollowBackProlongation()
2878 // for details). Do also MC label calculation and PID if propagation successfully.
2881 Double_t alpha = AliTRDgeometry::GetAlpha();
2882 Double_t shift = AliTRDgeometry::GetAlpha()/2.0;
2885 c[ 0] = 0.2; // s^2_y
2886 c[ 1] = 0.0; c[ 2] = 2.0; // s^2_z
2887 c[ 3] = 0.0; c[ 4] = 0.0; c[ 5] = 0.02; // s^2_snp
2888 c[ 6] = 0.0; c[ 7] = 0.0; c[ 8] = 0.0; c[ 9] = 0.1; // s^2_tgl
2889 c[10] = 0.0; c[11] = 0.0; c[12] = 0.0; c[13] = 0.0; c[14] = params[5]*params[5]*0.01; // s^2_1/pt
2891 AliTRDtrackV1 track(seeds, ¶ms[1], c, params[0], params[6]*alpha+shift);
2892 track.PropagateTo(params[0]-5.0);
2893 AliTRDseedV1 *ptrTracklet = NULL;
2895 // skip Kalman filter for HLT
2896 if(/*fkReconstructor->IsHLT()*/kFALSE){
2897 for (Int_t jLayer = 0; jLayer < AliTRDgeometry::kNlayer; jLayer++) {
2898 track.UnsetTracklet(jLayer);
2899 ptrTracklet = &seeds[jLayer];
2900 if(!ptrTracklet->IsOK()) continue;
2901 if(TMath::Abs(ptrTracklet->GetYref(1) - ptrTracklet->GetYfit(1)) >= .2) continue; // check this condition with Marian
2902 ptrTracklet = SetTracklet(ptrTracklet);
2903 ptrTracklet->UseClusters();
2904 track.SetTracklet(ptrTracklet, fTracklets->GetEntriesFast()-1);
2906 AliTRDtrackV1 *ptrTrack = SetTrack(&track);
2907 ptrTrack->CookPID();
2908 ptrTrack->CookLabel(.9);
2909 ptrTrack->SetReconstructor(fkReconstructor);
2913 track.ResetCovariance(1);
2914 Int_t nc = TMath::Abs(FollowBackProlongation(track));
2915 if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) > 5 && fkReconstructor->IsDebugStreaming()){
2916 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2917 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2918 Double_t p[5]; // Track Params for the Debug Stream
2919 track.GetExternalParameters(params[0], p);
2920 TTreeSRedirector &cs = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
2922 << "EventNumber=" << eventNumber
2923 << "CandidateNumber=" << candidateNumber
2925 << "X=" << params[0]
2931 << "Yin=" << params[1]
2932 << "Zin=" << params[2]
2933 << "snpin=" << params[3]
2934 << "tndin=" << params[4]
2935 << "crvin=" << params[5]
2936 << "track.=" << &track
2939 if (nc < 30) return NULL;
2941 AliTRDtrackV1 *ptrTrack = SetTrack(&track);
2942 ptrTrack->SetReconstructor(fkReconstructor);
2943 ptrTrack->CookLabel(.9);
2945 // computes PID for track
2946 ptrTrack->CookPID();
2947 // update calibration references using this track
2948 AliTRDCalibraFillHisto *calibra = AliTRDCalibraFillHisto::Instance();
2950 AliInfo("Could not get Calibra instance\n");
2951 if(calibra->GetHisto2d()) calibra->UpdateHistogramsV1(ptrTrack);
2957 //____________________________________________________________________
2958 Int_t AliTRDtrackerV1::ImproveSeedQuality(AliTRDtrackingChamber **stack, AliTRDseedV1 *cseed)
2961 // Sort tracklets according to "quality" and try to "improve" the first 4 worst
2964 // layers : Array of propagation layers for a stack/supermodule
2965 // cseed : Array of 6 seeding tracklets which has to be improved
2968 // cssed : Improved seeds
2970 // Detailed description
2972 // Iterative procedure in which new clusters are searched for each
2973 // tracklet seed such that the seed quality (see AliTRDseed::GetQuality())
2974 // can be maximized. If some optimization is found the old seeds are replaced.
2979 // make a local working copy
2980 AliTRDtrackingChamber *chamber = NULL;
2981 AliTRDseedV1 bseed[6];
2983 for (Int_t jLayer = 0; jLayer < 6; jLayer++) bseed[jLayer] = cseed[jLayer];
2985 Float_t lastquality = 10000.0;
2986 Float_t lastchi2 = 10000.0;
2987 Float_t chi2 = 1000.0;
2989 for (Int_t iter = 0; iter < 4; iter++) {
2990 Float_t sumquality = 0.0;
2991 Float_t squality[6];
2992 Int_t sortindexes[6];
2994 for (Int_t jLayer = 0; jLayer < 6; jLayer++) {
2995 squality[jLayer] = bseed[jLayer].IsOK() ? bseed[jLayer].GetQuality(kTRUE) : 1000.;
2996 sumquality += squality[jLayer];
2998 if ((sumquality >= lastquality) || (chi2 > lastchi2)) break;
3001 lastquality = sumquality;
3003 if (iter > 0) for (Int_t jLayer = 0; jLayer < 6; jLayer++) cseed[jLayer] = bseed[jLayer];
3005 TMath::Sort(6, squality, sortindexes, kFALSE);
3006 for (Int_t jLayer = 5; jLayer > 1; jLayer--) {
3007 Int_t bLayer = sortindexes[jLayer];
3008 if(!(chamber = stack[bLayer])) continue;
3009 bseed[bLayer].AttachClusters(chamber, kTRUE);
3010 bseed[bLayer].Fit(kTRUE);
3011 if(bseed[bLayer].IsOK()) nLayers++;
3014 chi2 = FitTiltedRieman(bseed, kTRUE);
3015 if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) >= 7 && fkReconstructor->IsDebugStreaming()){
3016 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
3017 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
3018 TLinearFitter *tiltedRieman = GetTiltedRiemanFitter();
3019 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
3020 cstreamer << "ImproveSeedQuality"
3021 << "EventNumber=" << eventNumber
3022 << "CandidateNumber=" << candidateNumber
3023 << "Iteration=" << iter
3024 << "S0.=" << &bseed[0]
3025 << "S1.=" << &bseed[1]
3026 << "S2.=" << &bseed[2]
3027 << "S3.=" << &bseed[3]
3028 << "S4.=" << &bseed[4]
3029 << "S5.=" << &bseed[5]
3030 << "FitterT.=" << tiltedRieman
3034 // we are sure that at least 2 tracklets are OK !
3038 //_________________________________________________________________________
3039 Double_t AliTRDtrackerV1::CalculateTrackLikelihood(const AliTRDseedV1 *const tracklets, Double_t *chi2){
3041 // Calculates the Track Likelihood value. This parameter serves as main quality criterion for
3042 // the track selection
3043 // The likelihood value containes:
3044 // - The chi2 values from the both fitters and the chi2 values in z-direction from a linear fit
3045 // - The Sum of the Parameter |slope_ref - slope_fit|/Sigma of the tracklets
3046 // For all Parameters an exponential dependency is used
3048 // Parameters: - Array of tracklets (AliTRDseedV1) related to the track candidate
3049 // - Array of chi2 values:
3050 // * Non-Constrained Tilted Riemann fit
3051 // * Vertex-Constrained Tilted Riemann fit
3052 // * z-Direction from Linear fit
3053 // Output: - The calculated track likelihood
3058 Double_t chi2phi = 0, nLayers = 0;
3059 for (Int_t iLayer = 0; iLayer < kNPlanes; iLayer++) {
3060 if(!tracklets[iLayer].IsOK()) continue;
3061 chi2phi += tracklets[iLayer].GetChi2Phi();
3064 chi2phi /= Float_t (nLayers - 2.0);
3066 Double_t likeChi2Z = TMath::Exp(-chi2[2] * 0.14); // Chi2Z
3067 Double_t likeChi2TC = (fkReconstructor->GetRecoParam()->IsVertexConstrained()) ?
3068 TMath::Exp(-chi2[1] * 0.677) : 1; // Constrained Tilted Riemann
3069 Double_t likeChi2TR = TMath::Exp(-chi2[0] * 0.0078); // Non-constrained Tilted Riemann
3070 Double_t likeChi2Phi= TMath::Exp(-chi2phi * 3.23);//3.23
3071 Double_t trackLikelihood = likeChi2Z * likeChi2TR * likeChi2Phi;
3073 if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) >= 2 && fkReconstructor->IsDebugStreaming()){
3074 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
3075 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
3076 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
3077 cstreamer << "CalculateTrackLikelihood0"
3078 << "EventNumber=" << eventNumber
3079 << "CandidateNumber=" << candidateNumber
3080 << "LikeChi2Z=" << likeChi2Z
3081 << "LikeChi2TR=" << likeChi2TR
3082 << "LikeChi2TC=" << likeChi2TC
3083 << "LikeChi2Phi=" << likeChi2Phi
3084 << "TrackLikelihood=" << trackLikelihood
3088 return trackLikelihood;
3091 //____________________________________________________________________
3092 Double_t AliTRDtrackerV1::CookLikelihood(AliTRDseedV1 *cseed, Int_t planes[4])
3095 // Calculate the probability of this track candidate.
3098 // cseeds : array of candidate tracklets
3099 // planes : array of seeding planes (see seeding configuration)
3100 // chi2 : chi2 values (on the Z and Y direction) from the rieman fit of the track.
3105 // Detailed description
3107 // The track quality is estimated based on the following 4 criteria:
3108 // 1. precision of the rieman fit on the Y direction (likea)
3109 // 2. chi2 on the Y direction (likechi2y)
3110 // 3. chi2 on the Z direction (likechi2z)
3111 // 4. number of attached clusters compared to a reference value
3112 // (see AliTRDrecoParam::fkFindable) (likeN)
3114 // The distributions for each type of probabilities are given below as of
3115 // (date). They have to be checked to assure consistency of estimation.
3118 // ratio of the total number of clusters/track which are expected to be found by the tracker.
3119 const AliTRDrecoParam *fRecoPars = fkReconstructor->GetRecoParam();
3121 Double_t chi2y = GetChi2Y(&cseed[0]);
3122 Double_t chi2z = GetChi2Z(&cseed[0]);
3124 Float_t nclusters = 0.;
3125 Double_t sumda = 0.;
3126 for(UChar_t ilayer = 0; ilayer < 4; ilayer++){
3127 Int_t jlayer = planes[ilayer];
3128 nclusters += cseed[jlayer].GetN2();
3129 sumda += TMath::Abs(cseed[jlayer].GetYfit(1) - cseed[jlayer].GetYref(1));
3133 Double_t likea = TMath::Exp(-sumda * fRecoPars->GetPhiSlope());
3134 Double_t likechi2y = 0.0000000001;
3135 if (fkReconstructor->IsCosmic() || chi2y < fRecoPars->GetChi2YCut()) likechi2y += TMath::Exp(-TMath::Sqrt(chi2y) * fRecoPars->GetChi2YSlope());
3136 Double_t likechi2z = TMath::Exp(-chi2z * fRecoPars->GetChi2ZSlope());
3137 Double_t likeN = TMath::Exp(-(fRecoPars->GetNMeanClusters() - nclusters) / fRecoPars->GetNSigmaClusters());
3138 Double_t like = likea * likechi2y * likechi2z * likeN;
3140 if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) >= 2 && fkReconstructor->IsDebugStreaming()){
3141 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
3142 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
3143 Int_t nTracklets = 0; Float_t meanNcls = 0;
3144 for(Int_t iseed=0; iseed < kNPlanes; iseed++){
3145 if(!cseed[iseed].IsOK()) continue;
3147 meanNcls += cseed[iseed].GetN2();
3149 if(nTracklets) meanNcls /= nTracklets;
3150 // The Debug Stream contains the seed
3151 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
3152 cstreamer << "CookLikelihood"
3153 << "EventNumber=" << eventNumber
3154 << "CandidateNumber=" << candidateNumber
3155 << "tracklet0.=" << &cseed[0]
3156 << "tracklet1.=" << &cseed[1]
3157 << "tracklet2.=" << &cseed[2]
3158 << "tracklet3.=" << &cseed[3]
3159 << "tracklet4.=" << &cseed[4]
3160 << "tracklet5.=" << &cseed[5]
3161 << "sumda=" << sumda
3162 << "chi2y=" << chi2y
3163 << "chi2z=" << chi2z
3164 << "likea=" << likea
3165 << "likechi2y=" << likechi2y
3166 << "likechi2z=" << likechi2z
3167 << "nclusters=" << nclusters
3168 << "likeN=" << likeN
3170 << "meanncls=" << meanNcls
3177 //____________________________________________________________________
3178 void AliTRDtrackerV1::GetSeedingConfig(Int_t iconfig, Int_t planes[4])
3181 // Map seeding configurations to detector planes.
3184 // iconfig : configuration index
3185 // planes : member planes of this configuration. On input empty.
3188 // planes : contains the planes which are defining the configuration
3190 // Detailed description
3192 // Here is the list of seeding planes configurations together with
3193 // their topological classification:
3211 // The topologic quality is modeled as follows:
3212 // 1. The general model is define by the equation:
3213 // p(conf) = exp(-conf/2)
3214 // 2. According to the topologic classification, configurations from the same
3215 // class are assigned the agerage value over the model values.
3216 // 3. Quality values are normalized.
3218 // The topologic quality distribution as function of configuration is given below:
3220 // <img src="gif/topologicQA.gif">
3225 case 0: // 5432 TQ 0
3231 case 1: // 4321 TQ 0
3237 case 2: // 3210 TQ 0
3243 case 3: // 5321 TQ 1
3249 case 4: // 4210 TQ 1
3255 case 5: // 5431 TQ 1
3261 case 6: // 4320 TQ 1
3267 case 7: // 5430 TQ 2
3273 case 8: // 5210 TQ 2
3279 case 9: // 5421 TQ 3
3285 case 10: // 4310 TQ 3
3291 case 11: // 5410 TQ 4
3297 case 12: // 5420 TQ 5
3303 case 13: // 5320 TQ 5
3309 case 14: // 5310 TQ 5
3318 //____________________________________________________________________
3319 void AliTRDtrackerV1::GetExtrapolationConfig(Int_t iconfig, Int_t planes[2])
3322 // Returns the extrapolation planes for a seeding configuration.
3325 // iconfig : configuration index
3326 // planes : planes which are not in this configuration. On input empty.
3329 // planes : contains the planes which are not in the configuration
3331 // Detailed description
3335 case 0: // 5432 TQ 0
3339 case 1: // 4321 TQ 0
3343 case 2: // 3210 TQ 0
3347 case 3: // 5321 TQ 1
3351 case 4: // 4210 TQ 1
3355 case 5: // 5431 TQ 1
3359 case 6: // 4320 TQ 1
3363 case 7: // 5430 TQ 2
3367 case 8: // 5210 TQ 2
3371 case 9: // 5421 TQ 3
3375 case 10: // 4310 TQ 3
3379 case 11: // 5410 TQ 4
3383 case 12: // 5420 TQ 5
3387 case 13: // 5320 TQ 5
3391 case 14: // 5310 TQ 5
3398 //____________________________________________________________________
3399 AliCluster* AliTRDtrackerV1::GetCluster(Int_t idx) const
3401 Int_t ncls = fClusters->GetEntriesFast();
3402 return idx >= 0 && idx < ncls ? (AliCluster*)fClusters->UncheckedAt(idx) : NULL;
3405 //____________________________________________________________________
3406 AliTRDseedV1* AliTRDtrackerV1::GetTracklet(Int_t idx) const
3408 Int_t ntrklt = fTracklets->GetEntriesFast();
3409 return idx >= 0 && idx < ntrklt ? (AliTRDseedV1*)fTracklets->UncheckedAt(idx) : NULL;
3412 //____________________________________________________________________
3413 AliKalmanTrack* AliTRDtrackerV1::GetTrack(Int_t idx) const
3415 Int_t ntrk = fTracks->GetEntriesFast();
3416 return idx >= 0 && idx < ntrk ? (AliKalmanTrack*)fTracks->UncheckedAt(idx) : NULL;
3421 // //_____________________________________________________________________________
3422 // Int_t AliTRDtrackerV1::Freq(Int_t n, const Int_t *inlist
3423 // , Int_t *outlist, Bool_t down)
3426 // // Sort eleements according occurancy
3427 // // The size of output array has is 2*n
3434 // Int_t *sindexS = new Int_t[n]; // Temporary array for sorting
3435 // Int_t *sindexF = new Int_t[2*n];
3436 // for (Int_t i = 0; i < n; i++) {
3440 // TMath::Sort(n,inlist,sindexS,down);
3442 // Int_t last = inlist[sindexS[0]];
3443 // Int_t val = last;
3445 // sindexF[0+n] = last;
3446 // Int_t countPos = 0;
3448 // // Find frequency
3449 // for (Int_t i = 1; i < n; i++) {
3450 // val = inlist[sindexS[i]];
3451 // if (last == val) {
3452 // sindexF[countPos]++;
3456 // sindexF[countPos+n] = val;
3457 // sindexF[countPos]++;
3461 // if (last == val) {
3465 // // Sort according frequency
3466 // TMath::Sort(countPos,sindexF,sindexS,kTRUE);
3468 // for (Int_t i = 0; i < countPos; i++) {
3469 // outlist[2*i ] = sindexF[sindexS[i]+n];
3470 // outlist[2*i+1] = sindexF[sindexS[i]];
3473 // delete [] sindexS;
3474 // delete [] sindexF;
3481 //____________________________________________________________________
3482 void AliTRDtrackerV1::ResetSeedTB()
3484 // reset buffer for seeding time bin layers. If the time bin
3485 // layers are not allocated this function allocates them
3487 for(Int_t isl=0; isl<kNSeedPlanes; isl++){
3488 if(!fSeedTB[isl]) fSeedTB[isl] = new AliTRDchamberTimeBin();
3489 else fSeedTB[isl]->Clear();
3494 //_____________________________________________________________________________
3495 Float_t AliTRDtrackerV1::GetChi2Y(const AliTRDseedV1 * const tracklets) const
3497 // Calculates normalized chi2 in y-direction
3498 // chi2 = Sum chi2 / n_tracklets
3500 Double_t chi2 = 0.; Int_t n = 0;
3501 for(Int_t ipl = kNPlanes; ipl--;){
3502 if(!tracklets[ipl].IsOK()) continue;
3503 chi2 += tracklets[ipl].GetChi2Y();
3506 return n ? chi2/n : 0.;
3509 //_____________________________________________________________________________
3510 Float_t AliTRDtrackerV1::GetChi2Z(const AliTRDseedV1 *const tracklets) const
3512 // Calculates normalized chi2 in z-direction
3513 // chi2 = Sum chi2 / n_tracklets
3515 Double_t chi2 = 0; Int_t n = 0;
3516 for(Int_t ipl = kNPlanes; ipl--;){
3517 if(!tracklets[ipl].IsOK()) continue;
3518 chi2 += tracklets[ipl].GetChi2Z();
3521 return n ? chi2/n : 0.;
3524 //____________________________________________________________________
3525 Float_t AliTRDtrackerV1::CalculateReferenceX(const AliTRDseedV1 *const tracklets){
3527 // Calculates the reference x-position for the tilted Rieman fit defined as middle
3528 // of the stack (middle between layers 2 and 3). For the calculation all the tracklets
3529 // are taken into account
3531 // Parameters: - Array of tracklets(AliTRDseedV1)
3533 // Output: - The reference x-position(Float_t)
3534 // Only kept for compatibility with the old code
3536 Int_t nDistances = 0;
3537 Float_t meanDistance = 0.;
3538 Int_t startIndex = 5;
3539 for(Int_t il =5; il > 0; il--){
3540 if(tracklets[il].IsOK() && tracklets[il -1].IsOK()){
3541 Float_t xdiff = tracklets[il].GetX0() - tracklets[il -1].GetX0();
3542 meanDistance += xdiff;
3545 if(tracklets[il].IsOK()) startIndex = il;
3547 if(tracklets[0].IsOK()) startIndex = 0;
3549 // We should normally never get here
3550 Float_t xpos[2]; memset(xpos, 0, sizeof(Float_t) * 2);
3551 Int_t iok = 0, idiff = 0;
3552 // This attempt is worse and should be avoided:
3553 // check for two chambers which are OK and repeat this without taking the mean value
3554 // Strategy avoids a division by 0;
3555 for(Int_t il = 5; il >= 0; il--){
3556 if(tracklets[il].IsOK()){
3557 xpos[iok] = tracklets[il].GetX0();
3561 if(iok) idiff++; // to get the right difference;
3565 meanDistance = (xpos[0] - xpos[1])/idiff;
3568 // we have do not even have 2 layers which are OK? The we do not need to fit at all
3573 meanDistance /= nDistances;
3575 return tracklets[startIndex].GetX0() + (2.5 - startIndex) * meanDistance - 0.5 * (AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick());
3578 //_____________________________________________________________________________
3579 Double_t AliTRDtrackerV1::FitTiltedRiemanV1(AliTRDseedV1 *const tracklets){
3581 // Track Fitter Function using the new class implementation of
3584 AliTRDtrackFitterRieman fitter;
3585 fitter.SetRiemanFitter(GetTiltedRiemanFitter());
3587 for(Int_t il = 0; il < AliTRDgeometry::kNlayer; il++) fitter.SetTracklet(il, &tracklets[il]);
3588 Double_t chi2 = fitter.Eval();
3589 // Update the tracklets
3590 Double_t cov[15]; Double_t x0;
3591 memset(cov, 0, sizeof(Double_t) * 15);
3592 for(Int_t il = 0; il < AliTRDgeometry::kNlayer; il++){
3593 x0 = tracklets[il].GetX0();
3594 tracklets[il].SetYref(0, fitter.GetYat(x0));
3595 tracklets[il].SetZref(0, fitter.GetZat(x0));
3596 tracklets[il].SetYref(1, fitter.GetDyDxAt(x0));
3597 tracklets[il].SetZref(1, fitter.GetDzDx());
3598 tracklets[il].SetC(fitter.GetCurvature());
3599 fitter.GetCovAt(x0, cov);
3600 tracklets[il].SetCovRef(cov);
3601 tracklets[il].SetChi2(chi2);
3606 ///////////////////////////////////////////////////////
3608 // Resources of class AliTRDLeastSquare //
3610 ///////////////////////////////////////////////////////
3612 //_____________________________________________________________________________
3613 AliTRDtrackerV1::AliTRDLeastSquare::AliTRDLeastSquare(){
3615 // Constructor of the nested class AliTRDtrackFitterLeastSquare
3617 memset(fParams, 0, sizeof(Double_t) * 2);
3618 memset(fSums, 0, sizeof(Double_t) * 6);
3619 memset(fCovarianceMatrix, 0, sizeof(Double_t) * 3);
3623 //_____________________________________________________________________________
3624 void AliTRDtrackerV1::AliTRDLeastSquare::AddPoint(const Double_t *const x, Double_t y, Double_t sigmaY){
3626 // Adding Point to the fitter
3629 Double_t weight = 1/(sigmaY > 1e-9 ? sigmaY : 1e-9);
3631 const Double_t &xpt = *x;
3632 // printf("Adding point x = %f, y = %f, sigma = %f\n", xpt, y, sigmaY);
3634 fSums[1] += weight * xpt;
3635 fSums[2] += weight * y;
3636 fSums[3] += weight * xpt * y;
3637 fSums[4] += weight * xpt * xpt;
3638 fSums[5] += weight * y * y;
3641 //_____________________________________________________________________________
3642 void AliTRDtrackerV1::AliTRDLeastSquare::RemovePoint(const Double_t *const x, Double_t y, Double_t sigmaY){
3644 // Remove Point from the sample
3647 Double_t weight = 1/(sigmaY > 1e-9 ? sigmaY : 1e-9);
3649 const Double_t &xpt = *x;
3651 fSums[1] -= weight * xpt;
3652 fSums[2] -= weight * y;
3653 fSums[3] -= weight * xpt * y;
3654 fSums[4] -= weight * xpt * xpt;
3655 fSums[5] -= weight * y * y;
3658 //_____________________________________________________________________________
3659 void AliTRDtrackerV1::AliTRDLeastSquare::Eval(){
3661 // Evaluation of the fit:
3662 // Calculation of the parameters
3663 // Calculation of the covariance matrix
3666 Double_t denominator = fSums[0] * fSums[4] - fSums[1] *fSums[1];
3667 if(denominator==0) return;
3669 // for(Int_t isum = 0; isum < 5; isum++)
3670 // printf("fSums[%d] = %f\n", isum, fSums[isum]);
3671 // printf("denominator = %f\n", denominator);
3672 fParams[0] = (fSums[2] * fSums[4] - fSums[1] * fSums[3])/ denominator;
3673 fParams[1] = (fSums[0] * fSums[3] - fSums[1] * fSums[2]) / denominator;
3674 // printf("fParams[0] = %f, fParams[1] = %f\n", fParams[0], fParams[1]);
3676 // Covariance matrix
3677 fCovarianceMatrix[0] = fSums[4] / fSums[0] - fSums[1] * fSums[1] / (fSums[0] * fSums[0]);
3678 fCovarianceMatrix[1] = fSums[5] / fSums[0] - fSums[2] * fSums[2] / (fSums[0] * fSums[0]);
3679 fCovarianceMatrix[2] = fSums[3] / fSums[0] - fSums[1] * fSums[2] / (fSums[0] * fSums[0]);
3682 //_____________________________________________________________________________
3683 Double_t AliTRDtrackerV1::AliTRDLeastSquare::GetFunctionValue(const Double_t *const xpos) const {
3685 // Returns the Function value of the fitted function at a given x-position
3687 return fParams[0] + fParams[1] * (*xpos);
3690 //_____________________________________________________________________________
3691 void AliTRDtrackerV1::AliTRDLeastSquare::GetCovarianceMatrix(Double_t *storage) const {
3693 // Copies the values of the covariance matrix into the storage
3695 memcpy(storage, fCovarianceMatrix, sizeof(Double_t) * 3);
3698 //_____________________________________________________________________________
3699 void AliTRDtrackerV1::AliTRDLeastSquare::Reset(){
3703 memset(fParams, 0, sizeof(Double_t) * 2);
3704 memset(fCovarianceMatrix, 0, sizeof(Double_t) * 3);
3705 memset(fSums, 0, sizeof(Double_t) * 6);
3708 ///////////////////////////////////////////////////////
3710 // Resources of class AliTRDtrackFitterRieman //
3712 ///////////////////////////////////////////////////////
3714 //_____________________________________________________________________________
3715 AliTRDtrackerV1::AliTRDtrackFitterRieman::AliTRDtrackFitterRieman():
3721 fSysClusterError(0.)
3724 // Default constructor
3726 fZfitter = new AliTRDLeastSquare;
3727 fCovarPolY = new TMatrixD(3,3);
3728 fCovarPolZ = new TMatrixD(2,2);
3729 memset(fTracklets, 0, sizeof(AliTRDseedV1 *) * 6);
3730 memset(fParameters, 0, sizeof(Double_t) * 5);
3731 memset(fSumPolY, 0, sizeof(Double_t) * 5);
3732 memset(fSumPolZ, 0, sizeof(Double_t) * 2);
3735 //_____________________________________________________________________________
3736 AliTRDtrackerV1::AliTRDtrackFitterRieman::~AliTRDtrackFitterRieman(){
3740 if(fZfitter) delete fZfitter;
3741 if(fCovarPolY) delete fCovarPolY;
3742 if(fCovarPolZ) delete fCovarPolZ;
3745 //_____________________________________________________________________________
3746 void AliTRDtrackerV1::AliTRDtrackFitterRieman::Reset(){
3751 fTrackFitter->StoreData(kTRUE);
3752 fTrackFitter->ClearPoints();
3758 memset(fTracklets, 0, sizeof(AliTRDseedV1 *) * AliTRDgeometry::kNlayer);
3759 memset(fParameters, 0, sizeof(Double_t) * 5);
3760 memset(fSumPolY, 0, sizeof(Double_t) * 5);
3761 memset(fSumPolZ, 0, sizeof(Double_t) * 2);
3762 for(Int_t irow = 0; irow < fCovarPolY->GetNrows(); irow++)
3763 for(Int_t icol = 0; icol < fCovarPolY->GetNcols(); icol++){
3764 (*fCovarPolY)(irow, icol) = 0.;
3765 if(irow < 2 && icol < 2)
3766 (*fCovarPolZ)(irow, icol) = 0.;
3770 //_____________________________________________________________________________
3771 void AliTRDtrackerV1::AliTRDtrackFitterRieman::SetTracklet(Int_t itr, AliTRDseedV1 *tracklet){
3773 // Add tracklet into the fitter
3775 if(itr >= AliTRDgeometry::kNlayer) return;
3776 fTracklets[itr] = tracklet;
3779 //_____________________________________________________________________________
3780 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::Eval(){
3783 // 1. Apply linear transformation and store points in the fitter
3784 // 2. Evaluate the fit
3785 // 3. Check if the result of the fit in z-direction is reasonable
3787 // 3a. Fix the parameters 3 and 4 with the results of a simple least
3789 // 3b. Redo the fit with the fixed parameters
3790 // 4. Store fit results (parameters and errors)
3795 fXref = CalculateReferenceX();
3796 for(Int_t il = 0; il < AliTRDgeometry::kNlayer; il++) UpdateFitters(fTracklets[il]);
3797 if(!fTrackFitter->GetNpoints()) return 1e10;
3799 fTrackFitter->Eval();
3801 fParameters[3] = fTrackFitter->GetParameter(3);
3802 fParameters[4] = fTrackFitter->GetParameter(4);
3803 if(!CheckAcceptable(fParameters[3], fParameters[4])) {
3804 fTrackFitter->FixParameter(3, fZfitter->GetFunctionValue(&fXref));
3805 fTrackFitter->FixParameter(4, fZfitter->GetFunctionParameter(1));
3806 fTrackFitter->Eval();
3807 fTrackFitter->ReleaseParameter(3);
3808 fTrackFitter->ReleaseParameter(4);
3809 fParameters[3] = fTrackFitter->GetParameter(3);
3810 fParameters[4] = fTrackFitter->GetParameter(4);
3812 // Update the Fit Parameters and the errors
3813 fParameters[0] = fTrackFitter->GetParameter(0);
3814 fParameters[1] = fTrackFitter->GetParameter(1);
3815 fParameters[2] = fTrackFitter->GetParameter(2);
3817 // Prepare Covariance estimation
3818 (*fCovarPolY)(0,0) = fSumPolY[0]; (*fCovarPolY)(1,1) = fSumPolY[2]; (*fCovarPolY)(2,2) = fSumPolY[4];
3819 (*fCovarPolY)(1,0) = (*fCovarPolY)(0,1) = fSumPolY[1];
3820 (*fCovarPolY)(2,0) = (*fCovarPolY)(0,2) = fSumPolY[2];
3821 (*fCovarPolY)(2,1) = (*fCovarPolY)(1,2) = fSumPolY[3];
3822 fCovarPolY->Invert();
3823 (*fCovarPolZ)(0,0) = fSumPolZ[0]; (*fCovarPolZ)(1,1) = fSumPolZ[2];
3824 (*fCovarPolZ)(1,0) = (*fCovarPolZ)(0,1) = fSumPolZ[1];
3825 fCovarPolZ->Invert();
3826 return fTrackFitter->GetChisquare() / fTrackFitter->GetNpoints();
3829 //_____________________________________________________________________________
3830 void AliTRDtrackerV1::AliTRDtrackFitterRieman::UpdateFitters(AliTRDseedV1 * const tracklet){
3832 // Does the transformations and updates the fitters
3833 // The following transformation is applied
3835 AliTRDcluster *cl = NULL;
3836 Double_t x, y, z, dx, t, w, we, yerr, zerr;
3838 if(!tracklet || !tracklet->IsOK()) return;
3839 Double_t tilt = tracklet->GetTilt();
3840 for(Int_t itb = 0; itb < AliTRDseedV1::kNclusters; itb++){
3841 if(!(cl = tracklet->GetClusters(itb))) continue;
3842 if(!cl->IsInChamber()) continue;
3843 if (!tracklet->IsUsable(itb)) continue;
3850 uvt[0] = 2. * x * t;
3852 uvt[2] = 2. * tilt * t;
3853 uvt[3] = 2. * tilt * dx * t;
3854 w = 2. * (y + tilt*z) * t;
3855 // error definition changes for the different calls
3857 we *= TMath::Sqrt(cl->GetSigmaY2()+tilt*tilt*cl->GetSigmaZ2());
3858 // Update sums for error calculation
3859 yerr = 1./(TMath::Sqrt(cl->GetSigmaY2()) + fSysClusterError);
3861 zerr = 1./cl->GetSigmaZ2();
3862 for(Int_t ipol = 0; ipol < 5; ipol++){
3863 fSumPolY[ipol] += yerr;
3866 fSumPolZ[ipol] += zerr;
3870 fTrackFitter->AddPoint(uvt, w, we);
3871 fZfitter->AddPoint(&x, z, static_cast<Double_t>(TMath::Sqrt(cl->GetSigmaZ2())));
3875 //_____________________________________________________________________________
3876 Bool_t AliTRDtrackerV1::AliTRDtrackFitterRieman::CheckAcceptable(Double_t offset, Double_t slope){
3878 // Check whether z-results are acceptable
3879 // Definition: Distance between tracklet fit and track fit has to be
3880 // less then half a padlength
3881 // Point of comparision is at the anode wire
3883 Bool_t acceptablez = kTRUE;
3884 Double_t zref = 0.0;
3885 for (Int_t iLayer = 0; iLayer < kNPlanes; iLayer++) {
3886 if(!fTracklets[iLayer]->IsOK()) continue;
3887 zref = offset + slope * (fTracklets[iLayer]->GetX0() - fXref);
3888 if (TMath::Abs(fTracklets[iLayer]->GetZfit(0) - zref) > fTracklets[iLayer]->GetPadLength() * 0.5 + 1.0)
3889 acceptablez = kFALSE;
3894 //_____________________________________________________________________________
3895 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::GetYat(Double_t x) const {
3897 // Calculate y position out of the track parameters
3898 // y: R^2 = (x - x0)^2 + (y - y0)^2
3899 // => y = y0 +/- Sqrt(R^2 - (x - x0)^2)
3900 // R = Sqrt() = 1/Curvature
3901 // => y = y0 +/- Sqrt(1/Curvature^2 - (x - x0)^2)
3904 Double_t disc = (x * fParameters[0] + fParameters[1]);
3905 disc = 1 - fParameters[0]*fParameters[2] + fParameters[1]*fParameters[1] - disc*disc;
3907 disc = TMath::Sqrt(disc);
3908 y = (1.0 - disc) / fParameters[0];
3913 //_____________________________________________________________________________
3914 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::GetZat(Double_t x) const {
3916 // Return z position for a given x position
3917 // Simple linear function
3919 return fParameters[3] + fParameters[4] * (x - fXref);
3922 //_____________________________________________________________________________
3923 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::GetDyDxAt(Double_t x) const {
3925 // Calculate dydx at a given radial position out of the track parameters
3926 // dy: R^2 = (x - x0)^2 + (y - y0)^2
3927 // => y = +/- Sqrt(R^2 - (x - x0)^2) + y0
3928 // => dy/dx = (x - x0)/Sqrt(R^2 - (x - x0)^2)
3929 // Curvature: cr = 1/R = a/Sqrt(1 + b^2 - c*a)
3930 // => dy/dx = (x - x0)/(1/(cr^2) - (x - x0)^2)
3932 Double_t x0 = -fParameters[1] / fParameters[0];
3933 Double_t curvature = GetCurvature();
3935 if (-fParameters[2] * fParameters[0] + fParameters[1] * fParameters[1] + 1 > 0) {
3936 if (1.0/(curvature * curvature) - (x - x0) * (x - x0) > 0.0) {
3937 Double_t yderiv = (x - x0) / TMath::Sqrt(1.0/(curvature * curvature) - (x - x0) * (x - x0));
3938 if (fParameters[0] < 0) yderiv *= -1.0;
3945 //_____________________________________________________________________________
3946 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::GetCurvature() const {
3948 // Calculate track curvature
3951 Double_t curvature = 1.0 + fParameters[1]*fParameters[1] - fParameters[2]*fParameters[0];
3952 if (curvature > 0.0)
3953 curvature = fParameters[0] / TMath::Sqrt(curvature);
3957 //_____________________________________________________________________________
3958 void AliTRDtrackerV1::AliTRDtrackFitterRieman::GetCovAt(Double_t x, Double_t *cov) const {
3960 // Error Definition according to gauss error propagation
3962 TMatrixD transform(3,3);
3963 transform(0,0) = transform(1,1) = transform(2,2) = 1;
3964 transform(0,1) = transform(1,2) = x;
3965 transform(0,2) = x*x;
3966 TMatrixD covariance(transform, TMatrixD::kMult, *fCovarPolY);
3967 covariance *= transform.T();
3968 cov[0] = covariance(0,0);
3969 TMatrixD transformZ(2,2);
3970 transformZ(0,0) = transformZ(1,1) = 1;
3971 transformZ(0,1) = x;
3972 TMatrixD covarZ(transformZ, TMatrixD::kMult, *fCovarPolZ);
3973 covarZ *= transformZ.T();
3974 cov[1] = covarZ(0,0);
3978 //____________________________________________________________________
3979 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::CalculateReferenceX(){
3981 // Calculates the reference x-position for the tilted Rieman fit defined as middle
3982 // of the stack (middle between layers 2 and 3). For the calculation all the tracklets
3983 // are taken into account
3985 // Parameters: - Array of tracklets(AliTRDseedV1)
3987 // Output: - The reference x-position(Float_t)
3989 Int_t nDistances = 0;
3990 Float_t meanDistance = 0.;
3991 Int_t startIndex = 5;
3992 for(Int_t il =5; il > 0; il--){
3993 if(fTracklets[il]->IsOK() && fTracklets[il -1]->IsOK()){
3994 Float_t xdiff = fTracklets[il]->GetX0() - fTracklets[il -1]->GetX0();
3995 meanDistance += xdiff;
3998 if(fTracklets[il]->IsOK()) startIndex = il;
4000 if(fTracklets[0]->IsOK()) startIndex = 0;
4002 // We should normally never get here
4003 Float_t xpos[2]; memset(xpos, 0, sizeof(Float_t) * 2);
4004 Int_t iok = 0, idiff = 0;
4005 // This attempt is worse and should be avoided:
4006 // check for two chambers which are OK and repeat this without taking the mean value
4007 // Strategy avoids a division by 0;
4008 for(Int_t il = 5; il >= 0; il--){
4009 if(fTracklets[il]->IsOK()){
4010 xpos[iok] = fTracklets[il]->GetX0();
4014 if(iok) idiff++; // to get the right difference;
4018 meanDistance = (xpos[0] - xpos[1])/idiff;
4021 // we have do not even have 2 layers which are OK? The we do not need to fit at all
4026 meanDistance /= nDistances;
4028 return fTracklets[startIndex]->GetX0() + (2.5 - startIndex) * meanDistance - 0.5 * (AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick());