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->GetStreamLevel(AliTRDReconstructor::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->GetStreamLevel(AliTRDReconstructor::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->GetStreamLevel(AliTRDReconstructor::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 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
620 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
621 AliTRDtrackV1 track(t);
623 cstreamer << "FollowProlongation"
624 << "EventNumber=" << eventNumber
625 << "ncl=" << nClustersExpected
626 << "track.=" << &track
630 return nClustersExpected;
634 //_____________________________________________________________________________
635 Int_t AliTRDtrackerV1::FollowBackProlongation(AliTRDtrackV1 &t)
637 // Extrapolates/Build the TRD track in the TOF direction.
640 // t : the TRD track which has to be extrapolated
643 // number of clusters attached to the track
645 // Starting from current radial position of track <t> this function
646 // extrapolates the track through the 6 TRD layers. The following steps
647 // are being performed for each plane:
648 // 1. Propagate track to the entrance of the next chamber:
649 // - get chamber limits in the radial direction
650 // - check crossing sectors
651 // - check track inclination
652 // - check track prolongation against boundary conditions (see exclusion boundaries on AliTRDgeometry::IsOnBoundary())
653 // 2. Build tracklet (see AliTRDseed::AttachClusters() for details) for this layer if needed. If only
654 // Kalman filter is needed and tracklets are already linked to the track this step is skipped.
655 // 3. Fit tracklet using the information from the Kalman filter.
656 // 4. Propagate and update track at reference radial position of the tracklet.
657 // 5. Register tracklet with the tracker and track; update pulls monitoring.
660 // 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:
661 // - AliTRDtrackV1::kProlongation : track prolongation failed
662 // - AliTRDtrackV1::kPropagation : track prolongation failed
663 // - AliTRDtrackV1::kAdjustSector : failed during sector crossing
664 // - AliTRDtrackV1::kSnp : too large bending
665 // - AliTRDtrackV1::kTrackletInit : fail to initialize tracklet
666 // - AliTRDtrackV1::kUpdate : fail to attach clusters or fit the tracklet
667 // - AliTRDtrackV1::kUnknown : anything which is not covered before
668 // 2. By default the status of the track before first TRD update is saved.
673 // Alexandru Bercuci <A.Bercuci@gsi.de>
677 Double_t driftLength = .5*AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick();
678 AliTRDtrackingChamber *chamber = NULL;
680 AliTRDseedV1 tracklet, *ptrTracklet = NULL;
681 // in case of stand alone tracking we store all the pointers to the tracklets in a temporary array
682 AliTRDseedV1 *tracklets[kNPlanes];
683 memset(tracklets, 0, sizeof(AliTRDseedV1 *) * kNPlanes);
684 for(Int_t ip = 0; ip < kNPlanes; ip++){
685 tracklets[ip] = t.GetTracklet(ip);
688 Bool_t kStoreIn = kTRUE, kPropagateIn = kTRUE;
690 // Loop through the TRD layers
691 TGeoHMatrix *matrix = NULL;
693 for (Int_t ily=0, sm=-1, stk=-1, det=-1; ily < AliTRDgeometry::kNlayer; ily++) {
694 // rough estimate of the entry point
695 if (!t.GetProlongation(fR[ily], y, z)){
697 t.SetStatus(AliTRDtrackV1::kProlongation);
701 // find sector / stack / detector
703 // TODO cross check with y value !
704 stk = fGeom->GetStack(z, ily);
705 det = stk>=0 ? AliTRDgeometry::GetDetector(ily, stk, sm) : -1;
706 matrix = det>=0 ? fGeom->GetClusterMatrix(det) : NULL;
708 // check if supermodule/chamber is installed
709 if( !fGeom->GetSMstatus(sm) ||
711 fGeom->IsHole(ily, stk, sm) ||
713 // propagate to the default radial position
714 if(fR[ily] > (fgkMaxStep + t.GetX()) && !PropagateToX(t, fR[ily], fgkMaxStep)){
716 t.SetStatus(AliTRDtrackV1::kPropagation);
719 if(!AdjustSector(&t)){
721 t.SetStatus(AliTRDtrackV1::kAdjustSector);
724 if(TMath::Abs(t.GetSnp()) > fgkMaxSnp){
726 t.SetStatus(AliTRDtrackV1::kSnp);
729 t.SetStatus(AliTRDtrackV1::kGeometry, ily);
733 // retrieve rotation matrix for the current chamber
734 Double_t loc[] = {AliTRDgeometry::AnodePos()- driftLength, 0., 0.};
735 Double_t glb[] = {0., 0., 0.};
736 matrix->LocalToMaster(loc, glb);
738 // Propagate to the radial distance of the current layer
739 x = glb[0] - fgkMaxStep;
740 if(x > (fgkMaxStep + t.GetX()) && !PropagateToX(t, x, fgkMaxStep)){
742 t.SetStatus(AliTRDtrackV1::kPropagation);
745 if(!AdjustSector(&t)){
747 t.SetStatus(AliTRDtrackV1::kAdjustSector);
750 if(TMath::Abs(t.GetSnp()) > fgkMaxSnp) {
752 t.SetStatus(AliTRDtrackV1::kSnp);
755 Bool_t doRecalculate = kFALSE;
756 if(sm != t.GetSector()){
758 doRecalculate = kTRUE;
760 if(stk != fGeom->GetStack(z, ily)){
761 stk = fGeom->GetStack(z, ily);
762 doRecalculate = kTRUE;
765 det = AliTRDgeometry::GetDetector(ily, stk, sm);
766 if(!(matrix = fGeom->GetClusterMatrix(det))){
767 t.SetStatus(AliTRDtrackV1::kGeometry, ily);
770 matrix->LocalToMaster(loc, glb);
771 x = glb[0] - fgkMaxStep;
774 // check if track is well inside fiducial volume
775 if (!t.GetProlongation(x+fgkMaxStep, y, z)) {
777 t.SetStatus(AliTRDtrackV1::kProlongation);
780 if(fGeom->IsOnBoundary(det, y, z, .5)){
781 t.SetStatus(AliTRDtrackV1::kBoundary, ily);
784 // mark track as entering the FIDUCIAL volume of TRD
790 ptrTracklet = tracklets[ily];
791 if(!ptrTracklet){ // BUILD TRACKLET
792 // check data in supermodule
793 if(!fTrSec[sm].GetNChambers()){
794 t.SetStatus(AliTRDtrackV1::kNoClusters, ily);
797 if(fTrSec[sm].GetX(ily) < 1.){
798 t.SetStatus(AliTRDtrackV1::kNoClusters, ily);
802 // check data in chamber
803 if(!(chamber = fTrSec[sm].GetChamber(stk, ily))){
804 t.SetStatus(AliTRDtrackV1::kNoClusters, ily);
807 if(chamber->GetNClusters() < fgNTimeBins*fkReconstructor->GetRecoParam() ->GetFindableClusters()){
808 t.SetStatus(AliTRDtrackV1::kNoClusters, ily);
812 ptrTracklet = new(&tracklet) AliTRDseedV1(det);
813 ptrTracklet->SetReconstructor(fkReconstructor);
814 ptrTracklet->SetKink(t.IsKink());
815 ptrTracklet->SetPadPlane(fGeom->GetPadPlane(ily, stk));
816 ptrTracklet->SetX0(glb[0]+driftLength);
817 if(!tracklet.Init(&t)){
819 t.SetStatus(AliTRDtrackV1::kTrackletInit);
822 if(!tracklet.AttachClusters(chamber, kTRUE)){
823 t.SetStatus(AliTRDtrackV1::kNoAttach, ily);
826 if(tracklet.GetN() < fgNTimeBins*fkReconstructor->GetRecoParam() ->GetFindableClusters()){
827 t.SetStatus(AliTRDtrackV1::kNoClustersTracklet, ily);
830 ptrTracklet->UpdateUsed();
832 // propagate track to the radial position of the tracklet
833 ptrTracklet->UseClusters(); // TODO ? do we need this here ?
834 // fit tracklet no tilt correction
835 if(!ptrTracklet->Fit(kFALSE)){
836 t.SetStatus(AliTRDtrackV1::kNoFit, ily);
839 x = ptrTracklet->GetX(); //GetX0();
840 if(x > (fgkMaxStep + t.GetX()) && !PropagateToX(t, x, fgkMaxStep)) {
842 t.SetStatus(AliTRDtrackV1::kPropagation);
845 if(!AdjustSector(&t)) {
847 t.SetStatus(AliTRDtrackV1::kAdjustSector);
850 if(TMath::Abs(t.GetSnp()) > fgkMaxSnp) {
852 t.SetStatus(AliTRDtrackV1::kSnp);
857 kPropagateIn = kFALSE;
859 Double_t cov[3]; ptrTracklet->GetCovAt(x, cov);
860 Double_t p[2] = { ptrTracklet->GetY(), ptrTracklet->GetZ()};
861 Double_t chi2 = ((AliExternalTrackParam)t).GetPredictedChi2(p, cov);
862 if(fkReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 2){
863 Double_t ytrack = ptrTracklet->GetYref(0);
864 Double_t ztrack = ptrTracklet->GetZref(0);
865 Double_t ytracklet = ptrTracklet->GetYfit(0);
866 Double_t ztracklet = ptrTracklet->GetZfit(0);
867 Double_t phitrack = ptrTracklet->GetYref(1);
868 Double_t phitracklet = ptrTracklet->GetYfit(1);
869 Double_t thetatrack = ptrTracklet->GetZref(1);
870 Double_t thetatracklet = ptrTracklet->GetZfit(1);
872 TTreeSRedirector &mystreamer = *fkReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
873 mystreamer << "FollowBackProlongation1"
876 << "ytrack=" << ytrack
877 << "ztrack=" << ztrack
878 << "ytracklet=" << ytracklet
879 << "ztracklet=" << ztracklet
880 << "phitrack=" << phitrack
881 << "thetatrack=" << thetatrack
882 << "phitracklet=" << phitracklet
883 << "thetatracklet=" << thetatracklet
887 // update Kalman with the TRD measurement
888 if(chi2>1e+10){ // TODO
889 t.SetStatus(AliTRDtrackV1::kChi2, ily);
892 if(!t.Update(p, cov, chi2)) {
894 t.SetStatus(AliTRDtrackV1::kUpdate);
898 AliTracker::FillResiduals(&t, p, cov, ptrTracklet->GetVolumeId());
901 // load tracklet to the tracker
902 ptrTracklet->Update(&t);
903 ptrTracklet = SetTracklet(ptrTracklet);
904 t.SetTracklet(ptrTracklet, fTracklets->GetEntriesFast()-1);
905 n += ptrTracklet->GetN();
907 // Reset material budget if 2 consecutive gold
908 // if(ilayer>0 && t.GetTracklet(ilayer-1) && ptrTracklet->GetN() + t.GetTracklet(ilayer-1)->GetN() > 20) t.SetBudget(2, 0.);
910 // Make backup of the track until is gold
911 // TO DO update quality check of the track.
912 // consider comparison with fTimeBinsRange
913 Float_t ratio0 = ptrTracklet->GetN() / Float_t(fgNTimeBins);
914 //Float_t ratio1 = Float_t(t.GetNumberOfClusters()+1) / Float_t(t.GetNExpected()+1);
919 //(ratio0+ratio1 > 1.5) &&
920 (t.GetNCross() == 0) &&
921 (TMath::Abs(t.GetSnp()) < 0.85) &&
922 (t.GetNumberOfClusters() > 20)){
926 //printf("clusters[%d] chi2[%f] x[%f] status[%d ", n, t.GetChi2(), t.GetX(), t.GetStatusTRD());
927 //for(int i=0; i<6; i++) printf("%d ", t.GetStatusTRD(i)); printf("]\n");
929 if(fkReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 1){
930 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
931 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
932 AliTRDtrackV1 track(t);
934 cstreamer << "FollowBackProlongation"
935 << "EventNumber=" << eventNumber
937 << "track.=" << &track
944 //_________________________________________________________________________
945 Float_t AliTRDtrackerV1::FitRieman(AliTRDseedV1 *tracklets, Double_t *chi2, Int_t *const planes){
947 // Fits a Riemann-circle to the given points without tilting pad correction.
948 // The fit is performed using an instance of the class AliRieman (equations
949 // and transformations see documentation of this class)
950 // Afterwards all the tracklets are Updated
952 // Parameters: - Array of tracklets (AliTRDseedV1)
953 // - Storage for the chi2 values (beginning with direction z)
954 // - Seeding configuration
955 // Output: - The curvature
957 AliRieman *fitter = AliTRDtrackerV1::GetRiemanFitter();
959 Int_t allplanes[] = {0, 1, 2, 3, 4, 5};
960 Int_t *ppl = &allplanes[0];
966 for(Int_t il = 0; il < maxLayers; il++){
967 if(!tracklets[ppl[il]].IsOK()) continue;
968 fitter->AddPoint(tracklets[ppl[il]].GetX0(), tracklets[ppl[il]].GetYfit(0), tracklets[ppl[il]].GetZfit(0),1,10);
971 // Set the reference position of the fit and calculate the chi2 values
972 memset(chi2, 0, sizeof(Double_t) * 2);
973 for(Int_t il = 0; il < maxLayers; il++){
974 // Reference positions
975 tracklets[ppl[il]].Init(fitter);
978 if((!tracklets[ppl[il]].IsOK()) && (!planes)) continue;
979 chi2[0] += tracklets[ppl[il]].GetChi2Y();
980 chi2[1] += tracklets[ppl[il]].GetChi2Z();
982 return fitter->GetC();
985 //_________________________________________________________________________
986 void AliTRDtrackerV1::FitRieman(AliTRDcluster **seedcl, Double_t chi2[2])
989 // Performs a Riemann helix fit using the seedclusters as spacepoints
990 // Afterwards the chi2 values are calculated and the seeds are updated
992 // Parameters: - The four seedclusters
993 // - The tracklet array (AliTRDseedV1)
994 // - The seeding configuration
999 AliRieman *fitter = AliTRDtrackerV1::GetRiemanFitter();
1001 for(Int_t i = 0; i < 4; i++){
1002 fitter->AddPoint(seedcl[i]->GetX(), seedcl[i]->GetY(), seedcl[i]->GetZ(), 1., 10.);
1007 // Update the seed and calculated the chi2 value
1008 chi2[0] = 0; chi2[1] = 0;
1009 for(Int_t ipl = 0; ipl < kNSeedPlanes; ipl++){
1011 chi2[0] += (seedcl[ipl]->GetZ() - fitter->GetZat(seedcl[ipl]->GetX())) * (seedcl[ipl]->GetZ() - fitter->GetZat(seedcl[ipl]->GetX()));
1012 chi2[1] += (seedcl[ipl]->GetY() - fitter->GetYat(seedcl[ipl]->GetX())) * (seedcl[ipl]->GetY() - fitter->GetYat(seedcl[ipl]->GetX()));
1017 //_________________________________________________________________________
1018 Float_t AliTRDtrackerV1::FitTiltedRiemanConstraint(AliTRDseedV1 *tracklets, Double_t zVertex)
1021 // Fits a helix to the clusters. Pad tilting is considered. As constraint it is
1022 // assumed that the vertex position is set to 0.
1023 // This method is very usefull for high-pt particles
1024 // Basis for the fit: (x - x0)^2 + (y - y0)^2 - R^2 = 0
1025 // x0, y0: Center of the circle
1026 // Measured y-position: ymeas = y - tan(phiT)(zc - zt)
1027 // zc: center of the pad row
1028 // Equation which has to be fitted (after transformation):
1029 // a + b * u + e * v + 2*(ymeas + tan(phiT)(z - zVertex))*t = 0
1031 // t = 1/(x^2 + y^2)
1033 // v = 2 * x * tan(phiT) * t
1034 // Parameters in the equation:
1035 // a = -1/y0, b = x0/y0, e = dz/dx
1037 // The Curvature is calculated by the following equation:
1038 // - curv = a/Sqrt(b^2 + 1) = 1/R
1039 // Parameters: - the 6 tracklets
1040 // - the Vertex constraint
1041 // Output: - the Chi2 value of the track
1046 TLinearFitter *fitter = GetTiltedRiemanFitterConstraint();
1047 fitter->StoreData(kTRUE);
1048 fitter->ClearPoints();
1049 AliTRDcluster *cl = NULL;
1051 Float_t x, y, z, w, t, error, tilt;
1054 for(Int_t ilr = 0; ilr < AliTRDgeometry::kNlayer; ilr++){
1055 if(!tracklets[ilr].IsOK()) continue;
1056 for(Int_t itb = 0; itb < AliTRDseedV1::kNclusters; itb++){
1057 if(!tracklets[ilr].IsUsable(itb)) continue;
1058 cl = tracklets[ilr].GetClusters(itb);
1059 if(!cl->IsInChamber()) continue;
1063 tilt = tracklets[ilr].GetTilt();
1065 t = 1./(x * x + y * y);
1066 uvt[0] = 2. * x * t;
1067 uvt[1] = 2. * x * t * tilt ;
1068 w = 2. * (y + tilt * (z - zVertex)) * t;
1069 error = 2. * TMath::Sqrt(cl->GetSigmaY2()+tilt*tilt*cl->GetSigmaZ2()) * t;
1070 fitter->AddPoint(uvt, w, error);
1074 if(fitter->Eval()) return 1.E10;
1076 // Calculate curvature
1077 Double_t a = fitter->GetParameter(0);
1078 Double_t b = fitter->GetParameter(1);
1079 Double_t curvature = a/TMath::Sqrt(b*b + 1);
1081 Float_t chi2track = fitter->GetChisquare()/Double_t(nPoints);
1082 for(Int_t ip = 0; ip < AliTRDtrackerV1::kNPlanes; ip++)
1083 tracklets[ip].SetC(curvature);
1085 /* if(fkReconstructor->GetStreamLevel() >= 5){
1086 //Linear Model on z-direction
1087 Double_t xref = CalculateReferenceX(tracklets); // Relative to the middle of the stack
1088 Double_t slope = fitter->GetParameter(2);
1089 Double_t zref = slope * xref;
1090 Float_t chi2Z = CalculateChi2Z(tracklets, zref, slope, xref);
1091 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
1092 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
1093 TTreeSRedirector &treeStreamer = *fkReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
1094 treeStreamer << "FitTiltedRiemanConstraint"
1095 << "EventNumber=" << eventNumber
1096 << "CandidateNumber=" << candidateNumber
1097 << "Curvature=" << curvature
1098 << "Chi2Track=" << chi2track
1099 << "Chi2Z=" << chi2Z
1106 //_________________________________________________________________________
1107 Float_t AliTRDtrackerV1::FitTiltedRieman(AliTRDseedV1 *tracklets, Bool_t sigError)
1110 // Performs a Riemann fit taking tilting pad correction into account
1111 // The equation of a Riemann circle, where the y position is substituted by the
1112 // measured y-position taking pad tilting into account, has to be transformed
1113 // into a 4-dimensional hyperplane equation
1114 // Riemann circle: (x-x0)^2 + (y-y0)^2 -R^2 = 0
1115 // Measured y-Position: ymeas = y - tan(phiT)(zc - zt)
1116 // zc: center of the pad row
1117 // zt: z-position of the track
1118 // The z-position of the track is assumed to be linear dependent on the x-position
1119 // Transformed equation: a + b * u + c * t + d * v + e * w - 2 * (ymeas + tan(phiT) * zc) * t = 0
1120 // Transformation: u = 2 * x * t
1121 // v = 2 * tan(phiT) * t
1122 // w = 2 * tan(phiT) * (x - xref) * t
1123 // t = 1 / (x^2 + ymeas^2)
1124 // Parameters: a = -1/y0
1126 // c = (R^2 -x0^2 - y0^2)/y0
1129 // If the offset respectively the slope in z-position is impossible, the parameters are fixed using
1130 // results from the simple riemann fit. Afterwards the fit is redone.
1131 // The curvature is calculated according to the formula:
1132 // curv = a/(1 + b^2 + c*a) = 1/R
1134 // Paramters: - Array of tracklets (connected to the track candidate)
1135 // - Flag selecting the error definition
1136 // Output: - Chi2 values of the track (in Parameter list)
1138 TLinearFitter *fitter = GetTiltedRiemanFitter();
1139 fitter->StoreData(kTRUE);
1140 fitter->ClearPoints();
1141 AliTRDLeastSquare zfitter;
1142 AliTRDcluster *cl = NULL;
1144 Double_t xref = CalculateReferenceX(tracklets);
1145 Double_t x, y, z, t, tilt, dx, w, we, erry, errz;
1146 Double_t uvt[4], sumPolY[5], sumPolZ[3];
1147 memset(sumPolY, 0, sizeof(Double_t) * 5);
1148 memset(sumPolZ, 0, sizeof(Double_t) * 3);
1150 // Containers for Least-square fitter
1151 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1152 if(!tracklets[ipl].IsOK()) continue;
1153 tilt = tracklets[ipl].GetTilt();
1154 for(Int_t itb = 0; itb < AliTRDseedV1::kNclusters; itb++){
1155 if(!(cl = tracklets[ipl].GetClusters(itb))) continue;
1156 if(!cl->IsInChamber()) continue;
1157 if (!tracklets[ipl].IsUsable(itb)) continue;
1164 uvt[0] = 2. * x * t;
1166 uvt[2] = 2. * tilt * t;
1167 uvt[3] = 2. * tilt * dx * t;
1168 w = 2. * (y + tilt*z) * t;
1169 // error definition changes for the different calls
1171 we *= sigError ? TMath::Sqrt(cl->GetSigmaY2()+tilt*tilt*cl->GetSigmaZ2()) : 0.2;
1172 fitter->AddPoint(uvt, w, we);
1173 zfitter.AddPoint(&x, z, static_cast<Double_t>(TMath::Sqrt(cl->GetSigmaZ2())));
1174 // adding points for covariance matrix estimation
1175 erry = 1./(TMath::Sqrt(cl->GetSigmaY2()) + 0.1); // 0.1 is a systematic error (due to misalignment and miscalibration)
1177 errz = 1./cl->GetSigmaZ2();
1178 for(Int_t ipol = 0; ipol < 5; ipol++){
1179 sumPolY[ipol] += erry;
1182 sumPolZ[ipol] += errz;
1189 if(fitter->Eval()) return 1.E10;
1192 Double_t offset = fitter->GetParameter(3);
1193 Double_t slope = fitter->GetParameter(4);
1195 // Linear fitter - not possible to make boundaries
1196 // Do not accept non possible z and dzdx combinations
1197 Bool_t acceptablez = kTRUE;
1198 Double_t zref = 0.0;
1199 for (Int_t iLayer = 0; iLayer < kNPlanes; iLayer++) {
1200 if(!tracklets[iLayer].IsOK()) continue;
1201 zref = offset + slope * (tracklets[iLayer].GetX0() - xref);
1202 if (TMath::Abs(tracklets[iLayer].GetZfit(0) - zref) > tracklets[iLayer].GetPadLength() * 0.5 + 1.0)
1203 acceptablez = kFALSE;
1206 Double_t dzmf = zfitter.GetFunctionParameter(1);
1207 Double_t zmf = zfitter.GetFunctionValue(&xref);
1208 fgTiltedRieman->FixParameter(3, zmf);
1209 fgTiltedRieman->FixParameter(4, dzmf);
1210 if (fitter->Eval()) return 1.E10;
1211 fitter->ReleaseParameter(3);
1212 fitter->ReleaseParameter(4);
1213 offset = fitter->GetParameter(3);
1214 slope = fitter->GetParameter(4);
1217 // Calculate Curvarture
1218 Double_t a = fitter->GetParameter(0);
1219 Double_t b = fitter->GetParameter(1);
1220 Double_t c = fitter->GetParameter(2);
1221 Double_t curvature = 1.0 + b*b - c*a;
1222 if (curvature > 0.0)
1223 curvature = a / TMath::Sqrt(curvature);
1225 Double_t chi2track = fitter->GetChisquare()/Double_t(nPoints);
1227 // Prepare error calculation
1228 TMatrixD covarPolY(3,3);
1229 covarPolY(0,0) = sumPolY[0]; covarPolY(1,1) = sumPolY[2]; covarPolY(2,2) = sumPolY[4];
1230 covarPolY(0,1) = covarPolY(1,0) = sumPolY[1];
1231 covarPolY(0,2) = covarPolY(2,0) = sumPolY[2];
1232 covarPolY(2,1) = covarPolY(1,2) = sumPolY[3];
1234 TMatrixD covarPolZ(2,2);
1235 covarPolZ(0,0) = sumPolZ[0]; covarPolZ(1,1) = sumPolZ[2];
1236 covarPolZ(1,0) = covarPolZ(0,1) = sumPolZ[1];
1239 // Update the tracklets
1240 Double_t x1, dy, dz;
1242 memset(cov, 0, sizeof(Double_t) * 15);
1243 for(Int_t iLayer = 0; iLayer < AliTRDtrackerV1::kNPlanes; iLayer++) {
1245 x = tracklets[iLayer].GetX0();
1251 memset(cov, 0, sizeof(Double_t) * 3);
1252 TMatrixD transform(3,3);
1255 transform(0,2) = x*x;
1259 TMatrixD covariance(transform, TMatrixD::kMult, covarPolY);
1260 covariance *= transform.T();
1261 TMatrixD transformZ(2,2);
1262 transformZ(0,0) = transformZ(1,1) = 1;
1263 transformZ(0,1) = x;
1264 TMatrixD covarZ(transformZ, TMatrixD::kMult, covarPolZ);
1265 covarZ *= transformZ.T();
1266 // y: R^2 = (x - x0)^2 + (y - y0)^2
1267 // => y = y0 +/- Sqrt(R^2 - (x - x0)^2)
1268 // R = Sqrt() = 1/Curvature
1269 // => y = y0 +/- Sqrt(1/Curvature^2 - (x - x0)^2)
1270 Double_t res = (x * a + b); // = (x - x0)/y0
1272 res = 1.0 - c * a + b * b - res; // = (R^2 - (x - x0)^2)/y0^2
1274 res = TMath::Sqrt(res);
1275 y = (1.0 - res) / a;
1277 cov[0] = covariance(0,0);
1278 cov[2] = covarZ(0,0);
1281 // dy: R^2 = (x - x0)^2 + (y - y0)^2
1282 // => y = +/- Sqrt(R^2 - (x - x0)^2) + y0
1283 // => dy/dx = (x - x0)/Sqrt(R^2 - (x - x0)^2)
1284 // Curvature: cr = 1/R = a/Sqrt(1 + b^2 - c*a)
1285 // => dy/dx = (x - x0)/(1/(cr^2) - (x - x0)^2)
1286 Double_t x0 = -b / a;
1287 if (-c * a + b * b + 1 > 0) {
1288 if (1.0/(curvature * curvature) - (x - x0) * (x - x0) > 0.0) {
1289 Double_t yderiv = (x - x0) / TMath::Sqrt(1.0/(curvature * curvature) - (x - x0) * (x - x0));
1290 if (a < 0) yderiv *= -1.0;
1294 z = offset + slope * (x - xref);
1296 tracklets[iLayer].SetYref(0, y);
1297 tracklets[iLayer].SetYref(1, dy);
1298 tracklets[iLayer].SetZref(0, z);
1299 tracklets[iLayer].SetZref(1, dz);
1300 tracklets[iLayer].SetC(curvature);
1301 tracklets[iLayer].SetCovRef(cov);
1302 tracklets[iLayer].SetChi2(chi2track);
1305 /* if(fkReconstructor->GetStreamLevel() >=5){
1306 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
1307 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
1308 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
1309 Double_t chi2z = CalculateChi2Z(tracklets, offset, slope, xref);
1310 cstreamer << "FitTiltedRieman0"
1311 << "EventNumber=" << eventNumber
1312 << "CandidateNumber=" << candidateNumber
1314 << "Chi2Z=" << chi2z
1321 //____________________________________________________________________
1322 Double_t AliTRDtrackerV1::FitLine(const AliTRDtrackV1 *track, AliTRDseedV1 *tracklets, Bool_t err, Int_t np, AliTrackPoint *points)
1325 // Fit track with a staight line
1326 // Fills an AliTrackPoint array with np points
1327 // Function should be used to refit tracks when no magnetic field was on
1329 AliTRDLeastSquare yfitter, zfitter;
1330 AliTRDcluster *cl = NULL;
1332 AliTRDseedV1 work[kNPlanes], *tracklet = NULL;
1334 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1335 if(!(tracklet = track->GetTracklet(ipl))) continue;
1336 if(!tracklet->IsOK()) continue;
1337 new(&work[ipl]) AliTRDseedV1(*tracklet);
1339 tracklets = &work[0];
1342 Double_t xref = CalculateReferenceX(tracklets);
1343 Double_t x, y, z, dx, ye, yr, tilt;
1344 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1345 if(!tracklets[ipl].IsOK()) continue;
1346 for(Int_t itb = 0; itb < fgNTimeBins; itb++){
1347 if(!(cl = tracklets[ipl].GetClusters(itb))) continue;
1348 if (!tracklets[ipl].IsUsable(itb)) continue;
1352 zfitter.AddPoint(&dx, z, static_cast<Double_t>(TMath::Sqrt(cl->GetSigmaZ2())));
1356 Double_t z0 = zfitter.GetFunctionParameter(0);
1357 Double_t dzdx = zfitter.GetFunctionParameter(1);
1358 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1359 if(!tracklets[ipl].IsOK()) continue;
1360 for(Int_t itb = 0; itb < fgNTimeBins; itb++){
1361 if(!(cl = tracklets[ipl].GetClusters(itb))) continue;
1362 if (!tracklets[ipl].IsUsable(itb)) continue;
1366 tilt = tracklets[ipl].GetTilt();
1368 yr = y + tilt*(z - z0 - dzdx*dx);
1369 // error definition changes for the different calls
1370 ye = tilt*TMath::Sqrt(cl->GetSigmaZ2());
1371 ye += err ? tracklets[ipl].GetSigmaY() : 0.2;
1372 yfitter.AddPoint(&dx, yr, ye);
1376 Double_t y0 = yfitter.GetFunctionParameter(0);
1377 Double_t dydx = yfitter.GetFunctionParameter(1);
1378 Double_t chi2 = 0.;//yfitter.GetChisquare()/Double_t(nPoints);
1380 //update track points array
1383 for(int ip=0; ip<np; ip++){
1384 points[ip].GetXYZ(xyz);
1385 xyz[1] = y0 + dydx * (xyz[0] - xref);
1386 xyz[2] = z0 + dzdx * (xyz[0] - xref);
1387 points[ip].SetXYZ(xyz);
1394 //_________________________________________________________________________
1395 Double_t AliTRDtrackerV1::FitRiemanTilt(const AliTRDtrackV1 *track, AliTRDseedV1 *tracklets, Bool_t sigError, Int_t np, AliTrackPoint *points)
1398 // Performs a Riemann fit taking tilting pad correction into account
1400 // Paramters: - Array of tracklets (connected to the track candidate)
1401 // - Flag selecting the error definition
1402 // Output: - Chi2 values of the track (in Parameter list)
1404 // The equations which has to be solved simultaneously are:
1406 // R^{2} = (x-x_{0})^{2} + (y^{*}-y_{0})^{2}
1407 // y^{*} = y - tg(h)(z - z_{t})
1408 // z_{t} = z_{0}+dzdx*(x-x_{r})
1410 // with (x, y, z) the coordinate of the cluster, (x_0, y_0, z_0) the coordinate of the center of the Riemann circle,
1411 // R its radius, x_r a constant refrence radial position in the middle of the TRD stack and dzdx the slope of the
1412 // track in the x-z plane. Using the following transformations
1414 // t = 1 / (x^{2} + y^{2})
1416 // v = 2 * tan(h) * t
1417 // w = 2 * tan(h) * (x - x_{r}) * t
1419 // One gets the following linear equation
1421 // a + b * u + c * t + d * v + e * w = 2 * (y + tg(h) * z) * t
1423 // where the coefficients have the following meaning
1427 // c = (R^{2} -x_{0}^{2} - y_{0}^{2})/y_{0}
1431 // The error calculation for the free term is thus
1433 // #sigma = 2 * #sqrt{#sigma^{2}_{y} + (tilt corr ...) + tg^{2}(h) * #sigma^{2}_{z}} * t
1436 // From this simple model one can compute chi^2 estimates and a rough approximation of pt from the curvature according
1439 // C = 1/R = a/(1 + b^{2} + c*a)
1443 // M.Ivanov <M.Ivanov@gsi.de>
1444 // A.Bercuci <A.Bercuci@gsi.de>
1445 // M.Fasel <M.Fasel@gsi.de>
1447 TLinearFitter *fitter = GetTiltedRiemanFitter();
1448 fitter->StoreData(kTRUE);
1449 fitter->ClearPoints();
1450 AliTRDLeastSquare zfitter;
1451 AliTRDcluster *cl = NULL;
1453 AliTRDseedV1 work[kNPlanes], *tracklet = NULL;
1455 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1456 if(!(tracklet = track->GetTracklet(ipl))) continue;
1457 if(!tracklet->IsOK()) continue;
1458 new(&work[ipl]) AliTRDseedV1(*tracklet);
1460 tracklets = &work[0];
1463 Double_t xref = CalculateReferenceX(tracklets);
1464 Double_t x, y, z, t, tilt, dx, w, we;
1467 // Containers for Least-square fitter
1468 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1469 if(!tracklets[ipl].IsOK()) continue;
1470 for(Int_t itb = 0; itb < AliTRDseedV1::kNclusters; itb++){
1471 if(!(cl = tracklets[ipl].GetClusters(itb))) continue;
1472 if (!tracklets[ipl].IsUsable(itb)) continue;
1476 tilt = tracklets[ipl].GetTilt();
1480 uvt[0] = 2. * x * t;
1482 uvt[2] = 2. * tilt * t;
1483 uvt[3] = 2. * tilt * dx * t;
1484 w = 2. * (y + tilt*z) * t;
1485 // error definition changes for the different calls
1487 we *= sigError ? TMath::Sqrt(cl->GetSigmaY2()) : 0.2;
1488 fitter->AddPoint(uvt, w, we);
1489 zfitter.AddPoint(&x, z, static_cast<Double_t>(TMath::Sqrt(cl->GetSigmaZ2())));
1493 if(fitter->Eval()) return 1.E10;
1495 Double_t z0 = fitter->GetParameter(3);
1496 Double_t dzdx = fitter->GetParameter(4);
1499 // Linear fitter - not possible to make boundaries
1500 // Do not accept non possible z and dzdx combinations
1501 Bool_t accept = kTRUE;
1502 Double_t zref = 0.0;
1503 for (Int_t iLayer = 0; iLayer < kNPlanes; iLayer++) {
1504 if(!tracklets[iLayer].IsOK()) continue;
1505 zref = z0 + dzdx * (tracklets[iLayer].GetX0() - xref);
1506 if (TMath::Abs(tracklets[iLayer].GetZfit(0) - zref) > tracklets[iLayer].GetPadLength() * 0.5 + 1.0)
1511 Double_t dzmf = zfitter.GetFunctionParameter(1);
1512 Double_t zmf = zfitter.GetFunctionValue(&xref);
1513 fitter->FixParameter(3, zmf);
1514 fitter->FixParameter(4, dzmf);
1515 if(fitter->Eval()) return 1.E10;
1516 fitter->ReleaseParameter(3);
1517 fitter->ReleaseParameter(4);
1518 z0 = fitter->GetParameter(3); // = zmf ?
1519 dzdx = fitter->GetParameter(4); // = dzmf ?
1522 // Calculate Curvature
1523 Double_t a = fitter->GetParameter(0);
1524 Double_t b = fitter->GetParameter(1);
1525 Double_t c = fitter->GetParameter(2);
1526 Double_t y0 = 1. / a;
1527 Double_t x0 = -b * y0;
1528 Double_t tmp = y0*y0 + x0*x0 - c*y0;
1529 if(tmp<=0.) return 1.E10;
1530 Double_t radius = TMath::Sqrt(tmp);
1531 Double_t curvature = 1.0 + b*b - c*a;
1532 if (curvature > 0.0) curvature = a / TMath::Sqrt(curvature);
1534 // Calculate chi2 of the fit
1535 Double_t chi2 = fitter->GetChisquare()/Double_t(nPoints);
1537 // Update the tracklets
1539 for(Int_t ip = 0; ip < kNPlanes; ip++) {
1540 x = tracklets[ip].GetX0();
1541 tmp = radius*radius-(x-x0)*(x-x0);
1542 if(tmp <= 0.) continue;
1543 tmp = TMath::Sqrt(tmp);
1545 // y: R^2 = (x - x0)^2 + (y - y0)^2
1546 // => y = y0 +/- Sqrt(R^2 - (x - x0)^2)
1547 tracklets[ip].SetYref(0, y0 - (y0>0.?1.:-1)*tmp);
1548 // => dy/dx = (x - x0)/Sqrt(R^2 - (x - x0)^2)
1549 tracklets[ip].SetYref(1, (x - x0) / tmp);
1550 tracklets[ip].SetZref(0, z0 + dzdx * (x - xref));
1551 tracklets[ip].SetZref(1, dzdx);
1552 tracklets[ip].SetC(curvature);
1553 tracklets[ip].SetChi2(chi2);
1556 //update track points array
1559 for(int ip=0; ip<np; ip++){
1560 points[ip].GetXYZ(xyz);
1561 xyz[1] = TMath::Abs(xyz[0] - x0) > radius ? 100. : y0 - (y0>0.?1.:-1.)*TMath::Sqrt((radius-(xyz[0]-x0))*(radius+(xyz[0]-x0)));
1562 xyz[2] = z0 + dzdx * (xyz[0] - xref);
1563 points[ip].SetXYZ(xyz);
1571 //____________________________________________________________________
1572 Double_t AliTRDtrackerV1::FitKalman(AliTRDtrackV1 *track, const AliTRDseedV1 * const tracklets, Bool_t up, Int_t np, AliTrackPoint *points)
1574 // Kalman filter implementation for the TRD.
1575 // It returns the positions of the fit in the array "points"
1577 // Author : A.Bercuci@gsi.de
1579 // printf("Start track @ x[%f]\n", track->GetX());
1581 //prepare marker points along the track
1582 Int_t ip = np ? 0 : 1;
1584 if((up?-1:1) * (track->GetX() - points[ip].GetX()) > 0.) break;
1585 //printf("AliTRDtrackerV1::FitKalman() : Skip track marker x[%d] = %7.3f. Before track start ( %7.3f ).\n", ip, points[ip].GetX(), track->GetX());
1588 //if(points) printf("First marker point @ x[%d] = %f\n", ip, points[ip].GetX());
1591 AliTRDseedV1 tracklet, *ptrTracklet = NULL;
1593 //Loop through the TRD planes
1594 for (Int_t jplane = 0; jplane < kNPlanes; jplane++) {
1595 // GET TRACKLET OR BUILT IT
1596 Int_t iplane = up ? jplane : kNPlanes - 1 - jplane;
1598 if(!(ptrTracklet = const_cast<AliTRDseedV1 *>(&tracklets[iplane]))) continue;
1600 if(!(ptrTracklet = track->GetTracklet(iplane))){
1601 /*AliTRDtrackerV1 *tracker = NULL;
1602 if(!(tracker = dynamic_cast<AliTRDtrackerV1*>( AliTRDReconstructor::Tracker()))) continue;
1603 ptrTracklet = new(&tracklet) AliTRDseedV1(iplane);
1604 if(!tracker->MakeTracklet(ptrTracklet, track)) */
1608 if(!ptrTracklet->IsOK()) continue;
1610 Double_t x = ptrTracklet->GetX0();
1613 //don't do anything if next marker is after next update point.
1614 if((up?-1:1) * (points[ip].GetX() - x) - fgkMaxStep < 0) break;
1615 if(((up?-1:1) * (points[ip].GetX() - track->GetX()) < 0) && !PropagateToX(*track, points[ip].GetX(), fgkMaxStep)) return -1.;
1617 Double_t xyz[3]; // should also get the covariance
1619 track->Global2LocalPosition(xyz, track->GetAlpha());
1620 points[ip].SetXYZ(xyz[0], xyz[1], xyz[2]);
1623 // printf("plane[%d] tracklet[%p] x[%f]\n", iplane, ptrTracklet, x);
1625 // Propagate closer to the next update point
1626 if(((up?-1:1) * (x - track->GetX()) + fgkMaxStep < 0) && !PropagateToX(*track, x + (up?-1:1)*fgkMaxStep, fgkMaxStep)) return -1.;
1628 if(!AdjustSector(track)) return -1;
1629 if(TMath::Abs(track->GetSnp()) > fgkMaxSnp) return -1;
1631 //load tracklet to the tracker and the track
1633 if((index = FindTracklet(ptrTracklet)) < 0){
1634 ptrTracklet = SetTracklet(&tracklet);
1635 index = fTracklets->GetEntriesFast()-1;
1637 track->SetTracklet(ptrTracklet, index);*/
1640 // register tracklet to track with tracklet creation !!
1641 // PropagateBack : loaded tracklet to the tracker and update index
1642 // RefitInward : update index
1643 // MakeTrack : loaded tracklet to the tracker and update index
1644 if(!tracklets) track->SetTracklet(ptrTracklet, -1);
1647 //Calculate the mean material budget along the path inside the chamber
1648 Double_t xyz0[3]; track->GetXYZ(xyz0);
1649 Double_t alpha = track->GetAlpha();
1650 Double_t xyz1[3], y, z;
1651 if(!track->GetProlongation(x, y, z)) return -1;
1652 xyz1[0] = x * TMath::Cos(alpha) - y * TMath::Sin(alpha);
1653 xyz1[1] = +x * TMath::Sin(alpha) + y * TMath::Cos(alpha);
1655 if((xyz0[0] - xyz1[9] < 1e-3) && (xyz0[0] - xyz1[9] < 1e-3)) continue; // check wheter we are at the same global x position
1657 if(AliTracker::MeanMaterialBudget(xyz0, xyz1, param) <=0.) break;
1658 Double_t xrho = param[0]*param[4]; // density*length
1659 Double_t xx0 = param[1]; // radiation length
1661 //Propagate the track
1662 track->PropagateTo(x, xx0, xrho);
1663 if (!AdjustSector(track)) break;
1666 Double_t cov[3]; ptrTracklet->GetCovAt(x, cov);
1667 Double_t p[2] = { ptrTracklet->GetY(), ptrTracklet->GetZ()};
1668 Double_t chi2 = ((AliExternalTrackParam*)track)->GetPredictedChi2(p, cov);
1669 if(chi2<1e+10) track->Update(p, cov, chi2);
1672 //Reset material budget if 2 consecutive gold
1673 if(iplane>0 && track->GetTracklet(iplane-1) && ptrTracklet->GetN() + track->GetTracklet(iplane-1)->GetN() > 20) track->SetBudget(2, 0.);
1674 } // end planes loop
1678 if(((up?-1:1) * (points[ip].GetX() - track->GetX()) < 0) && !PropagateToX(*track, points[ip].GetX(), fgkMaxStep)) return -1.;
1680 Double_t xyz[3]; // should also get the covariance
1682 track->Global2LocalPosition(xyz, track->GetAlpha());
1683 points[ip].SetXYZ(xyz[0], xyz[1], xyz[2]);
1687 return track->GetChi2();
1690 //_________________________________________________________________________
1691 Float_t AliTRDtrackerV1::CalculateChi2Z(AliTRDseedV1 *tracklets, Double_t offset, Double_t slope, Double_t xref)
1694 // Calculates the chi2-value of the track in z-Direction including tilting pad correction.
1695 // A linear dependence on the x-value serves as a model.
1696 // The parameters are related to the tilted Riemann fit.
1697 // Parameters: - Array of tracklets (AliTRDseedV1) related to the track candidate
1698 // - the offset for the reference x
1700 // - the reference x position
1701 // Output: - The Chi2 value of the track in z-Direction
1703 Float_t chi2Z = 0, nLayers = 0;
1704 for (Int_t iLayer = 0; iLayer < AliTRDgeometry::kNlayer; iLayer++) {
1705 if(!tracklets[iLayer].IsOK()) continue;
1706 Double_t z = offset + slope * (tracklets[iLayer].GetX0() - xref);
1707 chi2Z += TMath::Abs(tracklets[iLayer].GetZfit(0) - z);
1710 chi2Z /= TMath::Max((nLayers - 3.0),1.0);
1714 //_____________________________________________________________________________
1715 Int_t AliTRDtrackerV1::PropagateToX(AliTRDtrackV1 &t, Double_t xToGo, Double_t maxStep)
1718 // Starting from current X-position of track <t> this function
1719 // extrapolates the track up to radial position <xToGo>.
1720 // Returns 1 if track reaches the plane, and 0 otherwise
1723 const Double_t kEpsilon = 0.00001;
1725 // Current track X-position
1726 Double_t xpos = t.GetX();
1728 // Direction: inward or outward
1729 Double_t dir = (xpos < xToGo) ? 1.0 : -1.0;
1731 while (((xToGo - xpos) * dir) > kEpsilon) {
1740 // The next step size
1741 Double_t step = dir * TMath::Min(TMath::Abs(xToGo-xpos),maxStep);
1743 // Get the global position of the starting point
1746 // X-position after next step
1749 // Get local Y and Z at the X-position of the next step
1750 if(t.GetProlongation(x,y,z)<0) return 0; // No prolongation possible
1752 // The global position of the end point of this prolongation step
1753 xyz1[0] = x * TMath::Cos(t.GetAlpha()) - y * TMath::Sin(t.GetAlpha());
1754 xyz1[1] = +x * TMath::Sin(t.GetAlpha()) + y * TMath::Cos(t.GetAlpha());
1757 // Calculate the mean material budget between start and
1758 // end point of this prolongation step
1759 if(AliTracker::MeanMaterialBudget(xyz0, xyz1, param)<=0.) return 0;
1761 // Propagate the track to the X-position after the next step
1762 if (!t.PropagateTo(x, param[1], param[0]*param[4])) return 0;
1764 // Rotate the track if necessary
1767 // New track X-position
1777 //_____________________________________________________________________________
1778 Int_t AliTRDtrackerV1::ReadClusters(TClonesArray* &array, TTree *clusterTree) const
1781 // Reads AliTRDclusters from the file.
1782 // The names of the cluster tree and branches
1783 // should match the ones used in AliTRDclusterizer::WriteClusters()
1786 Int_t nsize = Int_t(clusterTree->GetTotBytes() / (sizeof(AliTRDcluster)));
1787 TObjArray *clusterArray = new TObjArray(nsize+1000);
1789 TBranch *branch = clusterTree->GetBranch("TRDcluster");
1791 AliError("Can't get the branch !");
1794 branch->SetAddress(&clusterArray);
1797 Float_t nclusters = fkReconstructor->GetRecoParam()->GetNClusters();
1798 if(fkReconstructor->IsHLT()) nclusters /= AliTRDgeometry::kNsector;
1799 array = new TClonesArray("AliTRDcluster", Int_t(nclusters));
1800 array->SetOwner(kTRUE);
1803 // Loop through all entries in the tree
1804 Int_t nEntries = (Int_t) clusterTree->GetEntries();
1807 AliTRDcluster *c = NULL;
1808 for (Int_t iEntry = 0; iEntry < nEntries; iEntry++) {
1810 nbytes += clusterTree->GetEvent(iEntry);
1812 // Get the number of points in the detector
1813 Int_t nCluster = clusterArray->GetEntriesFast();
1814 for (Int_t iCluster = 0; iCluster < nCluster; iCluster++) {
1815 if(!(c = (AliTRDcluster *) clusterArray->UncheckedAt(iCluster))) continue;
1816 new((*fClusters)[ncl++]) AliTRDcluster(*c);
1817 delete (clusterArray->RemoveAt(iCluster));
1821 delete clusterArray;
1826 //_____________________________________________________________________________
1827 Int_t AliTRDtrackerV1::LoadClusters(TTree *cTree)
1830 // Fills clusters into TRD tracking sectors
1833 if(!fkReconstructor->IsWritingClusters()){
1834 fClusters = AliTRDReconstructor::GetClusters();
1836 if (ReadClusters(fClusters, cTree)) {
1837 AliError("Problem with reading the clusters !");
1843 if(!fClusters || !fClusters->GetEntriesFast()){
1844 AliInfo("No TRD clusters");
1849 BuildTrackingContainers();
1851 //Int_t ncl = fClusters->GetEntriesFast();
1852 //AliInfo(Form("Clusters %d [%6.2f %% in the active volume]", ncl, 100.*float(nin)/ncl));
1857 //_____________________________________________________________________________
1858 Int_t AliTRDtrackerV1::LoadClusters(TClonesArray * const clusters)
1861 // Fills clusters into TRD tracking sectors
1862 // Function for use in the HLT
1864 if(!clusters || !clusters->GetEntriesFast()){
1865 AliInfo("No TRD clusters");
1869 fClusters = clusters;
1873 BuildTrackingContainers();
1875 //Int_t ncl = fClusters->GetEntriesFast();
1876 //AliInfo(Form("Clusters %d [%6.2f %% in the active volume]", ncl, 100.*float(nin)/ncl));
1882 //____________________________________________________________________
1883 Int_t AliTRDtrackerV1::BuildTrackingContainers()
1885 // Building tracking containers for clusters
1887 Int_t nin =0, icl = fClusters->GetEntriesFast();
1889 AliTRDcluster *c = (AliTRDcluster *) fClusters->UncheckedAt(icl);
1890 if(c->IsInChamber()) nin++;
1891 Int_t detector = c->GetDetector();
1892 Int_t sector = fGeom->GetSector(detector);
1893 Int_t stack = fGeom->GetStack(detector);
1894 Int_t layer = fGeom->GetLayer(detector);
1896 fTrSec[sector].GetChamber(stack, layer, kTRUE)->InsertCluster(c, icl);
1899 const AliTRDCalDet *cal = AliTRDcalibDB::Instance()->GetT0Det();
1900 for(int isector =0; isector<AliTRDgeometry::kNsector; isector++){
1901 if(!fTrSec[isector].GetNChambers()) continue;
1902 fTrSec[isector].Init(fkReconstructor, cal);
1910 //____________________________________________________________________
1911 void AliTRDtrackerV1::UnloadClusters()
1914 // Clears the arrays of clusters and tracks. Resets sectors and timebins
1915 // If option "force" is also set the containers are also deleted. This is useful
1920 if(HasRemoveContainers()){delete fTracks; fTracks = NULL;}
1923 fTracklets->Delete();
1924 if(HasRemoveContainers()){delete fTracklets; fTracklets = NULL;}
1927 if(IsClustersOwner()) fClusters->Delete();
1929 // save clusters array in the reconstructor for further use.
1930 if(!fkReconstructor->IsWritingClusters()){
1931 AliTRDReconstructor::SetClusters(fClusters);
1932 SetClustersOwner(kFALSE);
1933 } else AliTRDReconstructor::SetClusters(NULL);
1936 for (int i = 0; i < AliTRDgeometry::kNsector; i++) fTrSec[i].Clear();
1938 // Increment the Event Number
1939 AliTRDtrackerDebug::SetEventNumber(AliTRDtrackerDebug::GetEventNumber() + 1);
1942 // //____________________________________________________________________
1943 // void AliTRDtrackerV1::UseClusters(const AliKalmanTrack *t, Int_t) const
1945 // const AliTRDtrackV1 *track = dynamic_cast<const AliTRDtrackV1*>(t);
1946 // if(!track) return;
1948 // AliTRDseedV1 *tracklet = NULL;
1949 // for(Int_t ily=AliTRDgeometry::kNlayer; ily--;){
1950 // if(!(tracklet = track->GetTracklet(ily))) continue;
1951 // AliTRDcluster *c = NULL;
1952 // for(Int_t ic=AliTRDseed::kNclusters; ic--;){
1953 // if(!(c=tracklet->GetClusters(ic))) continue;
1960 //_____________________________________________________________________________
1961 Bool_t AliTRDtrackerV1::AdjustSector(AliTRDtrackV1 *const track)
1964 // Rotates the track when necessary
1967 Double_t alpha = AliTRDgeometry::GetAlpha();
1968 Double_t y = track->GetY();
1969 Double_t ymax = track->GetX()*TMath::Tan(0.5*alpha);
1972 if (!track->Rotate( alpha)) {
1976 else if (y < -ymax) {
1977 if (!track->Rotate(-alpha)) {
1987 //____________________________________________________________________
1988 AliTRDseedV1* AliTRDtrackerV1::GetTracklet(AliTRDtrackV1 *const track, Int_t p, Int_t &idx)
1990 // Find tracklet for TRD track <track>
1999 // Detailed description
2001 idx = track->GetTrackletIndex(p);
2002 AliTRDseedV1 *tracklet = (idx==0xffff) ? NULL : (AliTRDseedV1*)fTracklets->UncheckedAt(idx);
2007 //____________________________________________________________________
2008 AliTRDseedV1* AliTRDtrackerV1::SetTracklet(const AliTRDseedV1 * const tracklet)
2010 // Add this tracklet to the list of tracklets stored in the tracker
2013 // - tracklet : pointer to the tracklet to be added to the list
2016 // - the index of the new tracklet in the tracker tracklets list
2018 // Detailed description
2019 // Build the tracklets list if it is not yet created (late initialization)
2020 // and adds the new tracklet to the list.
2023 fTracklets = new TClonesArray("AliTRDseedV1", AliTRDgeometry::Nsector()*kMaxTracksStack);
2024 fTracklets->SetOwner(kTRUE);
2026 Int_t nentries = fTracklets->GetEntriesFast();
2027 return new ((*fTracklets)[nentries]) AliTRDseedV1(*tracklet);
2030 //____________________________________________________________________
2031 AliTRDtrackV1* AliTRDtrackerV1::SetTrack(const AliTRDtrackV1 * const track)
2033 // Add this track to the list of tracks stored in the tracker
2036 // - track : pointer to the track to be added to the list
2039 // - the pointer added
2041 // Detailed description
2042 // Build the tracks list if it is not yet created (late initialization)
2043 // and adds the new track to the list.
2046 fTracks = new TClonesArray("AliTRDtrackV1", AliTRDgeometry::Nsector()*kMaxTracksStack);
2047 fTracks->SetOwner(kTRUE);
2049 Int_t nentries = fTracks->GetEntriesFast();
2050 return new ((*fTracks)[nentries]) AliTRDtrackV1(*track);
2055 //____________________________________________________________________
2056 Int_t AliTRDtrackerV1::Clusters2TracksSM(Int_t sector, AliESDEvent *esd)
2059 // Steer tracking for one SM.
2062 // sector : Array of (SM) propagation layers containing clusters
2063 // esd : The current ESD event. On output it contains the also
2064 // the ESD (TRD) tracks found in this SM.
2067 // Number of tracks found in this TRD supermodule.
2069 // Detailed description
2071 // 1. Unpack AliTRDpropagationLayers objects for each stack.
2072 // 2. Launch stack tracking.
2073 // See AliTRDtrackerV1::Clusters2TracksStack() for details.
2074 // 3. Pack results in the ESD event.
2077 // allocate space for esd tracks in this SM
2078 TClonesArray esdTrackList("AliESDtrack", 2*kMaxTracksStack);
2079 esdTrackList.SetOwner();
2082 Int_t nChambers = 0;
2083 AliTRDtrackingChamber **stack = NULL, *chamber = NULL;
2084 for(int istack = 0; istack<AliTRDgeometry::kNstack; istack++){
2085 if(!(stack = fTrSec[sector].GetStack(istack))) continue;
2087 for(int ilayer=0; ilayer<AliTRDgeometry::kNlayer; ilayer++){
2088 if(!(chamber = stack[ilayer])) continue;
2089 if(chamber->GetNClusters() < fgNTimeBins * fkReconstructor->GetRecoParam() ->GetFindableClusters()) continue;
2091 //AliInfo(Form("sector %d stack %d layer %d clusters %d", sector, istack, ilayer, chamber->GetNClusters()));
2093 if(nChambers < 4) continue;
2094 //AliInfo(Form("Doing stack %d", istack));
2095 nTracks += Clusters2TracksStack(stack, &esdTrackList);
2097 //AliInfo(Form("Found %d tracks in SM %d [%d]\n", nTracks, sector, esd->GetNumberOfTracks()));
2099 for(int itrack=0; itrack<nTracks; itrack++)
2100 esd->AddTrack((AliESDtrack*)esdTrackList[itrack]);
2102 // Reset Track and Candidate Number
2103 AliTRDtrackerDebug::SetCandidateNumber(0);
2104 AliTRDtrackerDebug::SetTrackNumber(0);
2108 //____________________________________________________________________
2109 Int_t AliTRDtrackerV1::Clusters2TracksStack(AliTRDtrackingChamber **stack, TClonesArray * const esdTrackList)
2112 // Make tracks in one TRD stack.
2115 // layer : Array of stack propagation layers containing clusters
2116 // esdTrackList : Array of ESD tracks found by the stand alone tracker.
2117 // On exit the tracks found in this stack are appended.
2120 // Number of tracks found in this stack.
2122 // Detailed description
2124 // 1. Find the 3 most useful seeding chambers. See BuildSeedingConfigs() for details.
2125 // 2. Steer AliTRDtrackerV1::MakeSeeds() for 3 seeding layer configurations.
2126 // See AliTRDtrackerV1::MakeSeeds() for more details.
2127 // 3. Arrange track candidates in decreasing order of their quality
2128 // 4. Classify tracks in 5 categories according to:
2129 // a) number of layers crossed
2131 // 5. Sign clusters by tracks in decreasing order of track quality
2132 // 6. Build AliTRDtrack out of seeding tracklets
2134 // 8. Build ESD track and register it to the output list
2137 const AliTRDCalDet *cal = AliTRDcalibDB::Instance()->GetT0Det();
2138 AliTRDtrackingChamber *chamber = NULL;
2139 AliTRDtrackingChamber **ci = NULL;
2140 AliTRDseedV1 sseed[kMaxTracksStack*6]; // to be initialized
2141 Int_t pars[4]; // MakeSeeds parameters
2143 //Double_t alpha = AliTRDgeometry::GetAlpha();
2144 //Double_t shift = .5 * alpha;
2145 Int_t configs[kNConfigs];
2147 // Purge used clusters from the containers
2149 for(Int_t ic = kNPlanes; ic--; ci++){
2150 if(!(*ci)) continue;
2154 // Build initial seeding configurations
2155 Double_t quality = BuildSeedingConfigs(stack, configs);
2156 if(fkReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 10){
2157 AliInfo(Form("Plane config %d %d %d Quality %f"
2158 , configs[0], configs[1], configs[2], quality));
2162 // Initialize contors
2163 Int_t ntracks, // number of TRD track candidates
2164 ntracks1, // number of registered TRD tracks/iter
2165 ntracks2 = 0; // number of all registered TRD tracks in stack
2169 Int_t ic = 0; ci = &stack[0];
2170 while(ic<kNPlanes && !(*ci)){ic++; ci++;}
2171 if(!(*ci)) return ntracks2;
2172 Int_t istack = fGeom->GetStack((*ci)->GetDetector());
2175 // Loop over seeding configurations
2176 ntracks = 0; ntracks1 = 0;
2177 for (Int_t iconf = 0; iconf<3; iconf++) {
2178 pars[0] = configs[iconf];
2181 ntracks = MakeSeeds(stack, &sseed[6*ntracks], pars);
2182 //AliInfo(Form("Number of Tracks after iteration step %d: %d\n", iconf, ntracks));
2183 if(ntracks == kMaxTracksStack) break;
2185 if(fkReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 1) AliInfo(Form("Candidate TRD tracks %d in iteration %d.", ntracks, fSieveSeeding));
2189 // Sort the seeds according to their quality
2190 Int_t sort[kMaxTracksStack];
2191 TMath::Sort(ntracks, fTrackQuality, sort, kTRUE);
2193 // Initialize number of tracks so far and logic switches
2194 Int_t ntracks0 = esdTrackList->GetEntriesFast();
2195 Bool_t signedTrack[kMaxTracksStack];
2196 Bool_t fakeTrack[kMaxTracksStack];
2197 for (Int_t i=0; i<ntracks; i++){
2198 signedTrack[i] = kFALSE;
2199 fakeTrack[i] = kFALSE;
2201 //AliInfo("Selecting track candidates ...");
2203 // Sieve clusters in decreasing order of track quality
2204 Double_t trackParams[7];
2205 // AliTRDseedV1 *lseed = NULL;
2206 Int_t jSieve = 0, candidates;
2208 //AliInfo(Form("\t\tITER = %i ", jSieve));
2210 // Check track candidates
2212 for (Int_t itrack = 0; itrack < ntracks; itrack++) {
2213 Int_t trackIndex = sort[itrack];
2214 if (signedTrack[trackIndex] || fakeTrack[trackIndex]) continue;
2217 // Calculate track parameters from tracklets seeds
2222 for (Int_t jLayer = 0; jLayer < kNPlanes; jLayer++) {
2223 Int_t jseed = kNPlanes*trackIndex+jLayer;
2224 if(!sseed[jseed].IsOK()) continue;
2225 if (TMath::Abs(sseed[jseed].GetYref(0) / sseed[jseed].GetX0()) < 0.158) findable++;
2226 // TODO here we get a sig fault which should never happen !
2227 sseed[jseed].UpdateUsed();
2228 ncl += sseed[jseed].GetN2();
2229 nused += sseed[jseed].GetNUsed();
2233 // Filter duplicated tracks
2235 //printf("Skip %d nused %d\n", trackIndex, nused);
2236 fakeTrack[trackIndex] = kTRUE;
2239 if (Float_t(nused)/ncl >= .25){
2240 //printf("Skip %d nused/ncl >= .25\n", trackIndex);
2241 fakeTrack[trackIndex] = kTRUE;
2246 Bool_t skip = kFALSE;
2249 if(nlayers < 6) {skip = kTRUE; break;}
2250 if(TMath::Log(1.E-9+fTrackQuality[trackIndex]) < -5.){skip = kTRUE; break;}
2254 if(nlayers < findable){skip = kTRUE; break;}
2255 if(TMath::Log(1.E-9+fTrackQuality[trackIndex]) < -4.){skip = kTRUE; break;}
2259 if ((nlayers == findable) || (nlayers == 6)) { skip = kTRUE; break;}
2260 if (TMath::Log(1.E-9+fTrackQuality[trackIndex]) < -6.0){skip = kTRUE; break;}
2264 if (TMath::Log(1.E-9+fTrackQuality[trackIndex]) < -5.){skip = kTRUE; break;}
2268 if (nlayers == 3){skip = kTRUE; break;}
2269 //if (TMath::Log(1.E-9+fTrackQuality[trackIndex]) - nused/(nlayers-3.0) < -15.0){skip = kTRUE; break;}
2274 //printf("REJECTED : %d [%d] nlayers %d trackQuality = %e nused %d\n", itrack, trackIndex, nlayers, fTrackQuality[trackIndex], nused);
2277 signedTrack[trackIndex] = kTRUE;
2279 // Build track parameters
2280 AliTRDseedV1 *lseed =&sseed[trackIndex*6];
2282 while(idx<3 && !lseed->IsOK()) {
2286 Double_t x = lseed->GetX0();// - 3.5;
2287 trackParams[0] = x; //NEW AB
2288 trackParams[1] = lseed->GetYref(0); // lseed->GetYat(x);
2289 trackParams[2] = lseed->GetZref(0); // lseed->GetZat(x);
2290 trackParams[3] = TMath::Sin(TMath::ATan(lseed->GetYref(1)));
2291 trackParams[4] = lseed->GetZref(1) / TMath::Sqrt(1. + lseed->GetYref(1) * lseed->GetYref(1));
2292 trackParams[5] = lseed->GetC();
2293 Int_t ich = 0; while(!(chamber = stack[ich])) ich++;
2294 trackParams[6] = fGeom->GetSector(chamber->GetDetector());/* *alpha+shift; // Supermodule*/
2296 if(fkReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 1){
2297 //AliInfo(Form("Track %d [%d] nlayers %d trackQuality = %e nused %d, yref = %3.3f", itrack, trackIndex, nlayers, fTrackQuality[trackIndex], nused, trackParams[1]));
2299 AliTRDseedV1 *dseed[6];
2300 for(Int_t iseed = AliTRDgeometry::kNlayer; iseed--;) dseed[iseed] = new AliTRDseedV1(lseed[iseed]);
2302 //Int_t eventNrInFile = esd->GetEventNumberInFile();
2303 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2304 Int_t trackNumber = AliTRDtrackerDebug::GetTrackNumber();
2305 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2306 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
2307 cstreamer << "Clusters2TracksStack"
2308 << "EventNumber=" << eventNumber
2309 << "TrackNumber=" << trackNumber
2310 << "CandidateNumber=" << candidateNumber
2311 << "Iter=" << fSieveSeeding
2312 << "Like=" << fTrackQuality[trackIndex]
2313 << "S0.=" << dseed[0]
2314 << "S1.=" << dseed[1]
2315 << "S2.=" << dseed[2]
2316 << "S3.=" << dseed[3]
2317 << "S4.=" << dseed[4]
2318 << "S5.=" << dseed[5]
2319 << "p0=" << trackParams[0]
2320 << "p1=" << trackParams[1]
2321 << "p2=" << trackParams[2]
2322 << "p3=" << trackParams[3]
2323 << "p4=" << trackParams[4]
2324 << "p5=" << trackParams[5]
2325 << "p6=" << trackParams[6]
2327 << "NLayers=" << nlayers
2328 << "Findable=" << findable
2329 << "NUsed=" << nused
2333 AliTRDtrackV1 *track = MakeTrack(&sseed[trackIndex*kNPlanes], trackParams);
2335 AliWarning("Fail to build a TRD Track.");
2339 //AliInfo("End of MakeTrack()");
2340 AliESDtrack *esdTrack = new ((*esdTrackList)[ntracks0++]) AliESDtrack();
2341 esdTrack->UpdateTrackParams(track, AliESDtrack::kTRDout);
2342 esdTrack->SetLabel(track->GetLabel());
2343 track->UpdateESDtrack(esdTrack);
2344 // write ESD-friends if neccessary
2345 if (fkReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 0){
2346 AliTRDtrackV1 *calibTrack = new AliTRDtrackV1(*track);
2347 calibTrack->SetOwner();
2348 esdTrack->AddCalibObject(calibTrack);
2351 AliTRDtrackerDebug::SetTrackNumber(AliTRDtrackerDebug::GetTrackNumber() + 1);
2355 } while(jSieve<5 && candidates); // end track candidates sieve
2356 if(!ntracks1) break;
2358 // increment counters
2359 ntracks2 += ntracks1;
2361 if(fkReconstructor->IsHLT()) break;
2364 // Rebuild plane configurations and indices taking only unused clusters into account
2365 quality = BuildSeedingConfigs(stack, configs);
2366 if(quality < 1.E-7) break; //fkReconstructor->GetRecoParam() ->GetPlaneQualityThreshold()) break;
2368 for(Int_t ip = 0; ip < kNPlanes; ip++){
2369 if(!(chamber = stack[ip])) continue;
2370 chamber->Build(fGeom, cal);//Indices(fSieveSeeding);
2373 if(fkReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 10){
2374 AliInfo(Form("Sieve level %d Plane config %d %d %d Quality %f", fSieveSeeding, configs[0], configs[1], configs[2], quality));
2376 } while(fSieveSeeding<10); // end stack clusters sieve
2380 //AliInfo(Form("Registered TRD tracks %d in stack %d.", ntracks2, pars[1]));
2385 //___________________________________________________________________
2386 Double_t AliTRDtrackerV1::BuildSeedingConfigs(AliTRDtrackingChamber **stack, Int_t *configs)
2389 // Assign probabilities to chambers according to their
2390 // capability of producing seeds.
2394 // layers : Array of stack propagation layers for all 6 chambers in one stack
2395 // configs : On exit array of configuration indexes (see GetSeedingConfig()
2396 // for details) in the decreasing order of their seeding probabilities.
2400 // Return top configuration quality
2402 // Detailed description:
2404 // To each chamber seeding configuration (see GetSeedingConfig() for
2405 // the list of all configurations) one defines 2 quality factors:
2406 // - an apriori topological quality (see GetSeedingConfig() for details) and
2407 // - a data quality based on the uniformity of the distribution of
2408 // clusters over the x range (time bins population). See CookChamberQA() for details.
2409 // The overall chamber quality is given by the product of this 2 contributions.
2412 Double_t chamberQ[kNPlanes];memset(chamberQ, 0, kNPlanes*sizeof(Double_t));
2413 AliTRDtrackingChamber *chamber = NULL;
2414 for(int iplane=0; iplane<kNPlanes; iplane++){
2415 if(!(chamber = stack[iplane])) continue;
2416 chamberQ[iplane] = (chamber = stack[iplane]) ? chamber->GetQuality() : 0.;
2419 Double_t tconfig[kNConfigs];memset(tconfig, 0, kNConfigs*sizeof(Double_t));
2420 Int_t planes[] = {0, 0, 0, 0};
2421 for(int iconf=0; iconf<kNConfigs; iconf++){
2422 GetSeedingConfig(iconf, planes);
2423 tconfig[iconf] = fgTopologicQA[iconf];
2424 for(int iplane=0; iplane<4; iplane++) tconfig[iconf] *= chamberQ[planes[iplane]];
2427 TMath::Sort((Int_t)kNConfigs, tconfig, configs, kTRUE);
2428 // AliInfo(Form("q[%d] = %f", configs[0], tconfig[configs[0]]));
2429 // AliInfo(Form("q[%d] = %f", configs[1], tconfig[configs[1]]));
2430 // AliInfo(Form("q[%d] = %f", configs[2], tconfig[configs[2]]));
2432 return tconfig[configs[0]];
2435 //____________________________________________________________________
2436 Int_t AliTRDtrackerV1::MakeSeeds(AliTRDtrackingChamber **stack, const AliTRDseedV1 * const sseed, const Int_t * const ipar)
2439 // Seed tracklets and build candidate TRD tracks. The procedure is used during barrel tracking to account for tracks which are
2440 // either missed by TPC prolongation or conversions inside the TRD volume.
2441 // For stand alone tracking the procedure is used to estimate all tracks measured by TRD.
2444 // layers : Array of stack propagation layers containing clusters
2445 // sseed : Array of empty tracklet seeds. On exit they are filled.
2446 // ipar : Control parameters:
2447 // ipar[0] -> seeding chambers configuration
2448 // ipar[1] -> stack index
2449 // ipar[2] -> number of track candidates found so far
2452 // Number of tracks candidates found.
2454 // The following steps are performed:
2455 // 1. Build seeding layers by collapsing all time bins from each of the four seeding chambers along the
2456 // radial coordinate. See AliTRDtrackingChamber::GetSeedingLayer() for details. The chambers selection for seeding
2457 // is described in AliTRDtrackerV1::Clusters2TracksStack().
2458 // 2. Using the seeding clusters from the seeding layer (step 1) build combinatorics using the following algorithm:
2459 // - for each seeding cluster in the lower seeding layer find
2460 // - all seeding clusters in the upper seeding layer inside a road defined by a given phi angle. The angle
2461 // is calculated on the minimum pt of tracks from vertex accesible to the stand alone tracker.
2462 // - for each pair of two extreme seeding clusters select middle upper cluster using roads defined externally by the
2464 // - select last seeding cluster as the nearest to the linear approximation of the track described by the first three
2465 // seeding clusters.
2466 // The implementation of road calculation and cluster selection can be found in the functions AliTRDchamberTimeBin::BuildCond()
2467 // and AliTRDchamberTimeBin::GetClusters().
2468 // 3. Helix fit of the seeding clusters set. (see AliTRDtrackerFitter::FitRieman(AliTRDcluster**)). No tilt correction is
2469 // performed at this level
2470 // 4. Initialize seeding tracklets in the seeding chambers.
2471 // 5. *Filter 0* Chi2 cut on the Y and Z directions. The threshold is set externally by the reco params.
2472 // 6. Attach (true) clusters to seeding tracklets (see AliTRDseedV1::AttachClusters()) and fit tracklet (see
2473 // AliTRDseedV1::Fit()). The number of used clusters used by current seeds should not exceed ... (25).
2474 // 7. *Filter 1* Check if all 4 seeding tracklets are correctly constructed.
2475 // 8. Helix fit of the clusters from the seeding tracklets with tilt correction. Refit tracklets using the new
2476 // approximation of the track.
2477 // 9. *Filter 2* Calculate likelihood of the track. (See AliTRDtrackerV1::CookLikelihood()). The following quantities are
2478 // checked against the Riemann fit:
2479 // - position resolution in y
2480 // - angular resolution in the bending plane
2481 // - likelihood of the number of clusters attached to the tracklet
2482 // 10. Extrapolation of the helix fit to the other 2 chambers *non seeding* chambers:
2483 // - Initialization of extrapolation tracklets with the fit parameters
2484 // - Attach clusters to extrapolated tracklets
2485 // - Helix fit of tracklets
2486 // 11. Improve seeding tracklets quality by reassigning clusters based on the last parameters of the track
2487 // See AliTRDtrackerV1::ImproveSeedQuality() for details.
2488 // 12. Helix fit of all 6 seeding tracklets and chi2 calculation
2489 // 13. Hyperplane fit and track quality calculation. See AliTRDtrackerFitter::FitHyperplane() for details.
2490 // 14. Cooking labels for tracklets. Should be done only for MC
2491 // 15. Register seeds.
2494 // Marian Ivanov <M.Ivanov@gsi.de>
2495 // Alexandru Bercuci <A.Bercuci@gsi.de>
2496 // Markus Fasel <M.Fasel@gsi.de>
2498 AliTRDtrackingChamber *chamber = NULL;
2499 AliTRDcluster *c[kNSeedPlanes] = {NULL, NULL, NULL, NULL}; // initilize seeding clusters
2500 AliTRDseedV1 *cseed = const_cast<AliTRDseedV1 *>(&sseed[0]); // initialize tracklets for first track
2501 Int_t ncl, mcl; // working variable for looping over clusters
2502 Int_t index[AliTRDchamberTimeBin::kMaxClustersLayer], jndex[AliTRDchamberTimeBin::kMaxClustersLayer];
2504 // chi2[0] = tracklet chi2 on the Z direction
2505 // chi2[1] = tracklet chi2 on the R direction
2508 // this should be data member of AliTRDtrack TODO
2509 Double_t seedQuality[kMaxTracksStack];
2511 // unpack control parameters
2512 Int_t config = ipar[0];
2513 Int_t ntracks = ipar[1];
2514 Int_t istack = ipar[2];
2515 Int_t planes[kNSeedPlanes]; GetSeedingConfig(config, planes);
2516 Int_t planesExt[kNPlanes-kNSeedPlanes]; GetExtrapolationConfig(config, planesExt);
2519 // Init chambers geometry
2520 Double_t hL[kNPlanes]; // Tilting angle
2521 Float_t padlength[kNPlanes]; // pad lenghts
2522 Float_t padwidth[kNPlanes]; // pad widths
2523 AliTRDpadPlane *pp = NULL;
2524 for(int iplane=0; iplane<kNPlanes; iplane++){
2525 pp = fGeom->GetPadPlane(iplane, istack);
2526 hL[iplane] = TMath::Tan(TMath::DegToRad()*pp->GetTiltingAngle());
2527 padlength[iplane] = pp->GetLengthIPad();
2528 padwidth[iplane] = pp->GetWidthIPad();
2531 // Init anode wire position for chambers
2532 Double_t x0[kNPlanes], // anode wire position
2533 driftLength = .5*AliTRDgeometry::AmThick() - AliTRDgeometry::DrThick(); // drift length
2534 TGeoHMatrix *matrix = NULL;
2535 Double_t loc[] = {AliTRDgeometry::AnodePos(), 0., 0.};
2536 Double_t glb[] = {0., 0., 0.};
2537 AliTRDtrackingChamber **cIter = &stack[0];
2538 for(int iLayer=0; iLayer<kNPlanes; iLayer++,cIter++){
2539 if(!(*cIter)) continue;
2540 if(!(matrix = fGeom->GetClusterMatrix((*cIter)->GetDetector()))){
2542 x0[iLayer] = fgkX0[iLayer];
2544 matrix->LocalToMaster(loc, glb);
2545 x0[iLayer] = glb[0];
2548 if(fkReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 2){
2549 AliInfo(Form("Making seeds Stack[%d] Config[%d] Tracks[%d]...", istack, config, ntracks));
2552 // Build seeding layers
2555 for(int isl=0; isl<kNSeedPlanes; isl++){
2556 if(!(chamber = stack[planes[isl]])) continue;
2557 if(!chamber->GetSeedingLayer(fSeedTB[isl], fGeom, fkReconstructor)) continue;
2560 if(nlayers < kNSeedPlanes) return ntracks;
2563 // Start finding seeds
2564 Double_t cond0[4], cond1[4], cond2[4];
2566 while((c[3] = (*fSeedTB[3])[icl++])){
2568 fSeedTB[0]->BuildCond(c[3], cond0, 0);
2569 fSeedTB[0]->GetClusters(cond0, index, ncl);
2570 //printf("Found c[3] candidates 0 %d\n", ncl);
2573 c[0] = (*fSeedTB[0])[index[jcl++]];
2575 Double_t dx = c[3]->GetX() - c[0]->GetX();
2576 Double_t dzdx = (c[3]->GetZ() - c[0]->GetZ())/dx;
2577 Double_t dydx = (c[3]->GetY() - c[0]->GetY())/dx;
2578 fSeedTB[1]->BuildCond(c[0], cond1, 1, dzdx, dydx);
2579 fSeedTB[1]->GetClusters(cond1, jndex, mcl);
2580 //printf("Found c[0] candidates 1 %d\n", mcl);
2584 c[1] = (*fSeedTB[1])[jndex[kcl++]];
2586 fSeedTB[2]->BuildCond(c[1], cond2, 2, dzdx, dydx);
2587 c[2] = fSeedTB[2]->GetNearestCluster(cond2);
2588 //printf("Found c[1] candidate 2 %p\n", c[2]);
2591 //AliInfo("Seeding clusters found. Building seeds ...");
2592 //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());
2594 for (Int_t il = 0; il < kNPlanes; il++) cseed[il].Reset();
2598 AliTRDseedV1 *tseed = &cseed[0];
2600 for(int iLayer=0; iLayer<kNPlanes; iLayer++, tseed++, cIter++){
2601 Int_t det = (*cIter) ? (*cIter)->GetDetector() : -1;
2602 tseed->SetDetector(det);
2603 tseed->SetTilt(hL[iLayer]);
2604 tseed->SetPadLength(padlength[iLayer]);
2605 tseed->SetPadWidth(padwidth[iLayer]);
2606 tseed->SetReconstructor(fkReconstructor);
2607 tseed->SetX0(det<0 ? fR[iLayer]+driftLength : x0[iLayer]);
2608 tseed->Init(GetRiemanFitter());
2609 tseed->SetStandAlone(kTRUE);
2612 Bool_t isFake = kFALSE;
2613 if(fkReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) >= 2){
2614 if (c[0]->GetLabel(0) != c[3]->GetLabel(0)) isFake = kTRUE;
2615 if (c[1]->GetLabel(0) != c[3]->GetLabel(0)) isFake = kTRUE;
2616 if (c[2]->GetLabel(0) != c[3]->GetLabel(0)) isFake = kTRUE;
2619 for(Int_t l = 0; l < kNSeedPlanes; l++) xpos[l] = fSeedTB[l]->GetX();
2621 for(int il=0; il<4; il++) yref[il] = cseed[planes[il]].GetYref(0);
2622 Int_t ll = c[3]->GetLabel(0);
2623 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2624 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2625 AliRieman *rim = GetRiemanFitter();
2626 TTreeSRedirector &cs0 = *fkReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
2628 <<"EventNumber=" << eventNumber
2629 <<"CandidateNumber=" << candidateNumber
2630 <<"isFake=" << isFake
2631 <<"config=" << config
2633 <<"chi2z=" << chi2[0]
2634 <<"chi2y=" << chi2[1]
2635 <<"Y2exp=" << cond2[0]
2636 <<"Z2exp=" << cond2[1]
2637 <<"X0=" << xpos[0] //layer[sLayer]->GetX()
2638 <<"X1=" << xpos[1] //layer[sLayer + 1]->GetX()
2639 <<"X2=" << xpos[2] //layer[sLayer + 2]->GetX()
2640 <<"X3=" << xpos[3] //layer[sLayer + 3]->GetX()
2641 <<"yref0=" << yref[0]
2642 <<"yref1=" << yref[1]
2643 <<"yref2=" << yref[2]
2644 <<"yref3=" << yref[3]
2649 <<"Seed0.=" << &cseed[planes[0]]
2650 <<"Seed1.=" << &cseed[planes[1]]
2651 <<"Seed2.=" << &cseed[planes[2]]
2652 <<"Seed3.=" << &cseed[planes[3]]
2653 <<"RiemanFitter.=" << rim
2656 if(chi2[0] > fkReconstructor->GetRecoParam() ->GetChi2Z()/*7./(3. - sLayer)*//*iter*/){
2657 //AliInfo(Form("Failed chi2 filter on chi2Z [%f].", chi2[0]));
2658 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2661 if(chi2[1] > fkReconstructor->GetRecoParam() ->GetChi2Y()/*1./(3. - sLayer)*//*iter*/){
2662 //AliInfo(Form("Failed chi2 filter on chi2Y [%f].", chi2[1]));
2663 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2666 //AliInfo("Passed chi2 filter.");
2668 // try attaching clusters to tracklets
2670 AliTRDcluster *cl = NULL;
2671 for(int iLayer=0; iLayer<kNSeedPlanes; iLayer++){
2672 Int_t jLayer = planes[iLayer];
2673 Int_t nNotInChamber = 0;
2674 if(!cseed[jLayer].AttachClusters(stack[jLayer], kTRUE)) continue;
2675 if(fkReconstructor->IsHLT()){
2676 cseed[jLayer].UpdateUsed();
2677 if(!cseed[jLayer].IsOK()) continue;
2679 cseed[jLayer].Fit();
2680 cseed[jLayer].UpdateUsed();
2681 cseed[jLayer].ResetClusterIter();
2682 while((cl = cseed[jLayer].NextCluster())){
2683 if(!cl->IsInChamber()) nNotInChamber++;
2685 //printf("clusters[%d], used[%d], not in chamber[%d]\n", cseed[jLayer].GetN(), cseed[jLayer].GetNUsed(), nNotInChamber);
2686 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
2691 if(mlayers < kNSeedPlanes){
2692 //AliInfo(Form("Failed updating all seeds %d [%d].", mlayers, kNSeedPlanes));
2693 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2697 // temporary exit door for the HLT
2698 if(fkReconstructor->IsHLT()){
2699 // attach clusters to extrapolation chambers
2700 for(int iLayer=0; iLayer<kNPlanes-kNSeedPlanes; iLayer++){
2701 Int_t jLayer = planesExt[iLayer];
2702 if(!(chamber = stack[jLayer])) continue;
2703 cseed[jLayer].AttachClusters(chamber, kTRUE);
2704 //cseed[jLayer].Fit();
2706 fTrackQuality[ntracks] = 1.; // dummy value
2708 if(ntracks == kMaxTracksStack) return ntracks;
2714 // Update Seeds and calculate Likelihood
2715 // fit tracklets and cook likelihood
2716 FitTiltedRieman(&cseed[0], kTRUE);
2717 for(int iLayer=0; iLayer<kNSeedPlanes; iLayer++){
2718 Int_t jLayer = planes[iLayer];
2719 cseed[jLayer].Fit(kTRUE);
2721 Double_t like = CookLikelihood(&cseed[0], planes); // to be checked
2723 if (TMath::Log(1.E-9 + like) < fkReconstructor->GetRecoParam() ->GetTrackLikelihood()){
2724 //AliInfo(Form("Failed likelihood %f[%e].", TMath::Log(1.E-9 + like), like));
2725 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2728 //AliInfo(Form("Passed likelihood %f[%e].", TMath::Log(1.E-9 + like), like));
2730 // book preliminary results
2731 seedQuality[ntracks] = like;
2732 fSeedLayer[ntracks] = config;/*sLayer;*/
2734 // attach clusters to the extrapolation seeds
2735 for(int iLayer=0; iLayer<kNPlanes-kNSeedPlanes; iLayer++){
2736 Int_t jLayer = planesExt[iLayer];
2737 if(!(chamber = stack[jLayer])) continue;
2739 // fit extrapolated seed
2740 if ((jLayer == 0) && !(cseed[1].IsOK())) continue;
2741 if ((jLayer == 5) && !(cseed[4].IsOK())) continue;
2742 AliTRDseedV1 pseed = cseed[jLayer];
2743 if(!pseed.AttachClusters(chamber, kTRUE)) continue;
2745 cseed[jLayer] = pseed;
2746 FitTiltedRieman(cseed, kTRUE);
2747 cseed[jLayer].Fit(kTRUE);
2750 // AliInfo("Extrapolation done.");
2751 // Debug Stream containing all the 6 tracklets
2752 if(fkReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) >= 2){
2753 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
2754 TLinearFitter *tiltedRieman = GetTiltedRiemanFitter();
2755 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2756 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2757 cstreamer << "MakeSeeds1"
2758 << "EventNumber=" << eventNumber
2759 << "CandidateNumber=" << candidateNumber
2760 << "S0.=" << &cseed[0]
2761 << "S1.=" << &cseed[1]
2762 << "S2.=" << &cseed[2]
2763 << "S3.=" << &cseed[3]
2764 << "S4.=" << &cseed[4]
2765 << "S5.=" << &cseed[5]
2766 << "FitterT.=" << tiltedRieman
2770 if(fkReconstructor->HasImproveTracklets() && ImproveSeedQuality(stack, cseed) < 4){
2771 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2774 //AliInfo("Improve seed quality done.");
2776 // fit full track and cook likelihoods
2777 // Double_t curv = FitRieman(&cseed[0], chi2);
2778 // Double_t chi2ZF = chi2[0] / TMath::Max((mlayers - 3.), 1.);
2779 // Double_t chi2RF = chi2[1] / TMath::Max((mlayers - 3.), 1.);
2781 // do the final track fitting (Once with vertex constraint and once without vertex constraint)
2782 Double_t chi2Vals[3];
2783 chi2Vals[0] = FitTiltedRieman(&cseed[0], kTRUE);
2784 if(fkReconstructor->HasVertexConstrained())
2785 chi2Vals[1] = FitTiltedRiemanConstraint(&cseed[0], GetZ()); // Do Vertex Constrained fit if desired
2788 chi2Vals[2] = GetChi2Z(&cseed[0]) / TMath::Max((mlayers - 3.), 1.);
2789 // Chi2 definitions in testing stage
2790 //chi2Vals[2] = GetChi2ZTest(&cseed[0]);
2791 fTrackQuality[ntracks] = CalculateTrackLikelihood(&cseed[0], &chi2Vals[0]);
2792 //AliInfo("Hyperplane fit done\n");
2794 if(fkReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) >= 2){
2795 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
2796 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2797 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2798 TLinearFitter *fitterTC = GetTiltedRiemanFitterConstraint();
2799 TLinearFitter *fitterT = GetTiltedRiemanFitter();
2801 for(Int_t iseed = 0; iseed < kNPlanes; iseed++){
2802 ncls += cseed[iseed].IsOK() ? cseed[iseed].GetN2() : 0;
2804 cstreamer << "MakeSeeds2"
2805 << "EventNumber=" << eventNumber
2806 << "CandidateNumber=" << candidateNumber
2807 << "Chi2TR=" << chi2Vals[0]
2808 << "Chi2TC=" << chi2Vals[1]
2809 << "Nlayers=" << mlayers
2810 << "NClusters=" << ncls
2812 << "S0.=" << &cseed[0]
2813 << "S1.=" << &cseed[1]
2814 << "S2.=" << &cseed[2]
2815 << "S3.=" << &cseed[3]
2816 << "S4.=" << &cseed[4]
2817 << "S5.=" << &cseed[5]
2818 << "FitterT.=" << fitterT
2819 << "FitterTC.=" << fitterTC
2824 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2825 if(ntracks == kMaxTracksStack){
2826 AliWarning(Form("Number of seeds reached maximum allowed (%d) in stack.", kMaxTracksStack));
2837 //_____________________________________________________________________________
2838 AliTRDtrackV1* AliTRDtrackerV1::MakeTrack(const AliTRDseedV1 * const seeds, Double_t *params)
2841 // Build a TRD track out of tracklet candidates
2844 // seeds : array of tracklets
2845 // params : array of track parameters as they are estimated by stand alone tracker. 7 elements.
2846 // [0] - radial position of the track at reference point
2847 // [1] - y position of the fit at [0]
2848 // [2] - z position of the fit at [0]
2849 // [3] - snp of the first tracklet
2850 // [4] - tgl of the first tracklet
2851 // [5] - curvature of the Riemann fit - 1/pt
2852 // [6] - sector rotation angle
2857 // Initialize the TRD track based on the parameters of the fit and a parametric covariance matrix
2858 // (diagonal with constant variance terms TODO - correct parameterization)
2860 // In case of HLT just register the tracklets in the tracker and return values of the Riemann fit. For the
2861 // offline case perform a full Kalman filter on the already found tracklets (see AliTRDtrackerV1::FollowBackProlongation()
2862 // for details). Do also MC label calculation and PID if propagation successfully.
2865 Double_t alpha = AliTRDgeometry::GetAlpha();
2866 Double_t shift = AliTRDgeometry::GetAlpha()/2.0;
2869 c[ 0] = 0.2; // s^2_y
2870 c[ 1] = 0.0; c[ 2] = 2.0; // s^2_z
2871 c[ 3] = 0.0; c[ 4] = 0.0; c[ 5] = 0.02; // s^2_snp
2872 c[ 6] = 0.0; c[ 7] = 0.0; c[ 8] = 0.0; c[ 9] = 0.1; // s^2_tgl
2873 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
2875 AliTRDtrackV1 track(seeds, ¶ms[1], c, params[0], params[6]*alpha+shift);
2876 track.PropagateTo(params[0]-5.0);
2877 AliTRDseedV1 *ptrTracklet = NULL;
2879 // skip Kalman filter for HLT
2880 if(fkReconstructor->IsHLT()){
2881 for (Int_t jLayer = 0; jLayer < AliTRDgeometry::kNlayer; jLayer++) {
2882 track.UnsetTracklet(jLayer);
2883 ptrTracklet = const_cast<AliTRDseedV1 *>(&seeds[jLayer]);
2884 if(!ptrTracklet->IsOK()) continue;
2885 //if(TMath::Abs(ptrTracklet->GetYref(1) - ptrTracklet->GetYfit(1)) >= .2) continue; // check this condition with Marian
2886 ptrTracklet = SetTracklet(ptrTracklet);
2887 ptrTracklet->UseClusters();
2888 track.SetTracklet(ptrTracklet, fTracklets->GetEntriesFast()-1);
2890 AliTRDtrackV1 *ptrTrack = SetTrack(&track);
2891 ptrTrack->CookPID();
2892 ptrTrack->SetReconstructor(fkReconstructor);
2896 track.ResetCovariance(1);
2897 Int_t nc = TMath::Abs(FollowBackProlongation(track));
2898 if(fkReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 5){
2899 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2900 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2901 Double_t p[5]; // Track Params for the Debug Stream
2902 track.GetExternalParameters(params[0], p);
2903 TTreeSRedirector &cs = *fkReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
2905 << "EventNumber=" << eventNumber
2906 << "CandidateNumber=" << candidateNumber
2908 << "X=" << params[0]
2914 << "Yin=" << params[1]
2915 << "Zin=" << params[2]
2916 << "snpin=" << params[3]
2917 << "tndin=" << params[4]
2918 << "crvin=" << params[5]
2919 << "track.=" << &track
2922 if (nc < 30) return NULL;
2924 AliTRDtrackV1 *ptrTrack = SetTrack(&track);
2925 ptrTrack->SetReconstructor(fkReconstructor);
2926 ptrTrack->CookLabel(.9);
2928 // computes PID for track
2929 ptrTrack->CookPID();
2930 // update calibration references using this track
2931 AliTRDCalibraFillHisto *calibra = AliTRDCalibraFillHisto::Instance();
2933 AliInfo("Could not get Calibra instance\n");
2934 if(calibra->GetHisto2d()) calibra->UpdateHistogramsV1(ptrTrack);
2940 //____________________________________________________________________
2941 Int_t AliTRDtrackerV1::ImproveSeedQuality(AliTRDtrackingChamber **stack, AliTRDseedV1 *cseed)
2944 // Sort tracklets according to "quality" and try to "improve" the first 4 worst
2947 // layers : Array of propagation layers for a stack/supermodule
2948 // cseed : Array of 6 seeding tracklets which has to be improved
2951 // cssed : Improved seeds
2953 // Detailed description
2955 // Iterative procedure in which new clusters are searched for each
2956 // tracklet seed such that the seed quality (see AliTRDseed::GetQuality())
2957 // can be maximized. If some optimization is found the old seeds are replaced.
2962 // make a local working copy
2963 AliTRDtrackingChamber *chamber = NULL;
2964 AliTRDseedV1 bseed[6];
2966 for (Int_t jLayer = 0; jLayer < 6; jLayer++) bseed[jLayer] = cseed[jLayer];
2968 Float_t lastquality = 10000.0;
2969 Float_t lastchi2 = 10000.0;
2970 Float_t chi2 = 1000.0;
2972 for (Int_t iter = 0; iter < 4; iter++) {
2973 Float_t sumquality = 0.0;
2974 Float_t squality[6];
2975 Int_t sortindexes[6];
2977 for (Int_t jLayer = 0; jLayer < 6; jLayer++) {
2978 squality[jLayer] = bseed[jLayer].IsOK() ? bseed[jLayer].GetQuality(kTRUE) : 1000.;
2979 sumquality += squality[jLayer];
2981 if ((sumquality >= lastquality) || (chi2 > lastchi2)) break;
2984 lastquality = sumquality;
2986 if (iter > 0) for (Int_t jLayer = 0; jLayer < 6; jLayer++) cseed[jLayer] = bseed[jLayer];
2988 TMath::Sort(6, squality, sortindexes, kFALSE);
2989 for (Int_t jLayer = 5; jLayer > 1; jLayer--) {
2990 Int_t bLayer = sortindexes[jLayer];
2991 if(!(chamber = stack[bLayer])) continue;
2992 bseed[bLayer].AttachClusters(chamber, kTRUE);
2993 bseed[bLayer].Fit(kTRUE);
2994 if(bseed[bLayer].IsOK()) nLayers++;
2997 chi2 = FitTiltedRieman(bseed, kTRUE);
2998 if(fkReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) >= 7){
2999 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
3000 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
3001 TLinearFitter *tiltedRieman = GetTiltedRiemanFitter();
3002 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
3003 cstreamer << "ImproveSeedQuality"
3004 << "EventNumber=" << eventNumber
3005 << "CandidateNumber=" << candidateNumber
3006 << "Iteration=" << iter
3007 << "S0.=" << &bseed[0]
3008 << "S1.=" << &bseed[1]
3009 << "S2.=" << &bseed[2]
3010 << "S3.=" << &bseed[3]
3011 << "S4.=" << &bseed[4]
3012 << "S5.=" << &bseed[5]
3013 << "FitterT.=" << tiltedRieman
3017 // we are sure that at least 2 tracklets are OK !
3021 //_________________________________________________________________________
3022 Double_t AliTRDtrackerV1::CalculateTrackLikelihood(const AliTRDseedV1 *const tracklets, Double_t *chi2){
3024 // Calculates the Track Likelihood value. This parameter serves as main quality criterion for
3025 // the track selection
3026 // The likelihood value containes:
3027 // - The chi2 values from the both fitters and the chi2 values in z-direction from a linear fit
3028 // - The Sum of the Parameter |slope_ref - slope_fit|/Sigma of the tracklets
3029 // For all Parameters an exponential dependency is used
3031 // Parameters: - Array of tracklets (AliTRDseedV1) related to the track candidate
3032 // - Array of chi2 values:
3033 // * Non-Constrained Tilted Riemann fit
3034 // * Vertex-Constrained Tilted Riemann fit
3035 // * z-Direction from Linear fit
3036 // Output: - The calculated track likelihood
3041 Double_t chi2phi = 0, nLayers = 0;
3042 for (Int_t iLayer = 0; iLayer < kNPlanes; iLayer++) {
3043 if(!tracklets[iLayer].IsOK()) continue;
3044 chi2phi += tracklets[iLayer].GetChi2Phi();
3047 chi2phi /= Float_t (nLayers - 2.0);
3049 Double_t likeChi2Z = TMath::Exp(-chi2[2] * 0.14); // Chi2Z
3050 Double_t likeChi2TC = (fkReconstructor->HasVertexConstrained()) ?
3051 TMath::Exp(-chi2[1] * 0.677) : 1; // Constrained Tilted Riemann
3052 Double_t likeChi2TR = TMath::Exp(-chi2[0] * 0.0078); // Non-constrained Tilted Riemann
3053 Double_t likeChi2Phi= TMath::Exp(-chi2phi * 3.23);//3.23
3054 Double_t trackLikelihood = likeChi2Z * likeChi2TR * likeChi2Phi;
3056 if(fkReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) >= 2){
3057 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
3058 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
3059 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
3060 cstreamer << "CalculateTrackLikelihood0"
3061 << "EventNumber=" << eventNumber
3062 << "CandidateNumber=" << candidateNumber
3063 << "LikeChi2Z=" << likeChi2Z
3064 << "LikeChi2TR=" << likeChi2TR
3065 << "LikeChi2TC=" << likeChi2TC
3066 << "LikeChi2Phi=" << likeChi2Phi
3067 << "TrackLikelihood=" << trackLikelihood
3071 return trackLikelihood;
3074 //____________________________________________________________________
3075 Double_t AliTRDtrackerV1::CookLikelihood(AliTRDseedV1 *cseed, Int_t planes[4])
3078 // Calculate the probability of this track candidate.
3081 // cseeds : array of candidate tracklets
3082 // planes : array of seeding planes (see seeding configuration)
3083 // chi2 : chi2 values (on the Z and Y direction) from the rieman fit of the track.
3088 // Detailed description
3090 // The track quality is estimated based on the following 4 criteria:
3091 // 1. precision of the rieman fit on the Y direction (likea)
3092 // 2. chi2 on the Y direction (likechi2y)
3093 // 3. chi2 on the Z direction (likechi2z)
3094 // 4. number of attached clusters compared to a reference value
3095 // (see AliTRDrecoParam::fkFindable) (likeN)
3097 // The distributions for each type of probabilities are given below as of
3098 // (date). They have to be checked to assure consistency of estimation.
3101 // ratio of the total number of clusters/track which are expected to be found by the tracker.
3102 const AliTRDrecoParam *fRecoPars = fkReconstructor->GetRecoParam();
3104 Double_t chi2y = GetChi2Y(&cseed[0]);
3105 Double_t chi2z = GetChi2Z(&cseed[0]);
3107 Float_t nclusters = 0.;
3108 Double_t sumda = 0.;
3109 for(UChar_t ilayer = 0; ilayer < 4; ilayer++){
3110 Int_t jlayer = planes[ilayer];
3111 nclusters += cseed[jlayer].GetN2();
3112 sumda += TMath::Abs(cseed[jlayer].GetYfit(1) - cseed[jlayer].GetYref(1));
3116 Double_t likea = TMath::Exp(-sumda * fRecoPars->GetPhiSlope());
3117 Double_t likechi2y = 0.0000000001;
3118 if (fkReconstructor->IsCosmic() || chi2y < fRecoPars->GetChi2YCut()) likechi2y += TMath::Exp(-TMath::Sqrt(chi2y) * fRecoPars->GetChi2YSlope());
3119 Double_t likechi2z = TMath::Exp(-chi2z * fRecoPars->GetChi2ZSlope());
3120 Double_t likeN = TMath::Exp(-(fRecoPars->GetNMeanClusters() - nclusters) / fRecoPars->GetNSigmaClusters());
3121 Double_t like = likea * likechi2y * likechi2z * likeN;
3123 if(fkReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) >= 2){
3124 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
3125 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
3126 Int_t nTracklets = 0; Float_t meanNcls = 0;
3127 for(Int_t iseed=0; iseed < kNPlanes; iseed++){
3128 if(!cseed[iseed].IsOK()) continue;
3130 meanNcls += cseed[iseed].GetN2();
3132 if(nTracklets) meanNcls /= nTracklets;
3133 // The Debug Stream contains the seed
3134 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
3135 cstreamer << "CookLikelihood"
3136 << "EventNumber=" << eventNumber
3137 << "CandidateNumber=" << candidateNumber
3138 << "tracklet0.=" << &cseed[0]
3139 << "tracklet1.=" << &cseed[1]
3140 << "tracklet2.=" << &cseed[2]
3141 << "tracklet3.=" << &cseed[3]
3142 << "tracklet4.=" << &cseed[4]
3143 << "tracklet5.=" << &cseed[5]
3144 << "sumda=" << sumda
3145 << "chi2y=" << chi2y
3146 << "chi2z=" << chi2z
3147 << "likea=" << likea
3148 << "likechi2y=" << likechi2y
3149 << "likechi2z=" << likechi2z
3150 << "nclusters=" << nclusters
3151 << "likeN=" << likeN
3153 << "meanncls=" << meanNcls
3160 //____________________________________________________________________
3161 void AliTRDtrackerV1::GetSeedingConfig(Int_t iconfig, Int_t planes[4])
3164 // Map seeding configurations to detector planes.
3167 // iconfig : configuration index
3168 // planes : member planes of this configuration. On input empty.
3171 // planes : contains the planes which are defining the configuration
3173 // Detailed description
3175 // Here is the list of seeding planes configurations together with
3176 // their topological classification:
3194 // The topologic quality is modeled as follows:
3195 // 1. The general model is define by the equation:
3196 // p(conf) = exp(-conf/2)
3197 // 2. According to the topologic classification, configurations from the same
3198 // class are assigned the agerage value over the model values.
3199 // 3. Quality values are normalized.
3201 // The topologic quality distribution as function of configuration is given below:
3203 // <img src="gif/topologicQA.gif">
3208 case 0: // 5432 TQ 0
3214 case 1: // 4321 TQ 0
3220 case 2: // 3210 TQ 0
3226 case 3: // 5321 TQ 1
3232 case 4: // 4210 TQ 1
3238 case 5: // 5431 TQ 1
3244 case 6: // 4320 TQ 1
3250 case 7: // 5430 TQ 2
3256 case 8: // 5210 TQ 2
3262 case 9: // 5421 TQ 3
3268 case 10: // 4310 TQ 3
3274 case 11: // 5410 TQ 4
3280 case 12: // 5420 TQ 5
3286 case 13: // 5320 TQ 5
3292 case 14: // 5310 TQ 5
3301 //____________________________________________________________________
3302 void AliTRDtrackerV1::GetExtrapolationConfig(Int_t iconfig, Int_t planes[2])
3305 // Returns the extrapolation planes for a seeding configuration.
3308 // iconfig : configuration index
3309 // planes : planes which are not in this configuration. On input empty.
3312 // planes : contains the planes which are not in the configuration
3314 // Detailed description
3318 case 0: // 5432 TQ 0
3322 case 1: // 4321 TQ 0
3326 case 2: // 3210 TQ 0
3330 case 3: // 5321 TQ 1
3334 case 4: // 4210 TQ 1
3338 case 5: // 5431 TQ 1
3342 case 6: // 4320 TQ 1
3346 case 7: // 5430 TQ 2
3350 case 8: // 5210 TQ 2
3354 case 9: // 5421 TQ 3
3358 case 10: // 4310 TQ 3
3362 case 11: // 5410 TQ 4
3366 case 12: // 5420 TQ 5
3370 case 13: // 5320 TQ 5
3374 case 14: // 5310 TQ 5
3381 //____________________________________________________________________
3382 AliCluster* AliTRDtrackerV1::GetCluster(Int_t idx) const
3384 Int_t ncls = fClusters->GetEntriesFast();
3385 return idx >= 0 && idx < ncls ? (AliCluster*)fClusters->UncheckedAt(idx) : NULL;
3388 //____________________________________________________________________
3389 AliTRDseedV1* AliTRDtrackerV1::GetTracklet(Int_t idx) const
3391 Int_t ntrklt = fTracklets->GetEntriesFast();
3392 return idx >= 0 && idx < ntrklt ? (AliTRDseedV1*)fTracklets->UncheckedAt(idx) : NULL;
3395 //____________________________________________________________________
3396 AliKalmanTrack* AliTRDtrackerV1::GetTrack(Int_t idx) const
3398 Int_t ntrk = fTracks->GetEntriesFast();
3399 return idx >= 0 && idx < ntrk ? (AliKalmanTrack*)fTracks->UncheckedAt(idx) : NULL;
3404 // //_____________________________________________________________________________
3405 // Int_t AliTRDtrackerV1::Freq(Int_t n, const Int_t *inlist
3406 // , Int_t *outlist, Bool_t down)
3409 // // Sort eleements according occurancy
3410 // // The size of output array has is 2*n
3417 // Int_t *sindexS = new Int_t[n]; // Temporary array for sorting
3418 // Int_t *sindexF = new Int_t[2*n];
3419 // for (Int_t i = 0; i < n; i++) {
3423 // TMath::Sort(n,inlist,sindexS,down);
3425 // Int_t last = inlist[sindexS[0]];
3426 // Int_t val = last;
3428 // sindexF[0+n] = last;
3429 // Int_t countPos = 0;
3431 // // Find frequency
3432 // for (Int_t i = 1; i < n; i++) {
3433 // val = inlist[sindexS[i]];
3434 // if (last == val) {
3435 // sindexF[countPos]++;
3439 // sindexF[countPos+n] = val;
3440 // sindexF[countPos]++;
3444 // if (last == val) {
3448 // // Sort according frequency
3449 // TMath::Sort(countPos,sindexF,sindexS,kTRUE);
3451 // for (Int_t i = 0; i < countPos; i++) {
3452 // outlist[2*i ] = sindexF[sindexS[i]+n];
3453 // outlist[2*i+1] = sindexF[sindexS[i]];
3456 // delete [] sindexS;
3457 // delete [] sindexF;
3464 //____________________________________________________________________
3465 void AliTRDtrackerV1::ResetSeedTB()
3467 // reset buffer for seeding time bin layers. If the time bin
3468 // layers are not allocated this function allocates them
3470 for(Int_t isl=0; isl<kNSeedPlanes; isl++){
3471 if(!fSeedTB[isl]) fSeedTB[isl] = new AliTRDchamberTimeBin();
3472 else fSeedTB[isl]->Clear();
3477 //_____________________________________________________________________________
3478 Float_t AliTRDtrackerV1::GetChi2Y(const AliTRDseedV1 * const tracklets) const
3480 // Calculates normalized chi2 in y-direction
3481 // chi2 = Sum chi2 / n_tracklets
3483 Double_t chi2 = 0.; Int_t n = 0;
3484 for(Int_t ipl = kNPlanes; ipl--;){
3485 if(!tracklets[ipl].IsOK()) continue;
3486 chi2 += tracklets[ipl].GetChi2Y();
3489 return n ? chi2/n : 0.;
3492 //_____________________________________________________________________________
3493 Float_t AliTRDtrackerV1::GetChi2Z(const AliTRDseedV1 *const tracklets) const
3495 // Calculates normalized chi2 in z-direction
3496 // chi2 = Sum chi2 / n_tracklets
3498 Double_t chi2 = 0; Int_t n = 0;
3499 for(Int_t ipl = kNPlanes; ipl--;){
3500 if(!tracklets[ipl].IsOK()) continue;
3501 chi2 += tracklets[ipl].GetChi2Z();
3504 return n ? chi2/n : 0.;
3507 //____________________________________________________________________
3508 Float_t AliTRDtrackerV1::CalculateReferenceX(const AliTRDseedV1 *const tracklets){
3510 // Calculates the reference x-position for the tilted Rieman fit defined as middle
3511 // of the stack (middle between layers 2 and 3). For the calculation all the tracklets
3512 // are taken into account
3514 // Parameters: - Array of tracklets(AliTRDseedV1)
3516 // Output: - The reference x-position(Float_t)
3517 // Only kept for compatibility with the old code
3519 Int_t nDistances = 0;
3520 Float_t meanDistance = 0.;
3521 Int_t startIndex = 5;
3522 for(Int_t il =5; il > 0; il--){
3523 if(tracklets[il].IsOK() && tracklets[il -1].IsOK()){
3524 Float_t xdiff = tracklets[il].GetX0() - tracklets[il -1].GetX0();
3525 meanDistance += xdiff;
3528 if(tracklets[il].IsOK()) startIndex = il;
3530 if(tracklets[0].IsOK()) startIndex = 0;
3532 // We should normally never get here
3533 Float_t xpos[2]; memset(xpos, 0, sizeof(Float_t) * 2);
3534 Int_t iok = 0, idiff = 0;
3535 // This attempt is worse and should be avoided:
3536 // check for two chambers which are OK and repeat this without taking the mean value
3537 // Strategy avoids a division by 0;
3538 for(Int_t il = 5; il >= 0; il--){
3539 if(tracklets[il].IsOK()){
3540 xpos[iok] = tracklets[il].GetX0();
3544 if(iok) idiff++; // to get the right difference;
3548 meanDistance = (xpos[0] - xpos[1])/idiff;
3551 // we have do not even have 2 layers which are OK? The we do not need to fit at all
3556 meanDistance /= nDistances;
3558 return tracklets[startIndex].GetX0() + (2.5 - startIndex) * meanDistance - 0.5 * (AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick());
3561 //_____________________________________________________________________________
3562 Double_t AliTRDtrackerV1::FitTiltedRiemanV1(AliTRDseedV1 *const tracklets){
3564 // Track Fitter Function using the new class implementation of
3567 AliTRDtrackFitterRieman fitter;
3568 fitter.SetRiemanFitter(GetTiltedRiemanFitter());
3570 for(Int_t il = 0; il < AliTRDgeometry::kNlayer; il++) fitter.SetTracklet(il, &tracklets[il]);
3571 Double_t chi2 = fitter.Eval();
3572 // Update the tracklets
3573 Double_t cov[15]; Double_t x0;
3574 memset(cov, 0, sizeof(Double_t) * 15);
3575 for(Int_t il = 0; il < AliTRDgeometry::kNlayer; il++){
3576 x0 = tracklets[il].GetX0();
3577 tracklets[il].SetYref(0, fitter.GetYat(x0));
3578 tracklets[il].SetZref(0, fitter.GetZat(x0));
3579 tracklets[il].SetYref(1, fitter.GetDyDxAt(x0));
3580 tracklets[il].SetZref(1, fitter.GetDzDx());
3581 tracklets[il].SetC(fitter.GetCurvature());
3582 fitter.GetCovAt(x0, cov);
3583 tracklets[il].SetCovRef(cov);
3584 tracklets[il].SetChi2(chi2);
3589 ///////////////////////////////////////////////////////
3591 // Resources of class AliTRDLeastSquare //
3593 ///////////////////////////////////////////////////////
3595 //_____________________________________________________________________________
3596 AliTRDtrackerV1::AliTRDLeastSquare::AliTRDLeastSquare(){
3598 // Constructor of the nested class AliTRDtrackFitterLeastSquare
3600 memset(fParams, 0, sizeof(Double_t) * 2);
3601 memset(fSums, 0, sizeof(Double_t) * 6);
3602 memset(fCovarianceMatrix, 0, sizeof(Double_t) * 3);
3606 //_____________________________________________________________________________
3607 void AliTRDtrackerV1::AliTRDLeastSquare::AddPoint(const Double_t *const x, Double_t y, Double_t sigmaY){
3609 // Adding Point to the fitter
3611 Double_t weight = 1/(sigmaY > 1e-9 ? sigmaY : 1e-9);
3613 const Double_t &xpt = *x;
3614 // printf("Adding point x = %f, y = %f, sigma = %f\n", xpt, y, sigmaY);
3616 fSums[1] += weight * xpt;
3617 fSums[2] += weight * y;
3618 fSums[3] += weight * xpt * y;
3619 fSums[4] += weight * xpt * xpt;
3620 fSums[5] += weight * y * y;
3623 //_____________________________________________________________________________
3624 void AliTRDtrackerV1::AliTRDLeastSquare::RemovePoint(const Double_t *const x, Double_t y, Double_t sigmaY){
3626 // Remove Point from the sample
3629 Double_t weight = 1/(sigmaY > 1e-9 ? sigmaY : 1e-9);
3631 const Double_t &xpt = *x;
3633 fSums[1] -= weight * xpt;
3634 fSums[2] -= weight * y;
3635 fSums[3] -= weight * xpt * y;
3636 fSums[4] -= weight * xpt * xpt;
3637 fSums[5] -= weight * y * y;
3640 //_____________________________________________________________________________
3641 void AliTRDtrackerV1::AliTRDLeastSquare::Eval(){
3643 // Evaluation of the fit:
3644 // Calculation of the parameters
3645 // Calculation of the covariance matrix
3648 Double_t denominator = fSums[0] * fSums[4] - fSums[1] *fSums[1];
3649 if(denominator==0) return;
3651 // for(Int_t isum = 0; isum < 5; isum++)
3652 // printf("fSums[%d] = %f\n", isum, fSums[isum]);
3653 // printf("denominator = %f\n", denominator);
3654 fParams[0] = (fSums[2] * fSums[4] - fSums[1] * fSums[3])/ denominator;
3655 fParams[1] = (fSums[0] * fSums[3] - fSums[1] * fSums[2]) / denominator;
3656 // printf("fParams[0] = %f, fParams[1] = %f\n", fParams[0], fParams[1]);
3658 // Covariance matrix
3659 fCovarianceMatrix[0] = fSums[4] / fSums[0] - fSums[1] * fSums[1] / (fSums[0] * fSums[0]);
3660 fCovarianceMatrix[1] = fSums[5] / fSums[0] - fSums[2] * fSums[2] / (fSums[0] * fSums[0]);
3661 fCovarianceMatrix[2] = fSums[3] / fSums[0] - fSums[1] * fSums[2] / (fSums[0] * fSums[0]);
3664 //_____________________________________________________________________________
3665 Double_t AliTRDtrackerV1::AliTRDLeastSquare::GetFunctionValue(const Double_t *const xpos) const {
3667 // Returns the Function value of the fitted function at a given x-position
3669 return fParams[0] + fParams[1] * (*xpos);
3672 //_____________________________________________________________________________
3673 void AliTRDtrackerV1::AliTRDLeastSquare::GetCovarianceMatrix(Double_t *storage) const {
3675 // Copies the values of the covariance matrix into the storage
3677 memcpy(storage, fCovarianceMatrix, sizeof(Double_t) * 3);
3680 //_____________________________________________________________________________
3681 void AliTRDtrackerV1::AliTRDLeastSquare::Reset(){
3685 memset(fParams, 0, sizeof(Double_t) * 2);
3686 memset(fCovarianceMatrix, 0, sizeof(Double_t) * 3);
3687 memset(fSums, 0, sizeof(Double_t) * 6);
3690 ///////////////////////////////////////////////////////
3692 // Resources of class AliTRDtrackFitterRieman //
3694 ///////////////////////////////////////////////////////
3696 //_____________________________________________________________________________
3697 AliTRDtrackerV1::AliTRDtrackFitterRieman::AliTRDtrackFitterRieman():
3703 fSysClusterError(0.)
3706 // Default constructor
3708 fZfitter = new AliTRDLeastSquare;
3709 fCovarPolY = new TMatrixD(3,3);
3710 fCovarPolZ = new TMatrixD(2,2);
3711 memset(fTracklets, 0, sizeof(AliTRDseedV1 *) * 6);
3712 memset(fParameters, 0, sizeof(Double_t) * 5);
3713 memset(fSumPolY, 0, sizeof(Double_t) * 5);
3714 memset(fSumPolZ, 0, sizeof(Double_t) * 2);
3717 //_____________________________________________________________________________
3718 AliTRDtrackerV1::AliTRDtrackFitterRieman::~AliTRDtrackFitterRieman(){
3722 if(fZfitter) delete fZfitter;
3723 if(fCovarPolY) delete fCovarPolY;
3724 if(fCovarPolZ) delete fCovarPolZ;
3727 //_____________________________________________________________________________
3728 void AliTRDtrackerV1::AliTRDtrackFitterRieman::Reset(){
3733 fTrackFitter->StoreData(kTRUE);
3734 fTrackFitter->ClearPoints();
3740 memset(fTracklets, 0, sizeof(AliTRDseedV1 *) * AliTRDgeometry::kNlayer);
3741 memset(fParameters, 0, sizeof(Double_t) * 5);
3742 memset(fSumPolY, 0, sizeof(Double_t) * 5);
3743 memset(fSumPolZ, 0, sizeof(Double_t) * 2);
3744 for(Int_t irow = 0; irow < fCovarPolY->GetNrows(); irow++)
3745 for(Int_t icol = 0; icol < fCovarPolY->GetNcols(); icol++){
3746 (*fCovarPolY)(irow, icol) = 0.;
3747 if(irow < 2 && icol < 2)
3748 (*fCovarPolZ)(irow, icol) = 0.;
3752 //_____________________________________________________________________________
3753 void AliTRDtrackerV1::AliTRDtrackFitterRieman::SetTracklet(Int_t itr, AliTRDseedV1 *tracklet){
3755 // Add tracklet into the fitter
3757 if(itr >= AliTRDgeometry::kNlayer) return;
3758 fTracklets[itr] = tracklet;
3761 //_____________________________________________________________________________
3762 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::Eval(){
3765 // 1. Apply linear transformation and store points in the fitter
3766 // 2. Evaluate the fit
3767 // 3. Check if the result of the fit in z-direction is reasonable
3769 // 3a. Fix the parameters 3 and 4 with the results of a simple least
3771 // 3b. Redo the fit with the fixed parameters
3772 // 4. Store fit results (parameters and errors)
3777 fXref = CalculateReferenceX();
3778 for(Int_t il = 0; il < AliTRDgeometry::kNlayer; il++) UpdateFitters(fTracklets[il]);
3779 if(!fTrackFitter->GetNpoints()) return 1e10;
3781 fTrackFitter->Eval();
3783 fParameters[3] = fTrackFitter->GetParameter(3);
3784 fParameters[4] = fTrackFitter->GetParameter(4);
3785 if(!CheckAcceptable(fParameters[3], fParameters[4])) {
3786 fTrackFitter->FixParameter(3, fZfitter->GetFunctionValue(&fXref));
3787 fTrackFitter->FixParameter(4, fZfitter->GetFunctionParameter(1));
3788 fTrackFitter->Eval();
3789 fTrackFitter->ReleaseParameter(3);
3790 fTrackFitter->ReleaseParameter(4);
3791 fParameters[3] = fTrackFitter->GetParameter(3);
3792 fParameters[4] = fTrackFitter->GetParameter(4);
3794 // Update the Fit Parameters and the errors
3795 fParameters[0] = fTrackFitter->GetParameter(0);
3796 fParameters[1] = fTrackFitter->GetParameter(1);
3797 fParameters[2] = fTrackFitter->GetParameter(2);
3799 // Prepare Covariance estimation
3800 (*fCovarPolY)(0,0) = fSumPolY[0]; (*fCovarPolY)(1,1) = fSumPolY[2]; (*fCovarPolY)(2,2) = fSumPolY[4];
3801 (*fCovarPolY)(1,0) = (*fCovarPolY)(0,1) = fSumPolY[1];
3802 (*fCovarPolY)(2,0) = (*fCovarPolY)(0,2) = fSumPolY[2];
3803 (*fCovarPolY)(2,1) = (*fCovarPolY)(1,2) = fSumPolY[3];
3804 fCovarPolY->Invert();
3805 (*fCovarPolZ)(0,0) = fSumPolZ[0]; (*fCovarPolZ)(1,1) = fSumPolZ[2];
3806 (*fCovarPolZ)(1,0) = (*fCovarPolZ)(0,1) = fSumPolZ[1];
3807 fCovarPolZ->Invert();
3808 return fTrackFitter->GetChisquare() / fTrackFitter->GetNpoints();
3811 //_____________________________________________________________________________
3812 void AliTRDtrackerV1::AliTRDtrackFitterRieman::UpdateFitters(AliTRDseedV1 * const tracklet){
3814 // Does the transformations and updates the fitters
3815 // The following transformation is applied
3817 AliTRDcluster *cl = NULL;
3818 Double_t x, y, z, dx, t, w, we, yerr, zerr;
3820 if(!tracklet || !tracklet->IsOK()) return;
3821 Double_t tilt = tracklet->GetTilt();
3822 for(Int_t itb = 0; itb < AliTRDseedV1::kNclusters; itb++){
3823 if(!(cl = tracklet->GetClusters(itb))) continue;
3824 if(!cl->IsInChamber()) continue;
3825 if (!tracklet->IsUsable(itb)) continue;
3832 uvt[0] = 2. * x * t;
3834 uvt[2] = 2. * tilt * t;
3835 uvt[3] = 2. * tilt * dx * t;
3836 w = 2. * (y + tilt*z) * t;
3837 // error definition changes for the different calls
3839 we *= TMath::Sqrt(cl->GetSigmaY2()+tilt*tilt*cl->GetSigmaZ2());
3840 // Update sums for error calculation
3841 yerr = 1./(TMath::Sqrt(cl->GetSigmaY2()) + fSysClusterError);
3843 zerr = 1./cl->GetSigmaZ2();
3844 for(Int_t ipol = 0; ipol < 5; ipol++){
3845 fSumPolY[ipol] += yerr;
3848 fSumPolZ[ipol] += zerr;
3852 fTrackFitter->AddPoint(uvt, w, we);
3853 fZfitter->AddPoint(&x, z, static_cast<Double_t>(TMath::Sqrt(cl->GetSigmaZ2())));
3857 //_____________________________________________________________________________
3858 Bool_t AliTRDtrackerV1::AliTRDtrackFitterRieman::CheckAcceptable(Double_t offset, Double_t slope){
3860 // Check whether z-results are acceptable
3861 // Definition: Distance between tracklet fit and track fit has to be
3862 // less then half a padlength
3863 // Point of comparision is at the anode wire
3865 Bool_t acceptablez = kTRUE;
3866 Double_t zref = 0.0;
3867 for (Int_t iLayer = 0; iLayer < kNPlanes; iLayer++) {
3868 if(!fTracklets[iLayer]->IsOK()) continue;
3869 zref = offset + slope * (fTracklets[iLayer]->GetX0() - fXref);
3870 if (TMath::Abs(fTracklets[iLayer]->GetZfit(0) - zref) > fTracklets[iLayer]->GetPadLength() * 0.5 + 1.0)
3871 acceptablez = kFALSE;
3876 //_____________________________________________________________________________
3877 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::GetYat(Double_t x) const {
3879 // Calculate y position out of the track parameters
3880 // y: R^2 = (x - x0)^2 + (y - y0)^2
3881 // => y = y0 +/- Sqrt(R^2 - (x - x0)^2)
3882 // R = Sqrt() = 1/Curvature
3883 // => y = y0 +/- Sqrt(1/Curvature^2 - (x - x0)^2)
3886 Double_t disc = (x * fParameters[0] + fParameters[1]);
3887 disc = 1 - fParameters[0]*fParameters[2] + fParameters[1]*fParameters[1] - disc*disc;
3889 disc = TMath::Sqrt(disc);
3890 y = (1.0 - disc) / fParameters[0];
3895 //_____________________________________________________________________________
3896 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::GetZat(Double_t x) const {
3898 // Return z position for a given x position
3899 // Simple linear function
3901 return fParameters[3] + fParameters[4] * (x - fXref);
3904 //_____________________________________________________________________________
3905 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::GetDyDxAt(Double_t x) const {
3907 // Calculate dydx at a given radial position out of the track parameters
3908 // dy: R^2 = (x - x0)^2 + (y - y0)^2
3909 // => y = +/- Sqrt(R^2 - (x - x0)^2) + y0
3910 // => dy/dx = (x - x0)/Sqrt(R^2 - (x - x0)^2)
3911 // Curvature: cr = 1/R = a/Sqrt(1 + b^2 - c*a)
3912 // => dy/dx = (x - x0)/(1/(cr^2) - (x - x0)^2)
3914 Double_t x0 = -fParameters[1] / fParameters[0];
3915 Double_t curvature = GetCurvature();
3917 if (-fParameters[2] * fParameters[0] + fParameters[1] * fParameters[1] + 1 > 0) {
3918 if (1.0/(curvature * curvature) - (x - x0) * (x - x0) > 0.0) {
3919 Double_t yderiv = (x - x0) / TMath::Sqrt(1.0/(curvature * curvature) - (x - x0) * (x - x0));
3920 if (fParameters[0] < 0) yderiv *= -1.0;
3927 //_____________________________________________________________________________
3928 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::GetCurvature() const {
3930 // Calculate track curvature
3933 Double_t curvature = 1.0 + fParameters[1]*fParameters[1] - fParameters[2]*fParameters[0];
3934 if (curvature > 0.0)
3935 curvature = fParameters[0] / TMath::Sqrt(curvature);
3939 //_____________________________________________________________________________
3940 void AliTRDtrackerV1::AliTRDtrackFitterRieman::GetCovAt(Double_t x, Double_t *cov) const {
3942 // Error Definition according to gauss error propagation
3944 TMatrixD transform(3,3);
3945 transform(0,0) = transform(1,1) = transform(2,2) = 1;
3946 transform(0,1) = transform(1,2) = x;
3947 transform(0,2) = x*x;
3948 TMatrixD covariance(transform, TMatrixD::kMult, *fCovarPolY);
3949 covariance *= transform.T();
3950 cov[0] = covariance(0,0);
3951 TMatrixD transformZ(2,2);
3952 transformZ(0,0) = transformZ(1,1) = 1;
3953 transformZ(0,1) = x;
3954 TMatrixD covarZ(transformZ, TMatrixD::kMult, *fCovarPolZ);
3955 covarZ *= transformZ.T();
3956 cov[1] = covarZ(0,0);
3960 //____________________________________________________________________
3961 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::CalculateReferenceX(){
3963 // Calculates the reference x-position for the tilted Rieman fit defined as middle
3964 // of the stack (middle between layers 2 and 3). For the calculation all the tracklets
3965 // are taken into account
3967 // Parameters: - Array of tracklets(AliTRDseedV1)
3969 // Output: - The reference x-position(Float_t)
3971 Int_t nDistances = 0;
3972 Float_t meanDistance = 0.;
3973 Int_t startIndex = 5;
3974 for(Int_t il =5; il > 0; il--){
3975 if(fTracklets[il]->IsOK() && fTracklets[il -1]->IsOK()){
3976 Float_t xdiff = fTracklets[il]->GetX0() - fTracklets[il -1]->GetX0();
3977 meanDistance += xdiff;
3980 if(fTracklets[il]->IsOK()) startIndex = il;
3982 if(fTracklets[0]->IsOK()) startIndex = 0;
3984 // We should normally never get here
3985 Float_t xpos[2]; memset(xpos, 0, sizeof(Float_t) * 2);
3986 Int_t iok = 0, idiff = 0;
3987 // This attempt is worse and should be avoided:
3988 // check for two chambers which are OK and repeat this without taking the mean value
3989 // Strategy avoids a division by 0;
3990 for(Int_t il = 5; il >= 0; il--){
3991 if(fTracklets[il]->IsOK()){
3992 xpos[iok] = fTracklets[il]->GetX0();
3996 if(iok) idiff++; // to get the right difference;
4000 meanDistance = (xpos[0] - xpos[1])/idiff;
4003 // we have do not even have 2 layers which are OK? The we do not need to fit at all
4008 meanDistance /= nDistances;
4010 return fTracklets[startIndex]->GetX0() + (2.5 - startIndex) * meanDistance - 0.5 * (AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick());