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 *
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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 ///////////////////////////////////////////////////////////////////////////////
28 // #include <Riostream.h>
30 // #include <string.h>
33 #include <TDirectory.h>
34 #include <TLinearFitter.h>
36 #include <TClonesArray.h>
37 #include <TTreeStream.h>
38 #include <TGeoMatrix.h>
39 #include <TGeoManager.h>
42 #include "AliMathBase.h"
43 #include "AliESDEvent.h"
44 #include "AliGeomManager.h"
45 #include "AliRieman.h"
46 #include "AliTrackPointArray.h"
48 #include "AliTRDgeometry.h"
49 #include "AliTRDpadPlane.h"
50 #include "AliTRDcalibDB.h"
51 #include "AliTRDReconstructor.h"
52 #include "AliTRDCalibraFillHisto.h"
53 #include "AliTRDrecoParam.h"
55 #include "AliTRDcluster.h"
56 #include "AliTRDseedV1.h"
57 #include "AliTRDtrackV1.h"
58 #include "AliTRDtrackerV1.h"
59 #include "AliTRDtrackerDebug.h"
60 #include "AliTRDtrackingChamber.h"
61 #include "AliTRDchamberTimeBin.h"
65 ClassImp(AliTRDtrackerV1)
68 const Float_t AliTRDtrackerV1::fgkMinClustersInTrack = 0.5; //
69 const Float_t AliTRDtrackerV1::fgkLabelFraction = 0.8; //
70 const Double_t AliTRDtrackerV1::fgkMaxChi2 = 12.0; //
71 const Double_t AliTRDtrackerV1::fgkMaxSnp = 0.95; // Maximum local sine of the azimuthal angle
72 const Double_t AliTRDtrackerV1::fgkMaxStep = 2.0; // Maximal step size in propagation
73 Double_t AliTRDtrackerV1::fgTopologicQA[kNConfigs] = {
74 0.5112, 0.5112, 0.5112, 0.0786, 0.0786,
75 0.0786, 0.0786, 0.0579, 0.0579, 0.0474,
76 0.0474, 0.0408, 0.0335, 0.0335, 0.0335
78 const Double_t AliTRDtrackerV1::fgkX0[kNPlanes] = {
79 300.2, 312.8, 325.4, 338.0, 350.6, 363.2};
80 Int_t AliTRDtrackerV1::fgNTimeBins = 0;
81 AliRieman* AliTRDtrackerV1::fgRieman = 0x0;
82 TLinearFitter* AliTRDtrackerV1::fgTiltedRieman = 0x0;
83 TLinearFitter* AliTRDtrackerV1::fgTiltedRiemanConstrained = 0x0;
85 //____________________________________________________________________
86 AliTRDtrackerV1::AliTRDtrackerV1(AliTRDReconstructor *rec)
96 // Default constructor.
99 SetReconstructor(rec); // initialize reconstructor
101 // initialize geometry
102 if(!AliGeomManager::GetGeometry()){
103 AliFatal("Could not get geometry.");
105 fGeom = new AliTRDgeometry();
106 fGeom->CreateClusterMatrixArray();
107 TGeoHMatrix *matrix = 0x0;
108 Double_t loc[] = {0., 0., 0.};
109 Double_t glb[] = {0., 0., 0.};
110 for(Int_t ily=kNPlanes; ily--;){
112 while(!(matrix = fGeom->GetClusterMatrix(AliTRDgeometry::GetDetector(ily, 2, ism)))) ism++;
114 AliError(Form("Could not get transformation matrix for layer %d. Use default.", ily));
115 fR[ily] = fgkX0[ily];
118 matrix->LocalToMaster(loc, glb);
119 fR[ily] = glb[0]+ AliTRDgeometry::AnodePos()-.5*AliTRDgeometry::AmThick() - AliTRDgeometry::DrThick();
122 // initialize calibration values
123 AliTRDcalibDB *trd = 0x0;
124 if (!(trd = AliTRDcalibDB::Instance())) {
125 AliFatal("Could not get calibration.");
127 if(!fgNTimeBins) fgNTimeBins = trd->GetNumberOfTimeBins();
129 // initialize cluster containers
130 for (Int_t isector = 0; isector < AliTRDgeometry::kNsector; isector++) new(&fTrSec[isector]) AliTRDtrackingSector(fGeom, isector);
133 memset(fTrackQuality, 0, kMaxTracksStack*sizeof(Double_t));
134 memset(fSeedLayer, 0, kMaxTracksStack*sizeof(Int_t));
135 memset(fSeedTB, 0, kNSeedPlanes*sizeof(AliTRDchamberTimeBin*));
138 //____________________________________________________________________
139 AliTRDtrackerV1::~AliTRDtrackerV1()
145 if(fgRieman) delete fgRieman; fgRieman = 0x0;
146 if(fgTiltedRieman) delete fgTiltedRieman; fgTiltedRieman = 0x0;
147 if(fgTiltedRiemanConstrained) delete fgTiltedRiemanConstrained; fgTiltedRiemanConstrained = 0x0;
148 for(Int_t isl =0; isl<kNSeedPlanes; isl++) if(fSeedTB[isl]) delete fSeedTB[isl];
149 if(fTracks) {fTracks->Delete(); delete fTracks;}
150 if(fTracklets) {fTracklets->Delete(); delete fTracklets;}
152 fClusters->Delete(); delete fClusters;
154 if(fGeom) delete fGeom;
157 //____________________________________________________________________
158 Int_t AliTRDtrackerV1::Clusters2Tracks(AliESDEvent *esd)
161 // Steering stand alone tracking for full TRD detector
164 // esd : The ESD event. On output it contains
165 // the ESD tracks found in TRD.
168 // Number of tracks found in the TRD detector.
170 // Detailed description
171 // 1. Launch individual SM trackers.
172 // See AliTRDtrackerV1::Clusters2TracksSM() for details.
175 if(!fReconstructor->GetRecoParam() ){
176 AliError("Reconstruction configuration not initialized. Call first AliTRDReconstructor::SetRecoParam().");
180 //AliInfo("Start Track Finder ...");
182 for(int ism=0; ism<AliTRDgeometry::kNsector; ism++){
183 // for(int ism=1; ism<2; ism++){
184 //AliInfo(Form("Processing supermodule %i ...", ism));
185 ntracks += Clusters2TracksSM(ism, esd);
187 AliInfo(Form("Number of found tracks : %d", ntracks));
192 //_____________________________________________________________________________
193 Bool_t AliTRDtrackerV1::GetTrackPoint(Int_t index, AliTrackPoint &p) const
195 //AliInfo(Form("Asking for tracklet %d", index));
197 // reset position of the point before using it
198 p.SetXYZ(0., 0., 0.);
199 AliTRDseedV1 *tracklet = GetTracklet(index);
200 if (!tracklet) return kFALSE;
202 // get detector for this tracklet
203 Int_t det = tracklet->GetDetector();
204 Int_t sec = fGeom->GetSector(det);
205 Double_t alpha = (sec+.5)*AliTRDgeometry::GetAlpha(),
206 sinA = TMath::Sin(alpha),
207 cosA = TMath::Cos(alpha);
209 local[0] = tracklet->GetX();
210 local[1] = tracklet->GetY();
211 local[2] = tracklet->GetZ();
213 fGeom->RotateBack(det, local, global);
215 Double_t cov2D[3]; Float_t cov[6];
216 tracklet->GetCovAt(local[0], cov2D);
217 cov[0] = cov2D[0]*sinA*sinA;
218 cov[1] =-cov2D[0]*sinA*cosA;
219 cov[2] =-cov2D[1]*sinA;
220 cov[3] = cov2D[0]*cosA*cosA;
221 cov[4] = cov2D[1]*cosA;
223 // store the global position of the tracklet and its covariance matrix in the track point
224 p.SetXYZ(global[0],global[1],global[2], cov);
227 AliGeomManager::ELayerID iLayer = AliGeomManager::ELayerID(AliGeomManager::kTRD1+fGeom->GetLayer(det));
228 Int_t modId = fGeom->GetSector(det) * AliTRDgeometry::kNstack + fGeom->GetStack(det);
229 UShort_t volid = AliGeomManager::LayerToVolUID(iLayer, modId);
230 p.SetVolumeID(volid);
235 //____________________________________________________________________
236 TLinearFitter* AliTRDtrackerV1::GetTiltedRiemanFitter()
238 if(!fgTiltedRieman) fgTiltedRieman = new TLinearFitter(4, "hyp4");
239 return fgTiltedRieman;
242 //____________________________________________________________________
243 TLinearFitter* AliTRDtrackerV1::GetTiltedRiemanFitterConstraint()
245 if(!fgTiltedRiemanConstrained) fgTiltedRiemanConstrained = new TLinearFitter(2, "hyp2");
246 return fgTiltedRiemanConstrained;
249 //____________________________________________________________________
250 AliRieman* AliTRDtrackerV1::GetRiemanFitter()
252 if(!fgRieman) fgRieman = new AliRieman(AliTRDseedV1::kNtb * AliTRDgeometry::kNlayer);
256 //_____________________________________________________________________________
257 Int_t AliTRDtrackerV1::PropagateBack(AliESDEvent *event)
259 // Propagation of ESD tracks from TPC to TOF detectors and building of the TRD track. For building
260 // a TRD track an ESD track is used as seed. The informations obtained on the TRD track (measured points,
261 // covariance, PID, etc.) are than used to update the corresponding ESD track.
262 // Each track seed is first propagated to the geometrical limit of the TRD detector.
263 // Its prolongation is searched in the TRD and if corresponding clusters are found tracklets are
264 // constructed out of them (see AliTRDseedV1::AttachClusters()) and the track is updated.
265 // Otherwise the ESD track is left unchanged.
267 // The following steps are performed:
268 // 1. Selection of tracks based on the variance in the y-z plane.
269 // 2. Propagation to the geometrical limit of the TRD volume. If track propagation fails the AliESDtrack::kTRDStop is set.
270 // 3. Prolongation inside the fiducial volume (see AliTRDtrackerV1::FollowBackProlongation()) and marking
271 // the following status bits:
272 // - AliESDtrack::kTRDin - if the tracks enters the TRD fiducial volume
273 // - AliESDtrack::kTRDStop - if the tracks fails propagation
274 // - AliESDtrack::kTRDbackup - if the tracks fulfills chi2 conditions and qualify for refitting
275 // 4. Writting to friends, PID, MC label, quality etc. Setting status bit AliESDtrack::kTRDout.
276 // 5. Propagation to TOF. If track propagation fails the AliESDtrack::kTRDStop is set.
279 AliTRDCalibraFillHisto *calibra = AliTRDCalibraFillHisto::Instance(); // Calibration monitor
280 if (!calibra) AliInfo("Could not get Calibra instance\n");
283 Int_t nFound = 0, // number of tracks found
284 nSeeds = 0, // total number of ESD seeds
285 nTRDseeds= 0, // number of seeds in the TRD acceptance
286 nTPCseeds= 0; // number of TPC seeds
287 Float_t foundMin = 20.0;
289 Float_t *quality = 0x0;
291 nSeeds = event->GetNumberOfTracks();
292 // Sort tracks according to quality
293 // (covariance in the yz plane)
295 quality = new Float_t[nSeeds];
296 index = new Int_t[nSeeds];
297 for (Int_t iSeed = nSeeds; iSeed--;) {
298 AliESDtrack *seed = event->GetTrack(iSeed);
299 Double_t covariance[15];
300 seed->GetExternalCovariance(covariance);
301 quality[iSeed] = covariance[0] + covariance[2];
303 TMath::Sort(nSeeds, quality, index,kFALSE);
306 // Propagate all seeds
309 for (Int_t iSeed = 0; iSeed < nSeeds; iSeed++) {
311 // Get the seeds in sorted sequence
312 AliESDtrack *seed = event->GetTrack(index[iSeed]);
313 Float_t p4 = seed->GetC(seed->GetBz());
315 // Check the seed status
316 ULong_t status = seed->GetStatus();
317 if ((status & AliESDtrack::kTPCout) == 0) continue;
318 if ((status & AliESDtrack::kTRDout) != 0) continue;
320 // Propagate to the entrance in the TRD mother volume
321 new(&track) AliTRDtrackV1(*seed);
322 if(AliTRDgeometry::GetXtrdBeg() > (fgkMaxStep + track.GetX()) && !PropagateToX(track, AliTRDgeometry::GetXtrdBeg(), fgkMaxStep)){
323 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
326 if(!AdjustSector(&track)){
327 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
330 if(TMath::Abs(track.GetSnp()) > fgkMaxSnp) {
331 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
337 // store track status at TRD entrance
338 seed->UpdateTrackParams(&track, AliESDtrack::kTRDbackup);
340 // prepare track and do propagation in the TRD
341 track.SetReconstructor(fReconstructor);
342 track.SetKink(Bool_t(seed->GetKinkIndex(0)));
343 expectedClr = FollowBackProlongation(track);
344 // check if track entered the TRD fiducial volume
345 if(track.GetTrackLow()){
346 seed->UpdateTrackParams(&track, AliESDtrack::kTRDin);
349 // check if track was stopped in the TRD
351 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
357 // computes PID for track
359 // update calibration references using this track
360 if(calibra->GetHisto2d()) calibra->UpdateHistogramsV1(&track);
361 // save calibration object
362 if (fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 0){
363 AliTRDtrackV1 *calibTrack = new AliTRDtrackV1(track);
364 calibTrack->SetOwner();
365 seed->AddCalibObject(calibTrack);
368 if ((track.GetNumberOfClusters() > 15) && (track.GetNumberOfClusters() > 0.5*expectedClr)) {
369 seed->UpdateTrackParams(&track, AliESDtrack::kTRDout);
370 track.UpdateESDtrack(seed);
374 if ((TMath::Abs(track.GetC(track.GetBz()) - p4) / TMath::Abs(p4) < 0.2) ||(track.Pt() > 0.8)) {
376 // Make backup for back propagation
377 Int_t foundClr = track.GetNumberOfClusters();
378 if (foundClr >= foundMin) {
379 track.CookLabel(1. - fgkLabelFraction);
380 //if(track.GetBackupTrack()) UseClusters(track.GetBackupTrack());
382 // Sign only gold tracks
383 if (track.GetChi2() / track.GetNumberOfClusters() < 4) {
384 //if ((seed->GetKinkIndex(0) == 0) && (track.Pt() < 1.5)) UseClusters(&track);
386 Bool_t isGold = kFALSE;
389 if (track.GetChi2() / track.GetNumberOfClusters() < 5) {
390 if (track.GetBackupTrack()) seed->UpdateTrackParams(track.GetBackupTrack(),AliESDtrack::kTRDbackup);
396 if ((!isGold) && (track.GetNCross() == 0) && (track.GetChi2() / track.GetNumberOfClusters() < 7)) {
397 //seed->UpdateTrackParams(track, AliESDtrack::kTRDbackup);
398 if (track.GetBackupTrack()) seed->UpdateTrackParams(track.GetBackupTrack(),AliESDtrack::kTRDbackup);
403 if ((!isGold) && (track.GetBackupTrack())) {
404 if ((track.GetBackupTrack()->GetNumberOfClusters() > foundMin) && ((track.GetBackupTrack()->GetChi2()/(track.GetBackupTrack()->GetNumberOfClusters()+1)) < 7)) {
405 seed->UpdateTrackParams(track.GetBackupTrack(),AliESDtrack::kTRDbackup);
412 // Propagation to the TOF
413 if(!(seed->GetStatus()&AliESDtrack::kTRDStop)) {
414 Int_t sm = track.GetSector();
415 // default value in case we have problems with the geometry.
416 Double_t xtof = 371.;
417 //Calculate radial position of the beginning of the TOF
418 //mother volume. In order to avoid mixing of the TRD
419 //and TOF modules some hard values are needed. This are:
420 //1. The path to the TOF module.
421 //2. The width of the TOF (29.05 cm)
422 //(with the help of Annalisa de Caro Mar-17-2009)
424 gGeoManager->cd(Form("/ALIC_1/B077_1/BSEGMO%d_1/BTOF%d_1", sm, sm));
425 TGeoHMatrix *m = 0x0;
426 Double_t loc[]={0., 0., -.5*29.05}, glob[3];
428 if((m=gGeoManager->GetCurrentMatrix())){
429 m->LocalToMaster(loc, glob);
430 xtof = TMath::Sqrt(glob[0]*glob[0]+glob[1]*glob[1]);
433 if(xtof > (fgkMaxStep + track.GetX()) && !PropagateToX(track, xtof, fgkMaxStep)){
434 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
437 if(!AdjustSector(&track)){
438 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
441 if(TMath::Abs(track.GetSnp()) > fgkMaxSnp){
442 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
445 seed->UpdateTrackParams(&track, AliESDtrack::kTRDout);
446 // TODO obsolete - delete
447 seed->SetTRDQuality(track.StatusForTOF());
449 seed->SetTRDBudget(track.GetBudget(0));
451 if(index) delete [] index;
452 if(quality) delete [] quality;
454 AliInfo(Form("Number of seeds: TPCout[%d] TRDin[%d]", nTPCseeds, nTRDseeds));
455 AliInfo(Form("Number of tracks: TRDout[%d]", nFound));
457 // run stand alone tracking
458 if (fReconstructor->IsSeeding()) Clusters2Tracks(event);
464 //____________________________________________________________________
465 Int_t AliTRDtrackerV1::RefitInward(AliESDEvent *event)
468 // Refits tracks within the TRD. The ESD event is expected to contain seeds
469 // at the outer part of the TRD.
470 // The tracks are propagated to the innermost time bin
471 // of the TRD and the ESD event is updated
472 // Origin: Thomas KUHR (Thomas.Kuhr@cern.ch)
475 Int_t nseed = 0; // contor for loaded seeds
476 Int_t found = 0; // contor for updated TRD tracks
480 for (Int_t itrack = 0; itrack < event->GetNumberOfTracks(); itrack++) {
481 AliESDtrack *seed = event->GetTrack(itrack);
482 new(&track) AliTRDtrackV1(*seed);
484 if (track.GetX() < 270.0) {
485 seed->UpdateTrackParams(&track, AliESDtrack::kTRDbackup);
489 // reject tracks which failed propagation in the TRD or
490 // are produced by the TRD stand alone tracker
491 ULong_t status = seed->GetStatus();
492 if(!(status & AliESDtrack::kTRDout)) continue;
493 if(!(status & AliESDtrack::kTRDin)) continue;
496 track.ResetCovariance(50.0);
498 // do the propagation and processing
499 Bool_t kUPDATE = kFALSE;
500 Double_t xTPC = 250.0;
501 if(FollowProlongation(track)){
503 if (PropagateToX(track, xTPC, fgkMaxStep)) { // -with update
504 seed->UpdateTrackParams(&track, AliESDtrack::kTRDrefit);
509 // Update the friend track
510 if (fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 0){
511 TObject *o = 0x0; Int_t ic = 0;
512 AliTRDtrackV1 *calibTrack = 0x0;
513 while((o = seed->GetCalibObject(ic++))){
514 if(!(calibTrack = dynamic_cast<AliTRDtrackV1*>(o))) continue;
515 calibTrack->SetTrackHigh(track.GetTrackHigh());
520 // Prolongate to TPC without update
522 AliTRDtrackV1 tt(*seed);
523 if (PropagateToX(tt, xTPC, fgkMaxStep)) seed->UpdateTrackParams(&tt, AliESDtrack::kTRDbackup);
526 AliInfo(Form("Number of loaded seeds: %d",nseed));
527 AliInfo(Form("Number of found tracks from loaded seeds: %d",found));
532 //____________________________________________________________________
533 Int_t AliTRDtrackerV1::FollowProlongation(AliTRDtrackV1 &t)
535 // Extrapolates the TRD track in the TPC direction.
538 // t : the TRD track which has to be extrapolated
541 // number of clusters attached to the track
543 // Detailed description
545 // Starting from current radial position of track <t> this function
546 // extrapolates the track through the 6 TRD layers. The following steps
547 // are being performed for each plane:
549 // a. get plane limits in the local x direction
550 // b. check crossing sectors
551 // c. check track inclination
552 // 2. search tracklet in the tracker list (see GetTracklet() for details)
553 // 3. evaluate material budget using the geo manager
554 // 4. propagate and update track using the tracklet information.
559 Bool_t kStoreIn = kTRUE;
560 Int_t nClustersExpected = 0;
561 for (Int_t iplane = kNPlanes; iplane--;) {
563 AliTRDseedV1 *tracklet = GetTracklet(&t, iplane, index);
564 if(!tracklet) continue;
565 if(!tracklet->IsOK()) AliWarning("tracklet not OK");
567 Double_t x = tracklet->GetX();//GetX0();
568 // reject tracklets which are not considered for inward refit
569 if(x > t.GetX()+fgkMaxStep) continue;
571 // append tracklet to track
572 t.SetTracklet(tracklet, index);
574 if (x < (t.GetX()-fgkMaxStep) && !PropagateToX(t, x+fgkMaxStep, fgkMaxStep)) break;
575 if (!AdjustSector(&t)) break;
577 // Start global position
581 // End global position
582 Double_t alpha = t.GetAlpha(), y, z;
583 if (!t.GetProlongation(x,y,z)) break;
585 xyz1[0] = x * TMath::Cos(alpha) - y * TMath::Sin(alpha);
586 xyz1[1] = x * TMath::Sin(alpha) + y * TMath::Cos(alpha);
589 Double_t length = TMath::Sqrt(
590 (xyz0[0]-xyz1[0])*(xyz0[0]-xyz1[0]) +
591 (xyz0[1]-xyz1[1])*(xyz0[1]-xyz1[1]) +
592 (xyz0[2]-xyz1[2])*(xyz0[2]-xyz1[2])
595 // Get material budget
597 if(AliTracker::MeanMaterialBudget(xyz0, xyz1, param)<=0.) break;
598 Double_t xrho= param[0]*param[4];
599 Double_t xx0 = param[1]; // Get mean propagation parameters
601 // Propagate and update
602 t.PropagateTo(x, xx0, xrho);
603 if (!AdjustSector(&t)) break;
610 Double_t cov[3]; tracklet->GetCovAt(x, cov);
611 Double_t p[2] = { tracklet->GetY(), tracklet->GetZ()};
612 Double_t chi2 = ((AliExternalTrackParam)t).GetPredictedChi2(p, cov);
613 if (chi2 < 1e+10 && t.Update(p, cov, chi2)){
614 nClustersExpected += tracklet->GetN();
618 if(fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 1){
620 for(int iplane=0; iplane<AliTRDgeometry::kNlayer; iplane++){
621 AliTRDseedV1 *tracklet = GetTracklet(&t, iplane, index);
622 if(!tracklet) continue;
623 t.SetTracklet(tracklet, index);
626 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
627 TTreeSRedirector &cstreamer = *fReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
628 AliTRDtrackV1 track(t);
630 cstreamer << "FollowProlongation"
631 << "EventNumber=" << eventNumber
632 << "ncl=" << nClustersExpected
633 << "track.=" << &track
637 return nClustersExpected;
641 //_____________________________________________________________________________
642 Int_t AliTRDtrackerV1::FollowBackProlongation(AliTRDtrackV1 &t)
644 // Extrapolates/Build the TRD track in the TOF direction.
647 // t : the TRD track which has to be extrapolated
650 // number of clusters attached to the track
652 // Starting from current radial position of track <t> this function
653 // extrapolates the track through the 6 TRD layers. The following steps
654 // are being performed for each plane:
655 // 1. Propagate track to the entrance of the next chamber:
656 // - get chamber limits in the radial direction
657 // - check crossing sectors
658 // - check track inclination
659 // - check track prolongation against boundary conditions (see exclusion boundaries on AliTRDgeometry::IsOnBoundary())
660 // 2. Build tracklet (see AliTRDseed::AttachClusters() for details) for this layer if needed. If only
661 // Kalman filter is needed and tracklets are already linked to the track this step is skipped.
662 // 3. Fit tracklet using the information from the Kalman filter.
663 // 4. Propagate and update track at reference radial position of the tracklet.
664 // 5. Register tracklet with the tracker and track; update pulls monitoring.
667 // 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:
668 // - AliTRDtrackV1::kProlongation : track prolongation failed
669 // - AliTRDtrackV1::kPropagation : track prolongation failed
670 // - AliTRDtrackV1::kAdjustSector : failed during sector crossing
671 // - AliTRDtrackV1::kSnp : too large bending
672 // - AliTRDtrackV1::kTrackletInit : fail to initialize tracklet
673 // - AliTRDtrackV1::kUpdate : fail to attach clusters or fit the tracklet
674 // - AliTRDtrackV1::kUnknown : anything which is not covered before
675 // 2. By default the status of the track before first TRD update is saved.
680 // Alexandru Bercuci <A.Bercuci@gsi.de>
684 Double_t driftLength = .5*AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick();
685 AliTRDtrackingChamber *chamber = 0x0;
687 AliTRDseedV1 tracklet, *ptrTracklet = 0x0;
688 // in case of stand alone tracking we store all the pointers to the tracklets in a temporary array
689 AliTRDseedV1 *tracklets[kNPlanes];
690 memset(tracklets, 0, sizeof(AliTRDseedV1 *) * kNPlanes);
691 for(Int_t ip = 0; ip < kNPlanes; ip++){
692 tracklets[ip] = t.GetTracklet(ip);
695 Bool_t kStoreIn = kTRUE, kPropagateIn = kTRUE;
697 // Loop through the TRD layers
698 TGeoHMatrix *matrix = 0x0;
700 for (Int_t ily=0, sm=-1, stk=-1, det=-1; ily < AliTRDgeometry::kNlayer; ily++) {
701 // rough estimate of the entry point
702 if (!t.GetProlongation(fR[ily], y, z)){
704 t.SetStatus(AliTRDtrackV1::kProlongation);
708 // find sector / stack / detector
710 // TODO cross check with y value !
711 stk = fGeom->GetStack(z, ily);
712 det = stk>=0 ? AliTRDgeometry::GetDetector(ily, stk, sm) : -1;
713 matrix = det>=0 ? fGeom->GetClusterMatrix(det) : 0x0;
715 // check if supermodule/chamber is installed
716 if( !fGeom->GetSMstatus(sm) ||
718 fGeom->IsHole(ily, stk, sm) ||
720 // propagate to the default radial position
721 if(fR[ily] > (fgkMaxStep + t.GetX()) && !PropagateToX(t, fR[ily], fgkMaxStep)){
723 t.SetStatus(AliTRDtrackV1::kPropagation);
726 if(!AdjustSector(&t)){
728 t.SetStatus(AliTRDtrackV1::kAdjustSector);
731 if(TMath::Abs(t.GetSnp()) > fgkMaxSnp){
733 t.SetStatus(AliTRDtrackV1::kSnp);
736 t.SetStatus(AliTRDtrackV1::kGeometry, ily);
740 // retrieve rotation matrix for the current chamber
741 Double_t loc[] = {AliTRDgeometry::AnodePos()- driftLength, 0., 0.};
742 Double_t glb[] = {0., 0., 0.};
743 matrix->LocalToMaster(loc, glb);
745 // Propagate to the radial distance of the current layer
746 x = glb[0] - fgkMaxStep;
747 if(x > (fgkMaxStep + t.GetX()) && !PropagateToX(t, x, fgkMaxStep)){
749 t.SetStatus(AliTRDtrackV1::kPropagation);
752 if(!AdjustSector(&t)){
754 t.SetStatus(AliTRDtrackV1::kAdjustSector);
757 if(TMath::Abs(t.GetSnp()) > fgkMaxSnp) {
759 t.SetStatus(AliTRDtrackV1::kSnp);
762 Bool_t RECALCULATE = kFALSE;
763 if(sm != t.GetSector()){
767 if(stk != fGeom->GetStack(z, ily)){
768 stk = fGeom->GetStack(z, ily);
772 det = AliTRDgeometry::GetDetector(ily, stk, sm);
773 if(!(matrix = fGeom->GetClusterMatrix(det))){
774 t.SetStatus(AliTRDtrackV1::kGeometry, ily);
777 matrix->LocalToMaster(loc, glb);
778 x = glb[0] - fgkMaxStep;
781 // check if track is well inside fiducial volume
782 if (!t.GetProlongation(x+fgkMaxStep, y, z)) {
784 t.SetStatus(AliTRDtrackV1::kProlongation);
787 if(fGeom->IsOnBoundary(det, y, z, .5)){
788 t.SetStatus(AliTRDtrackV1::kBoundary, ily);
791 // mark track as entering the FIDUCIAL volume of TRD
797 ptrTracklet = tracklets[ily];
798 if(!ptrTracklet){ // BUILD TRACKLET
799 // check data in supermodule
800 if(!fTrSec[sm].GetNChambers()){
801 t.SetStatus(AliTRDtrackV1::kNoClusters, ily);
804 if(fTrSec[sm].GetX(ily) < 1.){
805 t.SetStatus(AliTRDtrackV1::kNoClusters, ily);
809 // check data in chamber
810 if(!(chamber = fTrSec[sm].GetChamber(stk, ily))){
811 t.SetStatus(AliTRDtrackV1::kNoClusters, ily);
814 if(chamber->GetNClusters() < fgNTimeBins*fReconstructor->GetRecoParam() ->GetFindableClusters()){
815 t.SetStatus(AliTRDtrackV1::kNoClusters, ily);
819 ptrTracklet = new(&tracklet) AliTRDseedV1(det);
820 ptrTracklet->SetReconstructor(fReconstructor);
821 ptrTracklet->SetKink(t.IsKink());
822 ptrTracklet->SetPadPlane(fGeom->GetPadPlane(ily, stk));
823 ptrTracklet->SetX0(glb[0]+driftLength);
824 if(!tracklet.Init(&t)){
826 t.SetStatus(AliTRDtrackV1::kTrackletInit);
829 if(!tracklet.AttachClusters(chamber, kTRUE)){
830 t.SetStatus(AliTRDtrackV1::kNoAttach, ily);
833 if(tracklet.GetN() < fgNTimeBins*fReconstructor->GetRecoParam() ->GetFindableClusters()){
834 t.SetStatus(AliTRDtrackV1::kNoClustersTracklet, ily);
837 ptrTracklet->UpdateUsed();
839 // propagate track to the radial position of the tracklet
840 ptrTracklet->UseClusters(); // TODO ? do we need this here ?
841 // fit tracklet no tilt correction
842 if(!ptrTracklet->Fit(kFALSE)){
843 t.SetStatus(AliTRDtrackV1::kNoFit, ily);
846 x = ptrTracklet->GetX(); //GetX0();
847 if(x > (fgkMaxStep + t.GetX()) && !PropagateToX(t, x, fgkMaxStep)) {
849 t.SetStatus(AliTRDtrackV1::kPropagation);
852 if(!AdjustSector(&t)) {
854 t.SetStatus(AliTRDtrackV1::kAdjustSector);
857 if(TMath::Abs(t.GetSnp()) > fgkMaxSnp) {
859 t.SetStatus(AliTRDtrackV1::kSnp);
864 kPropagateIn = kFALSE;
866 Double_t cov[3]; ptrTracklet->GetCovAt(x, cov);
867 Double_t p[2] = { ptrTracklet->GetY(), ptrTracklet->GetZ()};
868 Double_t chi2 = ((AliExternalTrackParam)t).GetPredictedChi2(p, cov);
869 if(fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 2){
870 Double_t ytrack = ptrTracklet->GetYref(0);
871 Double_t ztrack = ptrTracklet->GetZref(0);
872 Double_t ytracklet = ptrTracklet->GetYfit(0);
873 Double_t ztracklet = ptrTracklet->GetZfit(0);
874 Double_t phitrack = ptrTracklet->GetYref(1);
875 Double_t phitracklet = ptrTracklet->GetYfit(1);
876 Double_t thetatrack = ptrTracklet->GetZref(1);
877 Double_t thetatracklet = ptrTracklet->GetZfit(1);
879 TTreeSRedirector &mystreamer = *fReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
880 mystreamer << "FollowBackProlongation1"
883 << "ytrack=" << ytrack
884 << "ztrack=" << ztrack
885 << "ytracklet=" << ytracklet
886 << "ztracklet=" << ztracklet
887 << "phitrack=" << phitrack
888 << "thetatrack=" << thetatrack
889 << "phitracklet=" << phitracklet
890 << "thetatracklet=" << thetatracklet
894 // update Kalman with the TRD measurement
895 if(chi2>1e+10){ // TODO
896 t.SetStatus(AliTRDtrackV1::kChi2, ily);
899 if(!t.Update(p, cov, chi2)) {
901 t.SetStatus(AliTRDtrackV1::kUpdate);
905 AliTracker::FillResiduals(&t, p, cov, ptrTracklet->GetVolumeId());
908 // load tracklet to the tracker
909 ptrTracklet->Update(&t);
910 ptrTracklet = SetTracklet(ptrTracklet);
911 t.SetTracklet(ptrTracklet, fTracklets->GetEntriesFast()-1);
912 n += ptrTracklet->GetN();
914 // Reset material budget if 2 consecutive gold
915 // if(ilayer>0 && t.GetTracklet(ilayer-1) && ptrTracklet->GetN() + t.GetTracklet(ilayer-1)->GetN() > 20) t.SetBudget(2, 0.);
917 // Make backup of the track until is gold
918 // TO DO update quality check of the track.
919 // consider comparison with fTimeBinsRange
920 Float_t ratio0 = ptrTracklet->GetN() / Float_t(fgNTimeBins);
921 //Float_t ratio1 = Float_t(t.GetNumberOfClusters()+1) / Float_t(t.GetNExpected()+1);
926 //(ratio0+ratio1 > 1.5) &&
927 (t.GetNCross() == 0) &&
928 (TMath::Abs(t.GetSnp()) < 0.85) &&
929 (t.GetNumberOfClusters() > 20)){
933 //printf("clusters[%d] chi2[%f] x[%f] status[%d ", n, t.GetChi2(), t.GetX(), t.GetStatusTRD());
934 //for(int i=0; i<6; i++) printf("%d ", t.GetStatusTRD(i)); printf("]\n");
936 if(fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 1){
937 TTreeSRedirector &cstreamer = *fReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
938 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
939 AliTRDtrackV1 track(t);
941 cstreamer << "FollowBackProlongation"
942 << "EventNumber=" << eventNumber
944 << "track.=" << &track
951 //_________________________________________________________________________
952 Float_t AliTRDtrackerV1::FitRieman(AliTRDseedV1 *tracklets, Double_t *chi2, Int_t *planes){
954 // Fits a Riemann-circle to the given points without tilting pad correction.
955 // The fit is performed using an instance of the class AliRieman (equations
956 // and transformations see documentation of this class)
957 // Afterwards all the tracklets are Updated
959 // Parameters: - Array of tracklets (AliTRDseedV1)
960 // - Storage for the chi2 values (beginning with direction z)
961 // - Seeding configuration
962 // Output: - The curvature
964 AliRieman *fitter = AliTRDtrackerV1::GetRiemanFitter();
966 Int_t allplanes[] = {0, 1, 2, 3, 4, 5};
967 Int_t *ppl = &allplanes[0];
973 for(Int_t il = 0; il < maxLayers; il++){
974 if(!tracklets[ppl[il]].IsOK()) continue;
975 fitter->AddPoint(tracklets[ppl[il]].GetX0(), tracklets[ppl[il]].GetYfit(0), tracklets[ppl[il]].GetZfit(0),1,10);
978 // Set the reference position of the fit and calculate the chi2 values
979 memset(chi2, 0, sizeof(Double_t) * 2);
980 for(Int_t il = 0; il < maxLayers; il++){
981 // Reference positions
982 tracklets[ppl[il]].Init(fitter);
985 if((!tracklets[ppl[il]].IsOK()) && (!planes)) continue;
986 chi2[0] += tracklets[ppl[il]].GetChi2Y();
987 chi2[1] += tracklets[ppl[il]].GetChi2Z();
989 return fitter->GetC();
992 //_________________________________________________________________________
993 void AliTRDtrackerV1::FitRieman(AliTRDcluster **seedcl, Double_t chi2[2])
996 // Performs a Riemann helix fit using the seedclusters as spacepoints
997 // Afterwards the chi2 values are calculated and the seeds are updated
999 // Parameters: - The four seedclusters
1000 // - The tracklet array (AliTRDseedV1)
1001 // - The seeding configuration
1006 AliRieman *fitter = AliTRDtrackerV1::GetRiemanFitter();
1008 for(Int_t i = 0; i < 4; i++){
1009 fitter->AddPoint(seedcl[i]->GetX(), seedcl[i]->GetY(), seedcl[i]->GetZ(), 1., 10.);
1014 // Update the seed and calculated the chi2 value
1015 chi2[0] = 0; chi2[1] = 0;
1016 for(Int_t ipl = 0; ipl < kNSeedPlanes; ipl++){
1018 chi2[0] += (seedcl[ipl]->GetZ() - fitter->GetZat(seedcl[ipl]->GetX())) * (seedcl[ipl]->GetZ() - fitter->GetZat(seedcl[ipl]->GetX()));
1019 chi2[1] += (seedcl[ipl]->GetY() - fitter->GetYat(seedcl[ipl]->GetX())) * (seedcl[ipl]->GetY() - fitter->GetYat(seedcl[ipl]->GetX()));
1024 //_________________________________________________________________________
1025 Float_t AliTRDtrackerV1::FitTiltedRiemanConstraint(AliTRDseedV1 *tracklets, Double_t zVertex)
1028 // Fits a helix to the clusters. Pad tilting is considered. As constraint it is
1029 // assumed that the vertex position is set to 0.
1030 // This method is very usefull for high-pt particles
1031 // Basis for the fit: (x - x0)^2 + (y - y0)^2 - R^2 = 0
1032 // x0, y0: Center of the circle
1033 // Measured y-position: ymeas = y - tan(phiT)(zc - zt)
1034 // zc: center of the pad row
1035 // Equation which has to be fitted (after transformation):
1036 // a + b * u + e * v + 2*(ymeas + tan(phiT)(z - zVertex))*t = 0
1038 // t = 1/(x^2 + y^2)
1040 // v = 2 * x * tan(phiT) * t
1041 // Parameters in the equation:
1042 // a = -1/y0, b = x0/y0, e = dz/dx
1044 // The Curvature is calculated by the following equation:
1045 // - curv = a/Sqrt(b^2 + 1) = 1/R
1046 // Parameters: - the 6 tracklets
1047 // - the Vertex constraint
1048 // Output: - the Chi2 value of the track
1053 TLinearFitter *fitter = GetTiltedRiemanFitterConstraint();
1054 fitter->StoreData(kTRUE);
1055 fitter->ClearPoints();
1056 AliTRDcluster *cl = 0x0;
1058 Float_t x, y, z, w, t, error, tilt;
1061 for(Int_t ilr = 0; ilr < AliTRDgeometry::kNlayer; ilr++){
1062 if(!tracklets[ilr].IsOK()) continue;
1063 for(Int_t itb = 0; itb < AliTRDseedV1::kNclusters; itb++){
1064 if(!tracklets[ilr].IsUsable(itb)) continue;
1065 cl = tracklets[ilr].GetClusters(itb);
1066 if(!cl->IsInChamber()) continue;
1070 tilt = tracklets[ilr].GetTilt();
1072 t = 1./(x * x + y * y);
1073 uvt[0] = 2. * x * t;
1074 uvt[1] = 2. * x * t * tilt ;
1075 w = 2. * (y + tilt * (z - zVertex)) * t;
1076 error = 2. * TMath::Sqrt(cl->GetSigmaY2()+tilt*tilt*cl->GetSigmaZ2()) * t;
1077 fitter->AddPoint(uvt, w, error);
1083 // Calculate curvature
1084 Double_t a = fitter->GetParameter(0);
1085 Double_t b = fitter->GetParameter(1);
1086 Double_t curvature = a/TMath::Sqrt(b*b + 1);
1088 Float_t chi2track = fitter->GetChisquare()/Double_t(nPoints);
1089 for(Int_t ip = 0; ip < AliTRDtrackerV1::kNPlanes; ip++)
1090 tracklets[ip].SetC(curvature);
1092 /* if(fReconstructor->GetStreamLevel() >= 5){
1093 //Linear Model on z-direction
1094 Double_t xref = CalculateReferenceX(tracklets); // Relative to the middle of the stack
1095 Double_t slope = fitter->GetParameter(2);
1096 Double_t zref = slope * xref;
1097 Float_t chi2Z = CalculateChi2Z(tracklets, zref, slope, xref);
1098 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
1099 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
1100 TTreeSRedirector &treeStreamer = *fReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
1101 treeStreamer << "FitTiltedRiemanConstraint"
1102 << "EventNumber=" << eventNumber
1103 << "CandidateNumber=" << candidateNumber
1104 << "Curvature=" << curvature
1105 << "Chi2Track=" << chi2track
1106 << "Chi2Z=" << chi2Z
1113 //_________________________________________________________________________
1114 Float_t AliTRDtrackerV1::FitTiltedRieman(AliTRDseedV1 *tracklets, Bool_t sigError)
1117 // Performs a Riemann fit taking tilting pad correction into account
1118 // The equation of a Riemann circle, where the y position is substituted by the
1119 // measured y-position taking pad tilting into account, has to be transformed
1120 // into a 4-dimensional hyperplane equation
1121 // Riemann circle: (x-x0)^2 + (y-y0)^2 -R^2 = 0
1122 // Measured y-Position: ymeas = y - tan(phiT)(zc - zt)
1123 // zc: center of the pad row
1124 // zt: z-position of the track
1125 // The z-position of the track is assumed to be linear dependent on the x-position
1126 // Transformed equation: a + b * u + c * t + d * v + e * w - 2 * (ymeas + tan(phiT) * zc) * t = 0
1127 // Transformation: u = 2 * x * t
1128 // v = 2 * tan(phiT) * t
1129 // w = 2 * tan(phiT) * (x - xref) * t
1130 // t = 1 / (x^2 + ymeas^2)
1131 // Parameters: a = -1/y0
1133 // c = (R^2 -x0^2 - y0^2)/y0
1136 // If the offset respectively the slope in z-position is impossible, the parameters are fixed using
1137 // results from the simple riemann fit. Afterwards the fit is redone.
1138 // The curvature is calculated according to the formula:
1139 // curv = a/(1 + b^2 + c*a) = 1/R
1141 // Paramters: - Array of tracklets (connected to the track candidate)
1142 // - Flag selecting the error definition
1143 // Output: - Chi2 values of the track (in Parameter list)
1145 TLinearFitter *fitter = GetTiltedRiemanFitter();
1146 fitter->StoreData(kTRUE);
1147 fitter->ClearPoints();
1148 AliTRDLeastSquare zfitter;
1149 AliTRDcluster *cl = 0x0;
1151 Double_t xref = CalculateReferenceX(tracklets);
1152 Double_t x, y, z, t, tilt, dx, w, we, erry, errz;
1153 Double_t uvt[4], sumPolY[5], sumPolZ[3];
1154 memset(sumPolY, 0, sizeof(Double_t) * 5);
1155 memset(sumPolZ, 0, sizeof(Double_t) * 3);
1157 // Containers for Least-square fitter
1158 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1159 if(!tracklets[ipl].IsOK()) continue;
1160 tilt = tracklets[ipl].GetTilt();
1161 for(Int_t itb = 0; itb < AliTRDseedV1::kNclusters; itb++){
1162 if(!(cl = tracklets[ipl].GetClusters(itb))) continue;
1163 if(!cl->IsInChamber()) continue;
1164 if (!tracklets[ipl].IsUsable(itb)) continue;
1171 uvt[0] = 2. * x * t;
1173 uvt[2] = 2. * tilt * t;
1174 uvt[3] = 2. * tilt * dx * t;
1175 w = 2. * (y + tilt*z) * t;
1176 // error definition changes for the different calls
1178 we *= sigError ? TMath::Sqrt(cl->GetSigmaY2()+tilt*tilt*cl->GetSigmaZ2()) : 0.2;
1179 fitter->AddPoint(uvt, w, we);
1180 zfitter.AddPoint(&x, z, static_cast<Double_t>(TMath::Sqrt(cl->GetSigmaZ2())));
1181 // adding points for covariance matrix estimation
1182 erry = 1./(TMath::Sqrt(cl->GetSigmaY2()) + 0.1); // 0.1 is a systematic error (due to misalignment and miscalibration)
1184 errz = 1./cl->GetSigmaZ2();
1185 for(Int_t ipol = 0; ipol < 5; ipol++){
1186 sumPolY[ipol] += erry;
1189 sumPolZ[ipol] += errz;
1199 Double_t offset = fitter->GetParameter(3);
1200 Double_t slope = fitter->GetParameter(4);
1202 // Linear fitter - not possible to make boundaries
1203 // Do not accept non possible z and dzdx combinations
1204 Bool_t acceptablez = kTRUE;
1205 Double_t zref = 0.0;
1206 for (Int_t iLayer = 0; iLayer < kNPlanes; iLayer++) {
1207 if(!tracklets[iLayer].IsOK()) continue;
1208 zref = offset + slope * (tracklets[iLayer].GetX0() - xref);
1209 if (TMath::Abs(tracklets[iLayer].GetZfit(0) - zref) > tracklets[iLayer].GetPadLength() * 0.5 + 1.0)
1210 acceptablez = kFALSE;
1213 Double_t dzmf = zfitter.GetFunctionParameter(1);
1214 Double_t zmf = zfitter.GetFunctionValue(&xref);
1215 fgTiltedRieman->FixParameter(3, zmf);
1216 fgTiltedRieman->FixParameter(4, dzmf);
1218 fitter->ReleaseParameter(3);
1219 fitter->ReleaseParameter(4);
1220 offset = fitter->GetParameter(3);
1221 slope = fitter->GetParameter(4);
1224 // Calculate Curvarture
1225 Double_t a = fitter->GetParameter(0);
1226 Double_t b = fitter->GetParameter(1);
1227 Double_t c = fitter->GetParameter(2);
1228 Double_t curvature = 1.0 + b*b - c*a;
1229 if (curvature > 0.0)
1230 curvature = a / TMath::Sqrt(curvature);
1232 Double_t chi2track = fitter->GetChisquare()/Double_t(nPoints);
1234 // Prepare error calculation
1235 TMatrixD covarPolY(3,3);
1236 covarPolY(0,0) = sumPolY[0]; covarPolY(1,1) = sumPolY[2]; covarPolY(2,2) = sumPolY[4];
1237 covarPolY(0,1) = covarPolY(1,0) = sumPolY[1];
1238 covarPolY(0,2) = covarPolY(2,0) = sumPolY[2];
1239 covarPolY(2,1) = covarPolY(1,2) = sumPolY[3];
1241 TMatrixD covarPolZ(2,2);
1242 covarPolZ(0,0) = sumPolZ[0]; covarPolZ(1,1) = sumPolZ[2];
1243 covarPolZ(1,0) = covarPolZ(0,1) = sumPolZ[1];
1246 // Update the tracklets
1247 Double_t x1, dy, dz;
1249 memset(cov, 0, sizeof(Double_t) * 15);
1250 for(Int_t iLayer = 0; iLayer < AliTRDtrackerV1::kNPlanes; iLayer++) {
1252 x = tracklets[iLayer].GetX0();
1258 memset(cov, 0, sizeof(Double_t) * 3);
1259 TMatrixD transform(3,3);
1262 transform(0,2) = x*x;
1266 TMatrixD covariance(transform, TMatrixD::kMult, covarPolY);
1267 covariance *= transform.T();
1268 TMatrixD transformZ(2,2);
1269 transformZ(0,0) = transformZ(1,1) = 1;
1270 transformZ(0,1) = x;
1271 TMatrixD covarZ(transformZ, TMatrixD::kMult, covarPolZ);
1272 covarZ *= transformZ.T();
1273 // y: R^2 = (x - x0)^2 + (y - y0)^2
1274 // => y = y0 +/- Sqrt(R^2 - (x - x0)^2)
1275 // R = Sqrt() = 1/Curvature
1276 // => y = y0 +/- Sqrt(1/Curvature^2 - (x - x0)^2)
1277 Double_t res = (x * a + b); // = (x - x0)/y0
1279 res = 1.0 - c * a + b * b - res; // = (R^2 - (x - x0)^2)/y0^2
1281 res = TMath::Sqrt(res);
1282 y = (1.0 - res) / a;
1284 cov[0] = covariance(0,0);
1285 cov[2] = covarZ(0,0);
1288 // dy: R^2 = (x - x0)^2 + (y - y0)^2
1289 // => y = +/- Sqrt(R^2 - (x - x0)^2) + y0
1290 // => dy/dx = (x - x0)/Sqrt(R^2 - (x - x0)^2)
1291 // Curvature: cr = 1/R = a/Sqrt(1 + b^2 - c*a)
1292 // => dy/dx = (x - x0)/(1/(cr^2) - (x - x0)^2)
1293 Double_t x0 = -b / a;
1294 if (-c * a + b * b + 1 > 0) {
1295 if (1.0/(curvature * curvature) - (x - x0) * (x - x0) > 0.0) {
1296 Double_t yderiv = (x - x0) / TMath::Sqrt(1.0/(curvature * curvature) - (x - x0) * (x - x0));
1297 if (a < 0) yderiv *= -1.0;
1301 z = offset + slope * (x - xref);
1303 tracklets[iLayer].SetYref(0, y);
1304 tracklets[iLayer].SetYref(1, dy);
1305 tracklets[iLayer].SetZref(0, z);
1306 tracklets[iLayer].SetZref(1, dz);
1307 tracklets[iLayer].SetC(curvature);
1308 tracklets[iLayer].SetCovRef(cov);
1309 tracklets[iLayer].SetChi2(chi2track);
1312 /* if(fReconstructor->GetStreamLevel() >=5){
1313 TTreeSRedirector &cstreamer = *fReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
1314 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
1315 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
1316 Double_t chi2z = CalculateChi2Z(tracklets, offset, slope, xref);
1317 cstreamer << "FitTiltedRieman0"
1318 << "EventNumber=" << eventNumber
1319 << "CandidateNumber=" << candidateNumber
1321 << "Chi2Z=" << chi2z
1328 //____________________________________________________________________
1329 Double_t AliTRDtrackerV1::FitLine(const AliTRDtrackV1 *track, AliTRDseedV1 *tracklets, Bool_t err, Int_t np, AliTrackPoint *points)
1331 AliTRDLeastSquare yfitter, zfitter;
1332 AliTRDcluster *cl = 0x0;
1334 AliTRDseedV1 work[kNPlanes], *tracklet = 0x0;
1336 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1337 if(!(tracklet = track->GetTracklet(ipl))) continue;
1338 if(!tracklet->IsOK()) continue;
1339 new(&work[ipl]) AliTRDseedV1(*tracklet);
1341 tracklets = &work[0];
1344 Double_t xref = CalculateReferenceX(tracklets);
1345 Double_t x, y, z, dx, ye, yr, tilt;
1346 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1347 if(!tracklets[ipl].IsOK()) continue;
1348 for(Int_t itb = 0; itb < fgNTimeBins; itb++){
1349 if(!(cl = tracklets[ipl].GetClusters(itb))) continue;
1350 if (!tracklets[ipl].IsUsable(itb)) continue;
1354 zfitter.AddPoint(&dx, z, static_cast<Double_t>(TMath::Sqrt(cl->GetSigmaZ2())));
1358 Double_t z0 = zfitter.GetFunctionParameter(0);
1359 Double_t dzdx = zfitter.GetFunctionParameter(1);
1360 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1361 if(!tracklets[ipl].IsOK()) continue;
1362 for(Int_t itb = 0; itb < fgNTimeBins; itb++){
1363 if(!(cl = tracklets[ipl].GetClusters(itb))) continue;
1364 if (!tracklets[ipl].IsUsable(itb)) continue;
1368 tilt = tracklets[ipl].GetTilt();
1370 yr = y + tilt*(z - z0 - dzdx*dx);
1371 // error definition changes for the different calls
1372 ye = tilt*TMath::Sqrt(cl->GetSigmaZ2());
1373 ye += err ? tracklets[ipl].GetSigmaY() : 0.2;
1374 yfitter.AddPoint(&dx, yr, ye);
1378 Double_t y0 = yfitter.GetFunctionParameter(0);
1379 Double_t dydx = yfitter.GetFunctionParameter(1);
1380 Double_t chi2 = 0.;//yfitter.GetChisquare()/Double_t(nPoints);
1382 //update track points array
1385 for(int ip=0; ip<np; ip++){
1386 points[ip].GetXYZ(xyz);
1387 xyz[1] = y0 + dydx * (xyz[0] - xref);
1388 xyz[2] = z0 + dzdx * (xyz[0] - xref);
1389 points[ip].SetXYZ(xyz);
1396 //_________________________________________________________________________
1397 Double_t AliTRDtrackerV1::FitRiemanTilt(const AliTRDtrackV1 *track, AliTRDseedV1 *tracklets, Bool_t sigError, Int_t np, AliTrackPoint *points)
1400 // Performs a Riemann fit taking tilting pad correction into account
1402 // Paramters: - Array of tracklets (connected to the track candidate)
1403 // - Flag selecting the error definition
1404 // Output: - Chi2 values of the track (in Parameter list)
1406 // The equations which has to be solved simultaneously are:
1408 // R^{2} = (x-x_{0})^{2} + (y^{*}-y_{0})^{2}
1409 // y^{*} = y - tg(h)(z - z_{t})
1410 // z_{t} = z_{0}+dzdx*(x-x_{r})
1412 // with (x, y, z) the coordinate of the cluster, (x_0, y_0, z_0) the coordinate of the center of the Riemann circle,
1413 // R its radius, x_r a constant refrence radial position in the middle of the TRD stack and dzdx the slope of the
1414 // track in the x-z plane. Using the following transformations
1416 // t = 1 / (x^{2} + y^{2})
1418 // v = 2 * tan(h) * t
1419 // w = 2 * tan(h) * (x - x_{r}) * t
1421 // One gets the following linear equation
1423 // a + b * u + c * t + d * v + e * w = 2 * (y + tg(h) * z) * t
1425 // where the coefficients have the following meaning
1429 // c = (R^{2} -x_{0}^{2} - y_{0}^{2})/y_{0}
1433 // The error calculation for the free term is thus
1435 // #sigma = 2 * #sqrt{#sigma^{2}_{y} + (tilt corr ...) + tg^{2}(h) * #sigma^{2}_{z}} * t
1438 // From this simple model one can compute chi^2 estimates and a rough approximation of pt from the curvature according
1441 // C = 1/R = a/(1 + b^{2} + c*a)
1445 // M.Ivanov <M.Ivanov@gsi.de>
1446 // A.Bercuci <A.Bercuci@gsi.de>
1447 // M.Fasel <M.Fasel@gsi.de>
1449 TLinearFitter *fitter = GetTiltedRiemanFitter();
1450 fitter->StoreData(kTRUE);
1451 fitter->ClearPoints();
1452 AliTRDLeastSquare zfitter;
1453 AliTRDcluster *cl = 0x0;
1455 AliTRDseedV1 work[kNPlanes], *tracklet = 0x0;
1457 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1458 if(!(tracklet = track->GetTracklet(ipl))) continue;
1459 if(!tracklet->IsOK()) continue;
1460 new(&work[ipl]) AliTRDseedV1(*tracklet);
1462 tracklets = &work[0];
1465 Double_t xref = CalculateReferenceX(tracklets);
1466 Double_t x, y, z, t, tilt, dx, w, we;
1469 // Containers for Least-square fitter
1470 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1471 if(!tracklets[ipl].IsOK()) continue;
1472 for(Int_t itb = 0; itb < AliTRDseedV1::kNclusters; itb++){
1473 if(!(cl = tracklets[ipl].GetClusters(itb))) continue;
1474 if (!tracklets[ipl].IsUsable(itb)) continue;
1478 tilt = tracklets[ipl].GetTilt();
1482 uvt[0] = 2. * x * t;
1484 uvt[2] = 2. * tilt * t;
1485 uvt[3] = 2. * tilt * dx * t;
1486 w = 2. * (y + tilt*z) * t;
1487 // error definition changes for the different calls
1489 we *= sigError ? TMath::Sqrt(cl->GetSigmaY2()) : 0.2;
1490 fitter->AddPoint(uvt, w, we);
1491 zfitter.AddPoint(&x, z, static_cast<Double_t>(TMath::Sqrt(cl->GetSigmaZ2())));
1495 if(fitter->Eval()) return 1.E10;
1497 Double_t z0 = fitter->GetParameter(3);
1498 Double_t dzdx = fitter->GetParameter(4);
1501 // Linear fitter - not possible to make boundaries
1502 // Do not accept non possible z and dzdx combinations
1503 Bool_t accept = kTRUE;
1504 Double_t zref = 0.0;
1505 for (Int_t iLayer = 0; iLayer < kNPlanes; iLayer++) {
1506 if(!tracklets[iLayer].IsOK()) continue;
1507 zref = z0 + dzdx * (tracklets[iLayer].GetX0() - xref);
1508 if (TMath::Abs(tracklets[iLayer].GetZfit(0) - zref) > tracklets[iLayer].GetPadLength() * 0.5 + 1.0)
1513 Double_t dzmf = zfitter.GetFunctionParameter(1);
1514 Double_t zmf = zfitter.GetFunctionValue(&xref);
1515 fitter->FixParameter(3, zmf);
1516 fitter->FixParameter(4, dzmf);
1518 fitter->ReleaseParameter(3);
1519 fitter->ReleaseParameter(4);
1520 z0 = fitter->GetParameter(3); // = zmf ?
1521 dzdx = fitter->GetParameter(4); // = dzmf ?
1524 // Calculate Curvature
1525 Double_t a = fitter->GetParameter(0);
1526 Double_t b = fitter->GetParameter(1);
1527 Double_t c = fitter->GetParameter(2);
1528 Double_t y0 = 1. / a;
1529 Double_t x0 = -b * y0;
1530 Double_t tmp = y0*y0 + x0*x0 - c*y0;
1531 if(tmp<=0.) return 1.E10;
1532 Double_t R = TMath::Sqrt(tmp);
1533 Double_t C = 1.0 + b*b - c*a;
1534 if (C > 0.0) C = a / TMath::Sqrt(C);
1536 // Calculate chi2 of the fit
1537 Double_t chi2 = fitter->GetChisquare()/Double_t(nPoints);
1539 // Update the tracklets
1541 for(Int_t ip = 0; ip < kNPlanes; ip++) {
1542 x = tracklets[ip].GetX0();
1543 tmp = R*R-(x-x0)*(x-x0);
1544 if(tmp <= 0.) continue;
1545 tmp = TMath::Sqrt(tmp);
1547 // y: R^2 = (x - x0)^2 + (y - y0)^2
1548 // => y = y0 +/- Sqrt(R^2 - (x - x0)^2)
1549 tracklets[ip].SetYref(0, y0 - (y0>0.?1.:-1)*tmp);
1550 // => dy/dx = (x - x0)/Sqrt(R^2 - (x - x0)^2)
1551 tracklets[ip].SetYref(1, (x - x0) / tmp);
1552 tracklets[ip].SetZref(0, z0 + dzdx * (x - xref));
1553 tracklets[ip].SetZref(1, dzdx);
1554 tracklets[ip].SetC(C);
1555 tracklets[ip].SetChi2(chi2);
1558 //update track points array
1561 for(int ip=0; ip<np; ip++){
1562 points[ip].GetXYZ(xyz);
1563 xyz[1] = TMath::Abs(xyz[0] - x0) > R ? 100. : y0 - (y0>0.?1.:-1.)*TMath::Sqrt((R-(xyz[0]-x0))*(R+(xyz[0]-x0)));
1564 xyz[2] = z0 + dzdx * (xyz[0] - xref);
1565 points[ip].SetXYZ(xyz);
1573 //____________________________________________________________________
1574 Double_t AliTRDtrackerV1::FitKalman(AliTRDtrackV1 *track, AliTRDseedV1 *tracklets, Bool_t up, Int_t np, AliTrackPoint *points)
1576 // Kalman filter implementation for the TRD.
1577 // It returns the positions of the fit in the array "points"
1579 // Author : A.Bercuci@gsi.de
1581 // printf("Start track @ x[%f]\n", track->GetX());
1583 //prepare marker points along the track
1584 Int_t ip = np ? 0 : 1;
1586 if((up?-1:1) * (track->GetX() - points[ip].GetX()) > 0.) break;
1587 //printf("AliTRDtrackerV1::FitKalman() : Skip track marker x[%d] = %7.3f. Before track start ( %7.3f ).\n", ip, points[ip].GetX(), track->GetX());
1590 //if(points) printf("First marker point @ x[%d] = %f\n", ip, points[ip].GetX());
1593 AliTRDseedV1 tracklet, *ptrTracklet = 0x0;
1595 //Loop through the TRD planes
1596 for (Int_t jplane = 0; jplane < kNPlanes; jplane++) {
1597 // GET TRACKLET OR BUILT IT
1598 Int_t iplane = up ? jplane : kNPlanes - 1 - jplane;
1600 if(!(ptrTracklet = &tracklets[iplane])) continue;
1602 if(!(ptrTracklet = track->GetTracklet(iplane))){
1603 /*AliTRDtrackerV1 *tracker = 0x0;
1604 if(!(tracker = dynamic_cast<AliTRDtrackerV1*>( AliTRDReconstructor::Tracker()))) continue;
1605 ptrTracklet = new(&tracklet) AliTRDseedV1(iplane);
1606 if(!tracker->MakeTracklet(ptrTracklet, track)) */
1610 if(!ptrTracklet->IsOK()) continue;
1612 Double_t x = ptrTracklet->GetX0();
1615 //don't do anything if next marker is after next update point.
1616 if((up?-1:1) * (points[ip].GetX() - x) - fgkMaxStep < 0) break;
1617 if(((up?-1:1) * (points[ip].GetX() - track->GetX()) < 0) && !PropagateToX(*track, points[ip].GetX(), fgkMaxStep)) return -1.;
1619 Double_t xyz[3]; // should also get the covariance
1621 track->Global2LocalPosition(xyz, track->GetAlpha());
1622 points[ip].SetXYZ(xyz[0], xyz[1], xyz[2]);
1625 // printf("plane[%d] tracklet[%p] x[%f]\n", iplane, ptrTracklet, x);
1627 // Propagate closer to the next update point
1628 if(((up?-1:1) * (x - track->GetX()) + fgkMaxStep < 0) && !PropagateToX(*track, x + (up?-1:1)*fgkMaxStep, fgkMaxStep)) return -1.;
1630 if(!AdjustSector(track)) return -1;
1631 if(TMath::Abs(track->GetSnp()) > fgkMaxSnp) return -1;
1633 //load tracklet to the tracker and the track
1635 if((index = FindTracklet(ptrTracklet)) < 0){
1636 ptrTracklet = SetTracklet(&tracklet);
1637 index = fTracklets->GetEntriesFast()-1;
1639 track->SetTracklet(ptrTracklet, index);*/
1642 // register tracklet to track with tracklet creation !!
1643 // PropagateBack : loaded tracklet to the tracker and update index
1644 // RefitInward : update index
1645 // MakeTrack : loaded tracklet to the tracker and update index
1646 if(!tracklets) track->SetTracklet(ptrTracklet, -1);
1649 //Calculate the mean material budget along the path inside the chamber
1650 Double_t xyz0[3]; track->GetXYZ(xyz0);
1651 Double_t alpha = track->GetAlpha();
1652 Double_t xyz1[3], y, z;
1653 if(!track->GetProlongation(x, y, z)) return -1;
1654 xyz1[0] = x * TMath::Cos(alpha) - y * TMath::Sin(alpha);
1655 xyz1[1] = +x * TMath::Sin(alpha) + y * TMath::Cos(alpha);
1657 if((xyz0[0] - xyz1[9] < 1e-3) && (xyz0[0] - xyz1[9] < 1e-3)) continue; // check wheter we are at the same global x position
1659 if(AliTracker::MeanMaterialBudget(xyz0, xyz1, param) <=0.) break;
1660 Double_t xrho = param[0]*param[4]; // density*length
1661 Double_t xx0 = param[1]; // radiation length
1663 //Propagate the track
1664 track->PropagateTo(x, xx0, xrho);
1665 if (!AdjustSector(track)) break;
1668 Double_t cov[3]; ptrTracklet->GetCovAt(x, cov);
1669 Double_t p[2] = { ptrTracklet->GetY(), ptrTracklet->GetZ()};
1670 Double_t chi2 = ((AliExternalTrackParam*)track)->GetPredictedChi2(p, cov);
1671 if(chi2<1e+10) track->Update(p, cov, chi2);
1674 //Reset material budget if 2 consecutive gold
1675 if(iplane>0 && track->GetTracklet(iplane-1) && ptrTracklet->GetN() + track->GetTracklet(iplane-1)->GetN() > 20) track->SetBudget(2, 0.);
1676 } // end planes loop
1680 if(((up?-1:1) * (points[ip].GetX() - track->GetX()) < 0) && !PropagateToX(*track, points[ip].GetX(), fgkMaxStep)) return -1.;
1682 Double_t xyz[3]; // should also get the covariance
1684 track->Global2LocalPosition(xyz, track->GetAlpha());
1685 points[ip].SetXYZ(xyz[0], xyz[1], xyz[2]);
1689 return track->GetChi2();
1692 //_________________________________________________________________________
1693 Float_t AliTRDtrackerV1::CalculateChi2Z(AliTRDseedV1 *tracklets, Double_t offset, Double_t slope, Double_t xref)
1696 // Calculates the chi2-value of the track in z-Direction including tilting pad correction.
1697 // A linear dependence on the x-value serves as a model.
1698 // The parameters are related to the tilted Riemann fit.
1699 // Parameters: - Array of tracklets (AliTRDseedV1) related to the track candidate
1700 // - the offset for the reference x
1702 // - the reference x position
1703 // Output: - The Chi2 value of the track in z-Direction
1705 Float_t chi2Z = 0, nLayers = 0;
1706 for (Int_t iLayer = 0; iLayer < AliTRDgeometry::kNlayer; iLayer++) {
1707 if(!tracklets[iLayer].IsOK()) continue;
1708 Double_t z = offset + slope * (tracklets[iLayer].GetX0() - xref);
1709 chi2Z += TMath::Abs(tracklets[iLayer].GetZfit(0) - z);
1712 chi2Z /= TMath::Max((nLayers - 3.0),1.0);
1716 //_____________________________________________________________________________
1717 Int_t AliTRDtrackerV1::PropagateToX(AliTRDtrackV1 &t, Double_t xToGo, Double_t maxStep)
1720 // Starting from current X-position of track <t> this function
1721 // extrapolates the track up to radial position <xToGo>.
1722 // Returns 1 if track reaches the plane, and 0 otherwise
1725 const Double_t kEpsilon = 0.00001;
1727 // Current track X-position
1728 Double_t xpos = t.GetX();
1730 // Direction: inward or outward
1731 Double_t dir = (xpos < xToGo) ? 1.0 : -1.0;
1733 while (((xToGo - xpos) * dir) > kEpsilon) {
1742 // The next step size
1743 Double_t step = dir * TMath::Min(TMath::Abs(xToGo-xpos),maxStep);
1745 // Get the global position of the starting point
1748 // X-position after next step
1751 // Get local Y and Z at the X-position of the next step
1752 if(t.GetProlongation(x,y,z)<0) return 0; // No prolongation possible
1754 // The global position of the end point of this prolongation step
1755 xyz1[0] = x * TMath::Cos(t.GetAlpha()) - y * TMath::Sin(t.GetAlpha());
1756 xyz1[1] = +x * TMath::Sin(t.GetAlpha()) + y * TMath::Cos(t.GetAlpha());
1759 // Calculate the mean material budget between start and
1760 // end point of this prolongation step
1761 if(AliTracker::MeanMaterialBudget(xyz0, xyz1, param)<=0.) return 0;
1763 // Propagate the track to the X-position after the next step
1764 if (!t.PropagateTo(x, param[1], param[0]*param[4])) return 0;
1766 // Rotate the track if necessary
1769 // New track X-position
1779 //_____________________________________________________________________________
1780 Int_t AliTRDtrackerV1::ReadClusters(TClonesArray* &array, TTree *clusterTree) const
1783 // Reads AliTRDclusters from the file.
1784 // The names of the cluster tree and branches
1785 // should match the ones used in AliTRDclusterizer::WriteClusters()
1788 Int_t nsize = Int_t(clusterTree->GetTotBytes() / (sizeof(AliTRDcluster)));
1789 TObjArray *clusterArray = new TObjArray(nsize+1000);
1791 TBranch *branch = clusterTree->GetBranch("TRDcluster");
1793 AliError("Can't get the branch !");
1796 branch->SetAddress(&clusterArray);
1799 Float_t nclusters = fReconstructor->GetRecoParam()->GetNClusters();
1800 if(fReconstructor->IsHLT()) nclusters /= AliTRDgeometry::kNsector;
1801 array = new TClonesArray("AliTRDcluster", Int_t(nclusters));
1802 array->SetOwner(kTRUE);
1805 // Loop through all entries in the tree
1806 Int_t nEntries = (Int_t) clusterTree->GetEntries();
1809 AliTRDcluster *c = 0x0;
1810 for (Int_t iEntry = 0; iEntry < nEntries; iEntry++) {
1812 nbytes += clusterTree->GetEvent(iEntry);
1814 // Get the number of points in the detector
1815 Int_t nCluster = clusterArray->GetEntriesFast();
1816 for (Int_t iCluster = 0; iCluster < nCluster; iCluster++) {
1817 if(!(c = (AliTRDcluster *) clusterArray->UncheckedAt(iCluster))) continue;
1818 new((*fClusters)[ncl++]) AliTRDcluster(*c);
1819 delete (clusterArray->RemoveAt(iCluster));
1823 delete clusterArray;
1828 //_____________________________________________________________________________
1829 Int_t AliTRDtrackerV1::LoadClusters(TTree *cTree)
1832 // Fills clusters into TRD tracking sectors
1835 if(!fReconstructor->IsWritingClusters()){
1836 fClusters = AliTRDReconstructor::GetClusters();
1838 if (ReadClusters(fClusters, cTree)) {
1839 AliError("Problem with reading the clusters !");
1845 if(!fClusters || !fClusters->GetEntriesFast()){
1846 AliInfo("No TRD clusters");
1851 BuildTrackingContainers();
1853 //Int_t ncl = fClusters->GetEntriesFast();
1854 //AliInfo(Form("Clusters %d [%6.2f %% in the active volume]", ncl, 100.*float(nin)/ncl));
1859 //_____________________________________________________________________________
1860 Int_t AliTRDtrackerV1::LoadClusters(TClonesArray *clusters)
1863 // Fills clusters into TRD tracking sectors
1864 // Function for use in the HLT
1866 if(!clusters || !clusters->GetEntriesFast()){
1867 AliInfo("No TRD clusters");
1871 fClusters = clusters;
1875 BuildTrackingContainers();
1877 //Int_t ncl = fClusters->GetEntriesFast();
1878 //AliInfo(Form("Clusters %d [%6.2f %% in the active volume]", ncl, 100.*float(nin)/ncl));
1884 //____________________________________________________________________
1885 Int_t AliTRDtrackerV1::BuildTrackingContainers()
1887 // Building tracking containers for clusters
1889 Int_t nin =0, icl = fClusters->GetEntriesFast();
1891 AliTRDcluster *c = (AliTRDcluster *) fClusters->UncheckedAt(icl);
1892 if(c->IsInChamber()) nin++;
1893 Int_t detector = c->GetDetector();
1894 Int_t sector = fGeom->GetSector(detector);
1895 Int_t stack = fGeom->GetStack(detector);
1896 Int_t layer = fGeom->GetLayer(detector);
1898 fTrSec[sector].GetChamber(stack, layer, kTRUE)->InsertCluster(c, icl);
1901 const AliTRDCalDet *cal = AliTRDcalibDB::Instance()->GetT0Det();
1902 for(int isector =0; isector<AliTRDgeometry::kNsector; isector++){
1903 if(!fTrSec[isector].GetNChambers()) continue;
1904 fTrSec[isector].Init(fReconstructor, cal);
1912 //____________________________________________________________________
1913 void AliTRDtrackerV1::UnloadClusters()
1916 // Clears the arrays of clusters and tracks. Resets sectors and timebins
1917 // If option "force" is also set the containers are also deleted. This is useful
1922 if(HasRemoveContainers()){delete fTracks; fTracks = 0x0;}
1925 fTracklets->Delete();
1926 if(HasRemoveContainers()){delete fTracklets; fTracklets = 0x0;}
1929 if(IsClustersOwner()) fClusters->Delete();
1931 // save clusters array in the reconstructor for further use.
1932 if(!fReconstructor->IsWritingClusters()){
1933 AliTRDReconstructor::SetClusters(fClusters);
1934 SetClustersOwner(kFALSE);
1935 } else AliTRDReconstructor::SetClusters(0x0);
1938 for (int i = 0; i < AliTRDgeometry::kNsector; i++) fTrSec[i].Clear();
1940 // Increment the Event Number
1941 AliTRDtrackerDebug::SetEventNumber(AliTRDtrackerDebug::GetEventNumber() + 1);
1944 // //____________________________________________________________________
1945 // void AliTRDtrackerV1::UseClusters(const AliKalmanTrack *t, Int_t) const
1947 // const AliTRDtrackV1 *track = dynamic_cast<const AliTRDtrackV1*>(t);
1948 // if(!track) return;
1950 // AliTRDseedV1 *tracklet = 0x0;
1951 // for(Int_t ily=AliTRDgeometry::kNlayer; ily--;){
1952 // if(!(tracklet = track->GetTracklet(ily))) continue;
1953 // AliTRDcluster *c = 0x0;
1954 // for(Int_t ic=AliTRDseed::kNclusters; ic--;){
1955 // if(!(c=tracklet->GetClusters(ic))) continue;
1962 //_____________________________________________________________________________
1963 Bool_t AliTRDtrackerV1::AdjustSector(AliTRDtrackV1 *track)
1966 // Rotates the track when necessary
1969 Double_t alpha = AliTRDgeometry::GetAlpha();
1970 Double_t y = track->GetY();
1971 Double_t ymax = track->GetX()*TMath::Tan(0.5*alpha);
1974 if (!track->Rotate( alpha)) {
1978 else if (y < -ymax) {
1979 if (!track->Rotate(-alpha)) {
1989 //____________________________________________________________________
1990 AliTRDseedV1* AliTRDtrackerV1::GetTracklet(AliTRDtrackV1 *track, Int_t p, Int_t &idx)
1992 // Find tracklet for TRD track <track>
2001 // Detailed description
2003 idx = track->GetTrackletIndex(p);
2004 AliTRDseedV1 *tracklet = (idx==0xffff) ? 0x0 : (AliTRDseedV1*)fTracklets->UncheckedAt(idx);
2009 //____________________________________________________________________
2010 AliTRDseedV1* AliTRDtrackerV1::SetTracklet(AliTRDseedV1 *tracklet)
2012 // Add this tracklet to the list of tracklets stored in the tracker
2015 // - tracklet : pointer to the tracklet to be added to the list
2018 // - the index of the new tracklet in the tracker tracklets list
2020 // Detailed description
2021 // Build the tracklets list if it is not yet created (late initialization)
2022 // and adds the new tracklet to the list.
2025 fTracklets = new TClonesArray("AliTRDseedV1", AliTRDgeometry::Nsector()*kMaxTracksStack);
2026 fTracklets->SetOwner(kTRUE);
2028 Int_t nentries = fTracklets->GetEntriesFast();
2029 return new ((*fTracklets)[nentries]) AliTRDseedV1(*tracklet);
2032 //____________________________________________________________________
2033 AliTRDtrackV1* AliTRDtrackerV1::SetTrack(AliTRDtrackV1 *track)
2035 // Add this track to the list of tracks stored in the tracker
2038 // - track : pointer to the track to be added to the list
2041 // - the pointer added
2043 // Detailed description
2044 // Build the tracks list if it is not yet created (late initialization)
2045 // and adds the new track to the list.
2048 fTracks = new TClonesArray("AliTRDtrackV1", AliTRDgeometry::Nsector()*kMaxTracksStack);
2049 fTracks->SetOwner(kTRUE);
2051 Int_t nentries = fTracks->GetEntriesFast();
2052 return new ((*fTracks)[nentries]) AliTRDtrackV1(*track);
2057 //____________________________________________________________________
2058 Int_t AliTRDtrackerV1::Clusters2TracksSM(Int_t sector, AliESDEvent *esd)
2061 // Steer tracking for one SM.
2064 // sector : Array of (SM) propagation layers containing clusters
2065 // esd : The current ESD event. On output it contains the also
2066 // the ESD (TRD) tracks found in this SM.
2069 // Number of tracks found in this TRD supermodule.
2071 // Detailed description
2073 // 1. Unpack AliTRDpropagationLayers objects for each stack.
2074 // 2. Launch stack tracking.
2075 // See AliTRDtrackerV1::Clusters2TracksStack() for details.
2076 // 3. Pack results in the ESD event.
2079 // allocate space for esd tracks in this SM
2080 TClonesArray esdTrackList("AliESDtrack", 2*kMaxTracksStack);
2081 esdTrackList.SetOwner();
2084 Int_t nChambers = 0;
2085 AliTRDtrackingChamber **stack = 0x0, *chamber = 0x0;
2086 for(int istack = 0; istack<AliTRDgeometry::kNstack; istack++){
2087 if(!(stack = fTrSec[sector].GetStack(istack))) continue;
2089 for(int ilayer=0; ilayer<AliTRDgeometry::kNlayer; ilayer++){
2090 if(!(chamber = stack[ilayer])) continue;
2091 if(chamber->GetNClusters() < fgNTimeBins * fReconstructor->GetRecoParam() ->GetFindableClusters()) continue;
2093 //AliInfo(Form("sector %d stack %d layer %d clusters %d", sector, istack, ilayer, chamber->GetNClusters()));
2095 if(nChambers < 4) continue;
2096 //AliInfo(Form("Doing stack %d", istack));
2097 nTracks += Clusters2TracksStack(stack, &esdTrackList);
2099 //AliInfo(Form("Found %d tracks in SM %d [%d]\n", nTracks, sector, esd->GetNumberOfTracks()));
2101 for(int itrack=0; itrack<nTracks; itrack++)
2102 esd->AddTrack((AliESDtrack*)esdTrackList[itrack]);
2104 // Reset Track and Candidate Number
2105 AliTRDtrackerDebug::SetCandidateNumber(0);
2106 AliTRDtrackerDebug::SetTrackNumber(0);
2110 //____________________________________________________________________
2111 Int_t AliTRDtrackerV1::Clusters2TracksStack(AliTRDtrackingChamber **stack, TClonesArray *esdTrackList)
2114 // Make tracks in one TRD stack.
2117 // layer : Array of stack propagation layers containing clusters
2118 // esdTrackList : Array of ESD tracks found by the stand alone tracker.
2119 // On exit the tracks found in this stack are appended.
2122 // Number of tracks found in this stack.
2124 // Detailed description
2126 // 1. Find the 3 most useful seeding chambers. See BuildSeedingConfigs() for details.
2127 // 2. Steer AliTRDtrackerV1::MakeSeeds() for 3 seeding layer configurations.
2128 // See AliTRDtrackerV1::MakeSeeds() for more details.
2129 // 3. Arrange track candidates in decreasing order of their quality
2130 // 4. Classify tracks in 5 categories according to:
2131 // a) number of layers crossed
2133 // 5. Sign clusters by tracks in decreasing order of track quality
2134 // 6. Build AliTRDtrack out of seeding tracklets
2136 // 8. Build ESD track and register it to the output list
2139 const AliTRDCalDet *cal = AliTRDcalibDB::Instance()->GetT0Det();
2140 AliTRDtrackingChamber *chamber = 0x0;
2141 AliTRDtrackingChamber **ci = 0x0;
2142 AliTRDseedV1 sseed[kMaxTracksStack*6]; // to be initialized
2143 Int_t pars[4]; // MakeSeeds parameters
2145 //Double_t alpha = AliTRDgeometry::GetAlpha();
2146 //Double_t shift = .5 * alpha;
2147 Int_t configs[kNConfigs];
2149 // Purge used clusters from the containers
2151 for(Int_t ic = kNPlanes; ic--; ci++){
2152 if(!(*ci)) continue;
2156 // Build initial seeding configurations
2157 Double_t quality = BuildSeedingConfigs(stack, configs);
2158 if(fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 10){
2159 AliInfo(Form("Plane config %d %d %d Quality %f"
2160 , configs[0], configs[1], configs[2], quality));
2164 // Initialize contors
2165 Int_t ntracks, // number of TRD track candidates
2166 ntracks1, // number of registered TRD tracks/iter
2167 ntracks2 = 0; // number of all registered TRD tracks in stack
2171 Int_t ic = 0; ci = &stack[0];
2172 while(ic<kNPlanes && !(*ci)){ic++; ci++;}
2173 if(!(*ci)) return ntracks2;
2174 Int_t istack = fGeom->GetStack((*ci)->GetDetector());
2177 // Loop over seeding configurations
2178 ntracks = 0; ntracks1 = 0;
2179 for (Int_t iconf = 0; iconf<3; iconf++) {
2180 pars[0] = configs[iconf];
2183 ntracks = MakeSeeds(stack, &sseed[6*ntracks], pars);
2184 //AliInfo(Form("Number of Tracks after iteration step %d: %d\n", iconf, ntracks));
2185 if(ntracks == kMaxTracksStack) break;
2187 if(fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 1) AliInfo(Form("Candidate TRD tracks %d in iteration %d.", ntracks, fSieveSeeding));
2191 // Sort the seeds according to their quality
2192 Int_t sort[kMaxTracksStack];
2193 TMath::Sort(ntracks, fTrackQuality, sort, kTRUE);
2195 // Initialize number of tracks so far and logic switches
2196 Int_t ntracks0 = esdTrackList->GetEntriesFast();
2197 Bool_t signedTrack[kMaxTracksStack];
2198 Bool_t fakeTrack[kMaxTracksStack];
2199 for (Int_t i=0; i<ntracks; i++){
2200 signedTrack[i] = kFALSE;
2201 fakeTrack[i] = kFALSE;
2203 //AliInfo("Selecting track candidates ...");
2205 // Sieve clusters in decreasing order of track quality
2206 Double_t trackParams[7];
2207 // AliTRDseedV1 *lseed = 0x0;
2208 Int_t jSieve = 0, candidates;
2210 //AliInfo(Form("\t\tITER = %i ", jSieve));
2212 // Check track candidates
2214 for (Int_t itrack = 0; itrack < ntracks; itrack++) {
2215 Int_t trackIndex = sort[itrack];
2216 if (signedTrack[trackIndex] || fakeTrack[trackIndex]) continue;
2219 // Calculate track parameters from tracklets seeds
2224 for (Int_t jLayer = 0; jLayer < kNPlanes; jLayer++) {
2225 Int_t jseed = kNPlanes*trackIndex+jLayer;
2226 if(!sseed[jseed].IsOK()) continue;
2227 if (TMath::Abs(sseed[jseed].GetYref(0) / sseed[jseed].GetX0()) < 0.158) findable++;
2228 // TODO here we get a sig fault which should never happen !
2229 sseed[jseed].UpdateUsed();
2230 ncl += sseed[jseed].GetN2();
2231 nused += sseed[jseed].GetNUsed();
2235 // Filter duplicated tracks
2237 //printf("Skip %d nused %d\n", trackIndex, nused);
2238 fakeTrack[trackIndex] = kTRUE;
2241 if (Float_t(nused)/ncl >= .25){
2242 //printf("Skip %d nused/ncl >= .25\n", trackIndex);
2243 fakeTrack[trackIndex] = kTRUE;
2248 Bool_t skip = kFALSE;
2251 if(nlayers < 6) {skip = kTRUE; break;}
2252 if(TMath::Log(1.E-9+fTrackQuality[trackIndex]) < -5.){skip = kTRUE; break;}
2256 if(nlayers < findable){skip = kTRUE; break;}
2257 if(TMath::Log(1.E-9+fTrackQuality[trackIndex]) < -4.){skip = kTRUE; break;}
2261 if ((nlayers == findable) || (nlayers == 6)) { skip = kTRUE; break;}
2262 if (TMath::Log(1.E-9+fTrackQuality[trackIndex]) < -6.0){skip = kTRUE; break;}
2266 if (TMath::Log(1.E-9+fTrackQuality[trackIndex]) < -5.){skip = kTRUE; break;}
2270 if (nlayers == 3){skip = kTRUE; break;}
2271 //if (TMath::Log(1.E-9+fTrackQuality[trackIndex]) - nused/(nlayers-3.0) < -15.0){skip = kTRUE; break;}
2276 //printf("REJECTED : %d [%d] nlayers %d trackQuality = %e nused %d\n", itrack, trackIndex, nlayers, fTrackQuality[trackIndex], nused);
2279 signedTrack[trackIndex] = kTRUE;
2281 // Build track parameters
2282 AliTRDseedV1 *lseed =&sseed[trackIndex*6];
2284 while(idx<3 && !lseed->IsOK()) {
2288 Double_t x = lseed->GetX0();// - 3.5;
2289 trackParams[0] = x; //NEW AB
2290 trackParams[1] = lseed->GetYref(0); // lseed->GetYat(x);
2291 trackParams[2] = lseed->GetZref(0); // lseed->GetZat(x);
2292 trackParams[3] = TMath::Sin(TMath::ATan(lseed->GetYref(1)));
2293 trackParams[4] = lseed->GetZref(1) / TMath::Sqrt(1. + lseed->GetYref(1) * lseed->GetYref(1));
2294 trackParams[5] = lseed->GetC();
2295 Int_t ich = 0; while(!(chamber = stack[ich])) ich++;
2296 trackParams[6] = fGeom->GetSector(chamber->GetDetector());/* *alpha+shift; // Supermodule*/
2298 if(fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 1){
2299 //AliInfo(Form("Track %d [%d] nlayers %d trackQuality = %e nused %d, yref = %3.3f", itrack, trackIndex, nlayers, fTrackQuality[trackIndex], nused, trackParams[1]));
2301 AliTRDseedV1 *dseed[6];
2302 for(Int_t iseed = AliTRDgeometry::kNlayer; iseed--;) dseed[iseed] = new AliTRDseedV1(lseed[iseed]);
2304 //Int_t eventNrInFile = esd->GetEventNumberInFile();
2305 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2306 Int_t trackNumber = AliTRDtrackerDebug::GetTrackNumber();
2307 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2308 TTreeSRedirector &cstreamer = *fReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
2309 cstreamer << "Clusters2TracksStack"
2310 << "EventNumber=" << eventNumber
2311 << "TrackNumber=" << trackNumber
2312 << "CandidateNumber=" << candidateNumber
2313 << "Iter=" << fSieveSeeding
2314 << "Like=" << fTrackQuality[trackIndex]
2315 << "S0.=" << dseed[0]
2316 << "S1.=" << dseed[1]
2317 << "S2.=" << dseed[2]
2318 << "S3.=" << dseed[3]
2319 << "S4.=" << dseed[4]
2320 << "S5.=" << dseed[5]
2321 << "p0=" << trackParams[0]
2322 << "p1=" << trackParams[1]
2323 << "p2=" << trackParams[2]
2324 << "p3=" << trackParams[3]
2325 << "p4=" << trackParams[4]
2326 << "p5=" << trackParams[5]
2327 << "p6=" << trackParams[6]
2329 << "NLayers=" << nlayers
2330 << "Findable=" << findable
2331 << "NUsed=" << nused
2335 AliTRDtrackV1 *track = MakeTrack(&sseed[trackIndex*kNPlanes], trackParams);
2337 AliWarning("Fail to build a TRD Track.");
2341 //AliInfo("End of MakeTrack()");
2342 AliESDtrack *esdTrack = new ((*esdTrackList)[ntracks0++]) AliESDtrack();
2343 esdTrack->UpdateTrackParams(track, AliESDtrack::kTRDout);
2344 esdTrack->SetLabel(track->GetLabel());
2345 track->UpdateESDtrack(esdTrack);
2346 // write ESD-friends if neccessary
2347 if (fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 0){
2348 AliTRDtrackV1 *calibTrack = new AliTRDtrackV1(*track);
2349 calibTrack->SetOwner();
2350 esdTrack->AddCalibObject(calibTrack);
2353 AliTRDtrackerDebug::SetTrackNumber(AliTRDtrackerDebug::GetTrackNumber() + 1);
2357 } while(jSieve<5 && candidates); // end track candidates sieve
2358 if(!ntracks1) break;
2360 // increment counters
2361 ntracks2 += ntracks1;
2363 if(fReconstructor->IsHLT()) break;
2366 // Rebuild plane configurations and indices taking only unused clusters into account
2367 quality = BuildSeedingConfigs(stack, configs);
2368 if(quality < 1.E-7) break; //fReconstructor->GetRecoParam() ->GetPlaneQualityThreshold()) break;
2370 for(Int_t ip = 0; ip < kNPlanes; ip++){
2371 if(!(chamber = stack[ip])) continue;
2372 chamber->Build(fGeom, cal);//Indices(fSieveSeeding);
2375 if(fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 10){
2376 AliInfo(Form("Sieve level %d Plane config %d %d %d Quality %f", fSieveSeeding, configs[0], configs[1], configs[2], quality));
2378 } while(fSieveSeeding<10); // end stack clusters sieve
2382 //AliInfo(Form("Registered TRD tracks %d in stack %d.", ntracks2, pars[1]));
2387 //___________________________________________________________________
2388 Double_t AliTRDtrackerV1::BuildSeedingConfigs(AliTRDtrackingChamber **stack, Int_t *configs)
2391 // Assign probabilities to chambers according to their
2392 // capability of producing seeds.
2396 // layers : Array of stack propagation layers for all 6 chambers in one stack
2397 // configs : On exit array of configuration indexes (see GetSeedingConfig()
2398 // for details) in the decreasing order of their seeding probabilities.
2402 // Return top configuration quality
2404 // Detailed description:
2406 // To each chamber seeding configuration (see GetSeedingConfig() for
2407 // the list of all configurations) one defines 2 quality factors:
2408 // - an apriori topological quality (see GetSeedingConfig() for details) and
2409 // - a data quality based on the uniformity of the distribution of
2410 // clusters over the x range (time bins population). See CookChamberQA() for details.
2411 // The overall chamber quality is given by the product of this 2 contributions.
2414 Double_t chamberQ[kNPlanes];memset(chamberQ, 0, kNPlanes*sizeof(Double_t));
2415 AliTRDtrackingChamber *chamber = 0x0;
2416 for(int iplane=0; iplane<kNPlanes; iplane++){
2417 if(!(chamber = stack[iplane])) continue;
2418 chamberQ[iplane] = (chamber = stack[iplane]) ? chamber->GetQuality() : 0.;
2421 Double_t tconfig[kNConfigs];memset(tconfig, 0, kNConfigs*sizeof(Double_t));
2422 Int_t planes[] = {0, 0, 0, 0};
2423 for(int iconf=0; iconf<kNConfigs; iconf++){
2424 GetSeedingConfig(iconf, planes);
2425 tconfig[iconf] = fgTopologicQA[iconf];
2426 for(int iplane=0; iplane<4; iplane++) tconfig[iconf] *= chamberQ[planes[iplane]];
2429 TMath::Sort((Int_t)kNConfigs, tconfig, configs, kTRUE);
2430 // AliInfo(Form("q[%d] = %f", configs[0], tconfig[configs[0]]));
2431 // AliInfo(Form("q[%d] = %f", configs[1], tconfig[configs[1]]));
2432 // AliInfo(Form("q[%d] = %f", configs[2], tconfig[configs[2]]));
2434 return tconfig[configs[0]];
2437 //____________________________________________________________________
2438 Int_t AliTRDtrackerV1::MakeSeeds(AliTRDtrackingChamber **stack, AliTRDseedV1 *sseed, Int_t *ipar)
2441 // Seed tracklets and build candidate TRD tracks. The procedure is used during barrel tracking to account for tracks which are
2442 // either missed by TPC prolongation or conversions inside the TRD volume.
2443 // For stand alone tracking the procedure is used to estimate all tracks measured by TRD.
2446 // layers : Array of stack propagation layers containing clusters
2447 // sseed : Array of empty tracklet seeds. On exit they are filled.
2448 // ipar : Control parameters:
2449 // ipar[0] -> seeding chambers configuration
2450 // ipar[1] -> stack index
2451 // ipar[2] -> number of track candidates found so far
2454 // Number of tracks candidates found.
2456 // The following steps are performed:
2457 // 1. Build seeding layers by collapsing all time bins from each of the four seeding chambers along the
2458 // radial coordinate. See AliTRDtrackingChamber::GetSeedingLayer() for details. The chambers selection for seeding
2459 // is described in AliTRDtrackerV1::Clusters2TracksStack().
2460 // 2. Using the seeding clusters from the seeding layer (step 1) build combinatorics using the following algorithm:
2461 // - for each seeding cluster in the lower seeding layer find
2462 // - all seeding clusters in the upper seeding layer inside a road defined by a given phi angle. The angle
2463 // is calculated on the minimum pt of tracks from vertex accesible to the stand alone tracker.
2464 // - for each pair of two extreme seeding clusters select middle upper cluster using roads defined externally by the
2466 // - select last seeding cluster as the nearest to the linear approximation of the track described by the first three
2467 // seeding clusters.
2468 // The implementation of road calculation and cluster selection can be found in the functions AliTRDchamberTimeBin::BuildCond()
2469 // and AliTRDchamberTimeBin::GetClusters().
2470 // 3. Helix fit of the seeding clusters set. (see AliTRDtrackerFitter::FitRieman(AliTRDcluster**)). No tilt correction is
2471 // performed at this level
2472 // 4. Initialize seeding tracklets in the seeding chambers.
2473 // 5. *Filter 0* Chi2 cut on the Y and Z directions. The threshold is set externally by the reco params.
2474 // 6. Attach (true) clusters to seeding tracklets (see AliTRDseedV1::AttachClusters()) and fit tracklet (see
2475 // AliTRDseedV1::Fit()). The number of used clusters used by current seeds should not exceed ... (25).
2476 // 7. *Filter 1* Check if all 4 seeding tracklets are correctly constructed.
2477 // 8. Helix fit of the clusters from the seeding tracklets with tilt correction. Refit tracklets using the new
2478 // approximation of the track.
2479 // 9. *Filter 2* Calculate likelihood of the track. (See AliTRDtrackerV1::CookLikelihood()). The following quantities are
2480 // checked against the Riemann fit:
2481 // - position resolution in y
2482 // - angular resolution in the bending plane
2483 // - likelihood of the number of clusters attached to the tracklet
2484 // 10. Extrapolation of the helix fit to the other 2 chambers *non seeding* chambers:
2485 // - Initialization of extrapolation tracklets with the fit parameters
2486 // - Attach clusters to extrapolated tracklets
2487 // - Helix fit of tracklets
2488 // 11. Improve seeding tracklets quality by reassigning clusters based on the last parameters of the track
2489 // See AliTRDtrackerV1::ImproveSeedQuality() for details.
2490 // 12. Helix fit of all 6 seeding tracklets and chi2 calculation
2491 // 13. Hyperplane fit and track quality calculation. See AliTRDtrackerFitter::FitHyperplane() for details.
2492 // 14. Cooking labels for tracklets. Should be done only for MC
2493 // 15. Register seeds.
2496 // Marian Ivanov <M.Ivanov@gsi.de>
2497 // Alexandru Bercuci <A.Bercuci@gsi.de>
2498 // Markus Fasel <M.Fasel@gsi.de>
2500 AliTRDtrackingChamber *chamber = 0x0;
2501 AliTRDcluster *c[kNSeedPlanes] = {0x0, 0x0, 0x0, 0x0}; // initilize seeding clusters
2502 AliTRDseedV1 *cseed = &sseed[0]; // initialize tracklets for first track
2503 Int_t ncl, mcl; // working variable for looping over clusters
2504 Int_t index[AliTRDchamberTimeBin::kMaxClustersLayer], jndex[AliTRDchamberTimeBin::kMaxClustersLayer];
2506 // chi2[0] = tracklet chi2 on the Z direction
2507 // chi2[1] = tracklet chi2 on the R direction
2510 // this should be data member of AliTRDtrack TODO
2511 Double_t seedQuality[kMaxTracksStack];
2513 // unpack control parameters
2514 Int_t config = ipar[0];
2515 Int_t ntracks = ipar[1];
2516 Int_t istack = ipar[2];
2517 Int_t planes[kNSeedPlanes]; GetSeedingConfig(config, planes);
2518 Int_t planesExt[kNPlanes-kNSeedPlanes]; GetExtrapolationConfig(config, planesExt);
2521 // Init chambers geometry
2522 Double_t hL[kNPlanes]; // Tilting angle
2523 Float_t padlength[kNPlanes]; // pad lenghts
2524 Float_t padwidth[kNPlanes]; // pad widths
2525 AliTRDpadPlane *pp = 0x0;
2526 for(int iplane=0; iplane<kNPlanes; iplane++){
2527 pp = fGeom->GetPadPlane(iplane, istack);
2528 hL[iplane] = TMath::Tan(TMath::DegToRad()*pp->GetTiltingAngle());
2529 padlength[iplane] = pp->GetLengthIPad();
2530 padwidth[iplane] = pp->GetWidthIPad();
2533 // Init anode wire position for chambers
2534 Double_t x0[kNPlanes], // anode wire position
2535 driftLength = .5*AliTRDgeometry::AmThick() - AliTRDgeometry::DrThick(); // drift length
2536 TGeoHMatrix *matrix = 0x0;
2537 Double_t loc[] = {AliTRDgeometry::AnodePos(), 0., 0.};
2538 Double_t glb[] = {0., 0., 0.};
2539 AliTRDtrackingChamber **cIter = &stack[0];
2540 for(int iLayer=0; iLayer<kNPlanes; iLayer++,cIter++){
2541 if(!(*cIter)) continue;
2542 if(!(matrix = fGeom->GetClusterMatrix((*cIter)->GetDetector()))){
2544 x0[iLayer] = fgkX0[iLayer];
2546 matrix->LocalToMaster(loc, glb);
2547 x0[iLayer] = glb[0];
2550 if(fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 2){
2551 AliInfo(Form("Making seeds Stack[%d] Config[%d] Tracks[%d]...", istack, config, ntracks));
2554 // Build seeding layers
2557 for(int isl=0; isl<kNSeedPlanes; isl++){
2558 if(!(chamber = stack[planes[isl]])) continue;
2559 if(!chamber->GetSeedingLayer(fSeedTB[isl], fGeom, fReconstructor)) continue;
2562 if(nlayers < kNSeedPlanes) return ntracks;
2565 // Start finding seeds
2566 Double_t cond0[4], cond1[4], cond2[4];
2568 while((c[3] = (*fSeedTB[3])[icl++])){
2570 fSeedTB[0]->BuildCond(c[3], cond0, 0);
2571 fSeedTB[0]->GetClusters(cond0, index, ncl);
2572 //printf("Found c[3] candidates 0 %d\n", ncl);
2575 c[0] = (*fSeedTB[0])[index[jcl++]];
2577 Double_t dx = c[3]->GetX() - c[0]->GetX();
2578 Double_t dzdx = (c[3]->GetZ() - c[0]->GetZ())/dx;
2579 Double_t dydx = (c[3]->GetY() - c[0]->GetY())/dx;
2580 fSeedTB[1]->BuildCond(c[0], cond1, 1, dzdx, dydx);
2581 fSeedTB[1]->GetClusters(cond1, jndex, mcl);
2582 //printf("Found c[0] candidates 1 %d\n", mcl);
2586 c[1] = (*fSeedTB[1])[jndex[kcl++]];
2588 fSeedTB[2]->BuildCond(c[1], cond2, 2, dzdx, dydx);
2589 c[2] = fSeedTB[2]->GetNearestCluster(cond2);
2590 //printf("Found c[1] candidate 2 %p\n", c[2]);
2593 //AliInfo("Seeding clusters found. Building seeds ...");
2594 //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());
2596 for (Int_t il = 0; il < kNPlanes; il++) cseed[il].Reset();
2600 AliTRDseedV1 *tseed = &cseed[0];
2602 for(int iLayer=0; iLayer<kNPlanes; iLayer++, tseed++, cIter++){
2603 Int_t det = (*cIter) ? (*cIter)->GetDetector() : -1;
2604 tseed->SetDetector(det);
2605 tseed->SetTilt(hL[iLayer]);
2606 tseed->SetPadLength(padlength[iLayer]);
2607 tseed->SetPadWidth(padwidth[iLayer]);
2608 tseed->SetReconstructor(fReconstructor);
2609 tseed->SetX0(det<0 ? fR[iLayer]+driftLength : x0[iLayer]);
2610 tseed->Init(GetRiemanFitter());
2611 tseed->SetStandAlone(kTRUE);
2614 Bool_t isFake = kFALSE;
2615 if(fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) >= 2){
2616 if (c[0]->GetLabel(0) != c[3]->GetLabel(0)) isFake = kTRUE;
2617 if (c[1]->GetLabel(0) != c[3]->GetLabel(0)) isFake = kTRUE;
2618 if (c[2]->GetLabel(0) != c[3]->GetLabel(0)) isFake = kTRUE;
2621 for(Int_t l = 0; l < kNSeedPlanes; l++) xpos[l] = fSeedTB[l]->GetX();
2623 for(int il=0; il<4; il++) yref[il] = cseed[planes[il]].GetYref(0);
2624 Int_t ll = c[3]->GetLabel(0);
2625 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2626 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2627 AliRieman *rim = GetRiemanFitter();
2628 TTreeSRedirector &cs0 = *fReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
2630 <<"EventNumber=" << eventNumber
2631 <<"CandidateNumber=" << candidateNumber
2632 <<"isFake=" << isFake
2633 <<"config=" << config
2635 <<"chi2z=" << chi2[0]
2636 <<"chi2y=" << chi2[1]
2637 <<"Y2exp=" << cond2[0]
2638 <<"Z2exp=" << cond2[1]
2639 <<"X0=" << xpos[0] //layer[sLayer]->GetX()
2640 <<"X1=" << xpos[1] //layer[sLayer + 1]->GetX()
2641 <<"X2=" << xpos[2] //layer[sLayer + 2]->GetX()
2642 <<"X3=" << xpos[3] //layer[sLayer + 3]->GetX()
2643 <<"yref0=" << yref[0]
2644 <<"yref1=" << yref[1]
2645 <<"yref2=" << yref[2]
2646 <<"yref3=" << yref[3]
2651 <<"Seed0.=" << &cseed[planes[0]]
2652 <<"Seed1.=" << &cseed[planes[1]]
2653 <<"Seed2.=" << &cseed[planes[2]]
2654 <<"Seed3.=" << &cseed[planes[3]]
2655 <<"RiemanFitter.=" << rim
2658 if(chi2[0] > fReconstructor->GetRecoParam() ->GetChi2Z()/*7./(3. - sLayer)*//*iter*/){
2659 //AliInfo(Form("Failed chi2 filter on chi2Z [%f].", chi2[0]));
2660 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2663 if(chi2[1] > fReconstructor->GetRecoParam() ->GetChi2Y()/*1./(3. - sLayer)*//*iter*/){
2664 //AliInfo(Form("Failed chi2 filter on chi2Y [%f].", chi2[1]));
2665 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2668 //AliInfo("Passed chi2 filter.");
2670 // try attaching clusters to tracklets
2672 AliTRDcluster *cl = NULL;
2673 for(int iLayer=0; iLayer<kNSeedPlanes; iLayer++){
2674 Int_t jLayer = planes[iLayer];
2675 Int_t nNotInChamber = 0;
2676 if(!cseed[jLayer].AttachClusters(stack[jLayer], kTRUE)) continue;
2677 cseed[jLayer].Fit();
2678 cseed[jLayer].UpdateUsed();
2679 cseed[jLayer].ResetClusterIter();
2680 while((cl = cseed[jLayer].NextCluster())){
2681 if(!cl->IsInChamber()) nNotInChamber++;
2683 //printf("clusters[%d], used[%d], not in chamber[%d]\n", cseed[jLayer].GetN(), cseed[jLayer].GetNUsed(), nNotInChamber);
2684 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
2688 if(mlayers < kNSeedPlanes){
2689 //AliInfo(Form("Failed updating all seeds %d [%d].", mlayers, kNSeedPlanes));
2690 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2694 // temporary exit door for the HLT
2695 if(fReconstructor->IsHLT()){
2696 // attach clusters to extrapolation chambers
2697 for(int iLayer=0; iLayer<kNPlanes-kNSeedPlanes; iLayer++){
2698 Int_t jLayer = planesExt[iLayer];
2699 if(!(chamber = stack[jLayer])) continue;
2700 cseed[jLayer].AttachClusters(chamber, kTRUE);
2701 cseed[jLayer].Fit();
2703 fTrackQuality[ntracks] = 1.; // dummy value
2705 if(ntracks == kMaxTracksStack) return ntracks;
2711 // Update Seeds and calculate Likelihood
2712 // fit tracklets and cook likelihood
2713 FitTiltedRieman(&cseed[0], kTRUE);
2714 for(int iLayer=0; iLayer<kNSeedPlanes; iLayer++){
2715 Int_t jLayer = planes[iLayer];
2716 cseed[jLayer].Fit(kTRUE);
2718 Double_t like = CookLikelihood(&cseed[0], planes); // to be checked
2720 if (TMath::Log(1.E-9 + like) < fReconstructor->GetRecoParam() ->GetTrackLikelihood()){
2721 //AliInfo(Form("Failed likelihood %f[%e].", TMath::Log(1.E-9 + like), like));
2722 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2725 //AliInfo(Form("Passed likelihood %f[%e].", TMath::Log(1.E-9 + like), like));
2727 // book preliminary results
2728 seedQuality[ntracks] = like;
2729 fSeedLayer[ntracks] = config;/*sLayer;*/
2731 // attach clusters to the extrapolation seeds
2732 for(int iLayer=0; iLayer<kNPlanes-kNSeedPlanes; iLayer++){
2733 Int_t jLayer = planesExt[iLayer];
2734 if(!(chamber = stack[jLayer])) continue;
2736 // fit extrapolated seed
2737 if ((jLayer == 0) && !(cseed[1].IsOK())) continue;
2738 if ((jLayer == 5) && !(cseed[4].IsOK())) continue;
2739 AliTRDseedV1 pseed = cseed[jLayer];
2740 if(!pseed.AttachClusters(chamber, kTRUE)) continue;
2742 cseed[jLayer] = pseed;
2743 FitTiltedRieman(cseed, kTRUE);
2744 cseed[jLayer].Fit(kTRUE);
2747 // AliInfo("Extrapolation done.");
2748 // Debug Stream containing all the 6 tracklets
2749 if(fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) >= 2){
2750 TTreeSRedirector &cstreamer = *fReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
2751 TLinearFitter *tiltedRieman = GetTiltedRiemanFitter();
2752 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2753 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2754 cstreamer << "MakeSeeds1"
2755 << "EventNumber=" << eventNumber
2756 << "CandidateNumber=" << candidateNumber
2757 << "S0.=" << &cseed[0]
2758 << "S1.=" << &cseed[1]
2759 << "S2.=" << &cseed[2]
2760 << "S3.=" << &cseed[3]
2761 << "S4.=" << &cseed[4]
2762 << "S5.=" << &cseed[5]
2763 << "FitterT.=" << tiltedRieman
2767 if(fReconstructor->HasImproveTracklets() && ImproveSeedQuality(stack, cseed) < 4){
2768 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2771 //AliInfo("Improve seed quality done.");
2773 // fit full track and cook likelihoods
2774 // Double_t curv = FitRieman(&cseed[0], chi2);
2775 // Double_t chi2ZF = chi2[0] / TMath::Max((mlayers - 3.), 1.);
2776 // Double_t chi2RF = chi2[1] / TMath::Max((mlayers - 3.), 1.);
2778 // do the final track fitting (Once with vertex constraint and once without vertex constraint)
2779 Double_t chi2Vals[3];
2780 chi2Vals[0] = FitTiltedRieman(&cseed[0], kTRUE);
2781 if(fReconstructor->HasVertexConstrained())
2782 chi2Vals[1] = FitTiltedRiemanConstraint(&cseed[0], GetZ()); // Do Vertex Constrained fit if desired
2785 chi2Vals[2] = GetChi2Z(&cseed[0]) / TMath::Max((mlayers - 3.), 1.);
2786 // Chi2 definitions in testing stage
2787 //chi2Vals[2] = GetChi2ZTest(&cseed[0]);
2788 fTrackQuality[ntracks] = CalculateTrackLikelihood(&cseed[0], &chi2Vals[0]);
2789 //AliInfo("Hyperplane fit done\n");
2791 if(fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) >= 2){
2792 TTreeSRedirector &cstreamer = *fReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
2793 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2794 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2795 TLinearFitter *fitterTC = GetTiltedRiemanFitterConstraint();
2796 TLinearFitter *fitterT = GetTiltedRiemanFitter();
2798 for(Int_t iseed = 0; iseed < kNPlanes; iseed++){
2799 ncls += cseed[iseed].IsOK() ? cseed[iseed].GetN2() : 0;
2801 cstreamer << "MakeSeeds2"
2802 << "EventNumber=" << eventNumber
2803 << "CandidateNumber=" << candidateNumber
2804 << "Chi2TR=" << chi2Vals[0]
2805 << "Chi2TC=" << chi2Vals[1]
2806 << "Nlayers=" << mlayers
2807 << "NClusters=" << ncls
2809 << "S0.=" << &cseed[0]
2810 << "S1.=" << &cseed[1]
2811 << "S2.=" << &cseed[2]
2812 << "S3.=" << &cseed[3]
2813 << "S4.=" << &cseed[4]
2814 << "S5.=" << &cseed[5]
2815 << "FitterT.=" << fitterT
2816 << "FitterTC.=" << fitterTC
2821 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2822 if(ntracks == kMaxTracksStack){
2823 AliWarning(Form("Number of seeds reached maximum allowed (%d) in stack.", kMaxTracksStack));
2834 //_____________________________________________________________________________
2835 AliTRDtrackV1* AliTRDtrackerV1::MakeTrack(AliTRDseedV1 *seeds, Double_t *params)
2838 // Build a TRD track out of tracklet candidates
2841 // seeds : array of tracklets
2842 // params : array of track parameters as they are estimated by stand alone tracker. 7 elements.
2843 // [0] - radial position of the track at reference point
2844 // [1] - y position of the fit at [0]
2845 // [2] - z position of the fit at [0]
2846 // [3] - snp of the first tracklet
2847 // [4] - tgl of the first tracklet
2848 // [5] - curvature of the Riemann fit - 1/pt
2849 // [6] - sector rotation angle
2854 // Initialize the TRD track based on the parameters of the fit and a parametric covariance matrix
2855 // (diagonal with constant variance terms TODO - correct parameterization)
2857 // In case of HLT just register the tracklets in the tracker and return values of the Riemann fit. For the
2858 // offline case perform a full Kalman filter on the already found tracklets (see AliTRDtrackerV1::FollowBackProlongation()
2859 // for details). Do also MC label calculation and PID if propagation successfully.
2862 Double_t alpha = AliTRDgeometry::GetAlpha();
2863 Double_t shift = AliTRDgeometry::GetAlpha()/2.0;
2866 c[ 0] = 0.2; // s^2_y
2867 c[ 1] = 0.0; c[ 2] = 2.0; // s^2_z
2868 c[ 3] = 0.0; c[ 4] = 0.0; c[ 5] = 0.02; // s^2_snp
2869 c[ 6] = 0.0; c[ 7] = 0.0; c[ 8] = 0.0; c[ 9] = 0.1; // s^2_tgl
2870 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
2872 AliTRDtrackV1 track(seeds, ¶ms[1], c, params[0], params[6]*alpha+shift);
2873 track.PropagateTo(params[0]-5.0);
2874 AliTRDseedV1 *ptrTracklet = 0x0;
2876 // skip Kalman filter for HLT
2877 if(fReconstructor->IsHLT()){
2878 for (Int_t jLayer = 0; jLayer < AliTRDgeometry::kNlayer; jLayer++) {
2879 track.UnsetTracklet(jLayer);
2880 ptrTracklet = &seeds[jLayer];
2881 if(!ptrTracklet->IsOK()) continue;
2882 if(TMath::Abs(ptrTracklet->GetYref(1) - ptrTracklet->GetYfit(1)) >= .2) continue; // check this condition with Marian
2883 ptrTracklet = SetTracklet(ptrTracklet);
2884 ptrTracklet->UseClusters();
2885 track.SetTracklet(ptrTracklet, fTracklets->GetEntriesFast()-1);
2887 AliTRDtrackV1 *ptrTrack = SetTrack(&track);
2888 ptrTrack->CookPID();
2889 ptrTrack->SetReconstructor(fReconstructor);
2893 track.ResetCovariance(1);
2894 Int_t nc = TMath::Abs(FollowBackProlongation(track));
2895 if(fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) > 5){
2896 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2897 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2898 Double_t p[5]; // Track Params for the Debug Stream
2899 track.GetExternalParameters(params[0], p);
2900 TTreeSRedirector &cs = *fReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
2902 << "EventNumber=" << eventNumber
2903 << "CandidateNumber=" << candidateNumber
2905 << "X=" << params[0]
2911 << "Yin=" << params[1]
2912 << "Zin=" << params[2]
2913 << "snpin=" << params[3]
2914 << "tndin=" << params[4]
2915 << "crvin=" << params[5]
2916 << "track.=" << &track
2919 if (nc < 30) return 0x0;
2921 AliTRDtrackV1 *ptrTrack = SetTrack(&track);
2922 ptrTrack->SetReconstructor(fReconstructor);
2923 ptrTrack->CookLabel(.9);
2925 // computes PID for track
2926 ptrTrack->CookPID();
2927 // update calibration references using this track
2928 AliTRDCalibraFillHisto *calibra = AliTRDCalibraFillHisto::Instance();
2930 AliInfo("Could not get Calibra instance\n");
2931 if(calibra->GetHisto2d()) calibra->UpdateHistogramsV1(ptrTrack);
2937 //____________________________________________________________________
2938 Int_t AliTRDtrackerV1::ImproveSeedQuality(AliTRDtrackingChamber **stack, AliTRDseedV1 *cseed)
2941 // Sort tracklets according to "quality" and try to "improve" the first 4 worst
2944 // layers : Array of propagation layers for a stack/supermodule
2945 // cseed : Array of 6 seeding tracklets which has to be improved
2948 // cssed : Improved seeds
2950 // Detailed description
2952 // Iterative procedure in which new clusters are searched for each
2953 // tracklet seed such that the seed quality (see AliTRDseed::GetQuality())
2954 // can be maximized. If some optimization is found the old seeds are replaced.
2959 // make a local working copy
2960 AliTRDtrackingChamber *chamber = 0x0;
2961 AliTRDseedV1 bseed[6];
2963 for (Int_t jLayer = 0; jLayer < 6; jLayer++) bseed[jLayer] = cseed[jLayer];
2965 Float_t lastquality = 10000.0;
2966 Float_t lastchi2 = 10000.0;
2967 Float_t chi2 = 1000.0;
2969 for (Int_t iter = 0; iter < 4; iter++) {
2970 Float_t sumquality = 0.0;
2971 Float_t squality[6];
2972 Int_t sortindexes[6];
2974 for (Int_t jLayer = 0; jLayer < 6; jLayer++) {
2975 squality[jLayer] = bseed[jLayer].IsOK() ? bseed[jLayer].GetQuality(kTRUE) : 1000.;
2976 sumquality += squality[jLayer];
2978 if ((sumquality >= lastquality) || (chi2 > lastchi2)) break;
2981 lastquality = sumquality;
2983 if (iter > 0) for (Int_t jLayer = 0; jLayer < 6; jLayer++) cseed[jLayer] = bseed[jLayer];
2985 TMath::Sort(6, squality, sortindexes, kFALSE);
2986 for (Int_t jLayer = 5; jLayer > 1; jLayer--) {
2987 Int_t bLayer = sortindexes[jLayer];
2988 if(!(chamber = stack[bLayer])) continue;
2989 bseed[bLayer].AttachClusters(chamber, kTRUE);
2990 bseed[bLayer].Fit(kTRUE);
2991 if(bseed[bLayer].IsOK()) nLayers++;
2994 chi2 = FitTiltedRieman(bseed, kTRUE);
2995 if(fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) >= 7){
2996 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2997 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2998 TLinearFitter *tiltedRieman = GetTiltedRiemanFitter();
2999 TTreeSRedirector &cstreamer = *fReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
3000 cstreamer << "ImproveSeedQuality"
3001 << "EventNumber=" << eventNumber
3002 << "CandidateNumber=" << candidateNumber
3003 << "Iteration=" << iter
3004 << "S0.=" << &bseed[0]
3005 << "S1.=" << &bseed[1]
3006 << "S2.=" << &bseed[2]
3007 << "S3.=" << &bseed[3]
3008 << "S4.=" << &bseed[4]
3009 << "S5.=" << &bseed[5]
3010 << "FitterT.=" << tiltedRieman
3014 // we are sure that at least 2 tracklets are OK !
3018 //_________________________________________________________________________
3019 Double_t AliTRDtrackerV1::CalculateTrackLikelihood(AliTRDseedV1 *tracklets, Double_t *chi2){
3021 // Calculates the Track Likelihood value. This parameter serves as main quality criterion for
3022 // the track selection
3023 // The likelihood value containes:
3024 // - The chi2 values from the both fitters and the chi2 values in z-direction from a linear fit
3025 // - The Sum of the Parameter |slope_ref - slope_fit|/Sigma of the tracklets
3026 // For all Parameters an exponential dependency is used
3028 // Parameters: - Array of tracklets (AliTRDseedV1) related to the track candidate
3029 // - Array of chi2 values:
3030 // * Non-Constrained Tilted Riemann fit
3031 // * Vertex-Constrained Tilted Riemann fit
3032 // * z-Direction from Linear fit
3033 // Output: - The calculated track likelihood
3038 Double_t chi2phi = 0, nLayers = 0;
3039 for (Int_t iLayer = 0; iLayer < kNPlanes; iLayer++) {
3040 if(!tracklets[iLayer].IsOK()) continue;
3041 chi2phi += tracklets[iLayer].GetChi2Phi();
3044 chi2phi /= Float_t (nLayers - 2.0);
3046 Double_t likeChi2Z = TMath::Exp(-chi2[2] * 0.14); // Chi2Z
3047 Double_t likeChi2TC = (fReconstructor->HasVertexConstrained()) ?
3048 TMath::Exp(-chi2[1] * 0.677) : 1; // Constrained Tilted Riemann
3049 Double_t likeChi2TR = TMath::Exp(-chi2[0] * 0.0078); // Non-constrained Tilted Riemann
3050 Double_t likeChi2Phi= TMath::Exp(-chi2phi * 3.23);//3.23
3051 Double_t trackLikelihood = likeChi2Z * likeChi2TR * likeChi2Phi;
3053 if(fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) >= 2){
3054 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
3055 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
3056 TTreeSRedirector &cstreamer = *fReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
3057 cstreamer << "CalculateTrackLikelihood0"
3058 << "EventNumber=" << eventNumber
3059 << "CandidateNumber=" << candidateNumber
3060 << "LikeChi2Z=" << likeChi2Z
3061 << "LikeChi2TR=" << likeChi2TR
3062 << "LikeChi2TC=" << likeChi2TC
3063 << "LikeChi2Phi=" << likeChi2Phi
3064 << "TrackLikelihood=" << trackLikelihood
3068 return trackLikelihood;
3071 //____________________________________________________________________
3072 Double_t AliTRDtrackerV1::CookLikelihood(AliTRDseedV1 *cseed, Int_t planes[4])
3075 // Calculate the probability of this track candidate.
3078 // cseeds : array of candidate tracklets
3079 // planes : array of seeding planes (see seeding configuration)
3080 // chi2 : chi2 values (on the Z and Y direction) from the rieman fit of the track.
3085 // Detailed description
3087 // The track quality is estimated based on the following 4 criteria:
3088 // 1. precision of the rieman fit on the Y direction (likea)
3089 // 2. chi2 on the Y direction (likechi2y)
3090 // 3. chi2 on the Z direction (likechi2z)
3091 // 4. number of attached clusters compared to a reference value
3092 // (see AliTRDrecoParam::fkFindable) (likeN)
3094 // The distributions for each type of probabilities are given below as of
3095 // (date). They have to be checked to assure consistency of estimation.
3098 // ratio of the total number of clusters/track which are expected to be found by the tracker.
3099 const AliTRDrecoParam *fRecoPars = fReconstructor->GetRecoParam();
3101 Double_t chi2y = GetChi2Y(&cseed[0]);
3102 Double_t chi2z = GetChi2Z(&cseed[0]);
3104 Float_t nclusters = 0.;
3105 Double_t sumda = 0.;
3106 for(UChar_t ilayer = 0; ilayer < 4; ilayer++){
3107 Int_t jlayer = planes[ilayer];
3108 nclusters += cseed[jlayer].GetN2();
3109 sumda += TMath::Abs(cseed[jlayer].GetYfit(1) - cseed[jlayer].GetYref(1));
3113 Double_t likea = TMath::Exp(-sumda * fRecoPars->GetPhiSlope());
3114 Double_t likechi2y = 0.0000000001;
3115 if (fReconstructor->IsCosmic() || chi2y < fRecoPars->GetChi2YCut()) likechi2y += TMath::Exp(-TMath::Sqrt(chi2y) * fRecoPars->GetChi2YSlope());
3116 Double_t likechi2z = TMath::Exp(-chi2z * fRecoPars->GetChi2ZSlope());
3117 Double_t likeN = TMath::Exp(-(fRecoPars->GetNMeanClusters() - nclusters) / fRecoPars->GetNSigmaClusters());
3118 Double_t like = likea * likechi2y * likechi2z * likeN;
3120 if(fReconstructor->GetStreamLevel(AliTRDReconstructor::kTracker) >= 2){
3121 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
3122 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
3123 Int_t nTracklets = 0; Float_t mean_ncls = 0;
3124 for(Int_t iseed=0; iseed < kNPlanes; iseed++){
3125 if(!cseed[iseed].IsOK()) continue;
3127 mean_ncls += cseed[iseed].GetN2();
3129 if(nTracklets) mean_ncls /= nTracklets;
3130 // The Debug Stream contains the seed
3131 TTreeSRedirector &cstreamer = *fReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
3132 cstreamer << "CookLikelihood"
3133 << "EventNumber=" << eventNumber
3134 << "CandidateNumber=" << candidateNumber
3135 << "tracklet0.=" << &cseed[0]
3136 << "tracklet1.=" << &cseed[1]
3137 << "tracklet2.=" << &cseed[2]
3138 << "tracklet3.=" << &cseed[3]
3139 << "tracklet4.=" << &cseed[4]
3140 << "tracklet5.=" << &cseed[5]
3141 << "sumda=" << sumda
3142 << "chi2y=" << chi2y
3143 << "chi2z=" << chi2z
3144 << "likea=" << likea
3145 << "likechi2y=" << likechi2y
3146 << "likechi2z=" << likechi2z
3147 << "nclusters=" << nclusters
3148 << "likeN=" << likeN
3150 << "meanncls=" << mean_ncls
3157 //____________________________________________________________________
3158 void AliTRDtrackerV1::GetSeedingConfig(Int_t iconfig, Int_t planes[4])
3161 // Map seeding configurations to detector planes.
3164 // iconfig : configuration index
3165 // planes : member planes of this configuration. On input empty.
3168 // planes : contains the planes which are defining the configuration
3170 // Detailed description
3172 // Here is the list of seeding planes configurations together with
3173 // their topological classification:
3191 // The topologic quality is modeled as follows:
3192 // 1. The general model is define by the equation:
3193 // p(conf) = exp(-conf/2)
3194 // 2. According to the topologic classification, configurations from the same
3195 // class are assigned the agerage value over the model values.
3196 // 3. Quality values are normalized.
3198 // The topologic quality distribution as function of configuration is given below:
3200 // <img src="gif/topologicQA.gif">
3205 case 0: // 5432 TQ 0
3211 case 1: // 4321 TQ 0
3217 case 2: // 3210 TQ 0
3223 case 3: // 5321 TQ 1
3229 case 4: // 4210 TQ 1
3235 case 5: // 5431 TQ 1
3241 case 6: // 4320 TQ 1
3247 case 7: // 5430 TQ 2
3253 case 8: // 5210 TQ 2
3259 case 9: // 5421 TQ 3
3265 case 10: // 4310 TQ 3
3271 case 11: // 5410 TQ 4
3277 case 12: // 5420 TQ 5
3283 case 13: // 5320 TQ 5
3289 case 14: // 5310 TQ 5
3298 //____________________________________________________________________
3299 void AliTRDtrackerV1::GetExtrapolationConfig(Int_t iconfig, Int_t planes[2])
3302 // Returns the extrapolation planes for a seeding configuration.
3305 // iconfig : configuration index
3306 // planes : planes which are not in this configuration. On input empty.
3309 // planes : contains the planes which are not in the configuration
3311 // Detailed description
3315 case 0: // 5432 TQ 0
3319 case 1: // 4321 TQ 0
3323 case 2: // 3210 TQ 0
3327 case 3: // 5321 TQ 1
3331 case 4: // 4210 TQ 1
3335 case 5: // 5431 TQ 1
3339 case 6: // 4320 TQ 1
3343 case 7: // 5430 TQ 2
3347 case 8: // 5210 TQ 2
3351 case 9: // 5421 TQ 3
3355 case 10: // 4310 TQ 3
3359 case 11: // 5410 TQ 4
3363 case 12: // 5420 TQ 5
3367 case 13: // 5320 TQ 5
3371 case 14: // 5310 TQ 5
3378 //____________________________________________________________________
3379 AliCluster* AliTRDtrackerV1::GetCluster(Int_t idx) const
3381 Int_t ncls = fClusters->GetEntriesFast();
3382 return idx >= 0 && idx < ncls ? (AliCluster*)fClusters->UncheckedAt(idx) : 0x0;
3385 //____________________________________________________________________
3386 AliTRDseedV1* AliTRDtrackerV1::GetTracklet(Int_t idx) const
3388 Int_t ntrklt = fTracklets->GetEntriesFast();
3389 return idx >= 0 && idx < ntrklt ? (AliTRDseedV1*)fTracklets->UncheckedAt(idx) : 0x0;
3392 //____________________________________________________________________
3393 AliKalmanTrack* AliTRDtrackerV1::GetTrack(Int_t idx) const
3395 Int_t ntrk = fTracks->GetEntriesFast();
3396 return idx >= 0 && idx < ntrk ? (AliKalmanTrack*)fTracks->UncheckedAt(idx) : 0x0;
3401 // //_____________________________________________________________________________
3402 // Int_t AliTRDtrackerV1::Freq(Int_t n, const Int_t *inlist
3403 // , Int_t *outlist, Bool_t down)
3406 // // Sort eleements according occurancy
3407 // // The size of output array has is 2*n
3414 // Int_t *sindexS = new Int_t[n]; // Temporary array for sorting
3415 // Int_t *sindexF = new Int_t[2*n];
3416 // for (Int_t i = 0; i < n; i++) {
3420 // TMath::Sort(n,inlist,sindexS,down);
3422 // Int_t last = inlist[sindexS[0]];
3423 // Int_t val = last;
3425 // sindexF[0+n] = last;
3426 // Int_t countPos = 0;
3428 // // Find frequency
3429 // for (Int_t i = 1; i < n; i++) {
3430 // val = inlist[sindexS[i]];
3431 // if (last == val) {
3432 // sindexF[countPos]++;
3436 // sindexF[countPos+n] = val;
3437 // sindexF[countPos]++;
3441 // if (last == val) {
3445 // // Sort according frequency
3446 // TMath::Sort(countPos,sindexF,sindexS,kTRUE);
3448 // for (Int_t i = 0; i < countPos; i++) {
3449 // outlist[2*i ] = sindexF[sindexS[i]+n];
3450 // outlist[2*i+1] = sindexF[sindexS[i]];
3453 // delete [] sindexS;
3454 // delete [] sindexF;
3461 //____________________________________________________________________
3462 void AliTRDtrackerV1::ResetSeedTB()
3464 // reset buffer for seeding time bin layers. If the time bin
3465 // layers are not allocated this function allocates them
3467 for(Int_t isl=0; isl<kNSeedPlanes; isl++){
3468 if(!fSeedTB[isl]) fSeedTB[isl] = new AliTRDchamberTimeBin();
3469 else fSeedTB[isl]->Clear();
3474 //_____________________________________________________________________________
3475 Float_t AliTRDtrackerV1::GetChi2Y(AliTRDseedV1 *tracklets) const
3477 // Calculates normalized chi2 in y-direction
3478 // chi2 = Sum chi2 / n_tracklets
3480 Double_t chi2 = 0.; Int_t n = 0;
3481 for(Int_t ipl = kNPlanes; ipl--;){
3482 if(!tracklets[ipl].IsOK()) continue;
3483 chi2 += tracklets[ipl].GetChi2Y();
3486 return n ? chi2/n : 0.;
3489 //_____________________________________________________________________________
3490 Float_t AliTRDtrackerV1::GetChi2Z(AliTRDseedV1 *tracklets) const
3492 // Calculates normalized chi2 in z-direction
3493 // chi2 = Sum chi2 / n_tracklets
3495 Double_t chi2 = 0; Int_t n = 0;
3496 for(Int_t ipl = kNPlanes; ipl--;){
3497 if(!tracklets[ipl].IsOK()) continue;
3498 chi2 += tracklets[ipl].GetChi2Z();
3501 return n ? chi2/n : 0.;
3504 //____________________________________________________________________
3505 Float_t AliTRDtrackerV1::CalculateReferenceX(AliTRDseedV1 *tracklets){
3507 // Calculates the reference x-position for the tilted Rieman fit defined as middle
3508 // of the stack (middle between layers 2 and 3). For the calculation all the tracklets
3509 // are taken into account
3511 // Parameters: - Array of tracklets(AliTRDseedV1)
3513 // Output: - The reference x-position(Float_t)
3514 // Only kept for compatibility with the old code
3516 Int_t nDistances = 0;
3517 Float_t meanDistance = 0.;
3518 Int_t startIndex = 5;
3519 for(Int_t il =5; il > 0; il--){
3520 if(tracklets[il].IsOK() && tracklets[il -1].IsOK()){
3521 Float_t xdiff = tracklets[il].GetX0() - tracklets[il -1].GetX0();
3522 meanDistance += xdiff;
3525 if(tracklets[il].IsOK()) startIndex = il;
3527 if(tracklets[0].IsOK()) startIndex = 0;
3529 // We should normally never get here
3530 Float_t xpos[2]; memset(xpos, 0, sizeof(Float_t) * 2);
3531 Int_t iok = 0, idiff = 0;
3532 // This attempt is worse and should be avoided:
3533 // check for two chambers which are OK and repeat this without taking the mean value
3534 // Strategy avoids a division by 0;
3535 for(Int_t il = 5; il >= 0; il--){
3536 if(tracklets[il].IsOK()){
3537 xpos[iok] = tracklets[il].GetX0();
3541 if(iok) idiff++; // to get the right difference;
3545 meanDistance = (xpos[0] - xpos[1])/idiff;
3548 // we have do not even have 2 layers which are OK? The we do not need to fit at all
3553 meanDistance /= nDistances;
3555 return tracklets[startIndex].GetX0() + (2.5 - startIndex) * meanDistance - 0.5 * (AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick());
3558 //_____________________________________________________________________________
3559 Double_t AliTRDtrackerV1::FitTiltedRiemanV1(AliTRDseedV1 *tracklets){
3561 // Track Fitter Function using the new class implementation of
3564 AliTRDtrackFitterRieman fitter;
3565 fitter.SetRiemanFitter(GetTiltedRiemanFitter());
3567 for(Int_t il = 0; il < AliTRDgeometry::kNlayer; il++) fitter.SetTracklet(il, &tracklets[il]);
3568 Double_t chi2 = fitter.Eval();
3569 // Update the tracklets
3570 Double_t cov[15]; Double_t x0;
3571 memset(cov, 0, sizeof(Double_t) * 15);
3572 for(Int_t il = 0; il < AliTRDgeometry::kNlayer; il++){
3573 x0 = tracklets[il].GetX0();
3574 tracklets[il].SetYref(0, fitter.GetYat(x0));
3575 tracklets[il].SetZref(0, fitter.GetZat(x0));
3576 tracklets[il].SetYref(1, fitter.GetDyDxAt(x0));
3577 tracklets[il].SetZref(1, fitter.GetDzDx());
3578 tracklets[il].SetC(fitter.GetCurvature());
3579 fitter.GetCovAt(x0, cov);
3580 tracklets[il].SetCovRef(cov);
3581 tracklets[il].SetChi2(chi2);
3586 ///////////////////////////////////////////////////////
3588 // Resources of class AliTRDLeastSquare //
3590 ///////////////////////////////////////////////////////
3592 //_____________________________________________________________________________
3593 AliTRDtrackerV1::AliTRDLeastSquare::AliTRDLeastSquare(){
3595 // Constructor of the nested class AliTRDtrackFitterLeastSquare
3597 memset(fParams, 0, sizeof(Double_t) * 2);
3598 memset(fSums, 0, sizeof(Double_t) * 5);
3599 memset(fCovarianceMatrix, 0, sizeof(Double_t) * 3);
3603 //_____________________________________________________________________________
3604 void AliTRDtrackerV1::AliTRDLeastSquare::AddPoint(Double_t *x, Double_t y, Double_t sigmaY){
3606 // Adding Point to the fitter
3608 Double_t weight = 1/(sigmaY > 1e-9 ? sigmaY : 1e-9);
3611 // printf("Adding point x = %f, y = %f, sigma = %f\n", xpt, y, sigmaY);
3613 fSums[1] += weight * xpt;
3614 fSums[2] += weight * y;
3615 fSums[3] += weight * xpt * y;
3616 fSums[4] += weight * xpt * xpt;
3617 fSums[5] += weight * y * y;
3620 //_____________________________________________________________________________
3621 void AliTRDtrackerV1::AliTRDLeastSquare::RemovePoint(Double_t *x, Double_t y, Double_t sigmaY){
3623 // Remove Point from the sample
3626 Double_t weight = 1/(sigmaY > 1e-9 ? sigmaY : 1e-9);
3630 fSums[1] -= weight * xpt;
3631 fSums[2] -= weight * y;
3632 fSums[3] -= weight * xpt * y;
3633 fSums[4] -= weight * xpt * xpt;
3634 fSums[5] -= weight * y * y;
3637 //_____________________________________________________________________________
3638 void AliTRDtrackerV1::AliTRDLeastSquare::Eval(){
3640 // Evaluation of the fit:
3641 // Calculation of the parameters
3642 // Calculation of the covariance matrix
3645 Double_t denominator = fSums[0] * fSums[4] - fSums[1] *fSums[1];
3646 if(denominator==0) return;
3648 // for(Int_t isum = 0; isum < 5; isum++)
3649 // printf("fSums[%d] = %f\n", isum, fSums[isum]);
3650 // printf("denominator = %f\n", denominator);
3651 fParams[0] = (fSums[2] * fSums[4] - fSums[1] * fSums[3])/ denominator;
3652 fParams[1] = (fSums[0] * fSums[3] - fSums[1] * fSums[2]) / denominator;
3653 // printf("fParams[0] = %f, fParams[1] = %f\n", fParams[0], fParams[1]);
3655 // Covariance matrix
3656 fCovarianceMatrix[0] = fSums[4] / fSums[0] - fSums[1] * fSums[1] / (fSums[0] * fSums[0]);
3657 fCovarianceMatrix[1] = fSums[5] / fSums[0] - fSums[2] * fSums[2] / (fSums[0] * fSums[0]);
3658 fCovarianceMatrix[2] = fSums[3] / fSums[0] - fSums[1] * fSums[2] / (fSums[0] * fSums[0]);
3661 //_____________________________________________________________________________
3662 Double_t AliTRDtrackerV1::AliTRDLeastSquare::GetFunctionValue(Double_t *xpos) const {
3664 // Returns the Function value of the fitted function at a given x-position
3666 return fParams[0] + fParams[1] * (*xpos);
3669 //_____________________________________________________________________________
3670 void AliTRDtrackerV1::AliTRDLeastSquare::GetCovarianceMatrix(Double_t *storage) const {
3672 // Copies the values of the covariance matrix into the storage
3674 memcpy(storage, fCovarianceMatrix, sizeof(Double_t) * 3);
3677 //_____________________________________________________________________________
3678 void AliTRDtrackerV1::AliTRDLeastSquare::Reset(){
3682 memset(fParams, 0, sizeof(Double_t) * 2);
3683 memset(fCovarianceMatrix, 0, sizeof(Double_t) * 3);
3684 memset(fSums, 0, sizeof(Double_t) * 6);
3687 ///////////////////////////////////////////////////////
3689 // Resources of class AliTRDtrackFitterRieman //
3691 ///////////////////////////////////////////////////////
3693 //_____________________________________________________________________________
3694 AliTRDtrackerV1::AliTRDtrackFitterRieman::AliTRDtrackFitterRieman():
3700 fSysClusterError(0.)
3703 // Default constructor
3705 fZfitter = new AliTRDLeastSquare;
3706 fCovarPolY = new TMatrixD(3,3);
3707 fCovarPolZ = new TMatrixD(2,2);
3708 memset(fTracklets, 0, sizeof(AliTRDseedV1 *) * 6);
3709 memset(fParameters, 0, sizeof(Double_t) * 5);
3710 memset(fSumPolY, 0, sizeof(Double_t) * 5);
3711 memset(fSumPolZ, 0, sizeof(Double_t) * 2);
3714 //_____________________________________________________________________________
3715 AliTRDtrackerV1::AliTRDtrackFitterRieman::~AliTRDtrackFitterRieman(){
3719 if(fZfitter) delete fZfitter;
3720 if(fCovarPolY) delete fCovarPolY;
3721 if(fCovarPolZ) delete fCovarPolZ;
3724 //_____________________________________________________________________________
3725 void AliTRDtrackerV1::AliTRDtrackFitterRieman::Reset(){
3730 fTrackFitter->StoreData(kTRUE);
3731 fTrackFitter->ClearPoints();
3737 memset(fTracklets, 0, sizeof(AliTRDseedV1 *) * AliTRDgeometry::kNlayer);
3738 memset(fParameters, 0, sizeof(Double_t) * 5);
3739 memset(fSumPolY, 0, sizeof(Double_t) * 5);
3740 memset(fSumPolZ, 0, sizeof(Double_t) * 2);
3741 for(Int_t irow = 0; irow < fCovarPolY->GetNrows(); irow++)
3742 for(Int_t icol = 0; icol < fCovarPolY->GetNcols(); icol++){
3743 (*fCovarPolY)(irow, icol) = 0.;
3744 if(irow < 2 && icol < 2)
3745 (*fCovarPolZ)(irow, icol) = 0.;
3749 //_____________________________________________________________________________
3750 void AliTRDtrackerV1::AliTRDtrackFitterRieman::SetTracklet(Int_t itr, AliTRDseedV1 *tracklet){
3752 // Add tracklet into the fitter
3754 if(itr >= AliTRDgeometry::kNlayer) return;
3755 fTracklets[itr] = tracklet;
3758 //_____________________________________________________________________________
3759 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::Eval(){
3762 // 1. Apply linear transformation and store points in the fitter
3763 // 2. Evaluate the fit
3764 // 3. Check if the result of the fit in z-direction is reasonable
3766 // 3a. Fix the parameters 3 and 4 with the results of a simple least
3768 // 3b. Redo the fit with the fixed parameters
3769 // 4. Store fit results (parameters and errors)
3774 fXref = CalculateReferenceX();
3775 for(Int_t il = 0; il < AliTRDgeometry::kNlayer; il++) UpdateFitters(fTracklets[il]);
3776 if(!fTrackFitter->GetNpoints()) return 1e10;
3778 fTrackFitter->Eval();
3780 fParameters[3] = fTrackFitter->GetParameter(3);
3781 fParameters[4] = fTrackFitter->GetParameter(4);
3782 if(!CheckAcceptable(fParameters[3], fParameters[4])) {
3783 fTrackFitter->FixParameter(3, fZfitter->GetFunctionValue(&fXref));
3784 fTrackFitter->FixParameter(4, fZfitter->GetFunctionParameter(1));
3785 fTrackFitter->Eval();
3786 fTrackFitter->ReleaseParameter(3);
3787 fTrackFitter->ReleaseParameter(4);
3788 fParameters[3] = fTrackFitter->GetParameter(3);
3789 fParameters[4] = fTrackFitter->GetParameter(4);
3791 // Update the Fit Parameters and the errors
3792 fParameters[0] = fTrackFitter->GetParameter(0);
3793 fParameters[1] = fTrackFitter->GetParameter(1);
3794 fParameters[2] = fTrackFitter->GetParameter(2);
3796 // Prepare Covariance estimation
3797 (*fCovarPolY)(0,0) = fSumPolY[0]; (*fCovarPolY)(1,1) = fSumPolY[2]; (*fCovarPolY)(2,2) = fSumPolY[4];
3798 (*fCovarPolY)(1,0) = (*fCovarPolY)(0,1) = fSumPolY[1];
3799 (*fCovarPolY)(2,0) = (*fCovarPolY)(0,2) = fSumPolY[2];
3800 (*fCovarPolY)(2,1) = (*fCovarPolY)(1,2) = fSumPolY[3];
3801 fCovarPolY->Invert();
3802 (*fCovarPolZ)(0,0) = fSumPolZ[0]; (*fCovarPolZ)(1,1) = fSumPolZ[2];
3803 (*fCovarPolZ)(1,0) = (*fCovarPolZ)(0,1) = fSumPolZ[1];
3804 fCovarPolZ->Invert();
3805 return fTrackFitter->GetChisquare() / fTrackFitter->GetNpoints();
3808 //_____________________________________________________________________________
3809 void AliTRDtrackerV1::AliTRDtrackFitterRieman::UpdateFitters(AliTRDseedV1 *tracklet){
3811 // Does the transformations and updates the fitters
3812 // The following transformation is applied
3814 AliTRDcluster *cl = NULL;
3815 Double_t x, y, z, dx, t, w, we, yerr, zerr;
3817 if(!tracklet || !tracklet->IsOK()) return;
3818 Double_t tilt = tracklet->GetTilt();
3819 for(Int_t itb = 0; itb < AliTRDseedV1::kNclusters; itb++){
3820 if(!(cl = tracklet->GetClusters(itb))) continue;
3821 if(!cl->IsInChamber()) continue;
3822 if (!tracklet->IsUsable(itb)) continue;
3829 uvt[0] = 2. * x * t;
3831 uvt[2] = 2. * tilt * t;
3832 uvt[3] = 2. * tilt * dx * t;
3833 w = 2. * (y + tilt*z) * t;
3834 // error definition changes for the different calls
3836 we *= TMath::Sqrt(cl->GetSigmaY2()+tilt*tilt*cl->GetSigmaZ2());
3837 // Update sums for error calculation
3838 yerr = 1./(TMath::Sqrt(cl->GetSigmaY2()) + fSysClusterError);
3840 zerr = 1./cl->GetSigmaZ2();
3841 for(Int_t ipol = 0; ipol < 5; ipol++){
3842 fSumPolY[ipol] += yerr;
3845 fSumPolZ[ipol] += zerr;
3849 fTrackFitter->AddPoint(uvt, w, we);
3850 fZfitter->AddPoint(&x, z, static_cast<Double_t>(TMath::Sqrt(cl->GetSigmaZ2())));
3854 //_____________________________________________________________________________
3855 Bool_t AliTRDtrackerV1::AliTRDtrackFitterRieman::CheckAcceptable(Double_t offset, Double_t slope){
3857 // Check whether z-results are acceptable
3858 // Definition: Distance between tracklet fit and track fit has to be
3859 // less then half a padlength
3860 // Point of comparision is at the anode wire
3862 Bool_t acceptablez = kTRUE;
3863 Double_t zref = 0.0;
3864 for (Int_t iLayer = 0; iLayer < kNPlanes; iLayer++) {
3865 if(!fTracklets[iLayer]->IsOK()) continue;
3866 zref = offset + slope * (fTracklets[iLayer]->GetX0() - fXref);
3867 if (TMath::Abs(fTracklets[iLayer]->GetZfit(0) - zref) > fTracklets[iLayer]->GetPadLength() * 0.5 + 1.0)
3868 acceptablez = kFALSE;
3873 //_____________________________________________________________________________
3874 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::GetYat(Double_t x) const {
3876 // Calculate y position out of the track parameters
3877 // y: R^2 = (x - x0)^2 + (y - y0)^2
3878 // => y = y0 +/- Sqrt(R^2 - (x - x0)^2)
3879 // R = Sqrt() = 1/Curvature
3880 // => y = y0 +/- Sqrt(1/Curvature^2 - (x - x0)^2)
3883 Double_t disc = (x * fParameters[0] + fParameters[1]);
3884 disc = 1 - fParameters[0]*fParameters[2] + fParameters[1]*fParameters[1] - disc*disc;
3886 disc = TMath::Sqrt(disc);
3887 y = (1.0 - disc) / fParameters[0];
3892 //_____________________________________________________________________________
3893 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::GetZat(Double_t x) const {
3895 // Return z position for a given x position
3896 // Simple linear function
3898 return fParameters[3] + fParameters[4] * (x - fXref);
3901 //_____________________________________________________________________________
3902 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::GetDyDxAt(Double_t x) const {
3904 // Calculate dydx at a given radial position out of the track parameters
3905 // dy: R^2 = (x - x0)^2 + (y - y0)^2
3906 // => y = +/- Sqrt(R^2 - (x - x0)^2) + y0
3907 // => dy/dx = (x - x0)/Sqrt(R^2 - (x - x0)^2)
3908 // Curvature: cr = 1/R = a/Sqrt(1 + b^2 - c*a)
3909 // => dy/dx = (x - x0)/(1/(cr^2) - (x - x0)^2)
3911 Double_t x0 = -fParameters[1] / fParameters[0];
3912 Double_t curvature = GetCurvature();
3914 if (-fParameters[2] * fParameters[0] + fParameters[1] * fParameters[1] + 1 > 0) {
3915 if (1.0/(curvature * curvature) - (x - x0) * (x - x0) > 0.0) {
3916 Double_t yderiv = (x - x0) / TMath::Sqrt(1.0/(curvature * curvature) - (x - x0) * (x - x0));
3917 if (fParameters[0] < 0) yderiv *= -1.0;
3924 //_____________________________________________________________________________
3925 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::GetCurvature() const {
3927 // Calculate track curvature
3930 Double_t curvature = 1.0 + fParameters[1]*fParameters[1] - fParameters[2]*fParameters[0];
3931 if (curvature > 0.0)
3932 curvature = fParameters[0] / TMath::Sqrt(curvature);
3936 //_____________________________________________________________________________
3937 void AliTRDtrackerV1::AliTRDtrackFitterRieman::GetCovAt(Double_t x, Double_t *cov) const {
3939 // Error Definition according to gauss error propagation
3941 TMatrixD transform(3,3);
3942 transform(0,0) = transform(1,1) = transform(2,2) = 1;
3943 transform(0,1) = transform(1,2) = x;
3944 transform(0,2) = x*x;
3945 TMatrixD covariance(transform, TMatrixD::kMult, *fCovarPolY);
3946 covariance *= transform.T();
3947 cov[0] = covariance(0,0);
3948 TMatrixD transformZ(2,2);
3949 transformZ(0,0) = transformZ(1,1) = 1;
3950 transformZ(0,1) = x;
3951 TMatrixD covarZ(transformZ, TMatrixD::kMult, *fCovarPolZ);
3952 covarZ *= transformZ.T();
3953 cov[1] = covarZ(0,0);
3957 //____________________________________________________________________
3958 Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::CalculateReferenceX(){
3960 // Calculates the reference x-position for the tilted Rieman fit defined as middle
3961 // of the stack (middle between layers 2 and 3). For the calculation all the tracklets
3962 // are taken into account
3964 // Parameters: - Array of tracklets(AliTRDseedV1)
3966 // Output: - The reference x-position(Float_t)
3968 Int_t nDistances = 0;
3969 Float_t meanDistance = 0.;
3970 Int_t startIndex = 5;
3971 for(Int_t il =5; il > 0; il--){
3972 if(fTracklets[il]->IsOK() && fTracklets[il -1]->IsOK()){
3973 Float_t xdiff = fTracklets[il]->GetX0() - fTracklets[il -1]->GetX0();
3974 meanDistance += xdiff;
3977 if(fTracklets[il]->IsOK()) startIndex = il;
3979 if(fTracklets[0]->IsOK()) startIndex = 0;
3981 // We should normally never get here
3982 Float_t xpos[2]; memset(xpos, 0, sizeof(Float_t) * 2);
3983 Int_t iok = 0, idiff = 0;
3984 // This attempt is worse and should be avoided:
3985 // check for two chambers which are OK and repeat this without taking the mean value
3986 // Strategy avoids a division by 0;
3987 for(Int_t il = 5; il >= 0; il--){
3988 if(fTracklets[il]->IsOK()){
3989 xpos[iok] = fTracklets[il]->GetX0();
3993 if(iok) idiff++; // to get the right difference;
3997 meanDistance = (xpos[0] - xpos[1])/idiff;
4000 // we have do not even have 2 layers which are OK? The we do not need to fit at all
4005 meanDistance /= nDistances;
4007 return fTracklets[startIndex]->GetX0() + (2.5 - startIndex) * meanDistance - 0.5 * (AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick());