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Adding multiplicity cut (Marek)
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1/**************************************************************************
2* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
3* *
4* Author: The ALICE Off-line Project. *
5* Contributors are mentioned in the code where appropriate. *
6* *
7* Permission to use, copy, modify and distribute this software and its *
8* documentation strictly for non-commercial purposes is hereby granted *
9* without fee, provided that the above copyright notice appears in all *
10* copies and that both the copyright notice and this permission notice *
11* appear in the supporting documentation. The authors make no claims *
12* about the suitability of this software for any purpose. It is *
13* provided "as is" without express or implied warranty. *
14**************************************************************************/
15
16/* $Id$ */
17
18///////////////////////////////////////////////////////////////////////////////
19// //
20// Track finder //
21// //
22// Authors: //
23// Alex Bercuci <A.Bercuci@gsi.de> //
24// Markus Fasel <M.Fasel@gsi.de> //
25// //
26///////////////////////////////////////////////////////////////////////////////
27
28#include <TBranch.h>
29#include <TDirectory.h>
30#include <TLinearFitter.h>
31#include <TTree.h>
32#include <TClonesArray.h>
33#include <TTreeStream.h>
34#include <TGeoMatrix.h>
35#include <TGeoManager.h>
36
37#include "AliLog.h"
38#include "AliMathBase.h"
39#include "AliESDEvent.h"
40#include "AliGeomManager.h"
41#include "AliRieman.h"
42#include "AliTrackPointArray.h"
43
44#include "AliTRDgeometry.h"
45#include "AliTRDpadPlane.h"
46#include "AliTRDcalibDB.h"
47#include "AliTRDReconstructor.h"
48#include "AliTRDCalibraFillHisto.h"
49#include "AliTRDrecoParam.h"
50
51#include "AliTRDcluster.h"
52#include "AliTRDdigitsParam.h"
53#include "AliTRDseedV1.h"
54#include "AliTRDtrackV1.h"
55#include "AliTRDtrackerV1.h"
56#include "AliTRDtrackerDebug.h"
57#include "AliTRDtrackingChamber.h"
58#include "AliTRDchamberTimeBin.h"
59
60ClassImp(AliTRDtrackerV1)
61ClassImp(AliTRDtrackerV1::AliTRDLeastSquare)
62ClassImp(AliTRDtrackerV1::AliTRDtrackFitterRieman)
63
64const Float_t AliTRDtrackerV1::fgkMinClustersInTrack = 0.5; //
65const Float_t AliTRDtrackerV1::fgkLabelFraction = 0.8; //
66const Double_t AliTRDtrackerV1::fgkMaxChi2 = 12.0; //
67const Double_t AliTRDtrackerV1::fgkMaxSnp = 0.95; // Maximum local sine of the azimuthal angle
68const Double_t AliTRDtrackerV1::fgkMaxStep = 2.0; // Maximal step size in propagation
69Double_t AliTRDtrackerV1::fgTopologicQA[kNConfigs] = {
70 0.5112, 0.5112, 0.5112, 0.0786, 0.0786,
71 0.0786, 0.0786, 0.0579, 0.0579, 0.0474,
72 0.0474, 0.0408, 0.0335, 0.0335, 0.0335
73};
74const Double_t AliTRDtrackerV1::fgkX0[kNPlanes] = {
75 300.2, 312.8, 325.4, 338.0, 350.6, 363.2};
76Int_t AliTRDtrackerV1::fgNTimeBins = 0;
77AliRieman* AliTRDtrackerV1::fgRieman = NULL;
78TLinearFitter* AliTRDtrackerV1::fgTiltedRieman = NULL;
79TLinearFitter* AliTRDtrackerV1::fgTiltedRiemanConstrained = NULL;
80
81//____________________________________________________________________
82AliTRDtrackerV1::AliTRDtrackerV1(AliTRDReconstructor *rec)
83 :AliTracker()
84 ,fkReconstructor(NULL)
85 ,fkRecoParam(NULL)
86 ,fGeom(NULL)
87 ,fClusters(NULL)
88 ,fTracklets(NULL)
89 ,fTracks(NULL)
90 ,fTracksESD(NULL)
91 ,fSieveSeeding(0)
92{
93 //
94 // Default constructor.
95 //
96
97 SetReconstructor(rec); // initialize reconstructor
98
99 // initialize geometry
100 if(!AliGeomManager::GetGeometry()){
101 AliFatal("Could not get geometry.");
102 }
103 fGeom = new AliTRDgeometry();
104 fGeom->CreateClusterMatrixArray();
105 TGeoHMatrix *matrix = NULL;
106 Double_t loc[] = {0., 0., 0.};
107 Double_t glb[] = {0., 0., 0.};
108 for(Int_t ily=kNPlanes; ily--;){
109 Int_t ism = 0;
110 while(!(matrix = fGeom->GetClusterMatrix(AliTRDgeometry::GetDetector(ily, 2, ism)))) ism++;
111 if(!matrix){
112 AliError(Form("Could not get transformation matrix for layer %d. Use default.", ily));
113 fR[ily] = fgkX0[ily];
114 continue;
115 }
116 matrix->LocalToMaster(loc, glb);
117 fR[ily] = glb[0]+ AliTRDgeometry::AnodePos()-.5*AliTRDgeometry::AmThick() - AliTRDgeometry::DrThick();
118 }
119
120 // initialize cluster containers
121 for (Int_t isector = 0; isector < AliTRDgeometry::kNsector; isector++) new(&fTrSec[isector]) AliTRDtrackingSector(fGeom, isector);
122
123 // initialize arrays
124 memset(fTrackQuality, 0, kMaxTracksStack*sizeof(Double_t));
125 memset(fSeedLayer, 0, kMaxTracksStack*sizeof(Int_t));
126 memset(fSeedTB, 0, kNSeedPlanes*sizeof(AliTRDchamberTimeBin*));
127 fTracksESD = new TClonesArray("AliESDtrack", 2*kMaxTracksStack);
128 fTracksESD->SetOwner();
129}
130
131//____________________________________________________________________
132AliTRDtrackerV1::~AliTRDtrackerV1()
133{
134 //
135 // Destructor
136 //
137
138 if(fgRieman) delete fgRieman; fgRieman = NULL;
139 if(fgTiltedRieman) delete fgTiltedRieman; fgTiltedRieman = NULL;
140 if(fgTiltedRiemanConstrained) delete fgTiltedRiemanConstrained; fgTiltedRiemanConstrained = NULL;
141 for(Int_t isl =0; isl<kNSeedPlanes; isl++) if(fSeedTB[isl]) delete fSeedTB[isl];
142 if(fTracksESD){ fTracksESD->Delete(); delete fTracksESD; }
143 if(fTracks) {fTracks->Delete(); delete fTracks;}
144 if(fTracklets) {fTracklets->Delete(); delete fTracklets;}
145 if(fClusters) {
146 fClusters->Delete(); delete fClusters;
147 }
148 if(fGeom) delete fGeom;
149}
150
151//____________________________________________________________________
152Int_t AliTRDtrackerV1::Clusters2Tracks(AliESDEvent *esd)
153{
154 //
155 // Steering stand alone tracking for full TRD detector
156 //
157 // Parameters :
158 // esd : The ESD event. On output it contains
159 // the ESD tracks found in TRD.
160 //
161 // Output :
162 // Number of tracks found in the TRD detector.
163 //
164 // Detailed description
165 // 1. Launch individual SM trackers.
166 // See AliTRDtrackerV1::Clusters2TracksSM() for details.
167 //
168
169 if(!fkRecoParam){
170 AliError("Reconstruction configuration not initialized. Call first AliTRDReconstructor::SetRecoParam().");
171 return 0;
172 }
173
174 //AliInfo("Start Track Finder ...");
175 Int_t ntracks = 0;
176 for(int ism=0; ism<AliTRDgeometry::kNsector; ism++){
177 // for(int ism=1; ism<2; ism++){
178 //AliInfo(Form("Processing supermodule %i ...", ism));
179 ntracks += Clusters2TracksSM(ism, esd);
180 }
181 AliInfo(Form("Number of tracks: !TRDin[%d]", ntracks));
182 return ntracks;
183}
184
185
186//_____________________________________________________________________________
187Bool_t AliTRDtrackerV1::GetTrackPoint(Int_t index, AliTrackPoint &p) const
188{
189 //AliInfo(Form("Asking for tracklet %d", index));
190
191 // reset position of the point before using it
192 p.SetXYZ(0., 0., 0.);
193 AliTRDseedV1 *tracklet = GetTracklet(index);
194 if (!tracklet) return kFALSE;
195
196 // get detector for this tracklet
197 Int_t det = tracklet->GetDetector();
198 Int_t sec = fGeom->GetSector(det);
199 Double_t alpha = (sec+.5)*AliTRDgeometry::GetAlpha(),
200 sinA = TMath::Sin(alpha),
201 cosA = TMath::Cos(alpha);
202 Double_t local[3];
203 local[0] = tracklet->GetX();
204 local[1] = tracklet->GetY();
205 local[2] = tracklet->GetZ();
206 Double_t global[3];
207 fGeom->RotateBack(det, local, global);
208
209 Double_t cov2D[3]; Float_t cov[6];
210 tracklet->GetCovAt(local[0], cov2D);
211 cov[0] = cov2D[0]*sinA*sinA;
212 cov[1] =-cov2D[0]*sinA*cosA;
213 cov[2] =-cov2D[1]*sinA;
214 cov[3] = cov2D[0]*cosA*cosA;
215 cov[4] = cov2D[1]*cosA;
216 cov[5] = cov2D[2];
217 // store the global position of the tracklet and its covariance matrix in the track point
218 p.SetXYZ(global[0],global[1],global[2], cov);
219
220 // setting volume id
221 AliGeomManager::ELayerID iLayer = AliGeomManager::ELayerID(AliGeomManager::kTRD1+fGeom->GetLayer(det));
222 Int_t modId = fGeom->GetSector(det) * AliTRDgeometry::kNstack + fGeom->GetStack(det);
223 UShort_t volid = AliGeomManager::LayerToVolUID(iLayer, modId);
224 p.SetVolumeID(volid);
225
226 return kTRUE;
227}
228
229//____________________________________________________________________
230TLinearFitter* AliTRDtrackerV1::GetTiltedRiemanFitter()
231{
232 if(!fgTiltedRieman) fgTiltedRieman = new TLinearFitter(4, "hyp4");
233 return fgTiltedRieman;
234}
235
236//____________________________________________________________________
237TLinearFitter* AliTRDtrackerV1::GetTiltedRiemanFitterConstraint()
238{
239 if(!fgTiltedRiemanConstrained) fgTiltedRiemanConstrained = new TLinearFitter(2, "hyp2");
240 return fgTiltedRiemanConstrained;
241}
242
243//____________________________________________________________________
244AliRieman* AliTRDtrackerV1::GetRiemanFitter()
245{
246 if(!fgRieman) fgRieman = new AliRieman(AliTRDseedV1::kNtb * AliTRDgeometry::kNlayer);
247 return fgRieman;
248}
249
250//_____________________________________________________________________________
251Int_t AliTRDtrackerV1::PropagateBack(AliESDEvent *event)
252{
253// Propagation of ESD tracks from TPC to TOF detectors and building of the TRD track. For building
254// a TRD track an ESD track is used as seed. The informations obtained on the TRD track (measured points,
255// covariance, PID, etc.) are than used to update the corresponding ESD track.
256// Each track seed is first propagated to the geometrical limit of the TRD detector.
257// Its prolongation is searched in the TRD and if corresponding clusters are found tracklets are
258// constructed out of them (see AliTRDseedV1::AttachClusters()) and the track is updated.
259// Otherwise the ESD track is left unchanged.
260//
261// The following steps are performed:
262// 1. Selection of tracks based on the variance in the y-z plane.
263// 2. Propagation to the geometrical limit of the TRD volume. If track propagation fails the AliESDtrack::kTRDStop is set.
264// 3. Prolongation inside the fiducial volume (see AliTRDtrackerV1::FollowBackProlongation()) and marking
265// the following status bits:
266// - AliESDtrack::kTRDin - if the tracks enters the TRD fiducial volume
267// - AliESDtrack::kTRDStop - if the tracks fails propagation
268// - AliESDtrack::kTRDbackup - if the tracks fulfills chi2 conditions and qualify for refitting
269// 4. Writting to friends, PID, MC label, quality etc. Setting status bit AliESDtrack::kTRDout.
270// 5. Propagation to TOF. If track propagation fails the AliESDtrack::kTRDStop is set.
271//
272
273 if(!fClusters || !fClusters->GetEntriesFast()){
274 AliInfo("No TRD clusters");
275 return 0;
276 }
277 AliTRDCalibraFillHisto *calibra = AliTRDCalibraFillHisto::Instance(); // Calibration monitor
278 if (!calibra) AliInfo("Could not get Calibra instance");
279 if (!fgNTimeBins) fgNTimeBins = fkReconstructor->GetNTimeBins();
280
281 // Define scalers
282 Int_t nFound = 0, // number of tracks found
283 nBacked = 0, // number of tracks backed up for refit
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;
288
289 Float_t *quality = NULL;
290 Int_t *index = NULL;
291 nSeeds = event->GetNumberOfTracks();
292 // Sort tracks according to quality
293 // (covariance in the yz plane)
294 if(nSeeds){
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];
302 }
303 TMath::Sort(nSeeds, quality, index,kFALSE);
304 }
305
306 // Propagate all seeds
307 Int_t expectedClr;
308 AliTRDtrackV1 track;
309 for (Int_t iSeed = 0; iSeed < nSeeds; iSeed++) {
310
311 // Get the seeds in sorted sequence
312 AliESDtrack *seed = event->GetTrack(index[iSeed]);
313 Float_t p4 = seed->GetC(seed->GetBz());
314
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;
319
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);
324 continue;
325 }
326 if(!AdjustSector(&track)){
327 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
328 continue;
329 }
330 if(TMath::Abs(track.GetSnp()) > fgkMaxSnp) {
331 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
332 continue;
333 }
334
335 nTPCseeds++;
336
337 // store track status at TRD entrance
338 seed->UpdateTrackParams(&track, AliESDtrack::kTRDbackup);
339
340 // prepare track and do propagation in the TRD
341 track.SetReconstructor(fkReconstructor);
342 track.SetKink(Bool_t(seed->GetKinkIndex(0)));
343 track.SetPrimary(status & AliESDtrack::kTPCin);
344 expectedClr = FollowBackProlongation(track);
345 // check if track entered the TRD fiducial volume
346 if(track.GetTrackIn()){
347 seed->UpdateTrackParams(&track, AliESDtrack::kTRDin);
348 nTRDseeds++;
349 }
350 // check if track was stopped in the TRD
351 if (expectedClr<0){
352 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
353 continue;
354 }
355
356 if(expectedClr){
357 nFound++;
358 // computes PID for track
359 track.CookPID();
360 // update calibration references using this track
361 if(calibra->GetHisto2d()) calibra->UpdateHistogramsV1(&track);
362 // save calibration object
363 if (fkRecoParam->GetStreamLevel(AliTRDrecoParam::kTracker) > 0) {
364 AliTRDtrackV1 *calibTrack = new AliTRDtrackV1(track);
365 calibTrack->SetOwner();
366 seed->AddCalibObject(calibTrack);
367 }
368 //update ESD track
369 seed->UpdateTrackParams(&track, AliESDtrack::kTRDout);
370 track.UpdateESDtrack(seed);
371 }
372
373 if ((TMath::Abs(track.GetC(track.GetBz()) - p4) / TMath::Abs(p4) < 0.2) ||(track.Pt() > 0.8)) {
374
375 // Make backup for back propagation
376 Int_t foundClr = track.GetNumberOfClusters();
377 if (foundClr >= foundMin) {
378 track.CookLabel(1. - fgkLabelFraction);
379 //if(track.GetBackupTrack()) UseClusters(track.GetBackupTrack());
380
381 // Sign only gold tracks
382 if (track.GetChi2() / track.GetNumberOfClusters() < 4) {
383 //if ((seed->GetKinkIndex(0) == 0) && (track.Pt() < 1.5)) UseClusters(&track);
384 }
385 Bool_t isGold = kFALSE;
386
387 // Full gold track
388 if (track.GetChi2() / track.GetNumberOfClusters() < 5) {
389 if (track.GetBackupTrack()) seed->UpdateTrackParams(track.GetBackupTrack(),AliESDtrack::kTRDbackup);
390 nBacked++;
391 isGold = kTRUE;
392 }
393
394 // Almost gold track
395 if ((!isGold) && (track.GetNCross() == 0) && (track.GetChi2() / track.GetNumberOfClusters() < 7)) {
396 //seed->UpdateTrackParams(track, AliESDtrack::kTRDbackup);
397 if (track.GetBackupTrack()) seed->UpdateTrackParams(track.GetBackupTrack(),AliESDtrack::kTRDbackup);
398 nBacked++;
399 isGold = kTRUE;
400 }
401
402 if ((!isGold) && (track.GetBackupTrack())) {
403 if ((track.GetBackupTrack()->GetNumberOfClusters() > foundMin) && ((track.GetBackupTrack()->GetChi2()/(track.GetBackupTrack()->GetNumberOfClusters()+1)) < 7)) {
404 seed->UpdateTrackParams(track.GetBackupTrack(),AliESDtrack::kTRDbackup);
405 nBacked++;
406 isGold = kTRUE;
407 }
408 }
409 }
410 }
411
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)
423 if(gGeoManager){
424 gGeoManager->cd(Form("/ALIC_1/B077_1/BSEGMO%d_1/BTOF%d_1", sm, sm));
425 TGeoHMatrix *m = NULL;
426 Double_t loc[]={0., 0., -.5*29.05}, glob[3];
427
428 if((m=gGeoManager->GetCurrentMatrix())){
429 m->LocalToMaster(loc, glob);
430 xtof = TMath::Sqrt(glob[0]*glob[0]+glob[1]*glob[1]);
431 }
432 }
433 if(xtof > (fgkMaxStep + track.GetX()) && !PropagateToX(track, xtof, fgkMaxStep)){
434 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
435 continue;
436 }
437 if(!AdjustSector(&track)){
438 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
439 continue;
440 }
441 if(TMath::Abs(track.GetSnp()) > fgkMaxSnp){
442 seed->UpdateTrackParams(&track, AliESDtrack::kTRDStop);
443 continue;
444 }
445 //seed->UpdateTrackParams(&track, AliESDtrack::kTRDout);
446 // TODO obsolete - delete
447 seed->SetTRDQuality(track.StatusForTOF());
448 }
449 seed->SetTRDBudget(track.GetBudget(0));
450 }
451 if(index) delete [] index;
452 if(quality) delete [] quality;
453
454 AliInfo(Form("Number of seeds: TPCout[%d] TRDin[%d]", nTPCseeds, nTRDseeds));
455 AliInfo(Form("Number of tracks: TRDout[%d] TRDbackup[%d]", nFound, nBacked));
456
457 // run stand alone tracking
458 if (fkReconstructor->IsSeeding()) Clusters2Tracks(event);
459
460 return 0;
461}
462
463
464//____________________________________________________________________
465Int_t AliTRDtrackerV1::RefitInward(AliESDEvent *event)
466{
467 //
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)
473 //
474
475 Int_t nseed = 0; // contor for loaded seeds
476 Int_t found = 0; // contor for updated TRD tracks
477
478
479 if(!fClusters || !fClusters->GetEntriesFast()){
480 AliInfo("No TRD clusters");
481 return 0;
482 }
483 AliTRDtrackV1 track;
484 for (Int_t itrack = 0; itrack < event->GetNumberOfTracks(); itrack++) {
485 AliESDtrack *seed = event->GetTrack(itrack);
486 ULong_t status = seed->GetStatus();
487
488 new(&track) AliTRDtrackV1(*seed);
489 if (track.GetX() < 270.0) {
490 seed->UpdateTrackParams(&track, AliESDtrack::kTRDbackup);
491 continue;
492 }
493
494 // reject tracks which failed propagation in the TRD or
495 // are produced by the TRD stand alone tracker
496 if(!(status & AliESDtrack::kTRDout)) continue;
497 if(!(status & AliESDtrack::kTRDin)) continue;
498 nseed++;
499
500 track.ResetCovariance(50.0);
501
502 // do the propagation and processing
503 Bool_t kUPDATE = kFALSE;
504 Double_t xTPC = 250.0;
505 if(FollowProlongation(track)){
506 // Update the friend track
507 if (fkRecoParam->GetStreamLevel(AliTRDrecoParam::kTracker) > 0){
508 TObject *o = NULL; Int_t ic = 0;
509 AliTRDtrackV1 *calibTrack = NULL;
510 while((o = seed->GetCalibObject(ic++))){
511 if(!(calibTrack = dynamic_cast<AliTRDtrackV1*>(o))) continue;
512 calibTrack->SetTrackOut(&track);
513 }
514 }
515
516 // Prolongate to TPC
517 if (PropagateToX(track, xTPC, fgkMaxStep)) { // -with update
518 seed->UpdateTrackParams(&track, AliESDtrack::kTRDrefit);
519 found++;
520 kUPDATE = kTRUE;
521 }
522 }
523
524 // Prolongate to TPC without update
525 if(!kUPDATE) {
526 AliTRDtrackV1 tt(*seed);
527 if (PropagateToX(tt, xTPC, fgkMaxStep)) seed->UpdateTrackParams(&tt, AliESDtrack::kTRDbackup);
528 }
529 }
530 AliInfo(Form("Number of seeds: TRDout[%d]", nseed));
531 AliInfo(Form("Number of tracks: TRDrefit[%d]", found));
532
533 return 0;
534}
535
536//____________________________________________________________________
537Int_t AliTRDtrackerV1::FollowProlongation(AliTRDtrackV1 &t)
538{
539 // Extrapolates the TRD track in the TPC direction.
540 //
541 // Parameters
542 // t : the TRD track which has to be extrapolated
543 //
544 // Output
545 // number of clusters attached to the track
546 //
547 // Detailed description
548 //
549 // Starting from current radial position of track <t> this function
550 // extrapolates the track through the 6 TRD layers. The following steps
551 // are being performed for each plane:
552 // 1. prepare track:
553 // a. get plane limits in the local x direction
554 // b. check crossing sectors
555 // c. check track inclination
556 // 2. search tracklet in the tracker list (see GetTracklet() for details)
557 // 3. evaluate material budget using the geo manager
558 // 4. propagate and update track using the tracklet information.
559 //
560 // Debug level 2
561 //
562
563 Int_t nClustersExpected = 0;
564 for (Int_t iplane = kNPlanes; iplane--;) {
565 Int_t index(-1);
566 AliTRDseedV1 *tracklet = GetTracklet(&t, iplane, index);
567 AliDebug(2, Form("Tracklet[%p] ly[%d] idx[%d]", (void*)tracklet, iplane, index));
568 if(!tracklet) continue;
569 if(!tracklet->IsOK()){
570 AliDebug(1, Form("Tracklet Det[%d] !OK", tracklet->GetDetector()));
571 continue;
572 }
573 Double_t x = tracklet->GetX();//GetX0();
574 // reject tracklets which are not considered for inward refit
575 if(x > t.GetX()+fgkMaxStep) continue;
576
577 // append tracklet to track
578 t.SetTracklet(tracklet, index);
579
580 if (x < (t.GetX()-fgkMaxStep) && !PropagateToX(t, x+fgkMaxStep, fgkMaxStep)) break;
581 if (!AdjustSector(&t)) break;
582
583 // Start global position
584 Double_t xyz0[3];
585 t.GetXYZ(xyz0);
586
587 // End global position
588 Double_t alpha = t.GetAlpha(), y, z;
589 if (!t.GetProlongation(x,y,z)) break;
590 Double_t xyz1[3];
591 xyz1[0] = x * TMath::Cos(alpha) - y * TMath::Sin(alpha);
592 xyz1[1] = x * TMath::Sin(alpha) + y * TMath::Cos(alpha);
593 xyz1[2] = z;
594
595 Double_t length = TMath::Sqrt(
596 (xyz0[0]-xyz1[0])*(xyz0[0]-xyz1[0]) +
597 (xyz0[1]-xyz1[1])*(xyz0[1]-xyz1[1]) +
598 (xyz0[2]-xyz1[2])*(xyz0[2]-xyz1[2])
599 );
600 if(length>0.){
601 // Get material budget
602 Double_t param[7];
603 if(AliTracker::MeanMaterialBudget(xyz0, xyz1, param)<=0.) break;
604 Double_t xrho= param[0]*param[4];
605 Double_t xx0 = param[1]; // Get mean propagation parameters
606
607 // Propagate and update
608 t.PropagateTo(x, xx0, xrho);
609 if (!AdjustSector(&t)) break;
610 }
611
612 Double_t cov[3]; tracklet->GetCovAt(x, cov);
613 Double_t p[2] = { tracklet->GetY(), tracklet->GetZ()};
614 Double_t chi2 = ((AliExternalTrackParam)t).GetPredictedChi2(p, cov);
615 if (chi2 < 1e+10 && ((AliExternalTrackParam&)t).Update(p, cov)){
616 // Register info to track
617 t.SetNumberOfClusters();
618 t.UpdateChi2(chi2);
619 nClustersExpected += tracklet->GetN();
620 }
621 }
622
623 if(fkRecoParam->GetStreamLevel(AliTRDrecoParam::kTracker) > 1){
624 Int_t index;
625 for(int iplane=0; iplane<AliTRDgeometry::kNlayer; iplane++){
626 AliTRDseedV1 *tracklet = GetTracklet(&t, iplane, index);
627 if(!tracklet) continue;
628 t.SetTracklet(tracklet, index);
629 }
630
631 if(fkReconstructor->IsDebugStreaming()){
632 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
633 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
634 AliTRDtrackV1 track(t);
635 track.SetOwner();
636 cstreamer << "FollowProlongation"
637 << "EventNumber=" << eventNumber
638 << "ncl=" << nClustersExpected
639 << "track.=" << &track
640 << "\n";
641 }
642 }
643 return nClustersExpected;
644
645}
646
647//_____________________________________________________________________________
648Int_t AliTRDtrackerV1::FollowBackProlongation(AliTRDtrackV1 &t)
649{
650// Extrapolates/Build the TRD track in the TOF direction.
651//
652// Parameters
653// t : the TRD track which has to be extrapolated
654//
655// Output
656// number of clusters attached to the track
657//
658// Starting from current radial position of track <t> this function
659// extrapolates the track through the 6 TRD layers. The following steps
660// are being performed for each plane:
661// 1. Propagate track to the entrance of the next chamber:
662// - get chamber limits in the radial direction
663// - check crossing sectors
664// - check track inclination
665// - check track prolongation against boundary conditions (see exclusion boundaries on AliTRDgeometry::IsOnBoundary())
666// 2. Build tracklet (see AliTRDseed::AttachClusters() for details) for this layer if needed. If only
667// Kalman filter is needed and tracklets are already linked to the track this step is skipped.
668// 3. Fit tracklet using the information from the Kalman filter.
669// 4. Propagate and update track at reference radial position of the tracklet.
670// 5. Register tracklet with the tracker and track; update pulls monitoring.
671//
672// Observation
673// 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:
674// - AliTRDtrackV1::kProlongation : track prolongation failed
675// - AliTRDtrackV1::kPropagation : track prolongation failed
676// - AliTRDtrackV1::kAdjustSector : failed during sector crossing
677// - AliTRDtrackV1::kSnp : too large bending
678// - AliTRDtrackV1::kTrackletInit : fail to initialize tracklet
679// - AliTRDtrackV1::kUpdate : fail to attach clusters or fit the tracklet
680// - AliTRDtrackV1::kUnknown : anything which is not covered before
681// 2. By default the status of the track before first TRD update is saved.
682//
683// Debug level 2
684//
685// Author
686// Alexandru Bercuci <A.Bercuci@gsi.de>
687//
688
689 Int_t n = 0;
690 Double_t driftLength = .5*AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick();
691 AliTRDtrackingChamber *chamber = NULL;
692
693 Int_t debugLevel = fkReconstructor->IsDebugStreaming() ? fkRecoParam->GetStreamLevel(AliTRDrecoParam::kTracker) : 0;
694 TTreeSRedirector *cstreamer = fkReconstructor->IsDebugStreaming() ? fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker) : 0x0;
695
696 Bool_t kStoreIn(kTRUE), // toggel store track params. at TRD entry
697 kStandAlone(kFALSE), // toggle tracker awarness of stand alone seeding
698 kUseTRD(fkRecoParam->IsOverPtThreshold(t.Pt()));// use TRD measurment to update Kalman
699
700 Int_t startLayer(0);
701 AliTRDseedV1 tracklet, *ptrTracklet = NULL;
702 // Special case for stand alone tracking
703 // - store all tracklets found by seeding
704 // - start propagation from first tracklet found
705 AliTRDseedV1 *tracklets[kNPlanes];
706 memset(tracklets, 0, sizeof(AliTRDseedV1 *) * kNPlanes);
707 for(Int_t ip(kNPlanes); ip--;){
708 if(!(tracklets[ip] = t.GetTracklet(ip))) continue;
709 t.UnsetTracklet(ip);
710 if(tracklets[ip]->IsOK()) startLayer=ip;
711 kStandAlone = kTRUE;
712 kUseTRD = kTRUE;
713 }
714 AliDebug(4, Form("SA[%c] Start[%d]\n"
715 " [0]idx[%d] traklet[%p]\n"
716 " [1]idx[%d] traklet[%p]\n"
717 " [2]idx[%d] traklet[%p]\n"
718 " [3]idx[%d] traklet[%p]\n"
719 " [4]idx[%d] traklet[%p]\n"
720 " [5]idx[%d] traklet[%p]"
721 , kStandAlone?'y':'n', startLayer
722 , t.GetTrackletIndex(0), (void*)tracklets[0]
723 , t.GetTrackletIndex(1), (void*)tracklets[1]
724 , t.GetTrackletIndex(2), (void*)tracklets[2]
725 , t.GetTrackletIndex(3), (void*)tracklets[3]
726 , t.GetTrackletIndex(4), (void*)tracklets[4]
727 , t.GetTrackletIndex(5), (void*)tracklets[5]));
728
729 // Loop through the TRD layers
730 TGeoHMatrix *matrix = NULL;
731 Double_t x, y, z;
732 for (Int_t ily=startLayer, sm=-1, stk=-1, det=-1; ily < AliTRDgeometry::kNlayer; ily++) {
733 AliDebug(2, Form("Propagate to x[%d] = %7.2f", ily, fR[ily]));
734
735 // rough estimate of the entry point
736 if (!t.GetProlongation(fR[ily], y, z)){
737 n=-1;
738 t.SetStatus(AliTRDtrackV1::kProlongation);
739 AliDebug(4, Form("Failed Rough Prolongation to ly[%d] x[%7.2f] y[%7.2f] z[%7.2f]", ily, fR[ily], y, z));
740 break;
741 }
742
743 // find sector / stack / detector
744 sm = t.GetSector();
745 // TODO cross check with y value !
746 stk = fGeom->GetStack(z, ily);
747 det = stk>=0 ? AliTRDgeometry::GetDetector(ily, stk, sm) : -1;
748 matrix = det>=0 ? fGeom->GetClusterMatrix(det) : NULL;
749 AliDebug(3, Form("Propagate to det[%3d]", det));
750
751 // check if supermodule/chamber is installed
752 if( !fGeom->GetSMstatus(sm) ||
753 stk<0. ||
754 fGeom->IsHole(ily, stk, sm) ||
755 !matrix ){
756 AliDebug(4, Form("Missing Geometry ly[%d]. Guess radial position", ily));
757 // propagate to the default radial position
758 if(fR[ily] > (fgkMaxStep + t.GetX()) && !PropagateToX(t, fR[ily], fgkMaxStep)){
759 n=-1;
760 t.SetStatus(AliTRDtrackV1::kPropagation);
761 AliDebug(4, "Failed Propagation [Missing Geometry]");
762 break;
763 }
764 if(!AdjustSector(&t)){
765 n=-1;
766 t.SetStatus(AliTRDtrackV1::kAdjustSector);
767 AliDebug(4, "Failed Adjust Sector [Missing Geometry]");
768 break;
769 }
770 if(TMath::Abs(t.GetSnp()) > fgkMaxSnp){
771 n=-1;
772 t.SetStatus(AliTRDtrackV1::kSnp);
773 AliDebug(4, "Failed Max Snp [Missing Geometry]");
774 break;
775 }
776 t.SetStatus(AliTRDtrackV1::kGeometry, ily);
777 continue;
778 }
779
780 // retrieve rotation matrix for the current chamber
781 Double_t loc[] = {AliTRDgeometry::AnodePos()- driftLength, 0., 0.};
782 Double_t glb[] = {0., 0., 0.};
783 matrix->LocalToMaster(loc, glb);
784
785 // Propagate to the radial distance of the current layer
786 x = glb[0] - fgkMaxStep;
787 if(x > (fgkMaxStep + t.GetX()) && !PropagateToX(t, x, fgkMaxStep)){
788 n=-1;
789 t.SetStatus(AliTRDtrackV1::kPropagation);
790 AliDebug(4, Form("Failed Initial Propagation to x[%7.2f]", x));
791 break;
792 }
793 if(!AdjustSector(&t)){
794 n=-1;
795 t.SetStatus(AliTRDtrackV1::kAdjustSector);
796 AliDebug(4, "Failed Adjust Sector Start");
797 break;
798 }
799 if(TMath::Abs(t.GetSnp()) > fgkMaxSnp) {
800 n=-1;
801 t.SetStatus(AliTRDtrackV1::kSnp);
802 AliDebug(4, Form("Failed Max Snp[%f] MaxSnp[%f]", t.GetSnp(), fgkMaxSnp));
803 break;
804 }
805 Bool_t doRecalculate = kFALSE;
806 if(sm != t.GetSector()){
807 sm = t.GetSector();
808 doRecalculate = kTRUE;
809 }
810 if(stk != fGeom->GetStack(z, ily)){
811 stk = fGeom->GetStack(z, ily);
812 doRecalculate = kTRUE;
813 }
814 if(doRecalculate){
815 det = AliTRDgeometry::GetDetector(ily, stk, sm);
816 if(!(matrix = fGeom->GetClusterMatrix(det))){
817 t.SetStatus(AliTRDtrackV1::kGeometry, ily);
818 AliDebug(4, Form("Failed Geometry Matrix ly[%d]", ily));
819 continue;
820 }
821 matrix->LocalToMaster(loc, glb);
822 x = glb[0] - fgkMaxStep;
823 }
824
825 // check if track is well inside fiducial volume
826 if (!t.GetProlongation(x+fgkMaxStep, y, z)) {
827 n=-1;
828 t.SetStatus(AliTRDtrackV1::kProlongation);
829 AliDebug(4, Form("Failed Prolongation to x[%7.2f] y[%7.2f] z[%7.2f]", x+fgkMaxStep, y, z));
830 break;
831 }
832 if(fGeom->IsOnBoundary(det, y, z, .5)){
833 t.SetStatus(AliTRDtrackV1::kBoundary, ily);
834 AliDebug(4, "Failed Track on Boundary");
835 continue;
836 }
837 // mark track as entering the FIDUCIAL volume of TRD
838 if(kStoreIn){
839 t.SetTrackIn();
840 kStoreIn = kFALSE;
841 }
842
843 ptrTracklet = tracklets[ily];
844 if(!ptrTracklet){ // BUILD TRACKLET
845 AliDebug(3, Form("Building tracklet det[%d]", det));
846 // check data in supermodule
847 if(!fTrSec[sm].GetNChambers()){
848 t.SetStatus(AliTRDtrackV1::kNoClusters, ily);
849 AliDebug(4, "Failed NoClusters");
850 continue;
851 }
852 if(fTrSec[sm].GetX(ily) < 1.){
853 t.SetStatus(AliTRDtrackV1::kNoClusters, ily);
854 AliDebug(4, "Failed NoX");
855 continue;
856 }
857
858 // check data in chamber
859 if(!(chamber = fTrSec[sm].GetChamber(stk, ily))){
860 t.SetStatus(AliTRDtrackV1::kNoClusters, ily);
861 AliDebug(4, "Failed No Detector");
862 continue;
863 }
864 if(chamber->GetNClusters() < fgNTimeBins*fkRecoParam ->GetFindableClusters()){
865 t.SetStatus(AliTRDtrackV1::kNoClusters, ily);
866 AliDebug(4, "Failed Not Enough Clusters in Detector");
867 continue;
868 }
869 // build tracklet
870 ptrTracklet = new(&tracklet) AliTRDseedV1(det);
871 ptrTracklet->SetReconstructor(fkReconstructor);
872 ptrTracklet->SetKink(t.IsKink());
873 ptrTracklet->SetPrimary(t.IsPrimary());
874 ptrTracklet->SetPadPlane(fGeom->GetPadPlane(ily, stk));
875 ptrTracklet->SetX0(glb[0]+driftLength);
876 if(!tracklet.Init(&t)){
877 n=-1;
878 t.SetStatus(AliTRDtrackV1::kTrackletInit);
879 AliDebug(4, "Failed Tracklet Init");
880 break;
881 }
882 if(!tracklet.AttachClusters(chamber, kTRUE)){
883 t.SetStatus(AliTRDtrackV1::kNoAttach, ily);
884 if(debugLevel>3){
885 AliTRDseedV1 trackletCp(*ptrTracklet);
886 UChar_t status(t.GetStatusTRD(ily));
887 (*cstreamer) << "FollowBackProlongation2"
888 <<"status=" << status
889 <<"tracklet.=" << &trackletCp
890 << "\n";
891 }
892 AliDebug(4, "Failed Attach Clusters");
893 continue;
894 }
895 AliDebug(3, Form("Number of Clusters in Tracklet: %d", tracklet.GetN()));
896 if(tracklet.GetN() < fgNTimeBins*fkRecoParam ->GetFindableClusters()){
897 t.SetStatus(AliTRDtrackV1::kNoClustersTracklet, ily);
898 if(debugLevel>3){
899 AliTRDseedV1 trackletCp(*ptrTracklet);
900 UChar_t status(t.GetStatusTRD(ily));
901 (*cstreamer) << "FollowBackProlongation2"
902 <<"status=" << status
903 <<"tracklet.=" << &trackletCp
904 << "\n";
905 }
906 AliDebug(4, "Failed N Clusters Attached");
907 continue;
908 }
909 ptrTracklet->UpdateUsed();
910 } else AliDebug(2, Form("Use external tracklet ly[%d]", ily));
911 // propagate track to the radial position of the tracklet
912
913 // fit tracklet
914 // tilt correction options
915 // 0 : no correction
916 // 2 : pseudo tilt correction
917 if(!ptrTracklet->Fit(2)){
918 t.SetStatus(AliTRDtrackV1::kNoFit, ily);
919 AliDebug(4, "Failed Tracklet Fit");
920 continue;
921 }
922 x = ptrTracklet->GetX(); //GetX0();
923 if(x > (fgkMaxStep + t.GetX()) && !PropagateToX(t, x, fgkMaxStep)) {
924 n=-1;
925 t.SetStatus(AliTRDtrackV1::kPropagation);
926 AliDebug(4, Form("Failed Propagation to Tracklet x[%7.2f]", x));
927 break;
928 }
929 if(!AdjustSector(&t)) {
930 n=-1;
931 t.SetStatus(AliTRDtrackV1::kAdjustSector);
932 AliDebug(4, "Failed Adjust Sector");
933 break;
934 }
935 if(TMath::Abs(t.GetSnp()) > fgkMaxSnp) {
936 n=-1;
937 t.SetStatus(AliTRDtrackV1::kSnp);
938 AliDebug(4, Form("Failed Max Snp[%f] MaxSnp[%f]", t.GetSnp(), fgkMaxSnp));
939 break;
940 }
941 Double_t cov[3]; ptrTracklet->GetCovAt(x, cov);
942 Double_t p[2] = { ptrTracklet->GetY(), ptrTracklet->GetZ()};
943 Double_t chi2 = ((AliExternalTrackParam)t).GetPredictedChi2(p, cov);
944 // update Kalman with the TRD measurement
945 if(chi2>1e+10){ // TODO
946 t.SetStatus(AliTRDtrackV1::kChi2, ily);
947 if(debugLevel > 2){
948 UChar_t status(t.GetStatusTRD());
949 AliTRDseedV1 trackletCp(*ptrTracklet);
950 AliTRDtrackV1 trackCp(t);
951 trackCp.SetOwner();
952 (*cstreamer) << "FollowBackProlongation1"
953 << "status=" << status
954 << "tracklet.=" << &trackletCp
955 << "track.=" << &trackCp
956 << "\n";
957 }
958 AliDebug(4, Form("Failed Chi2[%f]", chi2));
959 continue;
960 }
961 if(kUseTRD){
962 if(!((AliExternalTrackParam&)t).Update(p, cov)) {
963 n=-1;
964 t.SetStatus(AliTRDtrackV1::kUpdate);
965 if(debugLevel > 2){
966 UChar_t status(t.GetStatusTRD());
967 AliTRDseedV1 trackletCp(*ptrTracklet);
968 AliTRDtrackV1 trackCp(t);
969 trackCp.SetOwner();
970 (*cstreamer) << "FollowBackProlongation1"
971 << "status=" << status
972 << "tracklet.=" << &trackletCp
973 << "track.=" << &trackCp
974 << "\n";
975 }
976 AliDebug(4, Form("Failed Track Update @ y[%7.2f] z[%7.2f] s2y[%f] s2z[%f] covyz[%f]", p[0], p[1], cov[0], cov[2], cov[1]));
977 break;
978 }
979 }
980 if(!kStandAlone) ptrTracklet->UseClusters();
981 // fill residuals ?!
982 AliTracker::FillResiduals(&t, p, cov, ptrTracklet->GetVolumeId());
983
984
985 // load tracklet to the tracker
986 ptrTracklet->Update(&t);
987 ptrTracklet = SetTracklet(ptrTracklet);
988 Int_t index(fTracklets->GetEntriesFast()-1);
989 t.SetTracklet(ptrTracklet, index);
990 // Register info to track
991 t.SetNumberOfClusters();
992 t.UpdateChi2(chi2);
993
994 n += ptrTracklet->GetN();
995 AliDebug(2, Form("Setting Tracklet[%d] @ Idx[%d]", ily, index));
996
997 // Reset material budget if 2 consecutive gold
998// if(ilayer>0 && t.GetTracklet(ilayer-1) && ptrTracklet->GetN() + t.GetTracklet(ilayer-1)->GetN() > 20) t.SetBudget(2, 0.);
999
1000 // Make backup of the track until is gold
1001 Int_t failed(0);
1002 if(!kStandAlone && (failed = t.MakeBackupTrack())) AliDebug(2, Form("Failed backup on cut[%d]", failed));
1003
1004 } // end layers loop
1005 //printf("clusters[%d] chi2[%f] x[%f] status[%d ", n, t.GetChi2(), t.GetX(), t.GetStatusTRD());
1006 //for(int i=0; i<6; i++) printf("%d ", t.GetStatusTRD(i)); printf("]\n");
1007
1008 if(debugLevel > 1){
1009 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
1010 AliTRDtrackV1 track(t);
1011 track.SetOwner();
1012 (*cstreamer) << "FollowBackProlongation0"
1013 << "EventNumber=" << eventNumber
1014 << "ncl=" << n
1015 << "track.=" << &track
1016 << "\n";
1017 }
1018
1019 return n;
1020}
1021
1022//_________________________________________________________________________
1023Float_t AliTRDtrackerV1::FitRieman(AliTRDseedV1 *tracklets, Double_t *chi2, Int_t *const planes){
1024 //
1025 // Fits a Riemann-circle to the given points without tilting pad correction.
1026 // The fit is performed using an instance of the class AliRieman (equations
1027 // and transformations see documentation of this class)
1028 // Afterwards all the tracklets are Updated
1029 //
1030 // Parameters: - Array of tracklets (AliTRDseedV1)
1031 // - Storage for the chi2 values (beginning with direction z)
1032 // - Seeding configuration
1033 // Output: - The curvature
1034 //
1035 AliRieman *fitter = AliTRDtrackerV1::GetRiemanFitter();
1036 fitter->Reset();
1037 Int_t allplanes[] = {0, 1, 2, 3, 4, 5};
1038 Int_t *ppl = &allplanes[0];
1039 Int_t maxLayers = 6;
1040 if(planes){
1041 maxLayers = 4;
1042 ppl = planes;
1043 }
1044 for(Int_t il = 0; il < maxLayers; il++){
1045 if(!tracklets[ppl[il]].IsOK()) continue;
1046 fitter->AddPoint(tracklets[ppl[il]].GetX0(), tracklets[ppl[il]].GetYfit(0), tracklets[ppl[il]].GetZfit(0),1,10);
1047 }
1048 fitter->Update();
1049 // Set the reference position of the fit and calculate the chi2 values
1050 memset(chi2, 0, sizeof(Double_t) * 2);
1051 for(Int_t il = 0; il < maxLayers; il++){
1052 // Reference positions
1053 tracklets[ppl[il]].Init(fitter);
1054
1055 // chi2
1056 if((!tracklets[ppl[il]].IsOK()) && (!planes)) continue;
1057 chi2[0] += tracklets[ppl[il]].GetChi2Y();
1058 chi2[1] += tracklets[ppl[il]].GetChi2Z();
1059 }
1060 return fitter->GetC();
1061}
1062
1063//_________________________________________________________________________
1064void AliTRDtrackerV1::FitRieman(AliTRDcluster **seedcl, Double_t chi2[2])
1065{
1066 //
1067 // Performs a Riemann helix fit using the seedclusters as spacepoints
1068 // Afterwards the chi2 values are calculated and the seeds are updated
1069 //
1070 // Parameters: - The four seedclusters
1071 // - The tracklet array (AliTRDseedV1)
1072 // - The seeding configuration
1073 // - Chi2 array
1074 //
1075 // debug level 2
1076 //
1077 AliRieman *fitter = AliTRDtrackerV1::GetRiemanFitter();
1078 fitter->Reset();
1079 for(Int_t i = 0; i < 4; i++){
1080 fitter->AddPoint(seedcl[i]->GetX(), seedcl[i]->GetY(), seedcl[i]->GetZ(), 1., 10.);
1081 }
1082 fitter->Update();
1083
1084
1085 // Update the seed and calculated the chi2 value
1086 chi2[0] = 0; chi2[1] = 0;
1087 for(Int_t ipl = 0; ipl < kNSeedPlanes; ipl++){
1088 // chi2
1089 chi2[0] += (seedcl[ipl]->GetZ() - fitter->GetZat(seedcl[ipl]->GetX())) * (seedcl[ipl]->GetZ() - fitter->GetZat(seedcl[ipl]->GetX()));
1090 chi2[1] += (seedcl[ipl]->GetY() - fitter->GetYat(seedcl[ipl]->GetX())) * (seedcl[ipl]->GetY() - fitter->GetYat(seedcl[ipl]->GetX()));
1091 }
1092}
1093
1094
1095//_________________________________________________________________________
1096Float_t AliTRDtrackerV1::FitTiltedRiemanConstraint(AliTRDseedV1 *tracklets, Double_t zVertex)
1097{
1098 //
1099 // Fits a helix to the clusters. Pad tilting is considered. As constraint it is
1100 // assumed that the vertex position is set to 0.
1101 // This method is very usefull for high-pt particles
1102 // Basis for the fit: (x - x0)^2 + (y - y0)^2 - R^2 = 0
1103 // x0, y0: Center of the circle
1104 // Measured y-position: ymeas = y - tan(phiT)(zc - zt)
1105 // zc: center of the pad row
1106 // Equation which has to be fitted (after transformation):
1107 // a + b * u + e * v + 2*(ymeas + tan(phiT)(z - zVertex))*t = 0
1108 // Transformation:
1109 // t = 1/(x^2 + y^2)
1110 // u = 2 * x * t
1111 // v = 2 * x * tan(phiT) * t
1112 // Parameters in the equation:
1113 // a = -1/y0, b = x0/y0, e = dz/dx
1114 //
1115 // The Curvature is calculated by the following equation:
1116 // - curv = a/Sqrt(b^2 + 1) = 1/R
1117 // Parameters: - the 6 tracklets
1118 // - the Vertex constraint
1119 // Output: - the Chi2 value of the track
1120 //
1121 // debug level 5
1122 //
1123
1124 TLinearFitter *fitter = GetTiltedRiemanFitterConstraint();
1125 fitter->StoreData(kTRUE);
1126 fitter->ClearPoints();
1127 AliTRDcluster *cl = NULL;
1128
1129 Float_t x, y, z, w, t, error, tilt;
1130 Double_t uvt[2];
1131 Int_t nPoints = 0;
1132 for(Int_t ilr = 0; ilr < AliTRDgeometry::kNlayer; ilr++){
1133 if(!tracklets[ilr].IsOK()) continue;
1134 for(Int_t itb = 0; itb < AliTRDseedV1::kNclusters; itb++){
1135 if(!tracklets[ilr].IsUsable(itb)) continue;
1136 if(!(cl = tracklets[ilr].GetClusters(itb))) continue;
1137 if(!cl->IsInChamber()) continue;
1138 x = cl->GetX();
1139 y = cl->GetY();
1140 z = cl->GetZ();
1141 tilt = tracklets[ilr].GetTilt();
1142 // Transformation
1143 t = 1./(x * x + y * y);
1144 uvt[0] = 2. * x * t;
1145 uvt[1] = 2. * x * t * tilt ;
1146 w = 2. * (y + tilt * (z - zVertex)) * t;
1147 error = 2. * TMath::Sqrt(cl->GetSigmaY2()+tilt*tilt*cl->GetSigmaZ2()) * t;
1148 fitter->AddPoint(uvt, w, error);
1149 nPoints++;
1150 }
1151 }
1152 fitter->Eval();
1153
1154 // Calculate curvature
1155 Double_t a = fitter->GetParameter(0);
1156 Double_t b = fitter->GetParameter(1);
1157 Double_t curvature = a/TMath::Sqrt(b*b + 1);
1158
1159 Float_t chi2track = fitter->GetChisquare()/Double_t(nPoints);
1160 for(Int_t ip = 0; ip < AliTRDtrackerV1::kNPlanes; ip++)
1161 tracklets[ip].SetC(curvature, 1);
1162
1163 if(AliLog::GetDebugLevel("TRD", "AliTRDtrackerV1")>3) printf("D-AliTRDtrackerV1::FitTiltedRiemanConstraint: Chi2[%f] C[%5.2e] pt[%8.3f]\n", chi2track, curvature, GetBz()*kB2C/curvature);
1164
1165/* if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker()) >= 5){
1166 //Linear Model on z-direction
1167 Double_t xref = CalculateReferenceX(tracklets); // Relative to the middle of the stack
1168 Double_t slope = fitter->GetParameter(2);
1169 Double_t zref = slope * xref;
1170 Float_t chi2Z = CalculateChi2Z(tracklets, zref, slope, xref);
1171 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
1172 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
1173 TTreeSRedirector &treeStreamer = *fkReconstructor->GetDebugStream(AliTRDReconstructor::kTracker);
1174 treeStreamer << "FitTiltedRiemanConstraint"
1175 << "EventNumber=" << eventNumber
1176 << "CandidateNumber=" << candidateNumber
1177 << "Curvature=" << curvature
1178 << "Chi2Track=" << chi2track
1179 << "Chi2Z=" << chi2Z
1180 << "zref=" << zref
1181 << "\n";
1182 }*/
1183 return chi2track;
1184}
1185
1186//_________________________________________________________________________
1187Float_t AliTRDtrackerV1::FitTiltedRieman(AliTRDseedV1 *tracklets, Bool_t sigError)
1188{
1189 //
1190 // Performs a Riemann fit taking tilting pad correction into account
1191 // The equation of a Riemann circle, where the y position is substituted by the
1192 // measured y-position taking pad tilting into account, has to be transformed
1193 // into a 4-dimensional hyperplane equation
1194 // Riemann circle: (x-x0)^2 + (y-y0)^2 -R^2 = 0
1195 // Measured y-Position: ymeas = y - tan(phiT)(zc - zt)
1196 // zc: center of the pad row
1197 // zt: z-position of the track
1198 // The z-position of the track is assumed to be linear dependent on the x-position
1199 // Transformed equation: a + b * u + c * t + d * v + e * w - 2 * (ymeas + tan(phiT) * zc) * t = 0
1200 // Transformation: u = 2 * x * t
1201 // v = 2 * tan(phiT) * t
1202 // w = 2 * tan(phiT) * (x - xref) * t
1203 // t = 1 / (x^2 + ymeas^2)
1204 // Parameters: a = -1/y0
1205 // b = x0/y0
1206 // c = (R^2 -x0^2 - y0^2)/y0
1207 // d = offset
1208 // e = dz/dx
1209 // If the offset respectively the slope in z-position is impossible, the parameters are fixed using
1210 // results from the simple riemann fit. Afterwards the fit is redone.
1211 // The curvature is calculated according to the formula:
1212 // curv = a/(1 + b^2 + c*a) = 1/R
1213 //
1214 // Paramters: - Array of tracklets (connected to the track candidate)
1215 // - Flag selecting the error definition
1216 // Output: - Chi2 values of the track (in Parameter list)
1217 //
1218 TLinearFitter *fitter = GetTiltedRiemanFitter();
1219 fitter->StoreData(kTRUE);
1220 fitter->ClearPoints();
1221 AliTRDLeastSquare zfitter;
1222 AliTRDcluster *cl = NULL;
1223
1224 Double_t xref = CalculateReferenceX(tracklets);
1225 Double_t x, y, z, t, tilt, dx, w, we, erry, errz;
1226 Double_t uvt[4], sumPolY[5], sumPolZ[3];
1227 memset(sumPolY, 0, sizeof(Double_t) * 5);
1228 memset(sumPolZ, 0, sizeof(Double_t) * 3);
1229 Int_t nPoints = 0;
1230 // Containers for Least-square fitter
1231 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1232 if(!tracklets[ipl].IsOK()) continue;
1233 tilt = tracklets[ipl].GetTilt();
1234 for(Int_t itb = 0; itb < AliTRDseedV1::kNclusters; itb++){
1235 if(!(cl = tracklets[ipl].GetClusters(itb))) continue;
1236 if(!cl->IsInChamber()) continue;
1237 if (!tracklets[ipl].IsUsable(itb)) continue;
1238 x = cl->GetX();
1239 y = cl->GetY();
1240 z = cl->GetZ();
1241 dx = x - xref;
1242 // Transformation
1243 t = 1./(x*x + y*y);
1244 uvt[0] = 2. * x * t;
1245 uvt[1] = t;
1246 uvt[2] = 2. * tilt * t;
1247 uvt[3] = 2. * tilt * dx * t;
1248 w = 2. * (y + tilt*z) * t;
1249 // error definition changes for the different calls
1250 we = 2. * t;
1251 we *= sigError ? TMath::Sqrt(cl->GetSigmaY2()+tilt*tilt*cl->GetSigmaZ2()) : 0.2;
1252 fitter->AddPoint(uvt, w, we);
1253 zfitter.AddPoint(&x, z, static_cast<Double_t>(TMath::Sqrt(cl->GetSigmaZ2())));
1254 // adding points for covariance matrix estimation
1255 erry = 1./(TMath::Sqrt(cl->GetSigmaY2()) + 0.1); // 0.1 is a systematic error (due to misalignment and miscalibration)
1256 erry *= erry;
1257 errz = 1./cl->GetSigmaZ2();
1258 for(Int_t ipol = 0; ipol < 5; ipol++){
1259 sumPolY[ipol] += erry;
1260 erry *= x;
1261 if(ipol < 3){
1262 sumPolZ[ipol] += errz;
1263 errz *= x;
1264 }
1265 }
1266 nPoints++;
1267 }
1268 }
1269 if (fitter->Eval()) return 1.e10;
1270 zfitter.Eval();
1271
1272 Double_t offset = fitter->GetParameter(3);
1273 Double_t slope = fitter->GetParameter(4);
1274
1275 // Linear fitter - not possible to make boundaries
1276 // Do not accept non possible z and dzdx combinations
1277 Bool_t acceptablez = kTRUE;
1278 Double_t zref = 0.0;
1279 for (Int_t iLayer = 0; iLayer < kNPlanes; iLayer++) {
1280 if(!tracklets[iLayer].IsOK()) continue;
1281 zref = offset + slope * (tracklets[iLayer].GetX0() - xref);
1282 if (TMath::Abs(tracklets[iLayer].GetZfit(0) - zref) > tracklets[iLayer].GetPadLength() * 0.5 + 1.0)
1283 acceptablez = kFALSE;
1284 }
1285 if (!acceptablez) {
1286 Double_t dzmf = zfitter.GetFunctionParameter(1);
1287 Double_t zmf = zfitter.GetFunctionValue(&xref);
1288 fgTiltedRieman->FixParameter(3, zmf);
1289 fgTiltedRieman->FixParameter(4, dzmf);
1290 fitter->Eval();
1291 fitter->ReleaseParameter(3);
1292 fitter->ReleaseParameter(4);
1293 offset = fitter->GetParameter(3);
1294 slope = fitter->GetParameter(4);
1295 }
1296
1297 // Calculate Curvarture
1298 Double_t a = fitter->GetParameter(0);
1299 Double_t b = fitter->GetParameter(1);
1300 Double_t c = fitter->GetParameter(2);
1301 Double_t curvature = 1.0 + b*b - c*a;
1302 if (curvature > 0.0) curvature = a / TMath::Sqrt(curvature);
1303
1304 Double_t chi2track = fitter->GetChisquare()/Double_t(nPoints);
1305
1306 // Prepare error calculation
1307 TMatrixD covarPolY(3,3);
1308 covarPolY(0,0) = sumPolY[0]; covarPolY(1,1) = sumPolY[2]; covarPolY(2,2) = sumPolY[4];
1309 covarPolY(0,1) = covarPolY(1,0) = sumPolY[1];
1310 covarPolY(0,2) = covarPolY(2,0) = sumPolY[2];
1311 covarPolY(2,1) = covarPolY(1,2) = sumPolY[3];
1312 covarPolY.Invert();
1313 TMatrixD covarPolZ(2,2);
1314 covarPolZ(0,0) = sumPolZ[0]; covarPolZ(1,1) = sumPolZ[2];
1315 covarPolZ(1,0) = covarPolZ(0,1) = sumPolZ[1];
1316 covarPolZ.Invert();
1317
1318 // Update the tracklets
1319 Double_t x1, dy, dz;
1320 Double_t cov[15];
1321 memset(cov, 0, sizeof(Double_t) * 15);
1322 for(Int_t iLayer = 0; iLayer < AliTRDtrackerV1::kNPlanes; iLayer++) {
1323
1324 x = tracklets[iLayer].GetX0();
1325 x1 = x - xref;
1326 y = 0;
1327 z = 0;
1328 dy = 0;
1329 dz = 0;
1330 memset(cov, 0, sizeof(Double_t) * 3);
1331 TMatrixD transform(3,3);
1332 transform(0,0) = 1;
1333 transform(0,1) = x;
1334 transform(0,2) = x*x;
1335 transform(1,1) = 1;
1336 transform(1,2) = x;
1337 transform(2,2) = 1;
1338 TMatrixD covariance(transform, TMatrixD::kMult, covarPolY);
1339 covariance *= transform.T();
1340 TMatrixD transformZ(2,2);
1341 transformZ(0,0) = transformZ(1,1) = 1;
1342 transformZ(0,1) = x;
1343 TMatrixD covarZ(transformZ, TMatrixD::kMult, covarPolZ);
1344 covarZ *= transformZ.T();
1345 // y: R^2 = (x - x0)^2 + (y - y0)^2
1346 // => y = y0 +/- Sqrt(R^2 - (x - x0)^2)
1347 // R = Sqrt() = 1/Curvature
1348 // => y = y0 +/- Sqrt(1/Curvature^2 - (x - x0)^2)
1349 Double_t res = (x * a + b); // = (x - x0)/y0
1350 res *= res;
1351 res = 1.0 - c * a + b * b - res; // = (R^2 - (x - x0)^2)/y0^2
1352 if (res >= 0) {
1353 res = TMath::Sqrt(res);
1354 y = (1.0 - res) / a;
1355 }
1356 cov[0] = covariance(0,0);
1357 cov[2] = covarZ(0,0);
1358 cov[1] = 0.;
1359
1360 // dy: R^2 = (x - x0)^2 + (y - y0)^2
1361 // => y = +/- Sqrt(R^2 - (x - x0)^2) + y0
1362 // => dy/dx = (x - x0)/Sqrt(R^2 - (x - x0)^2)
1363 // Curvature: cr = 1/R = a/Sqrt(1 + b^2 - c*a)
1364 // => dy/dx = (x - x0)/(1/(cr^2) - (x - x0)^2)
1365 Double_t x0 = -b / a;
1366 if (-c * a + b * b + 1 > 0) {
1367 if (1.0/(curvature * curvature) - (x - x0) * (x - x0) > 0.0) {
1368 Double_t yderiv = (x - x0) / TMath::Sqrt(1.0/(curvature * curvature) - (x - x0) * (x - x0));
1369 if (a < 0) yderiv *= -1.0;
1370 dy = yderiv;
1371 }
1372 }
1373 z = offset + slope * (x - xref);
1374 dz = slope;
1375 tracklets[iLayer].SetYref(0, y);
1376 tracklets[iLayer].SetYref(1, dy);
1377 tracklets[iLayer].SetZref(0, z);
1378 tracklets[iLayer].SetZref(1, dz);
1379 tracklets[iLayer].SetC(curvature);
1380 tracklets[iLayer].SetCovRef(cov);
1381 tracklets[iLayer].SetChi2(chi2track);
1382 }
1383 if(AliLog::GetDebugLevel("TRD", "AliTRDtrackerV1")>3) printf("D-AliTRDtrackerV1::FitTiltedRieman: Chi2[%f] C[%5.2e] pt[%8.3f]\n", chi2track, curvature, GetBz()*kB2C/curvature);
1384
1385/* if(fkReconstructor->GetRecoParam()->GetStreamLevel(AliTRDrecoParam::kTracker) >=5){
1386 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
1387 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
1388 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
1389 Double_t chi2z = CalculateChi2Z(tracklets, offset, slope, xref);
1390 cstreamer << "FitTiltedRieman0"
1391 << "EventNumber=" << eventNumber
1392 << "CandidateNumber=" << candidateNumber
1393 << "xref=" << xref
1394 << "Chi2Z=" << chi2z
1395 << "\n";
1396 }*/
1397 return chi2track;
1398}
1399
1400
1401//____________________________________________________________________
1402Double_t AliTRDtrackerV1::FitLine(const AliTRDtrackV1 *track, AliTRDseedV1 *tracklets, Bool_t err, Int_t np, AliTrackPoint *points)
1403{
1404 //
1405 // Fit track with a staight line
1406 // Fills an AliTrackPoint array with np points
1407 // Function should be used to refit tracks when no magnetic field was on
1408 //
1409 AliTRDLeastSquare yfitter, zfitter;
1410 AliTRDcluster *cl = NULL;
1411
1412 AliTRDseedV1 work[kNPlanes], *tracklet = NULL;
1413 if(!tracklets){
1414 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1415 if(!(tracklet = track->GetTracklet(ipl))) continue;
1416 if(!tracklet->IsOK()) continue;
1417 new(&work[ipl]) AliTRDseedV1(*tracklet);
1418 }
1419 tracklets = &work[0];
1420 }
1421
1422 Double_t xref = CalculateReferenceX(tracklets);
1423 Double_t x, y, z, dx, ye, yr, tilt;
1424 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1425 if(!tracklets[ipl].IsOK()) continue;
1426 for(Int_t itb = 0; itb < fgNTimeBins; itb++){
1427 if(!(cl = tracklets[ipl].GetClusters(itb))) continue;
1428 if (!tracklets[ipl].IsUsable(itb)) continue;
1429 x = cl->GetX();
1430 z = cl->GetZ();
1431 dx = x - xref;
1432 zfitter.AddPoint(&dx, z, static_cast<Double_t>(TMath::Sqrt(cl->GetSigmaZ2())));
1433 }
1434 }
1435 zfitter.Eval();
1436 Double_t z0 = zfitter.GetFunctionParameter(0);
1437 Double_t dzdx = zfitter.GetFunctionParameter(1);
1438 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1439 if(!tracklets[ipl].IsOK()) continue;
1440 for(Int_t itb = 0; itb < fgNTimeBins; itb++){
1441 if(!(cl = tracklets[ipl].GetClusters(itb))) continue;
1442 if (!tracklets[ipl].IsUsable(itb)) continue;
1443 x = cl->GetX();
1444 y = cl->GetY();
1445 z = cl->GetZ();
1446 tilt = tracklets[ipl].GetTilt();
1447 dx = x - xref;
1448 yr = y + tilt*(z - z0 - dzdx*dx);
1449 // error definition changes for the different calls
1450 ye = tilt*TMath::Sqrt(cl->GetSigmaZ2());
1451 ye += err ? tracklets[ipl].GetSigmaY() : 0.2;
1452 yfitter.AddPoint(&dx, yr, ye);
1453 }
1454 }
1455 yfitter.Eval();
1456 Double_t y0 = yfitter.GetFunctionParameter(0);
1457 Double_t dydx = yfitter.GetFunctionParameter(1);
1458 Double_t chi2 = 0.;//yfitter.GetChisquare()/Double_t(nPoints);
1459
1460 //update track points array
1461 if(np && points){
1462 Float_t xyz[3];
1463 for(int ip=0; ip<np; ip++){
1464 points[ip].GetXYZ(xyz);
1465 xyz[1] = y0 + dydx * (xyz[0] - xref);
1466 xyz[2] = z0 + dzdx * (xyz[0] - xref);
1467 points[ip].SetXYZ(xyz);
1468 }
1469 }
1470 return chi2;
1471}
1472
1473
1474//_________________________________________________________________________
1475Double_t AliTRDtrackerV1::FitRiemanTilt(const AliTRDtrackV1 *track, AliTRDseedV1 *tracklets, Bool_t sigError, Int_t np, AliTrackPoint *points)
1476{
1477//
1478// Performs a Riemann fit taking tilting pad correction into account
1479//
1480// Paramters: - Array of tracklets (connected to the track candidate)
1481// - Flag selecting the error definition
1482// Output: - Chi2 values of the track (in Parameter list)
1483//
1484// The equations which has to be solved simultaneously are:
1485// BEGIN_LATEX
1486// R^{2} = (x-x_{0})^{2} + (y^{*}-y_{0})^{2}
1487// y^{*} = y - tg(h)(z - z_{t})
1488// z_{t} = z_{0}+dzdx*(x-x_{r})
1489// END_LATEX
1490// with (x, y, z) the coordinate of the cluster, (x_0, y_0, z_0) the coordinate of the center of the Riemann circle,
1491// R its radius, x_r a constant refrence radial position in the middle of the TRD stack and dzdx the slope of the
1492// track in the x-z plane. Using the following transformations
1493// BEGIN_LATEX
1494// t = 1 / (x^{2} + y^{2})
1495// u = 2 * x * t
1496// v = 2 * tan(h) * t
1497// w = 2 * tan(h) * (x - x_{r}) * t
1498// END_LATEX
1499// One gets the following linear equation
1500// BEGIN_LATEX
1501// a + b * u + c * t + d * v + e * w = 2 * (y + tg(h) * z) * t
1502// END_LATEX
1503// where the coefficients have the following meaning
1504// BEGIN_LATEX
1505// a = -1/y_{0}
1506// b = x_{0}/y_{0}
1507// c = (R^{2} -x_{0}^{2} - y_{0}^{2})/y_{0}
1508// d = z_{0}
1509// e = dz/dx
1510// END_LATEX
1511// The error calculation for the free term is thus
1512// BEGIN_LATEX
1513// #sigma = 2 * #sqrt{#sigma^{2}_{y} + (tilt corr ...) + tg^{2}(h) * #sigma^{2}_{z}} * t
1514// END_LATEX
1515//
1516// From this simple model one can compute chi^2 estimates and a rough approximation of pt from the curvature according
1517// to the formula:
1518// BEGIN_LATEX
1519// C = 1/R = a/(1 + b^{2} + c*a)
1520// END_LATEX
1521//
1522// Authors
1523// M.Ivanov <M.Ivanov@gsi.de>
1524// A.Bercuci <A.Bercuci@gsi.de>
1525// M.Fasel <M.Fasel@gsi.de>
1526
1527 TLinearFitter *fitter = GetTiltedRiemanFitter();
1528 fitter->StoreData(kTRUE);
1529 fitter->ClearPoints();
1530 AliTRDLeastSquare zfitter;
1531 AliTRDcluster *cl = NULL;
1532
1533 AliTRDseedV1 work[kNPlanes], *tracklet = NULL;
1534 if(!tracklets){
1535 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1536 if(!(tracklet = track->GetTracklet(ipl))) continue;
1537 if(!tracklet->IsOK()) continue;
1538 new(&work[ipl]) AliTRDseedV1(*tracklet);
1539 }
1540 tracklets = &work[0];
1541 }
1542
1543 Double_t xref = CalculateReferenceX(tracklets);
1544 if(AliLog::GetDebugLevel("TRD", "AliTRDtrackerV1")>3) printf("D-AliTRDtrackerV1::FitRiemanTilt:\nx0[(0)%6.2f (1)%6.2f (2)%6.2f (3)%6.2f (4)%6.2f (5)%6.2f] xref[%6.2f]", tracklets[0].GetX0(), tracklets[1].GetX0(), tracklets[2].GetX0(), tracklets[3].GetX0(), tracklets[4].GetX0(), tracklets[5].GetX0(), xref);
1545 Double_t x, y, z, t, tilt, dx, w, we;
1546 Double_t uvt[4];
1547 Int_t nPoints = 0;
1548 // Containers for Least-square fitter
1549 for(Int_t ipl = 0; ipl < kNPlanes; ipl++){
1550 if(!tracklets[ipl].IsOK()) continue;
1551 for(Int_t itb = 0; itb < AliTRDseedV1::kNclusters; itb++){
1552 if(!(cl = tracklets[ipl].GetClusters(itb))) continue;
1553 //if (!tracklets[ipl].IsUsable(itb)) continue;
1554 x = cl->GetX();
1555 y = cl->GetY();
1556 z = cl->GetZ();
1557 tilt = tracklets[ipl].GetTilt();
1558 dx = x - xref;
1559 // Transformation
1560 t = 1./(x*x + y*y);
1561 uvt[0] = 2. * x * t;
1562 uvt[1] = t;
1563 uvt[2] = 2. * tilt * t;
1564 uvt[3] = 2. * tilt * dx * t;
1565 w = 2. * (y + tilt*z) * t;
1566 // error definition changes for the different calls
1567 we = 2. * t;
1568 we *= sigError ? TMath::Sqrt(cl->GetSigmaY2()) : 0.2;
1569 fitter->AddPoint(uvt, w, we);
1570 zfitter.AddPoint(&x, z, static_cast<Double_t>(TMath::Sqrt(cl->GetSigmaZ2())));
1571 nPoints++;
1572 }
1573 }
1574 if(fitter->Eval()) return 1.E10;
1575
1576 Double_t z0 = fitter->GetParameter(3);
1577 Double_t dzdx = fitter->GetParameter(4);
1578
1579
1580 // Linear fitter - not possible to make boundaries
1581 // Do not accept non possible z and dzdx combinations
1582 Bool_t accept = kTRUE;
1583 Double_t zref = 0.0;
1584 for (Int_t iLayer = 0; iLayer < kNPlanes; iLayer++) {
1585 if(!tracklets[iLayer].IsOK()) continue;
1586 zref = z0 + dzdx * (tracklets[iLayer].GetX0() - xref);
1587 if (TMath::Abs(tracklets[iLayer].GetZfit(0) - zref) > tracklets[iLayer].GetPadLength() * 0.5 + 1.0)
1588 accept = kFALSE;
1589 }
1590 if (!accept) {
1591 zfitter.Eval();
1592 Double_t dzmf = zfitter.GetFunctionParameter(1);
1593 Double_t zmf = zfitter.GetFunctionValue(&xref);
1594 fitter->FixParameter(3, zmf);
1595 fitter->FixParameter(4, dzmf);
1596 fitter->Eval();
1597 fitter->ReleaseParameter(3);
1598 fitter->ReleaseParameter(4);
1599 z0 = fitter->GetParameter(3); // = zmf ?
1600 dzdx = fitter->GetParameter(4); // = dzmf ?
1601 }
1602
1603 // Calculate Curvature
1604 Double_t a = fitter->GetParameter(0);
1605 Double_t b = fitter->GetParameter(1);
1606 Double_t c = fitter->GetParameter(2);
1607 Double_t y0 = 1. / a;
1608 Double_t x0 = -b * y0;
1609 Double_t tmp = y0*y0 + x0*x0 - c*y0;
1610 if(tmp<=0.) return 1.E10;
1611 Double_t radius = TMath::Sqrt(tmp);
1612 Double_t curvature = 1.0 + b*b - c*a;
1613 if (curvature > 0.0) curvature = a / TMath::Sqrt(curvature);
1614
1615 // Calculate chi2 of the fit
1616 Double_t chi2 = fitter->GetChisquare()/Double_t(nPoints);
1617 if(AliLog::GetDebugLevel("TRD", "AliTRDtrackerV1")>3) printf("D-AliTRDtrackerV1::FitRiemanTilt:x0[%6.2f] y0[%6.2f] R[%6.2f] chi2[%f]\n", x0, y0, radius, chi2);
1618
1619 // Update the tracklets
1620 if(!track){
1621 for(Int_t ip = 0; ip < kNPlanes; ip++) {
1622 x = tracklets[ip].GetX0();
1623 tmp = radius*radius-(x-x0)*(x-x0);
1624 if(tmp <= 0.) continue;
1625 tmp = TMath::Sqrt(tmp);
1626
1627 // y: R^2 = (x - x0)^2 + (y - y0)^2
1628 // => y = y0 +/- Sqrt(R^2 - (x - x0)^2)
1629 tracklets[ip].SetYref(0, y0 - (y0>0.?1.:-1)*tmp);
1630 // => dy/dx = (x - x0)/Sqrt(R^2 - (x - x0)^2)
1631 tracklets[ip].SetYref(1, (x - x0) / tmp);
1632 tracklets[ip].SetZref(0, z0 + dzdx * (x - xref));
1633 tracklets[ip].SetZref(1, dzdx);
1634 tracklets[ip].SetC(curvature);
1635 tracklets[ip].SetChi2(chi2);
1636 }
1637 }
1638 //update track points array
1639 if(np && points){
1640 Float_t xyz[3];
1641 for(int ip=0; ip<np; ip++){
1642 points[ip].GetXYZ(xyz);
1643 xyz[1] = TMath::Abs(xyz[0] - x0) > radius ? 100. : y0 - (y0>0.?1.:-1.)*TMath::Sqrt((radius-(xyz[0]-x0))*(radius+(xyz[0]-x0)));
1644 xyz[2] = z0 + dzdx * (xyz[0] - xref);
1645 points[ip].SetXYZ(xyz);
1646 }
1647 }
1648
1649 return chi2;
1650}
1651
1652
1653//____________________________________________________________________
1654Double_t AliTRDtrackerV1::FitKalman(AliTRDtrackV1 *track, AliTRDseedV1 * const tracklets, Bool_t up, Int_t np, AliTrackPoint *points)
1655{
1656// Kalman filter implementation for the TRD.
1657// It returns the positions of the fit in the array "points"
1658//
1659// Author : A.Bercuci@gsi.de
1660
1661 // printf("Start track @ x[%f]\n", track->GetX());
1662
1663 //prepare marker points along the track
1664 Int_t ip = np ? 0 : 1;
1665 while(ip<np){
1666 if((up?-1:1) * (track->GetX() - points[ip].GetX()) > 0.) break;
1667 //printf("AliTRDtrackerV1::FitKalman() : Skip track marker x[%d] = %7.3f. Before track start ( %7.3f ).\n", ip, points[ip].GetX(), track->GetX());
1668 ip++;
1669 }
1670 //if(points) printf("First marker point @ x[%d] = %f\n", ip, points[ip].GetX());
1671
1672
1673 AliTRDseedV1 tracklet, *ptrTracklet = NULL;
1674
1675 //Loop through the TRD planes
1676 for (Int_t jplane = 0; jplane < kNPlanes; jplane++) {
1677 // GET TRACKLET OR BUILT IT
1678 Int_t iplane = up ? jplane : kNPlanes - 1 - jplane;
1679 if(tracklets){
1680 if(!(ptrTracklet = &tracklets[iplane])) continue;
1681 }else{
1682 if(!(ptrTracklet = track->GetTracklet(iplane))){
1683 /*AliTRDtrackerV1 *tracker = NULL;
1684 if(!(tracker = dynamic_cast<AliTRDtrackerV1*>( AliTRDrecoParam:Tracker()))) continue;
1685 ptrTracklet = new(&tracklet) AliTRDseedV1(iplane);
1686 if(!tracker->MakeTracklet(ptrTracklet, track)) */
1687 continue;
1688 }
1689 }
1690 if(!ptrTracklet->IsOK()) continue;
1691
1692 Double_t x = ptrTracklet->GetX0();
1693
1694 while(ip < np){
1695 //don't do anything if next marker is after next update point.
1696 if((up?-1:1) * (points[ip].GetX() - x) - fgkMaxStep < 0) break;
1697 if(((up?-1:1) * (points[ip].GetX() - track->GetX()) < 0) && !PropagateToX(*track, points[ip].GetX(), fgkMaxStep)) return -1.;
1698
1699 Double_t xyz[3]; // should also get the covariance
1700 track->GetXYZ(xyz);
1701 track->Global2LocalPosition(xyz, track->GetAlpha());
1702 points[ip].SetXYZ(xyz[0], xyz[1], xyz[2]);
1703 ip++;
1704 }
1705 // printf("plane[%d] tracklet[%p] x[%f]\n", iplane, ptrTracklet, x);
1706
1707 // Propagate closer to the next update point
1708 if(((up?-1:1) * (x - track->GetX()) + fgkMaxStep < 0) && !PropagateToX(*track, x + (up?-1:1)*fgkMaxStep, fgkMaxStep)) return -1.;
1709
1710 if(!AdjustSector(track)) return -1;
1711 if(TMath::Abs(track->GetSnp()) > fgkMaxSnp) return -1;
1712
1713 //load tracklet to the tracker and the track
1714/* Int_t index;
1715 if((index = FindTracklet(ptrTracklet)) < 0){
1716 ptrTracklet = SetTracklet(&tracklet);
1717 index = fTracklets->GetEntriesFast()-1;
1718 }
1719 track->SetTracklet(ptrTracklet, index);*/
1720
1721
1722 // register tracklet to track with tracklet creation !!
1723 // PropagateBack : loaded tracklet to the tracker and update index
1724 // RefitInward : update index
1725 // MakeTrack : loaded tracklet to the tracker and update index
1726 if(!tracklets) track->SetTracklet(ptrTracklet, -1);
1727
1728
1729 //Calculate the mean material budget along the path inside the chamber
1730 Double_t xyz0[3]; track->GetXYZ(xyz0);
1731 Double_t alpha = track->GetAlpha();
1732 Double_t xyz1[3], y, z;
1733 if(!track->GetProlongation(x, y, z)) return -1;
1734 xyz1[0] = x * TMath::Cos(alpha) - y * TMath::Sin(alpha);
1735 xyz1[1] = +x * TMath::Sin(alpha) + y * TMath::Cos(alpha);
1736 xyz1[2] = z;
1737 if(TMath::Abs(xyz0[0] - xyz1[0]) < 1e-3 && TMath::Abs(xyz0[1] - xyz1[1]) < 1e-3) continue; // check wheter we are at the same global x position
1738 Double_t param[7];
1739 if(AliTracker::MeanMaterialBudget(xyz0, xyz1, param) <=0.) break;
1740 Double_t xrho = param[0]*param[4]; // density*length
1741 Double_t xx0 = param[1]; // radiation length
1742
1743 //Propagate the track
1744 track->PropagateTo(x, xx0, xrho);
1745 if (!AdjustSector(track)) break;
1746
1747 //Update track
1748 Double_t cov[3]; ptrTracklet->GetCovAt(x, cov);
1749 Double_t p[2] = { ptrTracklet->GetY(), ptrTracklet->GetZ()};
1750 Double_t chi2 = ((AliExternalTrackParam*)track)->GetPredictedChi2(p, cov);
1751 if(chi2<1e+10) ((AliExternalTrackParam*)track)->Update(p, cov);
1752 if(!up) continue;
1753
1754 //Reset material budget if 2 consecutive gold
1755 if(iplane>0 && track->GetTracklet(iplane-1) && ptrTracklet->GetN() + track->GetTracklet(iplane-1)->GetN() > 20) track->SetBudget(2, 0.);
1756 } // end planes loop
1757
1758 // extrapolation
1759 while(ip < np){
1760 if(((up?-1:1) * (points[ip].GetX() - track->GetX()) < 0) && !PropagateToX(*track, points[ip].GetX(), fgkMaxStep)) return -1.;
1761
1762 Double_t xyz[3]; // should also get the covariance
1763 track->GetXYZ(xyz);
1764 track->Global2LocalPosition(xyz, track->GetAlpha());
1765 points[ip].SetXYZ(xyz[0], xyz[1], xyz[2]);
1766 ip++;
1767 }
1768
1769 return track->GetChi2();
1770}
1771
1772//_________________________________________________________________________
1773Float_t AliTRDtrackerV1::CalculateChi2Z(AliTRDseedV1 *tracklets, Double_t offset, Double_t slope, Double_t xref)
1774{
1775 //
1776 // Calculates the chi2-value of the track in z-Direction including tilting pad correction.
1777 // A linear dependence on the x-value serves as a model.
1778 // The parameters are related to the tilted Riemann fit.
1779 // Parameters: - Array of tracklets (AliTRDseedV1) related to the track candidate
1780 // - the offset for the reference x
1781 // - the slope
1782 // - the reference x position
1783 // Output: - The Chi2 value of the track in z-Direction
1784 //
1785 Float_t chi2Z = 0, nLayers = 0;
1786 for (Int_t iLayer = 0; iLayer < AliTRDgeometry::kNlayer; iLayer++) {
1787 if(!tracklets[iLayer].IsOK()) continue;
1788 Double_t z = offset + slope * (tracklets[iLayer].GetX0() - xref);
1789 chi2Z += TMath::Abs(tracklets[iLayer].GetZfit(0) - z);
1790 nLayers++;
1791 }
1792 chi2Z /= TMath::Max((nLayers - 3.0),1.0);
1793 return chi2Z;
1794}
1795
1796//_____________________________________________________________________________
1797Int_t AliTRDtrackerV1::PropagateToX(AliTRDtrackV1 &t, Double_t xToGo, Double_t maxStep)
1798{
1799 //
1800 // Starting from current X-position of track <t> this function
1801 // extrapolates the track up to radial position <xToGo>.
1802 // Returns 1 if track reaches the plane, and 0 otherwise
1803 //
1804
1805 const Double_t kEpsilon = 0.00001;
1806
1807 // Current track X-position
1808 Double_t xpos = t.GetX();
1809
1810 // Direction: inward or outward
1811 Double_t dir = (xpos < xToGo) ? 1.0 : -1.0;
1812
1813 while (((xToGo - xpos) * dir) > kEpsilon) {
1814
1815 Double_t xyz0[3];
1816 Double_t xyz1[3];
1817 Double_t param[7];
1818 Double_t x;
1819 Double_t y;
1820 Double_t z;
1821
1822 // The next step size
1823 Double_t step = dir * TMath::Min(TMath::Abs(xToGo-xpos),maxStep);
1824
1825 // Get the global position of the starting point
1826 t.GetXYZ(xyz0);
1827
1828 // X-position after next step
1829 x = xpos + step;
1830
1831 // Get local Y and Z at the X-position of the next step
1832 if(t.GetProlongation(x,y,z)<0) return 0; // No prolongation possible
1833
1834 // The global position of the end point of this prolongation step
1835 xyz1[0] = x * TMath::Cos(t.GetAlpha()) - y * TMath::Sin(t.GetAlpha());
1836 xyz1[1] = +x * TMath::Sin(t.GetAlpha()) + y * TMath::Cos(t.GetAlpha());
1837 xyz1[2] = z;
1838
1839 // Calculate the mean material budget between start and
1840 // end point of this prolongation step
1841 if(AliTracker::MeanMaterialBudget(xyz0, xyz1, param)<=0.) return 0;
1842
1843 // Propagate the track to the X-position after the next step
1844 if (!t.PropagateTo(x, param[1], param[0]*param[4])) return 0;
1845
1846 // Rotate the track if necessary
1847 if(!AdjustSector(&t)) return 0;
1848
1849 // New track X-position
1850 xpos = t.GetX();
1851
1852 }
1853
1854 return 1;
1855
1856}
1857
1858
1859//_____________________________________________________________________________
1860Bool_t AliTRDtrackerV1::ReadClusters(TTree *clusterTree)
1861{
1862 //
1863 // Reads AliTRDclusters from the file.
1864 // The names of the cluster tree and branches
1865 // should match the ones used in AliTRDclusterizer::WriteClusters()
1866 //
1867
1868 Int_t nsize = Int_t(clusterTree->GetTotBytes() / (sizeof(AliTRDcluster)));
1869 TObjArray *clusterArray = new TObjArray(nsize+1000);
1870
1871 TBranch *branch = clusterTree->GetBranch("TRDcluster");
1872 if (!branch) {
1873 AliError("Can't get the branch !");
1874 return kFALSE;
1875 }
1876 branch->SetAddress(&clusterArray);
1877
1878 if(!fClusters){
1879 Float_t nclusters = fkRecoParam->GetNClusters();
1880 if(fkReconstructor->IsHLT()) nclusters /= AliTRDgeometry::kNsector;
1881 fClusters = new TClonesArray("AliTRDcluster", Int_t(nclusters));
1882 fClusters->SetOwner(kTRUE);
1883 }
1884
1885 // Loop through all entries in the tree
1886 Int_t nEntries = (Int_t) clusterTree->GetEntries();
1887 Int_t nbytes = 0;
1888 Int_t ncl = 0;
1889 AliTRDcluster *c = NULL;
1890 for (Int_t iEntry = 0; iEntry < nEntries; iEntry++) {
1891 // Import the tree
1892 nbytes += clusterTree->GetEvent(iEntry);
1893
1894 // Get the number of points in the detector
1895 Int_t nCluster = clusterArray->GetEntriesFast();
1896 for (Int_t iCluster = 0; iCluster < nCluster; iCluster++) {
1897 if(!(c = (AliTRDcluster *) clusterArray->UncheckedAt(iCluster))) continue;
1898 new((*fClusters)[ncl++]) AliTRDcluster(*c);
1899 delete (clusterArray->RemoveAt(iCluster));
1900 }
1901 }
1902 delete clusterArray;
1903
1904 return kTRUE;
1905}
1906
1907//_____________________________________________________________________________
1908Int_t AliTRDtrackerV1::LoadClusters(TTree *cTree)
1909{
1910 //
1911 // Fills clusters into TRD tracking sectors
1912 //
1913
1914 fkRecoParam = fkReconstructor->GetRecoParam(); // load reco param for this event
1915
1916 if(!fkReconstructor->IsWritingClusters()){
1917 fClusters = AliTRDReconstructor::GetClusters();
1918 } else {
1919 if(!ReadClusters(cTree)) {
1920 AliError("Problem with reading the clusters !");
1921 return 1;
1922 }
1923 }
1924 SetClustersOwner();
1925
1926 if(!fClusters || !fClusters->GetEntriesFast()){
1927 AliInfo("No TRD clusters");
1928 return 1;
1929 }
1930
1931 //Int_t nin =
1932 BuildTrackingContainers();
1933
1934 //Int_t ncl = fClusters->GetEntriesFast();
1935 //AliInfo(Form("Clusters %d [%6.2f %% in the active volume]", ncl, 100.*float(nin)/ncl));
1936
1937 return 0;
1938}
1939
1940//_____________________________________________________________________________
1941Int_t AliTRDtrackerV1::LoadClusters(TClonesArray * const clusters)
1942{
1943 //
1944 // Fills clusters into TRD tracking sectors
1945 // Function for use in the HLT
1946
1947 if(!clusters || !clusters->GetEntriesFast()){
1948 AliInfo("No TRD clusters");
1949 return 1;
1950 }
1951
1952 fClusters = clusters;
1953 SetClustersOwner();
1954
1955 fkRecoParam = fkReconstructor->GetRecoParam(); // load reco param for this event
1956 BuildTrackingContainers();
1957
1958 //Int_t ncl = fClusters->GetEntriesFast();
1959 //AliInfo(Form("Clusters %d [%6.2f %% in the active volume]", ncl, 100.*float(nin)/ncl));
1960
1961 return 0;
1962}
1963
1964
1965//____________________________________________________________________
1966Int_t AliTRDtrackerV1::BuildTrackingContainers()
1967{
1968// Building tracking containers for clusters
1969
1970 Int_t nin(0), ncl(fClusters->GetEntriesFast());
1971 while (ncl--) {
1972 AliTRDcluster *c = (AliTRDcluster *) fClusters->UncheckedAt(ncl);
1973 if(c->IsInChamber()) nin++;
1974 if(fkReconstructor->IsHLT()) c->SetRPhiMethod(AliTRDcluster::kCOG);
1975 Int_t detector = c->GetDetector();
1976 Int_t sector = fGeom->GetSector(detector);
1977 Int_t stack = fGeom->GetStack(detector);
1978 Int_t layer = fGeom->GetLayer(detector);
1979
1980 fTrSec[sector].GetChamber(stack, layer, kTRUE)->InsertCluster(c, ncl);
1981 }
1982
1983 for(int isector =0; isector<AliTRDgeometry::kNsector; isector++){
1984 if(!fTrSec[isector].GetNChambers()) continue;
1985 fTrSec[isector].Init(fkReconstructor);
1986 }
1987
1988 return nin;
1989}
1990
1991
1992
1993//____________________________________________________________________
1994void AliTRDtrackerV1::UnloadClusters()
1995{
1996//
1997// Clears the arrays of clusters and tracks. Resets sectors and timebins
1998// If option "force" is also set the containers are also deleted. This is useful
1999// in case of HLT
2000
2001 if(fTracks){
2002 fTracks->Delete();
2003 if(HasRemoveContainers()){delete fTracks; fTracks = NULL;}
2004 }
2005 if(fTracklets){
2006 fTracklets->Delete();
2007 if(HasRemoveContainers()){delete fTracklets; fTracklets = NULL;}
2008 }
2009 if(fClusters){
2010 if(IsClustersOwner()) fClusters->Delete();
2011
2012 // save clusters array in the reconstructor for further use.
2013 if(!fkReconstructor->IsWritingClusters()){
2014 AliTRDReconstructor::SetClusters(fClusters);
2015 SetClustersOwner(kFALSE);
2016 } else AliTRDReconstructor::SetClusters(NULL);
2017 }
2018
2019 for (int i = 0; i < AliTRDgeometry::kNsector; i++) fTrSec[i].Clear();
2020
2021 // Increment the Event Number
2022 AliTRDtrackerDebug::SetEventNumber(AliTRDtrackerDebug::GetEventNumber() + 1);
2023}
2024
2025// //____________________________________________________________________
2026// void AliTRDtrackerV1::UseClusters(const AliKalmanTrack *t, Int_t) const
2027// {
2028// const AliTRDtrackV1 *track = dynamic_cast<const AliTRDtrackV1*>(t);
2029// if(!track) return;
2030//
2031// AliTRDseedV1 *tracklet = NULL;
2032// for(Int_t ily=AliTRDgeometry::kNlayer; ily--;){
2033// if(!(tracklet = track->GetTracklet(ily))) continue;
2034// AliTRDcluster *c = NULL;
2035// for(Int_t ic=AliTRDseed::kNclusters; ic--;){
2036// if(!(c=tracklet->GetClusters(ic))) continue;
2037// c->Use();
2038// }
2039// }
2040// }
2041//
2042
2043//_____________________________________________________________________________
2044Bool_t AliTRDtrackerV1::AdjustSector(AliTRDtrackV1 *const track)
2045{
2046 //
2047 // Rotates the track when necessary
2048 //
2049
2050 Double_t alpha = AliTRDgeometry::GetAlpha();
2051 Double_t y = track->GetY();
2052 Double_t ymax = track->GetX()*TMath::Tan(0.5*alpha);
2053
2054 if (y > ymax) {
2055 if (!track->Rotate( alpha)) {
2056 return kFALSE;
2057 }
2058 }
2059 else if (y < -ymax) {
2060 if (!track->Rotate(-alpha)) {
2061 return kFALSE;
2062 }
2063 }
2064
2065 return kTRUE;
2066
2067}
2068
2069
2070//____________________________________________________________________
2071AliTRDseedV1* AliTRDtrackerV1::GetTracklet(AliTRDtrackV1 *const track, Int_t p, Int_t &idx)
2072{
2073 // Find tracklet for TRD track <track>
2074 // Parameters
2075 // - track
2076 // - sector
2077 // - plane
2078 // - index
2079 // Output
2080 // tracklet
2081 // index
2082 // Detailed description
2083 //
2084 idx = track->GetTrackletIndex(p);
2085 AliTRDseedV1 *tracklet = (idx<0) ? NULL : (AliTRDseedV1*)fTracklets->UncheckedAt(idx);
2086
2087 return tracklet;
2088}
2089
2090//____________________________________________________________________
2091AliTRDseedV1* AliTRDtrackerV1::SetTracklet(const AliTRDseedV1 * const tracklet)
2092{
2093 // Add this tracklet to the list of tracklets stored in the tracker
2094 //
2095 // Parameters
2096 // - tracklet : pointer to the tracklet to be added to the list
2097 //
2098 // Output
2099 // - the index of the new tracklet in the tracker tracklets list
2100 //
2101 // Detailed description
2102 // Build the tracklets list if it is not yet created (late initialization)
2103 // and adds the new tracklet to the list.
2104 //
2105 if(!fTracklets){
2106 fTracklets = new TClonesArray("AliTRDseedV1", AliTRDgeometry::Nsector()*kMaxTracksStack);
2107 fTracklets->SetOwner(kTRUE);
2108 }
2109 Int_t nentries = fTracklets->GetEntriesFast();
2110 return new ((*fTracklets)[nentries]) AliTRDseedV1(*tracklet);
2111}
2112
2113//____________________________________________________________________
2114AliTRDtrackV1* AliTRDtrackerV1::SetTrack(const AliTRDtrackV1 * const track)
2115{
2116 // Add this track to the list of tracks stored in the tracker
2117 //
2118 // Parameters
2119 // - track : pointer to the track to be added to the list
2120 //
2121 // Output
2122 // - the pointer added
2123 //
2124 // Detailed description
2125 // Build the tracks list if it is not yet created (late initialization)
2126 // and adds the new track to the list.
2127 //
2128 if(!fTracks){
2129 fTracks = new TClonesArray("AliTRDtrackV1", AliTRDgeometry::Nsector()*kMaxTracksStack);
2130 fTracks->SetOwner(kTRUE);
2131 }
2132 Int_t nentries = fTracks->GetEntriesFast();
2133 return new ((*fTracks)[nentries]) AliTRDtrackV1(*track);
2134}
2135
2136
2137
2138//____________________________________________________________________
2139Int_t AliTRDtrackerV1::Clusters2TracksSM(Int_t sector, AliESDEvent *esd)
2140{
2141 //
2142 // Steer tracking for one SM.
2143 //
2144 // Parameters :
2145 // sector : Array of (SM) propagation layers containing clusters
2146 // esd : The current ESD event. On output it contains the also
2147 // the ESD (TRD) tracks found in this SM.
2148 //
2149 // Output :
2150 // Number of tracks found in this TRD supermodule.
2151 //
2152 // Detailed description
2153 //
2154 // 1. Unpack AliTRDpropagationLayers objects for each stack.
2155 // 2. Launch stack tracking.
2156 // See AliTRDtrackerV1::Clusters2TracksStack() for details.
2157 // 3. Pack results in the ESD event.
2158 //
2159
2160 Int_t nTracks = 0;
2161 Int_t nChambers = 0;
2162 AliTRDtrackingChamber **stack = NULL, *chamber = NULL;
2163 for(int istack = 0; istack<AliTRDgeometry::kNstack; istack++){
2164 if(!(stack = fTrSec[sector].GetStack(istack))) continue;
2165 nChambers = 0;
2166 for(int ilayer=0; ilayer<AliTRDgeometry::kNlayer; ilayer++){
2167 if(!(chamber = stack[ilayer])) continue;
2168 if(chamber->GetNClusters() < fgNTimeBins * fkRecoParam->GetFindableClusters()) continue;
2169 nChambers++;
2170 //AliInfo(Form("sector %d stack %d layer %d clusters %d", sector, istack, ilayer, chamber->GetNClusters()));
2171 }
2172 if(nChambers < 4) continue;
2173 //AliInfo(Form("Doing stack %d", istack));
2174 nTracks += Clusters2TracksStack(stack, fTracksESD);
2175 }
2176 if(nTracks) AliDebug(2, Form("Number of tracks: SM_%02d[%d]", sector, nTracks));
2177
2178 for(int itrack=0; itrack<nTracks; itrack++){
2179 AliESDtrack *esdTrack((AliESDtrack*)(fTracksESD->operator[](itrack)));
2180 Int_t id = esd->AddTrack(esdTrack);
2181
2182 // set ESD id to stand alone TRD tracks
2183 if (fkRecoParam->GetStreamLevel(AliTRDrecoParam::kTracker) > 0){
2184 esdTrack=esd->GetTrack(id);
2185 TObject *o(NULL); Int_t ic(0);
2186 AliTRDtrackV1 *calibTrack(NULL);
2187 while((o = esdTrack->GetCalibObject(ic++))){
2188 if(!(calibTrack = dynamic_cast<AliTRDtrackV1*>(o))) continue;
2189 calibTrack->SetESDid(esdTrack->GetID());
2190 break;
2191 }
2192 }
2193 }
2194
2195 // Reset Track and Candidate Number
2196 AliTRDtrackerDebug::SetCandidateNumber(0);
2197 AliTRDtrackerDebug::SetTrackNumber(0);
2198
2199 // delete ESD tracks in the array
2200 fTracksESD->Delete();
2201 return nTracks;
2202}
2203
2204//____________________________________________________________________
2205Int_t AliTRDtrackerV1::Clusters2TracksStack(AliTRDtrackingChamber **stack, TClonesArray * const esdTrackList)
2206{
2207 //
2208 // Make tracks in one TRD stack.
2209 //
2210 // Parameters :
2211 // layer : Array of stack propagation layers containing clusters
2212 // esdTrackList : Array of ESD tracks found by the stand alone tracker.
2213 // On exit the tracks found in this stack are appended.
2214 //
2215 // Output :
2216 // Number of tracks found in this stack.
2217 //
2218 // Detailed description
2219 //
2220 // 1. Find the 3 most useful seeding chambers. See BuildSeedingConfigs() for details.
2221 // 2. Steer AliTRDtrackerV1::MakeSeeds() for 3 seeding layer configurations.
2222 // See AliTRDtrackerV1::MakeSeeds() for more details.
2223 // 3. Arrange track candidates in decreasing order of their quality
2224 // 4. Classify tracks in 5 categories according to:
2225 // a) number of layers crossed
2226 // b) track quality
2227 // 5. Sign clusters by tracks in decreasing order of track quality
2228 // 6. Build AliTRDtrack out of seeding tracklets
2229 // 7. Cook MC label
2230 // 8. Build ESD track and register it to the output list
2231 //
2232
2233 AliTRDtrackingChamber *chamber = NULL;
2234 AliTRDtrackingChamber **ci = NULL;
2235 AliTRDseedV1 sseed[kMaxTracksStack*6]; // to be initialized
2236 Int_t pars[4]; // MakeSeeds parameters
2237
2238 //Double_t alpha = AliTRDgeometry::GetAlpha();
2239 //Double_t shift = .5 * alpha;
2240 Int_t configs[kNConfigs];
2241
2242 // Purge used clusters from the containers
2243 ci = &stack[0];
2244 for(Int_t ic = kNPlanes; ic--; ci++){
2245 if(!(*ci)) continue;
2246 (*ci)->Update();
2247 }
2248
2249 // Build initial seeding configurations
2250 Double_t quality = BuildSeedingConfigs(stack, configs);
2251 if(fkRecoParam->GetStreamLevel(AliTRDrecoParam::kTracker) > 10){
2252 AliInfo(Form("Plane config %d %d %d Quality %f"
2253 , configs[0], configs[1], configs[2], quality));
2254 }
2255
2256
2257 // Initialize contors
2258 Int_t ntracks, // number of TRD track candidates
2259 ntracks1, // number of registered TRD tracks/iter
2260 ntracks2 = 0; // number of all registered TRD tracks in stack
2261 fSieveSeeding = 0;
2262
2263 // Get stack index
2264 Int_t ic = 0; ci = &stack[0];
2265 while(ic<kNPlanes && !(*ci)){ic++; ci++;}
2266 if(!(*ci)) return ntracks2;
2267 Int_t istack = fGeom->GetStack((*ci)->GetDetector());
2268
2269 do{
2270 // Loop over seeding configurations
2271 ntracks = 0; ntracks1 = 0;
2272 for (Int_t iconf = 0; iconf<fkRecoParam->GetNumberOfSeedConfigs(); iconf++) {
2273 pars[0] = configs[iconf];
2274 pars[1] = ntracks;
2275 pars[2] = istack;
2276 ntracks = MakeSeeds(stack, &sseed[6*ntracks], pars);
2277 //AliInfo(Form("Number of Tracks after iteration step %d: %d\n", iconf, ntracks));
2278 if(ntracks == kMaxTracksStack) break;
2279 }
2280 AliDebug(2, Form("Candidate TRD tracks %d in iteration %d.", ntracks, fSieveSeeding));
2281 if(!ntracks) break;
2282
2283 // Sort the seeds according to their quality
2284 Int_t sort[kMaxTracksStack];
2285 TMath::Sort(ntracks, fTrackQuality, sort, kTRUE);
2286 if(AliLog::GetDebugLevel("TRD", "AliTRDtrackerV1") > 2){
2287 AliDebug(3, "Track candidates classification:");
2288 for (Int_t it(0); it < ntracks; it++) {
2289 Int_t jt(sort[it]);
2290 printf(" %2d idx[%d] Quality[%e]\n", it, jt, fTrackQuality[jt]);
2291 }
2292 }
2293
2294 // Initialize number of tracks so far and logic switches
2295 Int_t ntracks0 = esdTrackList->GetEntriesFast();
2296 Bool_t signedTrack[kMaxTracksStack];
2297 Bool_t fakeTrack[kMaxTracksStack];
2298 for (Int_t i=0; i<ntracks; i++){
2299 signedTrack[i] = kFALSE;
2300 fakeTrack[i] = kFALSE;
2301 }
2302 //AliInfo("Selecting track candidates ...");
2303
2304 // Sieve clusters in decreasing order of track quality
2305 Int_t jSieve(0), rejectedCandidates(0);
2306 do{
2307 // Check track candidates
2308 rejectedCandidates=0;
2309 for (Int_t itrack = 0; itrack < ntracks; itrack++) {
2310 Int_t trackIndex = sort[itrack];
2311 if (signedTrack[trackIndex] || fakeTrack[trackIndex]) continue;
2312
2313 // Calculate track parameters from tracklets seeds
2314 Int_t ncl = 0;
2315 Int_t nused = 0;
2316 Int_t nlayers = 0;
2317 Int_t findable = 0;
2318 for (Int_t jLayer = 0; jLayer < kNPlanes; jLayer++) {
2319 Int_t jseed = kNPlanes*trackIndex+jLayer;
2320 sseed[jseed].UpdateUsed();
2321 if(!sseed[jseed].IsOK()) continue;
2322 // check if primary candidate
2323 if (TMath::Abs(sseed[jseed].GetYref(0) / sseed[jseed].GetX0()) < 0.158) findable++;
2324 ncl += sseed[jseed].GetN();
2325 nused += sseed[jseed].GetNUsed();
2326 nlayers++;
2327 }
2328
2329 // Filter duplicated tracks
2330 if (nused > 30){
2331 AliDebug(4, Form("REJECTED : %d idx[%d] quality[%e] tracklets[%d] usedClusters[%d]", itrack, trackIndex, fTrackQuality[trackIndex], nlayers, nused));
2332 fakeTrack[trackIndex] = kTRUE;
2333 continue;
2334 }
2335 if (ncl>0 && Float_t(nused)/ncl >= .25){
2336 AliDebug(4, Form("REJECTED : %d idx[%d] quality[%e] tracklets[%d] usedClusters[%d] used/ncl[%f]", itrack, trackIndex, fTrackQuality[trackIndex], nlayers, nused, Float_t(nused)/ncl));
2337 fakeTrack[trackIndex] = kTRUE;
2338 continue;
2339 }
2340
2341 AliDebug(4, Form("Candidate[%d] Quality[%e] Tracklets[%d] Findable[%d] Ncl[%d] Nused[%d]", trackIndex, fTrackQuality[trackIndex], nlayers, findable, ncl, nused));
2342
2343 // Classify tracks
2344 Bool_t skip = kFALSE;
2345 switch(jSieve){
2346 case 0: // select 6 tracklets primary tracks, good quality
2347 if(nlayers > findable || nlayers < kNPlanes) {skip = kTRUE; break;}
2348 if(TMath::Log(1.E-9+fTrackQuality[trackIndex]) < -5.){skip = kTRUE; break;}
2349 break;
2350
2351 case 1: // select shorter primary tracks, good quality
2352 //if(findable<4){skip = kTRUE; break;}
2353 if(nlayers < findable){skip = kTRUE; break;}
2354 if(TMath::Log(1.E-9+fTrackQuality[trackIndex]) < -4.){skip = kTRUE; break;}
2355 break;
2356
2357 case 2: // select 6 tracklets secondary tracks
2358 if(nlayers < kNPlanes) { skip = kTRUE; break;}
2359 if (TMath::Log(1.E-9+fTrackQuality[trackIndex]) < -6.0){skip = kTRUE; break;}
2360 break;
2361
2362 case 3: // select shorter tracks, good quality
2363 if (nlayers<4){skip = kTRUE; break;}
2364 if (TMath::Log(1.E-9+fTrackQuality[trackIndex]) < -5.){skip = kTRUE; break;}
2365 break;
2366
2367 case 4: // select anything with at least 4 tracklets
2368 if (nlayers<4){skip = kTRUE; break;}
2369 //if (TMath::Log(1.E-9+fTrackQuality[trackIndex]) - nused/(nlayers-3.0) < -15.0){skip = kTRUE; break;}
2370 break;
2371 }
2372 if(skip){
2373 rejectedCandidates++;
2374 AliDebug(4, Form("REJECTED : %d idx[%d] quality[%e] tracklets[%d] usedClusters[%d]", itrack, trackIndex, fTrackQuality[trackIndex], nlayers, nused));
2375 continue;
2376 } else AliDebug(4, Form("ACCEPTED : %d idx[%d] quality[%e] tracklets[%d] usedClusters[%d]", itrack, trackIndex, fTrackQuality[trackIndex], nlayers, nused));
2377
2378 signedTrack[trackIndex] = kTRUE;
2379
2380 AliTRDseedV1 *lseed =&sseed[trackIndex*kNPlanes];
2381 AliTRDtrackV1 *track = MakeTrack(lseed);
2382 if(!track){
2383 AliDebug(1, "Track building failed.");
2384 continue;
2385 } else {
2386 if(AliLog::GetDebugLevel("TRD", "AliTRDtrackerV1") > 1){
2387 Int_t ich = 0; while(!(chamber = stack[ich])) ich++;
2388 AliDebug(2, Form("Track pt=%7.2fGeV/c SM[%2d] Done.", track->Pt(), fGeom->GetSector(chamber->GetDetector())));
2389 }
2390 }
2391
2392 if(fkRecoParam->GetStreamLevel(AliTRDrecoParam::kTracker) > 1 && fkReconstructor->IsDebugStreaming()){
2393 //AliInfo(Form("Track %d [%d] nlayers %d trackQuality = %e nused %d, yref = %3.3f", itrack, trackIndex, nlayers, fTrackQuality[trackIndex], nused, trackParams[1]));
2394
2395 AliTRDseedV1 *dseed[6];
2396 for(Int_t iseed = AliTRDgeometry::kNlayer; iseed--;) dseed[iseed] = new AliTRDseedV1(lseed[iseed]);
2397
2398 //Int_t eventNrInFile = esd->GetEventNumberInFile();
2399 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2400 Int_t trackNumber = AliTRDtrackerDebug::GetTrackNumber();
2401 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2402 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
2403 cstreamer << "Clusters2TracksStack"
2404 << "EventNumber=" << eventNumber
2405 << "TrackNumber=" << trackNumber
2406 << "CandidateNumber=" << candidateNumber
2407 << "Iter=" << fSieveSeeding
2408 << "Like=" << fTrackQuality[trackIndex]
2409 << "S0.=" << dseed[0]
2410 << "S1.=" << dseed[1]
2411 << "S2.=" << dseed[2]
2412 << "S3.=" << dseed[3]
2413 << "S4.=" << dseed[4]
2414 << "S5.=" << dseed[5]
2415 << "Ncl=" << ncl
2416 << "NLayers=" << nlayers
2417 << "Findable=" << findable
2418 << "NUsed=" << nused
2419 << "\n";
2420 }
2421
2422
2423 AliESDtrack *esdTrack = new ((*esdTrackList)[ntracks0++]) AliESDtrack();
2424 esdTrack->UpdateTrackParams(track, AliESDtrack::kTRDout);
2425 esdTrack->SetLabel(track->GetLabel());
2426 track->UpdateESDtrack(esdTrack);
2427 // write ESD-friends if neccessary
2428 if (fkRecoParam->GetStreamLevel(AliTRDrecoParam::kTracker) > 0){
2429 AliTRDtrackV1 *calibTrack = new AliTRDtrackV1(*track);
2430 calibTrack->SetOwner();
2431 esdTrack->AddCalibObject(calibTrack);
2432 }
2433 ntracks1++;
2434 AliTRDtrackerDebug::SetTrackNumber(AliTRDtrackerDebug::GetTrackNumber() + 1);
2435 }
2436
2437 jSieve++;
2438 } while(jSieve<5 && rejectedCandidates); // end track candidates sieve
2439 if(!ntracks1) break;
2440
2441 // increment counters
2442 ntracks2 += ntracks1;
2443
2444 if(fkReconstructor->IsHLT()) break;
2445 fSieveSeeding++;
2446
2447 // Rebuild plane configurations and indices taking only unused clusters into account
2448 quality = BuildSeedingConfigs(stack, configs);
2449 if(quality < 1.E-7) break; //fkReconstructor->GetRecoParam() ->GetPlaneQualityThreshold()) break;
2450
2451 for(Int_t ip = 0; ip < kNPlanes; ip++){
2452 if(!(chamber = stack[ip])) continue;
2453 chamber->Build(fGeom);//Indices(fSieveSeeding);
2454 }
2455
2456 if(fkRecoParam->GetStreamLevel(AliTRDrecoParam::kTracker) > 10){
2457 AliInfo(Form("Sieve level %d Plane config %d %d %d Quality %f", fSieveSeeding, configs[0], configs[1], configs[2], quality));
2458 }
2459 } while(fSieveSeeding<10); // end stack clusters sieve
2460
2461
2462
2463 //AliInfo(Form("Registered TRD tracks %d in stack %d.", ntracks2, pars[1]));
2464
2465 return ntracks2;
2466}
2467
2468//___________________________________________________________________
2469Double_t AliTRDtrackerV1::BuildSeedingConfigs(AliTRDtrackingChamber **stack, Int_t *configs)
2470{
2471 //
2472 // Assign probabilities to chambers according to their
2473 // capability of producing seeds.
2474 //
2475 // Parameters :
2476 //
2477 // layers : Array of stack propagation layers for all 6 chambers in one stack
2478 // configs : On exit array of configuration indexes (see GetSeedingConfig()
2479 // for details) in the decreasing order of their seeding probabilities.
2480 //
2481 // Output :
2482 //
2483 // Return top configuration quality
2484 //
2485 // Detailed description:
2486 //
2487 // To each chamber seeding configuration (see GetSeedingConfig() for
2488 // the list of all configurations) one defines 2 quality factors:
2489 // - an apriori topological quality (see GetSeedingConfig() for details) and
2490 // - a data quality based on the uniformity of the distribution of
2491 // clusters over the x range (time bins population). See CookChamberQA() for details.
2492 // The overall chamber quality is given by the product of this 2 contributions.
2493 //
2494
2495 Double_t chamberQ[kNPlanes];memset(chamberQ, 0, kNPlanes*sizeof(Double_t));
2496 AliTRDtrackingChamber *chamber = NULL;
2497 for(int iplane=0; iplane<kNPlanes; iplane++){
2498 if(!(chamber = stack[iplane])) continue;
2499 chamberQ[iplane] = (chamber = stack[iplane]) ? chamber->GetQuality() : 0.;
2500 }
2501
2502 Double_t tconfig[kNConfigs];memset(tconfig, 0, kNConfigs*sizeof(Double_t));
2503 Int_t planes[] = {0, 0, 0, 0};
2504 for(int iconf=0; iconf<kNConfigs; iconf++){
2505 GetSeedingConfig(iconf, planes);
2506 tconfig[iconf] = fgTopologicQA[iconf];
2507 for(int iplane=0; iplane<4; iplane++) tconfig[iconf] *= chamberQ[planes[iplane]];
2508 }
2509
2510 TMath::Sort((Int_t)kNConfigs, tconfig, configs, kTRUE);
2511 // AliInfo(Form("q[%d] = %f", configs[0], tconfig[configs[0]]));
2512 // AliInfo(Form("q[%d] = %f", configs[1], tconfig[configs[1]]));
2513 // AliInfo(Form("q[%d] = %f", configs[2], tconfig[configs[2]]));
2514
2515 return tconfig[configs[0]];
2516}
2517
2518//____________________________________________________________________
2519Int_t AliTRDtrackerV1::MakeSeeds(AliTRDtrackingChamber **stack, AliTRDseedV1 * const sseed, const Int_t * const ipar)
2520{
2521//
2522// Seed tracklets and build candidate TRD tracks. The procedure is used during barrel tracking to account for tracks which are
2523// either missed by TPC prolongation or conversions inside the TRD volume.
2524// For stand alone tracking the procedure is used to estimate all tracks measured by TRD.
2525//
2526// Parameters :
2527// layers : Array of stack propagation layers containing clusters
2528// sseed : Array of empty tracklet seeds. On exit they are filled.
2529// ipar : Control parameters:
2530// ipar[0] -> seeding chambers configuration
2531// ipar[1] -> stack index
2532// ipar[2] -> number of track candidates found so far
2533//
2534// Output :
2535// Number of tracks candidates found.
2536//
2537// The following steps are performed:
2538// 1. Build seeding layers by collapsing all time bins from each of the four seeding chambers along the
2539// radial coordinate. See AliTRDtrackingChamber::GetSeedingLayer() for details. The chambers selection for seeding
2540// is described in AliTRDtrackerV1::Clusters2TracksStack().
2541// 2. Using the seeding clusters from the seeding layer (step 1) build combinatorics using the following algorithm:
2542// - for each seeding cluster in the lower seeding layer find
2543// - all seeding clusters in the upper seeding layer inside a road defined by a given phi angle. The angle
2544// is calculated on the minimum pt of tracks from vertex accesible to the stand alone tracker.
2545// - for each pair of two extreme seeding clusters select middle upper cluster using roads defined externally by the
2546// reco params
2547// - select last seeding cluster as the nearest to the linear approximation of the track described by the first three
2548// seeding clusters.
2549// The implementation of road calculation and cluster selection can be found in the functions AliTRDchamberTimeBin::BuildCond()
2550// and AliTRDchamberTimeBin::GetClusters().
2551// 3. Helix fit of the seeding clusters set. (see AliTRDtrackerFitter::FitRieman(AliTRDcluster**)). No tilt correction is
2552// performed at this level
2553// 4. Initialize seeding tracklets in the seeding chambers.
2554// 5. *Filter 0* Chi2 cut on the Y and Z directions. The threshold is set externally by the reco params.
2555// 6. Attach (true) clusters to seeding tracklets (see AliTRDseedV1::AttachClusters()) and fit tracklet (see
2556// AliTRDseedV1::Fit()). The number of used clusters used by current seeds should not exceed ... (25).
2557// 7. *Filter 1* Check if all 4 seeding tracklets are correctly constructed.
2558// 8. Helix fit of the clusters from the seeding tracklets with tilt correction. Refit tracklets using the new
2559// approximation of the track.
2560// 9. *Filter 2* Calculate likelihood of the track. (See AliTRDtrackerV1::CookLikelihood()). The following quantities are
2561// checked against the Riemann fit:
2562// - position resolution in y
2563// - angular resolution in the bending plane
2564// - likelihood of the number of clusters attached to the tracklet
2565// 10. Extrapolation of the helix fit to the other 2 chambers *non seeding* chambers:
2566// - Initialization of extrapolation tracklets with the fit parameters
2567// - Attach clusters to extrapolated tracklets
2568// - Helix fit of tracklets
2569// 11. Improve seeding tracklets quality by reassigning clusters based on the last parameters of the track
2570// See AliTRDtrackerV1::ImproveSeedQuality() for details.
2571// 12. Helix fit of all 6 seeding tracklets and chi2 calculation
2572// 13. Hyperplane fit and track quality calculation. See AliTRDtrackerFitter::FitHyperplane() for details.
2573// 14. Cooking labels for tracklets. Should be done only for MC
2574// 15. Register seeds.
2575//
2576// Authors:
2577// Marian Ivanov <M.Ivanov@gsi.de>
2578// Alexandru Bercuci <A.Bercuci@gsi.de>
2579// Markus Fasel <M.Fasel@gsi.de>
2580
2581 AliTRDtrackingChamber *chamber = NULL;
2582 AliTRDcluster *c[kNSeedPlanes] = {NULL, NULL, NULL, NULL}; // initilize seeding clusters
2583 AliTRDseedV1 *cseed = &sseed[0]; // initialize tracklets for first track
2584 Int_t ncl, mcl; // working variable for looping over clusters
2585 Int_t index[AliTRDchamberTimeBin::kMaxClustersLayer], jndex[AliTRDchamberTimeBin::kMaxClustersLayer];
2586 // chi2 storage
2587 // chi2[0] = tracklet chi2 on the Z direction
2588 // chi2[1] = tracklet chi2 on the R direction
2589 Double_t chi2[4];
2590
2591 // this should be data member of AliTRDtrack TODO
2592 Double_t seedQuality[kMaxTracksStack];
2593
2594 // unpack control parameters
2595 Int_t config = ipar[0];
2596 Int_t ntracks = ipar[1];
2597 Int_t istack = ipar[2];
2598 Int_t planes[kNSeedPlanes]; GetSeedingConfig(config, planes);
2599 Int_t planesExt[kNPlanes-kNSeedPlanes]; GetExtrapolationConfig(config, planesExt);
2600
2601
2602 // Init chambers geometry
2603 Double_t hL[kNPlanes]; // Tilting angle
2604 Float_t padlength[kNPlanes]; // pad lenghts
2605 Float_t padwidth[kNPlanes]; // pad widths
2606 AliTRDpadPlane *pp = NULL;
2607 for(int iplane=0; iplane<kNPlanes; iplane++){
2608 pp = fGeom->GetPadPlane(iplane, istack);
2609 hL[iplane] = TMath::Tan(TMath::DegToRad()*pp->GetTiltingAngle());
2610 padlength[iplane] = pp->GetLengthIPad();
2611 padwidth[iplane] = pp->GetWidthIPad();
2612 }
2613
2614 // Init anode wire position for chambers
2615 Double_t x0[kNPlanes], // anode wire position
2616 driftLength = .5*AliTRDgeometry::AmThick() - AliTRDgeometry::DrThick(); // drift length
2617 TGeoHMatrix *matrix = NULL;
2618 Double_t loc[] = {AliTRDgeometry::AnodePos(), 0., 0.};
2619 Double_t glb[] = {0., 0., 0.};
2620 AliTRDtrackingChamber **cIter = &stack[0];
2621 for(int iLayer=0; iLayer<kNPlanes; iLayer++,cIter++){
2622 if(!(*cIter)) continue;
2623 if(!(matrix = fGeom->GetClusterMatrix((*cIter)->GetDetector()))){
2624 x0[iLayer] = fgkX0[iLayer];
2625 continue;
2626 }
2627 matrix->LocalToMaster(loc, glb);
2628 x0[iLayer] = glb[0];
2629 }
2630
2631 AliDebug(2, Form("Making seeds Stack[%d] Config[%d] Tracks[%d]...", istack, config, ntracks));
2632
2633 // Build seeding layers
2634 ResetSeedTB();
2635 Int_t nlayers = 0;
2636 for(int isl=0; isl<kNSeedPlanes; isl++){
2637 if(!(chamber = stack[planes[isl]])) continue;
2638 if(!chamber->GetSeedingLayer(fSeedTB[isl], fGeom, fkReconstructor)) continue;
2639 nlayers++;
2640 }
2641 if(nlayers < kNSeedPlanes) return ntracks;
2642
2643
2644 // Start finding seeds
2645 Double_t cond0[4], cond1[4], cond2[4];
2646 Int_t icl = 0;
2647 while((c[3] = (*fSeedTB[3])[icl++])){
2648 if(!c[3]) continue;
2649 fSeedTB[0]->BuildCond(c[3], cond0, 0);
2650 fSeedTB[0]->GetClusters(cond0, index, ncl);
2651 //printf("Found c[3] candidates 0 %d\n", ncl);
2652 Int_t jcl = 0;
2653 while(jcl<ncl) {
2654 c[0] = (*fSeedTB[0])[index[jcl++]];
2655 if(!c[0]) continue;
2656 Double_t dx = c[3]->GetX() - c[0]->GetX();
2657 Double_t dzdx = (c[3]->GetZ() - c[0]->GetZ())/dx;
2658 Double_t dydx = (c[3]->GetY() - c[0]->GetY())/dx;
2659 fSeedTB[1]->BuildCond(c[0], cond1, 1, dzdx, dydx);
2660 fSeedTB[1]->GetClusters(cond1, jndex, mcl);
2661 //printf("Found c[0] candidates 1 %d\n", mcl);
2662
2663 Int_t kcl = 0;
2664 while(kcl<mcl) {
2665 c[1] = (*fSeedTB[1])[jndex[kcl++]];
2666 if(!c[1]) continue;
2667 fSeedTB[2]->BuildCond(c[1], cond2, 2, dzdx, dydx);
2668 c[2] = fSeedTB[2]->GetNearestCluster(cond2);
2669 //printf("Found c[1] candidate 2 %p\n", c[2]);
2670 if(!c[2]) continue;
2671
2672 AliDebug(3, Form("Seeding clusters\n 0[%6.3f %6.3f %6.3f]\n 1[%6.3f %6.3f %6.3f]\n 2[%6.3f %6.3f %6.3f]\n 3[%6.3f %6.3f %6.3f].",
2673 c[0]->GetX(), c[0]->GetY(), c[0]->GetZ(),
2674 c[1]->GetX(), c[1]->GetY(), c[1]->GetZ(),
2675 c[2]->GetX(), c[2]->GetY(), c[2]->GetZ(),
2676 c[3]->GetX(), c[3]->GetY(), c[3]->GetZ()));
2677
2678 for (Int_t il = 0; il < kNPlanes; il++) cseed[il].Reset();
2679
2680 FitRieman(c, chi2);
2681
2682 AliTRDseedV1 *tseed = &cseed[0];
2683 cIter = &stack[0];
2684 for(int iLayer=0; iLayer<kNPlanes; iLayer++, tseed++, cIter++){
2685 Int_t det = (*cIter) ? (*cIter)->GetDetector() : -1;
2686 tseed->SetDetector(det);
2687 tseed->SetTilt(hL[iLayer]);
2688 tseed->SetPadLength(padlength[iLayer]);
2689 tseed->SetPadWidth(padwidth[iLayer]);
2690 tseed->SetReconstructor(fkReconstructor);
2691 tseed->SetX0(det<0 ? fR[iLayer]+driftLength : x0[iLayer]);
2692 tseed->Init(GetRiemanFitter());
2693 tseed->SetStandAlone(kTRUE);
2694 }
2695
2696 Bool_t isFake = kFALSE;
2697 if(fkRecoParam->GetStreamLevel(AliTRDrecoParam::kTracker) >= 2 && fkReconstructor->IsDebugStreaming()){
2698 if (c[0]->GetLabel(0) != c[3]->GetLabel(0)) isFake = kTRUE;
2699 if (c[1]->GetLabel(0) != c[3]->GetLabel(0)) isFake = kTRUE;
2700 if (c[2]->GetLabel(0) != c[3]->GetLabel(0)) isFake = kTRUE;
2701
2702 Double_t xpos[4];
2703 for(Int_t l = 0; l < kNSeedPlanes; l++) xpos[l] = fSeedTB[l]->GetX();
2704 Float_t yref[4];
2705 for(int il=0; il<4; il++) yref[il] = cseed[planes[il]].GetYref(0);
2706 Int_t ll = c[3]->GetLabel(0);
2707 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2708 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2709 AliRieman *rim = GetRiemanFitter();
2710 TTreeSRedirector &cs0 = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
2711 cs0 << "MakeSeeds0"
2712 <<"EventNumber=" << eventNumber
2713 <<"CandidateNumber=" << candidateNumber
2714 <<"isFake=" << isFake
2715 <<"config=" << config
2716 <<"label=" << ll
2717 <<"chi2z=" << chi2[0]
2718 <<"chi2y=" << chi2[1]
2719 <<"Y2exp=" << cond2[0]
2720 <<"Z2exp=" << cond2[1]
2721 <<"X0=" << xpos[0] //layer[sLayer]->GetX()
2722 <<"X1=" << xpos[1] //layer[sLayer + 1]->GetX()
2723 <<"X2=" << xpos[2] //layer[sLayer + 2]->GetX()
2724 <<"X3=" << xpos[3] //layer[sLayer + 3]->GetX()
2725 <<"yref0=" << yref[0]
2726 <<"yref1=" << yref[1]
2727 <<"yref2=" << yref[2]
2728 <<"yref3=" << yref[3]
2729 <<"c0.=" << c[0]
2730 <<"c1.=" << c[1]
2731 <<"c2.=" << c[2]
2732 <<"c3.=" << c[3]
2733 <<"Seed0.=" << &cseed[planes[0]]
2734 <<"Seed1.=" << &cseed[planes[1]]
2735 <<"Seed2.=" << &cseed[planes[2]]
2736 <<"Seed3.=" << &cseed[planes[3]]
2737 <<"RiemanFitter.=" << rim
2738 <<"\n";
2739 }
2740 if(chi2[0] > fkRecoParam->GetChi2Z()/*7./(3. - sLayer)*//*iter*/){
2741 AliDebug(3, Form("Filter on chi2Z [%f].", chi2[0]));
2742 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2743 continue;
2744 }
2745 if(chi2[1] > fkRecoParam->GetChi2Y()/*1./(3. - sLayer)*//*iter*/){
2746 AliDebug(3, Form("Filter on chi2Y [%f].", chi2[1]));
2747 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2748 continue;
2749 }
2750 //AliInfo("Passed chi2 filter.");
2751
2752 // try attaching clusters to tracklets
2753 Int_t mlayers = 0;
2754 AliTRDcluster *cl = NULL;
2755 for(int iLayer=0; iLayer<kNSeedPlanes; iLayer++){
2756 Int_t jLayer = planes[iLayer];
2757 Int_t nNotInChamber = 0;
2758 if(!cseed[jLayer].AttachClusters(stack[jLayer], kTRUE)) continue;
2759 if(/*fkReconstructor->IsHLT()*/kFALSE){
2760 cseed[jLayer].UpdateUsed();
2761 if(!cseed[jLayer].IsOK()) continue;
2762 }else{
2763 cseed[jLayer].Fit();
2764 cseed[jLayer].UpdateUsed();
2765 cseed[jLayer].ResetClusterIter();
2766 while((cl = cseed[jLayer].NextCluster())){
2767 if(!cl->IsInChamber()) nNotInChamber++;
2768 }
2769 //printf("clusters[%d], used[%d], not in chamber[%d]\n", cseed[jLayer].GetN(), cseed[jLayer].GetNUsed(), nNotInChamber);
2770 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
2771 }
2772 mlayers++;
2773 }
2774
2775 if(mlayers < kNSeedPlanes){
2776 AliDebug(2, Form("Found only %d tracklets out of %d. Skip.", mlayers, kNSeedPlanes));
2777 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2778 continue;
2779 }
2780
2781 // temporary exit door for the HLT
2782 if(fkReconstructor->IsHLT()){
2783 // attach clusters to extrapolation chambers
2784 for(int iLayer=0; iLayer<kNPlanes-kNSeedPlanes; iLayer++){
2785 Int_t jLayer = planesExt[iLayer];
2786 if(!(chamber = stack[jLayer])) continue;
2787 if(!cseed[jLayer].AttachClusters(chamber, kTRUE)) continue;
2788 cseed[jLayer].Fit();
2789 }
2790 //FitTiltedRiemanConstraint(&cseed[0], GetZ());
2791 fTrackQuality[ntracks] = 1.; // dummy value
2792 ntracks++;
2793 if(ntracks == kMaxTracksStack) return ntracks;
2794 cseed += 6;
2795 continue;
2796 }
2797
2798
2799 // Update Seeds and calculate Likelihood
2800 // fit tracklets and cook likelihood
2801 Double_t chi2Vals[4];
2802 chi2Vals[0] = FitTiltedRieman(&cseed[0], kTRUE);
2803 for(int iLayer=0; iLayer<kNSeedPlanes; iLayer++){
2804 Int_t jLayer = planes[iLayer];
2805 cseed[jLayer].Fit(1);
2806 }
2807 Double_t like = CookLikelihood(&cseed[0], planes); // to be checked
2808
2809 if (TMath::Log(1.E-9 + like) < fkRecoParam->GetTrackLikelihood()){
2810 AliDebug(3, Form("Filter on likelihood %f[%e].", TMath::Log(1.E-9 + like), like));
2811 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2812 continue;
2813 }
2814 //AliInfo(Form("Passed likelihood %f[%e].", TMath::Log(1.E-9 + like), like));
2815
2816 // book preliminary results
2817 seedQuality[ntracks] = like;
2818 fSeedLayer[ntracks] = config;/*sLayer;*/
2819
2820 // attach clusters to the extrapolation seeds
2821 Int_t elayers(0);
2822 for(int iLayer=0; iLayer<kNPlanes-kNSeedPlanes; iLayer++){
2823 Int_t jLayer = planesExt[iLayer];
2824 if(!(chamber = stack[jLayer])) continue;
2825
2826 // fit extrapolated seed
2827 if ((jLayer == 0) && !(cseed[1].IsOK())) continue;
2828 if ((jLayer == 5) && !(cseed[4].IsOK())) continue;
2829 AliTRDseedV1 pseed = cseed[jLayer];
2830 if(!pseed.AttachClusters(chamber, kTRUE)) continue;
2831 pseed.Fit(1);
2832 cseed[jLayer] = pseed;
2833 chi2Vals[0] = FitTiltedRieman(cseed, kTRUE);
2834 cseed[jLayer].Fit(1);
2835 elayers++;
2836 }
2837
2838 // AliInfo("Extrapolation done.");
2839 // Debug Stream containing all the 6 tracklets
2840 if(fkRecoParam->GetStreamLevel(AliTRDrecoParam::kTracker) >= 2 && fkReconstructor->IsDebugStreaming()){
2841 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
2842 TLinearFitter *tiltedRieman = GetTiltedRiemanFitter();
2843 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2844 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2845 cstreamer << "MakeSeeds1"
2846 << "EventNumber=" << eventNumber
2847 << "CandidateNumber=" << candidateNumber
2848 << "S0.=" << &cseed[0]
2849 << "S1.=" << &cseed[1]
2850 << "S2.=" << &cseed[2]
2851 << "S3.=" << &cseed[3]
2852 << "S4.=" << &cseed[4]
2853 << "S5.=" << &cseed[5]
2854 << "FitterT.=" << tiltedRieman
2855 << "\n";
2856 }
2857
2858 if(fkRecoParam->HasImproveTracklets()){
2859 if(!ImproveSeedQuality(stack, cseed, chi2Vals[0])){
2860 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2861 AliDebug(3, "ImproveSeedQuality() failed.");
2862 }
2863 }
2864
2865 // do track fitting with vertex constraint
2866 if(fkRecoParam->IsVertexConstrained()) chi2Vals[1] = FitTiltedRiemanConstraint(&cseed[0], GetZ());
2867 else chi2Vals[1] = -1.;
2868 chi2Vals[2] = GetChi2Z(&cseed[0]);
2869 chi2Vals[3] = GetChi2Phi(&cseed[0]);
2870
2871 // calculate track quality
2872 fTrackQuality[ntracks] = CalculateTrackLikelihood(&chi2Vals[0]);
2873
2874 if(fkRecoParam->GetStreamLevel(AliTRDrecoParam::kTracker) >= 2 && fkReconstructor->IsDebugStreaming()){
2875 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
2876 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
2877 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
2878 TLinearFitter *fitterTC = GetTiltedRiemanFitterConstraint();
2879 TLinearFitter *fitterT = GetTiltedRiemanFitter();
2880 Int_t ncls = 0;
2881 for(Int_t iseed = 0; iseed < kNPlanes; iseed++){
2882 ncls += cseed[iseed].IsOK() ? cseed[iseed].GetN2() : 0;
2883 }
2884 cstreamer << "MakeSeeds2"
2885 << "EventNumber=" << eventNumber
2886 << "CandidateNumber=" << candidateNumber
2887 << "Chi2TR=" << chi2Vals[0]
2888 << "Chi2TC=" << chi2Vals[1]
2889 << "Nlayers=" << mlayers
2890 << "NClusters=" << ncls
2891 << "Like=" << like
2892 << "S0.=" << &cseed[0]
2893 << "S1.=" << &cseed[1]
2894 << "S2.=" << &cseed[2]
2895 << "S3.=" << &cseed[3]
2896 << "S4.=" << &cseed[4]
2897 << "S5.=" << &cseed[5]
2898 << "FitterT.=" << fitterT
2899 << "FitterTC.=" << fitterTC
2900 << "\n";
2901 }
2902 if(AliLog::GetDebugLevel("TRD", "AliTRDtrackerV1")){
2903 Double_t pt[]={0., 0.};
2904 for(Int_t il(0); il<kNPlanes; il++){
2905 if(!cseed[il].IsOK()) continue;
2906 pt[0] = GetBz()*kB2C/cseed[il].GetC();
2907 pt[1] = GetBz()*kB2C/cseed[il].GetC(1);
2908 break;
2909 }
2910 AliDebug(2, Form("Candidate[%2d] pt[%7.3f %7.3f] Q[%e]\n"
2911 " [0] x[%6.2f] n[%2d] nu[%d] OK[%c]\n"
2912 " [1] x[%6.2f] n[%2d] nu[%d] OK[%c]\n"
2913 " [2] x[%6.2f] n[%2d] nu[%d] OK[%c]\n"
2914 " [3] x[%6.2f] n[%2d] nu[%d] OK[%c]\n"
2915 " [4] x[%6.2f] n[%2d] nu[%d] OK[%c]\n"
2916 " [5] x[%6.2f] n[%2d] nu[%d] OK[%c]"
2917 , ntracks, pt[0], pt[1], fTrackQuality[ntracks]
2918 ,cseed[0].GetX(), cseed[0].GetN(), cseed[0].GetNUsed(), cseed[0].IsOK()?'y':'n'
2919 ,cseed[1].GetX(), cseed[1].GetN(), cseed[1].GetNUsed(), cseed[1].IsOK()?'y':'n'
2920 ,cseed[2].GetX(), cseed[2].GetN(), cseed[2].GetNUsed(), cseed[2].IsOK()?'y':'n'
2921 ,cseed[3].GetX(), cseed[3].GetN(), cseed[3].GetNUsed(), cseed[3].IsOK()?'y':'n'
2922 ,cseed[4].GetX(), cseed[4].GetN(), cseed[4].GetNUsed(), cseed[4].IsOK()?'y':'n'
2923 ,cseed[5].GetX(), cseed[5].GetN(), cseed[5].GetNUsed(), cseed[5].IsOK()?'y':'n'));
2924 }
2925 ntracks++;
2926 AliTRDtrackerDebug::SetCandidateNumber(AliTRDtrackerDebug::GetCandidateNumber() + 1);
2927 if(ntracks == kMaxTracksStack){
2928 AliWarning(Form("Number of seeds reached maximum allowed (%d) in stack.", kMaxTracksStack));
2929 return ntracks;
2930 }
2931 cseed += 6;
2932 }
2933 }
2934 }
2935
2936 return ntracks;
2937}
2938
2939//_____________________________________________________________________________
2940AliTRDtrackV1* AliTRDtrackerV1::MakeTrack(AliTRDseedV1 * const tracklet)
2941{
2942//
2943// Build a TRD track out of tracklet candidates
2944//
2945// Parameters :
2946// seeds : array of tracklets
2947// params : array of track parameters as they are estimated by stand alone tracker. 7 elements.
2948// [0] - radial position of the track at reference point
2949// [1] - y position of the fit at [0]
2950// [2] - z position of the fit at [0]
2951// [3] - snp of the first tracklet
2952// [4] - tgl of the first tracklet
2953// [5] - curvature of the Riemann fit - 1/pt
2954// [6] - sector rotation angle
2955//
2956// Output :
2957// The TRD track.
2958//
2959// Initialize the TRD track based on the parameters of the fit and a parametric covariance matrix
2960// (diagonal with constant variance terms TODO - correct parameterization)
2961//
2962// In case of HLT just register the tracklets in the tracker and return values of the Riemann fit. For the
2963// offline case perform a full Kalman filter on the already found tracklets (see AliTRDtrackerV1::FollowBackProlongation()
2964// for details). Do also MC label calculation and PID if propagation successfully.
2965
2966 if(fkReconstructor->IsHLT()) FitTiltedRiemanConstraint(tracklet, 0);
2967 Double_t alpha = AliTRDgeometry::GetAlpha();
2968 Double_t shift = AliTRDgeometry::GetAlpha()/2.0;
2969
2970 // find first good tracklet
2971 Int_t idx(0); while(idx<kNPlanes && !tracklet[idx].IsOK()) idx++;
2972 if(idx>2){ AliDebug(1, Form("Found suspect track start @ layer idx[%d]\n"
2973 " %c[0] x0[%f] n[%d] nu[%d] OK[%c]\n"
2974 " %c[1] x0[%f] n[%d] nu[%d] OK[%c]\n"
2975 " %c[2] x0[%f] n[%d] nu[%d] OK[%c]\n"
2976 " %c[3] x0[%f] n[%d] nu[%d] OK[%c]\n"
2977 " %c[4] x0[%f] n[%d] nu[%d] OK[%c]\n"
2978 " %c[5] x0[%f] n[%d] nu[%d] OK[%c]"
2979 ,idx
2980 ,idx==0?'*':' ', tracklet[0].GetX0(), tracklet[0].GetN(), tracklet[0].GetNUsed(), tracklet[0].IsOK()?'y':'n'
2981 ,idx==1?'*':' ', tracklet[1].GetX0(), tracklet[1].GetN(), tracklet[1].GetNUsed(), tracklet[1].IsOK()?'y':'n'
2982 ,idx==2?'*':' ', tracklet[2].GetX0(), tracklet[2].GetN(), tracklet[2].GetNUsed(), tracklet[2].IsOK()?'y':'n'
2983 ,idx==3?'*':' ', tracklet[3].GetX0(), tracklet[3].GetN(), tracklet[3].GetNUsed(), tracklet[3].IsOK()?'y':'n'
2984 ,idx==4?'*':' ', tracklet[4].GetX0(), tracklet[4].GetN(), tracklet[4].GetNUsed(), tracklet[4].IsOK()?'y':'n'
2985 ,idx==5?'*':' ', tracklet[5].GetX0(), tracklet[5].GetN(), tracklet[5].GetNUsed(), tracklet[5].IsOK()?'y':'n'));
2986 return NULL;
2987 }
2988
2989 Double_t dx(5.);
2990 Double_t x(tracklet[idx].GetX0() - dx);
2991 // Build track parameters
2992 Double_t params[] = {
2993 tracklet[idx].GetYref(0) - dx*tracklet[idx].GetYref(1) // y
2994 ,tracklet[idx].GetZref(0) - dx*tracklet[idx].GetZref(1) // z
2995 ,TMath::Sin(TMath::ATan(tracklet[idx].GetYref(1))) // snp
2996 ,tracklet[idx].GetZref(1) / TMath::Sqrt(1. + tracklet[idx].GetYref(1) * tracklet[idx].GetYref(1)) // tgl
2997 ,tracklet[idx].GetC(fkReconstructor->IsHLT()?1:0) // curvature -> 1/pt
2998 };
2999 Int_t sector(fGeom->GetSector(tracklet[idx].GetDetector()));
3000
3001 Double_t c[15];
3002 c[ 0] = 0.2; // s^2_y
3003 c[ 1] = 0.0; c[ 2] = 2.0; // s^2_z
3004 c[ 3] = 0.0; c[ 4] = 0.0; c[ 5] = 0.02; // s^2_snp
3005 c[ 6] = 0.0; c[ 7] = 0.0; c[ 8] = 0.0; c[ 9] = 0.1; // s^2_tgl
3006 c[10] = 0.0; c[11] = 0.0; c[12] = 0.0; c[13] = 0.0; c[14] = params[4]*params[4]*0.01; // s^2_1/pt
3007
3008 AliTRDtrackV1 track(tracklet, params, c, x, sector*alpha+shift);
3009
3010 AliTRDseedV1 *ptrTracklet = NULL;
3011
3012 // skip Kalman filter for HLT
3013 if(/*fkReconstructor->IsHLT()*/kFALSE){
3014 for (Int_t jLayer = 0; jLayer < AliTRDgeometry::kNlayer; jLayer++) {
3015 track.UnsetTracklet(jLayer);
3016 ptrTracklet = &tracklet[jLayer];
3017 if(!ptrTracklet->IsOK()) continue;
3018 if(TMath::Abs(ptrTracklet->GetYref(1) - ptrTracklet->GetYfit(1)) >= .2) continue; // check this condition with Marian
3019 ptrTracklet = SetTracklet(ptrTracklet);
3020 ptrTracklet->UseClusters();
3021 track.SetTracklet(ptrTracklet, fTracklets->GetEntriesFast()-1);
3022 }
3023 AliTRDtrackV1 *ptrTrack = SetTrack(&track);
3024 ptrTrack->CookPID();
3025 ptrTrack->CookLabel(.9);
3026 ptrTrack->SetReconstructor(fkReconstructor);
3027 return ptrTrack;
3028 }
3029
3030 // prevent the error message in AliTracker::MeanMaterialBudget: "start point out of geometry"
3031 if(TMath::Abs(track.GetX()) + TMath::Abs(track.GetY()) + TMath::Abs(track.GetZ()) > 10000) return NULL;
3032
3033 track.ResetCovariance(1);
3034 Int_t nc = TMath::Abs(FollowBackProlongation(track));
3035 if(fkRecoParam->GetStreamLevel(AliTRDrecoParam::kTracker) > 5 && fkReconstructor->IsDebugStreaming()){
3036 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
3037 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
3038 Double_t p[5]; // Track Params for the Debug Stream
3039 track.GetExternalParameters(x, p);
3040 TTreeSRedirector &cs = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
3041 cs << "MakeTrack"
3042 << "EventNumber=" << eventNumber
3043 << "CandidateNumber=" << candidateNumber
3044 << "nc=" << nc
3045 << "X=" << x
3046 << "Y=" << p[0]
3047 << "Z=" << p[1]
3048 << "snp=" << p[2]
3049 << "tnd=" << p[3]
3050 << "crv=" << p[4]
3051 << "Yin=" << params[0]
3052 << "Zin=" << params[1]
3053 << "snpin=" << params[2]
3054 << "tndin=" << params[3]
3055 << "crvin=" << params[4]
3056 << "track.=" << &track
3057 << "\n";
3058 }
3059 if (nc < 30){
3060 UnsetTrackletsTrack(&track);
3061 return NULL;
3062 }
3063 AliTRDtrackV1 *ptrTrack = SetTrack(&track);
3064 ptrTrack->SetReconstructor(fkReconstructor);
3065 ptrTrack->CookLabel(.9);
3066 for(Int_t il(kNPlanes); il--;){
3067 if(!(ptrTracklet = ptrTrack->GetTracklet(il))) continue;
3068 ptrTracklet->UseClusters();
3069 }
3070
3071 // computes PID for track
3072 ptrTrack->CookPID();
3073 // update calibration references using this track
3074 AliTRDCalibraFillHisto *calibra = AliTRDCalibraFillHisto::Instance();
3075 if(!calibra){
3076 AliInfo("Could not get Calibra instance.");
3077 } else if(calibra->GetHisto2d()){
3078 calibra->UpdateHistogramsV1(ptrTrack);
3079 }
3080 return ptrTrack;
3081}
3082
3083
3084//____________________________________________________________________
3085Bool_t AliTRDtrackerV1::ImproveSeedQuality(AliTRDtrackingChamber **stack, AliTRDseedV1 *cseed, Double_t &chi2)
3086{
3087 //
3088 // Sort tracklets according to "quality" and try to "improve" the first 4 worst
3089 //
3090 // Parameters :
3091 // layers : Array of propagation layers for a stack/supermodule
3092 // cseed : Array of 6 seeding tracklets which has to be improved
3093 //
3094 // Output :
3095 // cssed : Improved seeds
3096 //
3097 // Detailed description
3098 //
3099 // Iterative procedure in which new clusters are searched for each
3100 // tracklet seed such that the seed quality (see AliTRDseed::GetQuality())
3101 // can be maximized. If some optimization is found the old seeds are replaced.
3102 //
3103 // debug level: 7
3104 //
3105
3106 // make a local working copy
3107 AliTRDtrackingChamber *chamber = NULL;
3108 AliTRDseedV1 bseed[AliTRDgeometry::kNlayer];
3109
3110 Float_t quality(1.e3),
3111 lQuality[AliTRDgeometry::kNlayer] = {1.e3, 1.e3, 1.e3, 1.e3, 1.e3, 1.e3};
3112 Int_t rLayers(0);
3113 for(Int_t jLayer=AliTRDgeometry::kNlayer; jLayer--;){
3114 bseed[jLayer] = cseed[jLayer];
3115 if(!bseed[jLayer].IsOK()) continue;
3116 rLayers++;
3117 lQuality[jLayer] = bseed[jLayer].GetQuality(kTRUE);
3118 quality += lQuality[jLayer];
3119 }
3120 quality /= rLayers;
3121 AliDebug(2, Form("Start N[%d] Q[%f] chi2[%f]", rLayers, quality, chi2));
3122
3123 for (Int_t iter = 0; iter < 4; iter++) {
3124 // Try better cluster set
3125 Int_t nLayers(0); Float_t qualitynew(0.);
3126 Int_t indexes[AliTRDgeometry::kNlayer];
3127 TMath::Sort(Int_t(AliTRDgeometry::kNlayer), lQuality, indexes, kFALSE);
3128 for(Int_t jLayer=AliTRDgeometry::kNlayer; jLayer--;) {
3129 Int_t bLayer = indexes[jLayer];
3130 bseed[bLayer].Reset("c");
3131 if(!(chamber = stack[bLayer])) continue;
3132 if(!bseed[bLayer].AttachClusters(chamber, kTRUE)) continue;
3133 bseed[bLayer].Fit(1);
3134 if(!bseed[bLayer].IsOK()) continue;
3135 nLayers++;
3136 lQuality[jLayer] = bseed[jLayer].GetQuality(kTRUE);
3137 qualitynew += lQuality[jLayer];
3138 }
3139 if(rLayers > nLayers){
3140 AliDebug(1, Form("Lost %d tracklets while improving.", rLayers-nLayers));
3141 return iter>0?kTRUE:kFALSE;
3142 } else rLayers=nLayers;
3143 qualitynew /= rLayers;
3144
3145 if(qualitynew > quality){
3146 AliDebug(4, Form("Quality[%f] worsen in iter[%d] to ref[%f].", qualitynew, iter, quality));
3147 return iter>0?kTRUE:kFALSE;
3148 } else quality = qualitynew;
3149
3150 // try improve track parameters
3151 Float_t chi2new = FitTiltedRieman(bseed, kTRUE);
3152 if(chi2new > chi2){
3153 AliDebug(4, Form("Chi2[%f] worsen in iter[%d] to ref[%f].", chi2new, iter, chi2));
3154 return iter>0?kTRUE:kFALSE;
3155 } else chi2 = chi2new;
3156
3157 // store better tracklets
3158 for(Int_t jLayer=AliTRDgeometry::kNlayer; jLayer--;) cseed[jLayer]=bseed[jLayer];
3159 AliDebug(2, Form("Iter[%d] Q[%f] chi2[%f]", iter, quality, chi2));
3160
3161
3162 if(fkRecoParam->GetStreamLevel(AliTRDrecoParam::kTracker) >= 7 && fkReconstructor->IsDebugStreaming()){
3163 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
3164 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
3165 TLinearFitter *tiltedRieman = GetTiltedRiemanFitter();
3166 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
3167 cstreamer << "ImproveSeedQuality"
3168 << "EventNumber=" << eventNumber
3169 << "CandidateNumber=" << candidateNumber
3170 << "Iteration=" << iter
3171 << "S0.=" << &cseed[0]
3172 << "S1.=" << &cseed[1]
3173 << "S2.=" << &cseed[2]
3174 << "S3.=" << &cseed[3]
3175 << "S4.=" << &cseed[4]
3176 << "S5.=" << &cseed[5]
3177 << "FitterT.=" << tiltedRieman
3178 << "\n";
3179 }
3180 } // Loop: iter
3181
3182 // we are sure that at least 4 tracklets are OK !
3183 return kTRUE;
3184}
3185
3186//_________________________________________________________________________
3187Double_t AliTRDtrackerV1::CalculateTrackLikelihood(Double_t *chi2){
3188 //
3189 // Calculates the Track Likelihood value. This parameter serves as main quality criterion for
3190 // the track selection
3191 // The likelihood value containes:
3192 // - The chi2 values from the both fitters and the chi2 values in z-direction from a linear fit
3193 // - The Sum of the Parameter |slope_ref - slope_fit|/Sigma of the tracklets
3194 // For all Parameters an exponential dependency is used
3195 //
3196 // Parameters: - Array of tracklets (AliTRDseedV1) related to the track candidate
3197 // - Array of chi2 values:
3198 // * Non-Constrained Tilted Riemann fit
3199 // * Vertex-Constrained Tilted Riemann fit
3200 // * z-Direction from Linear fit
3201 // Output: - The calculated track likelihood
3202 //
3203 // debug level 2
3204 //
3205
3206 // Non-constrained Tilted Riemann
3207 Double_t likeChi2TR = TMath::Exp(-chi2[0] * 0.0078);
3208 // Constrained Tilted Riemann
3209 Double_t likeChi2TC(1.);
3210 if(chi2[1]>0.){
3211 likeChi2TC = TMath::Exp(-chi2[1] * 0.677);
3212 Double_t r = likeChi2TC/likeChi2TR;
3213 if(r>1.e2){;} // -> a primary track use TC
3214 else if(r<1.e2) // -> a secondary track use TR
3215 likeChi2TC =1.;
3216 else{;} // -> test not conclusive
3217 }
3218 // Chi2 only on Z direction
3219 Double_t likeChi2Z = TMath::Exp(-chi2[2] * 0.14);
3220 // Chi2 angular resolution
3221 Double_t likeChi2Phi= TMath::Exp(-chi2[3] * 3.23);
3222
3223 Double_t trackLikelihood = likeChi2Z * likeChi2TR * likeChi2TC * likeChi2Phi;
3224
3225 AliDebug(2, Form("Likelihood [%e]\n"
3226 " Rieman : chi2[%f] likelihood[%6.2e]\n"
3227 " Vertex : chi2[%f] likelihood[%6.2e]\n"
3228 " Z : chi2[%f] likelihood[%6.2e]\n"
3229 " Phi : chi2[%f] likelihood[%6.2e]"
3230 , trackLikelihood
3231 , chi2[0], likeChi2TR
3232 , chi2[1], likeChi2TC
3233 , chi2[2], likeChi2Z
3234 , chi2[3], likeChi2Phi
3235 ));
3236
3237 if(fkRecoParam->GetStreamLevel(AliTRDrecoParam::kTracker) >= 2 && fkReconstructor->IsDebugStreaming()){
3238 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
3239 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
3240 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
3241 cstreamer << "CalculateTrackLikelihood0"
3242 << "EventNumber=" << eventNumber
3243 << "CandidateNumber=" << candidateNumber
3244 << "LikeChi2Z=" << likeChi2Z
3245 << "LikeChi2TR=" << likeChi2TR
3246 << "LikeChi2TC=" << likeChi2TC
3247 << "LikeChi2Phi=" << likeChi2Phi
3248 << "TrackLikelihood=" << trackLikelihood
3249 << "\n";
3250 }
3251
3252 return trackLikelihood;
3253}
3254
3255//____________________________________________________________________
3256Double_t AliTRDtrackerV1::CookLikelihood(AliTRDseedV1 *cseed, Int_t planes[4])
3257{
3258 //
3259 // Calculate the probability of this track candidate.
3260 //
3261 // Parameters :
3262 // cseeds : array of candidate tracklets
3263 // planes : array of seeding planes (see seeding configuration)
3264 // chi2 : chi2 values (on the Z and Y direction) from the rieman fit of the track.
3265 //
3266 // Output :
3267 // likelihood value
3268 //
3269 // Detailed description
3270 //
3271 // The track quality is estimated based on the following 4 criteria:
3272 // 1. precision of the rieman fit on the Y direction (likea)
3273 // 2. chi2 on the Y direction (likechi2y)
3274 // 3. chi2 on the Z direction (likechi2z)
3275 // 4. number of attached clusters compared to a reference value
3276 // (see AliTRDrecoParam::fkFindable) (likeN)
3277 //
3278 // The distributions for each type of probabilities are given below as of
3279 // (date). They have to be checked to assure consistency of estimation.
3280 //
3281
3282 // ratio of the total number of clusters/track which are expected to be found by the tracker.
3283 Double_t chi2y = GetChi2Y(&cseed[0]);
3284 Double_t chi2z = GetChi2Z(&cseed[0]);
3285
3286 Float_t nclusters = 0.;
3287 Double_t sumda = 0.;
3288 for(UChar_t ilayer = 0; ilayer < 4; ilayer++){
3289 Int_t jlayer = planes[ilayer];
3290 nclusters += cseed[jlayer].GetN2();
3291 sumda += TMath::Abs(cseed[jlayer].GetYfit(1) - cseed[jlayer].GetYref(1));
3292 }
3293 nclusters *= .25;
3294
3295 Double_t likea = TMath::Exp(-sumda * fkRecoParam->GetPhiSlope());
3296 Double_t likechi2y = 0.0000000001;
3297 if (fkReconstructor->IsCosmic() || chi2y < fkRecoParam->GetChi2YCut()) likechi2y += TMath::Exp(-TMath::Sqrt(chi2y) * fkRecoParam->GetChi2YSlope());
3298 Double_t likechi2z = TMath::Exp(-chi2z * fkRecoParam->GetChi2ZSlope());
3299 Double_t likeN = TMath::Exp(-(fkRecoParam->GetNMeanClusters() - nclusters) / fkRecoParam->GetNSigmaClusters());
3300 Double_t like = likea * likechi2y * likechi2z * likeN;
3301
3302 if(fkRecoParam->GetStreamLevel(AliTRDrecoParam::kTracker) >= 2 && fkReconstructor->IsDebugStreaming()){
3303 Int_t eventNumber = AliTRDtrackerDebug::GetEventNumber();
3304 Int_t candidateNumber = AliTRDtrackerDebug::GetCandidateNumber();
3305 Int_t nTracklets = 0; Float_t meanNcls = 0;
3306 for(Int_t iseed=0; iseed < kNPlanes; iseed++){
3307 if(!cseed[iseed].IsOK()) continue;
3308 nTracklets++;
3309 meanNcls += cseed[iseed].GetN2();
3310 }
3311 if(nTracklets) meanNcls /= nTracklets;
3312 // The Debug Stream contains the seed
3313 TTreeSRedirector &cstreamer = *fkReconstructor->GetDebugStream(AliTRDrecoParam::kTracker);
3314 cstreamer << "CookLikelihood"
3315 << "EventNumber=" << eventNumber
3316 << "CandidateNumber=" << candidateNumber
3317 << "tracklet0.=" << &cseed[0]
3318 << "tracklet1.=" << &cseed[1]
3319 << "tracklet2.=" << &cseed[2]
3320 << "tracklet3.=" << &cseed[3]
3321 << "tracklet4.=" << &cseed[4]
3322 << "tracklet5.=" << &cseed[5]
3323 << "sumda=" << sumda
3324 << "chi2y=" << chi2y
3325 << "chi2z=" << chi2z
3326 << "likea=" << likea
3327 << "likechi2y=" << likechi2y
3328 << "likechi2z=" << likechi2z
3329 << "nclusters=" << nclusters
3330 << "likeN=" << likeN
3331 << "like=" << like
3332 << "meanncls=" << meanNcls
3333 << "\n";
3334 }
3335
3336 return like;
3337}
3338
3339//____________________________________________________________________
3340void AliTRDtrackerV1::GetSeedingConfig(Int_t iconfig, Int_t planes[4])
3341{
3342 //
3343 // Map seeding configurations to detector planes.
3344 //
3345 // Parameters :
3346 // iconfig : configuration index
3347 // planes : member planes of this configuration. On input empty.
3348 //
3349 // Output :
3350 // planes : contains the planes which are defining the configuration
3351 //
3352 // Detailed description
3353 //
3354 // Here is the list of seeding planes configurations together with
3355 // their topological classification:
3356 //
3357 // 0 - 5432 TQ 0
3358 // 1 - 4321 TQ 0
3359 // 2 - 3210 TQ 0
3360 // 3 - 5321 TQ 1
3361 // 4 - 4210 TQ 1
3362 // 5 - 5431 TQ 1
3363 // 6 - 4320 TQ 1
3364 // 7 - 5430 TQ 2
3365 // 8 - 5210 TQ 2
3366 // 9 - 5421 TQ 3
3367 // 10 - 4310 TQ 3
3368 // 11 - 5410 TQ 4
3369 // 12 - 5420 TQ 5
3370 // 13 - 5320 TQ 5
3371 // 14 - 5310 TQ 5
3372 //
3373 // The topologic quality is modeled as follows:
3374 // 1. The general model is define by the equation:
3375 // p(conf) = exp(-conf/2)
3376 // 2. According to the topologic classification, configurations from the same
3377 // class are assigned the agerage value over the model values.
3378 // 3. Quality values are normalized.
3379 //
3380 // The topologic quality distribution as function of configuration is given below:
3381 //Begin_Html
3382 // <img src="gif/topologicQA.gif">
3383 //End_Html
3384 //
3385
3386 switch(iconfig){
3387 case 0: // 5432 TQ 0
3388 planes[0] = 2;
3389 planes[1] = 3;
3390 planes[2] = 4;
3391 planes[3] = 5;
3392 break;
3393 case 1: // 4321 TQ 0
3394 planes[0] = 1;
3395 planes[1] = 2;
3396 planes[2] = 3;
3397 planes[3] = 4;
3398 break;
3399 case 2: // 3210 TQ 0
3400 planes[0] = 0;
3401 planes[1] = 1;
3402 planes[2] = 2;
3403 planes[3] = 3;
3404 break;
3405 case 3: // 5321 TQ 1
3406 planes[0] = 1;
3407 planes[1] = 2;
3408 planes[2] = 3;
3409 planes[3] = 5;
3410 break;
3411 case 4: // 4210 TQ 1
3412 planes[0] = 0;
3413 planes[1] = 1;
3414 planes[2] = 2;
3415 planes[3] = 4;
3416 break;
3417 case 5: // 5431 TQ 1
3418 planes[0] = 1;
3419 planes[1] = 3;
3420 planes[2] = 4;
3421 planes[3] = 5;
3422 break;
3423 case 6: // 4320 TQ 1
3424 planes[0] = 0;
3425 planes[1] = 2;
3426 planes[2] = 3;
3427 planes[3] = 4;
3428 break;
3429 case 7: // 5430 TQ 2
3430 planes[0] = 0;
3431 planes[1] = 3;
3432 planes[2] = 4;
3433 planes[3] = 5;
3434 break;
3435 case 8: // 5210 TQ 2
3436 planes[0] = 0;
3437 planes[1] = 1;
3438 planes[2] = 2;
3439 planes[3] = 5;
3440 break;
3441 case 9: // 5421 TQ 3
3442 planes[0] = 1;
3443 planes[1] = 2;
3444 planes[2] = 4;
3445 planes[3] = 5;
3446 break;
3447 case 10: // 4310 TQ 3
3448 planes[0] = 0;
3449 planes[1] = 1;
3450 planes[2] = 3;
3451 planes[3] = 4;
3452 break;
3453 case 11: // 5410 TQ 4
3454 planes[0] = 0;
3455 planes[1] = 1;
3456 planes[2] = 4;
3457 planes[3] = 5;
3458 break;
3459 case 12: // 5420 TQ 5
3460 planes[0] = 0;
3461 planes[1] = 2;
3462 planes[2] = 4;
3463 planes[3] = 5;
3464 break;
3465 case 13: // 5320 TQ 5
3466 planes[0] = 0;
3467 planes[1] = 2;
3468 planes[2] = 3;
3469 planes[3] = 5;
3470 break;
3471 case 14: // 5310 TQ 5
3472 planes[0] = 0;
3473 planes[1] = 1;
3474 planes[2] = 3;
3475 planes[3] = 5;
3476 break;
3477 }
3478}
3479
3480//____________________________________________________________________
3481void AliTRDtrackerV1::GetExtrapolationConfig(Int_t iconfig, Int_t planes[2])
3482{
3483 //
3484 // Returns the extrapolation planes for a seeding configuration.
3485 //
3486 // Parameters :
3487 // iconfig : configuration index
3488 // planes : planes which are not in this configuration. On input empty.
3489 //
3490 // Output :
3491 // planes : contains the planes which are not in the configuration
3492 //
3493 // Detailed description
3494 //
3495
3496 switch(iconfig){
3497 case 0: // 5432 TQ 0
3498 planes[0] = 1;
3499 planes[1] = 0;
3500 break;
3501 case 1: // 4321 TQ 0
3502 planes[0] = 5;
3503 planes[1] = 0;
3504 break;
3505 case 2: // 3210 TQ 0
3506 planes[0] = 4;
3507 planes[1] = 5;
3508 break;
3509 case 3: // 5321 TQ 1
3510 planes[0] = 4;
3511 planes[1] = 0;
3512 break;
3513 case 4: // 4210 TQ 1
3514 planes[0] = 5;
3515 planes[1] = 3;
3516 break;
3517 case 5: // 5431 TQ 1
3518 planes[0] = 2;
3519 planes[1] = 0;
3520 break;
3521 case 6: // 4320 TQ 1
3522 planes[0] = 5;
3523 planes[1] = 1;
3524 break;
3525 case 7: // 5430 TQ 2
3526 planes[0] = 2;
3527 planes[1] = 1;
3528 break;
3529 case 8: // 5210 TQ 2
3530 planes[0] = 4;
3531 planes[1] = 3;
3532 break;
3533 case 9: // 5421 TQ 3
3534 planes[0] = 3;
3535 planes[1] = 0;
3536 break;
3537 case 10: // 4310 TQ 3
3538 planes[0] = 5;
3539 planes[1] = 2;
3540 break;
3541 case 11: // 5410 TQ 4
3542 planes[0] = 3;
3543 planes[1] = 2;
3544 break;
3545 case 12: // 5420 TQ 5
3546 planes[0] = 3;
3547 planes[1] = 1;
3548 break;
3549 case 13: // 5320 TQ 5
3550 planes[0] = 4;
3551 planes[1] = 1;
3552 break;
3553 case 14: // 5310 TQ 5
3554 planes[0] = 4;
3555 planes[1] = 2;
3556 break;
3557 }
3558}
3559
3560//____________________________________________________________________
3561AliCluster* AliTRDtrackerV1::GetCluster(Int_t idx) const
3562{
3563 if(!fClusters) return NULL;
3564 Int_t ncls = fClusters->GetEntriesFast();
3565 return idx >= 0 && idx < ncls ? (AliCluster*)fClusters->UncheckedAt(idx) : NULL;
3566}
3567
3568//____________________________________________________________________
3569AliTRDseedV1* AliTRDtrackerV1::GetTracklet(Int_t idx) const
3570{
3571 if(!fTracklets) return NULL;
3572 Int_t ntrklt = fTracklets->GetEntriesFast();
3573 return idx >= 0 && idx < ntrklt ? (AliTRDseedV1*)fTracklets->UncheckedAt(idx) : NULL;
3574}
3575
3576//____________________________________________________________________
3577AliKalmanTrack* AliTRDtrackerV1::GetTrack(Int_t idx) const
3578{
3579 if(!fTracks) return NULL;
3580 Int_t ntrk = fTracks->GetEntriesFast();
3581 return idx >= 0 && idx < ntrk ? (AliKalmanTrack*)fTracks->UncheckedAt(idx) : NULL;
3582}
3583
3584
3585
3586// //_____________________________________________________________________________
3587// Int_t AliTRDtrackerV1::Freq(Int_t n, const Int_t *inlist
3588// , Int_t *outlist, Bool_t down)
3589// {
3590// //
3591// // Sort eleements according occurancy
3592// // The size of output array has is 2*n
3593// //
3594//
3595// if (n <= 0) {
3596// return 0;
3597// }
3598//
3599// Int_t *sindexS = new Int_t[n]; // Temporary array for sorting
3600// Int_t *sindexF = new Int_t[2*n];
3601// for (Int_t i = 0; i < n; i++) {
3602// sindexF[i] = 0;
3603// }
3604//
3605// TMath::Sort(n,inlist,sindexS,down);
3606//
3607// Int_t last = inlist[sindexS[0]];
3608// Int_t val = last;
3609// sindexF[0] = 1;
3610// sindexF[0+n] = last;
3611// Int_t countPos = 0;
3612//
3613// // Find frequency
3614// for (Int_t i = 1; i < n; i++) {
3615// val = inlist[sindexS[i]];
3616// if (last == val) {
3617// sindexF[countPos]++;
3618// }
3619// else {
3620// countPos++;
3621// sindexF[countPos+n] = val;
3622// sindexF[countPos]++;
3623// last = val;
3624// }
3625// }
3626// if (last == val) {
3627// countPos++;
3628// }
3629//
3630// // Sort according frequency
3631// TMath::Sort(countPos,sindexF,sindexS,kTRUE);
3632//
3633// for (Int_t i = 0; i < countPos; i++) {
3634// outlist[2*i ] = sindexF[sindexS[i]+n];
3635// outlist[2*i+1] = sindexF[sindexS[i]];
3636// }
3637//
3638// delete [] sindexS;
3639// delete [] sindexF;
3640//
3641// return countPos;
3642//
3643// }
3644
3645
3646//____________________________________________________________________
3647void AliTRDtrackerV1::ResetSeedTB()
3648{
3649// reset buffer for seeding time bin layers. If the time bin
3650// layers are not allocated this function allocates them
3651
3652 for(Int_t isl=0; isl<kNSeedPlanes; isl++){
3653 if(!fSeedTB[isl]) fSeedTB[isl] = new AliTRDchamberTimeBin();
3654 else fSeedTB[isl]->Clear();
3655 }
3656}
3657
3658
3659//_____________________________________________________________________________
3660Float_t AliTRDtrackerV1::GetChi2Y(const AliTRDseedV1 * const tracklets) const
3661{
3662 // Calculates normalized chi2 in y-direction
3663 // chi2 = Sum chi2 / n_tracklets
3664
3665 Double_t chi2 = 0.; Int_t n = 0;
3666 for(Int_t ipl = kNPlanes; ipl--;){
3667 if(!tracklets[ipl].IsOK()) continue;
3668 chi2 += tracklets[ipl].GetChi2Y();
3669 n++;
3670 }
3671 return n ? chi2/n : 0.;
3672}
3673
3674//_____________________________________________________________________________
3675Float_t AliTRDtrackerV1::GetChi2Z(const AliTRDseedV1 *const tracklets) const
3676{
3677 // Calculates normalized chi2 in z-direction
3678 // chi2 = Sum chi2 / n_tracklets
3679
3680 Double_t chi2 = 0; Int_t n = 0;
3681 for(Int_t ipl = kNPlanes; ipl--;){
3682 if(!tracklets[ipl].IsOK()) continue;
3683 chi2 += tracklets[ipl].GetChi2Z();
3684 n++;
3685 }
3686 return n ? chi2/n : 0.;
3687}
3688
3689//_____________________________________________________________________________
3690Float_t AliTRDtrackerV1::GetChi2Phi(const AliTRDseedV1 *const tracklets) const
3691{
3692 // Calculates normalized chi2 for angular resolution
3693 // chi2 = Sum chi2 / n_tracklets
3694
3695 Double_t chi2 = 0; Int_t n = 0;
3696 for (Int_t iLayer = 0; iLayer < kNPlanes; iLayer++) {
3697 if(!tracklets[iLayer].IsOK()) continue;
3698 chi2 += tracklets[iLayer].GetChi2Phi();
3699 n++;
3700 }
3701 return n ? chi2/n: 0.;
3702}
3703
3704//____________________________________________________________________
3705Float_t AliTRDtrackerV1::CalculateReferenceX(const AliTRDseedV1 *const tracklets){
3706 //
3707 // Calculates the reference x-position for the tilted Rieman fit defined as middle
3708 // of the stack (middle between layers 2 and 3). For the calculation all the tracklets
3709 // are taken into account
3710 //
3711 // Parameters: - Array of tracklets(AliTRDseedV1)
3712 //
3713 // Output: - The reference x-position(Float_t)
3714 // Only kept for compatibility with the old code
3715 //
3716 Int_t nDistances = 0;
3717 Float_t meanDistance = 0.;
3718 Int_t startIndex = 5;
3719 for(Int_t il =5; il > 0; il--){
3720 if(tracklets[il].IsOK() && tracklets[il -1].IsOK()){
3721 Float_t xdiff = tracklets[il].GetX0() - tracklets[il -1].GetX0();
3722 meanDistance += xdiff;
3723 nDistances++;
3724 }
3725 if(tracklets[il].IsOK()) startIndex = il;
3726 }
3727 if(tracklets[0].IsOK()) startIndex = 0;
3728 if(!nDistances){
3729 // We should normally never get here
3730 Float_t xpos[2]; memset(xpos, 0, sizeof(Float_t) * 2);
3731 Int_t iok = 0, idiff = 0;
3732 // This attempt is worse and should be avoided:
3733 // check for two chambers which are OK and repeat this without taking the mean value
3734 // Strategy avoids a division by 0;
3735 for(Int_t il = 5; il >= 0; il--){
3736 if(tracklets[il].IsOK()){
3737 xpos[iok] = tracklets[il].GetX0();
3738 iok++;
3739 startIndex = il;
3740 }
3741 if(iok) idiff++; // to get the right difference;
3742 if(iok > 1) break;
3743 }
3744 if(iok > 1){
3745 meanDistance = (xpos[0] - xpos[1])/idiff;
3746 }
3747 else{
3748 // we have do not even have 2 layers which are OK? The we do not need to fit at all
3749 return 331.;
3750 }
3751 }
3752 else{
3753 meanDistance /= nDistances;
3754 }
3755 return tracklets[startIndex].GetX0() + (2.5 - startIndex) * meanDistance - 0.5 * (AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick());
3756}
3757
3758//_____________________________________________________________________________
3759Double_t AliTRDtrackerV1::FitTiltedRiemanV1(AliTRDseedV1 *const tracklets){
3760 //
3761 // Track Fitter Function using the new class implementation of
3762 // the Rieman fit
3763 //
3764 AliTRDtrackFitterRieman fitter;
3765 fitter.SetRiemanFitter(GetTiltedRiemanFitter());
3766 fitter.Reset();
3767 for(Int_t il = 0; il < AliTRDgeometry::kNlayer; il++) fitter.SetTracklet(il, &tracklets[il]);
3768 Double_t chi2 = fitter.Eval();
3769 // Update the tracklets
3770 Double_t cov[15]; Double_t x0;
3771 memset(cov, 0, sizeof(Double_t) * 15);
3772 for(Int_t il = 0; il < AliTRDgeometry::kNlayer; il++){
3773 x0 = tracklets[il].GetX0();
3774 tracklets[il].SetYref(0, fitter.GetYat(x0));
3775 tracklets[il].SetZref(0, fitter.GetZat(x0));
3776 tracklets[il].SetYref(1, fitter.GetDyDxAt(x0));
3777 tracklets[il].SetZref(1, fitter.GetDzDx());
3778 tracklets[il].SetC(fitter.GetCurvature());
3779 fitter.GetCovAt(x0, cov);
3780 tracklets[il].SetCovRef(cov);
3781 tracklets[il].SetChi2(chi2);
3782 }
3783 return chi2;
3784}
3785
3786//____________________________________________________________________
3787void AliTRDtrackerV1::UnsetTrackletsTrack(const AliTRDtrackV1 * const track)
3788{
3789 Int_t idx(-1);
3790 for(Int_t il(0); il<kNPlanes; il++){
3791 if((idx = track->GetTrackletIndex(il)) < 0) continue;
3792 delete (fTracklets->RemoveAt(idx));
3793 }
3794}
3795
3796
3797///////////////////////////////////////////////////////
3798// //
3799// Resources of class AliTRDLeastSquare //
3800// //
3801///////////////////////////////////////////////////////
3802
3803//_____________________________________________________________________________
3804AliTRDtrackerV1::AliTRDLeastSquare::AliTRDLeastSquare(){
3805//
3806// Constructor of the nested class AliTRDtrackFitterLeastSquare
3807//
3808// Fast solving linear regresion in 2D
3809// y=a + bx
3810// The data members have the following meaning
3811// fParams[0] : a
3812// fParams[1] : b
3813//
3814// fSums[0] : S
3815// fSums[1] : Sx
3816// fSums[2] : Sy
3817// fSums[3] : Sxy
3818// fSums[4] : Sxx
3819// fSums[5] : Syy
3820//
3821// fCovarianceMatrix[0] : s2a
3822// fCovarianceMatrix[1] : s2b
3823// fCovarianceMatrix[2] : cov(ab)
3824
3825 memset(fParams, 0, sizeof(Double_t) * 2);
3826 memset(fSums, 0, sizeof(Double_t) * 6);
3827 memset(fCovarianceMatrix, 0, sizeof(Double_t) * 3);
3828
3829}
3830
3831//_____________________________________________________________________________
3832void AliTRDtrackerV1::AliTRDLeastSquare::AddPoint(const Double_t *const x, Double_t y, Double_t sigmaY){
3833 //
3834 // Adding Point to the fitter
3835 //
3836
3837 Double_t weight = 1/(sigmaY > 1e-9 ? sigmaY : 1e-9);
3838 weight *= weight;
3839 const Double_t &xpt = *x;
3840 // printf("Adding point x = %f, y = %f, sigma = %f\n", xpt, y, sigmaY);
3841 fSums[0] += weight;
3842 fSums[1] += weight * xpt;
3843 fSums[2] += weight * y;
3844 fSums[3] += weight * xpt * y;
3845 fSums[4] += weight * xpt * xpt;
3846 fSums[5] += weight * y * y;
3847}
3848
3849//_____________________________________________________________________________
3850void AliTRDtrackerV1::AliTRDLeastSquare::RemovePoint(const Double_t *const x, Double_t y, Double_t sigmaY){
3851 //
3852 // Remove Point from the sample
3853 //
3854
3855 Double_t weight = 1/(sigmaY > 1e-9 ? sigmaY : 1e-9);
3856 weight *= weight;
3857 const Double_t &xpt = *x;
3858 fSums[0] -= weight;
3859 fSums[1] -= weight * xpt;
3860 fSums[2] -= weight * y;
3861 fSums[3] -= weight * xpt * y;
3862 fSums[4] -= weight * xpt * xpt;
3863 fSums[5] -= weight * y * y;
3864}
3865
3866//_____________________________________________________________________________
3867Bool_t AliTRDtrackerV1::AliTRDLeastSquare::Eval(){
3868 //
3869 // Evaluation of the fit:
3870 // Calculation of the parameters
3871 // Calculation of the covariance matrix
3872 //
3873
3874 Double_t det = fSums[0] * fSums[4] - fSums[1] *fSums[1];
3875 if(det==0) return kFALSE;
3876
3877 // for(Int_t isum = 0; isum < 5; isum++)
3878 // printf("fSums[%d] = %f\n", isum, fSums[isum]);
3879 // printf("denominator = %f\n", denominator);
3880 fParams[0] = (fSums[2] * fSums[4] - fSums[1] * fSums[3])/det;
3881 fParams[1] = (fSums[0] * fSums[3] - fSums[1] * fSums[2])/det;
3882 // printf("fParams[0] = %f, fParams[1] = %f\n", fParams[0], fParams[1]);
3883
3884 // Covariance matrix
3885 Double_t den = fSums[0]*fSums[4] - fSums[1]*fSums[1];
3886 fCovarianceMatrix[0] = fSums[4] / den;
3887 fCovarianceMatrix[1] = fSums[0] / den;
3888 fCovarianceMatrix[2] = -fSums[1] / den;
3889/* fCovarianceMatrix[0] = fSums[4] / fSums[0] - fSums[1] * fSums[1] / (fSums[0] * fSums[0]);
3890 fCovarianceMatrix[1] = fSums[5] / fSums[0] - fSums[2] * fSums[2] / (fSums[0] * fSums[0]);
3891 fCovarianceMatrix[2] = fSums[3] / fSums[0] - fSums[1] * fSums[2] / (fSums[0] * fSums[0]);*/
3892
3893
3894
3895 return kTRUE;
3896}
3897
3898//_____________________________________________________________________________
3899Double_t AliTRDtrackerV1::AliTRDLeastSquare::GetFunctionValue(const Double_t *const xpos) const {
3900 //
3901 // Returns the Function value of the fitted function at a given x-position
3902 //
3903 return fParams[0] + fParams[1] * (*xpos);
3904}
3905
3906//_____________________________________________________________________________
3907void AliTRDtrackerV1::AliTRDLeastSquare::GetCovarianceMatrix(Double_t *storage) const {
3908 //
3909 // Copies the values of the covariance matrix into the storage
3910 //
3911 memcpy(storage, fCovarianceMatrix, sizeof(Double_t) * 3);
3912}
3913
3914//_____________________________________________________________________________
3915void AliTRDtrackerV1::AliTRDLeastSquare::Reset(){
3916 //
3917 // Reset the fitter
3918 //
3919 memset(fParams, 0, sizeof(Double_t) * 2);
3920 memset(fCovarianceMatrix, 0, sizeof(Double_t) * 3);
3921 memset(fSums, 0, sizeof(Double_t) * 6);
3922}
3923
3924///////////////////////////////////////////////////////
3925// //
3926// Resources of class AliTRDtrackFitterRieman //
3927// //
3928///////////////////////////////////////////////////////
3929
3930//_____________________________________________________________________________
3931AliTRDtrackerV1::AliTRDtrackFitterRieman::AliTRDtrackFitterRieman():
3932 fTrackFitter(NULL),
3933 fZfitter(NULL),
3934 fCovarPolY(NULL),
3935 fCovarPolZ(NULL),
3936 fXref(0.),
3937 fSysClusterError(0.)
3938{
3939 //
3940 // Default constructor
3941 //
3942 fZfitter = new AliTRDLeastSquare;
3943 fCovarPolY = new TMatrixD(3,3);
3944 fCovarPolZ = new TMatrixD(2,2);
3945 memset(fTracklets, 0, sizeof(AliTRDseedV1 *) * 6);
3946 memset(fParameters, 0, sizeof(Double_t) * 5);
3947 memset(fSumPolY, 0, sizeof(Double_t) * 5);
3948 memset(fSumPolZ, 0, sizeof(Double_t) * 2);
3949}
3950
3951//_____________________________________________________________________________
3952AliTRDtrackerV1::AliTRDtrackFitterRieman::~AliTRDtrackFitterRieman(){
3953 //
3954 // Destructor
3955 //
3956 if(fZfitter) delete fZfitter;
3957 if(fCovarPolY) delete fCovarPolY;
3958 if(fCovarPolZ) delete fCovarPolZ;
3959}
3960
3961//_____________________________________________________________________________
3962void AliTRDtrackerV1::AliTRDtrackFitterRieman::Reset(){
3963 //
3964 // Reset the Fitter
3965 //
3966 if(fTrackFitter){
3967 fTrackFitter->StoreData(kTRUE);
3968 fTrackFitter->ClearPoints();
3969 }
3970 if(fZfitter){
3971 fZfitter->Reset();
3972 }
3973 fXref = 0.;
3974 memset(fTracklets, 0, sizeof(AliTRDseedV1 *) * AliTRDgeometry::kNlayer);
3975 memset(fParameters, 0, sizeof(Double_t) * 5);
3976 memset(fSumPolY, 0, sizeof(Double_t) * 5);
3977 memset(fSumPolZ, 0, sizeof(Double_t) * 2);
3978 for(Int_t irow = 0; irow < fCovarPolY->GetNrows(); irow++)
3979 for(Int_t icol = 0; icol < fCovarPolY->GetNcols(); icol++){
3980 (*fCovarPolY)(irow, icol) = 0.;
3981 if(irow < 2 && icol < 2)
3982 (*fCovarPolZ)(irow, icol) = 0.;
3983 }
3984}
3985
3986//_____________________________________________________________________________
3987void AliTRDtrackerV1::AliTRDtrackFitterRieman::SetTracklet(Int_t itr, AliTRDseedV1 *tracklet){
3988 //
3989 // Add tracklet into the fitter
3990 //
3991 if(itr >= AliTRDgeometry::kNlayer) return;
3992 fTracklets[itr] = tracklet;
3993}
3994
3995//_____________________________________________________________________________
3996Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::Eval(){
3997 //
3998 // Perform the fit
3999 // 1. Apply linear transformation and store points in the fitter
4000 // 2. Evaluate the fit
4001 // 3. Check if the result of the fit in z-direction is reasonable
4002 // if not
4003 // 3a. Fix the parameters 3 and 4 with the results of a simple least
4004 // square fit
4005 // 3b. Redo the fit with the fixed parameters
4006 // 4. Store fit results (parameters and errors)
4007 //
4008 if(!fTrackFitter){
4009 return 1e10;
4010 }
4011 fXref = CalculateReferenceX();
4012 for(Int_t il = 0; il < AliTRDgeometry::kNlayer; il++) UpdateFitters(fTracklets[il]);
4013 if(!fTrackFitter->GetNpoints()) return 1e10;
4014 // perform the fit
4015 fTrackFitter->Eval();
4016 fZfitter->Eval();
4017 fParameters[3] = fTrackFitter->GetParameter(3);
4018 fParameters[4] = fTrackFitter->GetParameter(4);
4019 if(!CheckAcceptable(fParameters[3], fParameters[4])) {
4020 fTrackFitter->FixParameter(3, fZfitter->GetFunctionValue(&fXref));
4021 fTrackFitter->FixParameter(4, fZfitter->GetFunctionParameter(1));
4022 fTrackFitter->Eval();
4023 fTrackFitter->ReleaseParameter(3);
4024 fTrackFitter->ReleaseParameter(4);
4025 fParameters[3] = fTrackFitter->GetParameter(3);
4026 fParameters[4] = fTrackFitter->GetParameter(4);
4027 }
4028 // Update the Fit Parameters and the errors
4029 fParameters[0] = fTrackFitter->GetParameter(0);
4030 fParameters[1] = fTrackFitter->GetParameter(1);
4031 fParameters[2] = fTrackFitter->GetParameter(2);
4032
4033 // Prepare Covariance estimation
4034 (*fCovarPolY)(0,0) = fSumPolY[0]; (*fCovarPolY)(1,1) = fSumPolY[2]; (*fCovarPolY)(2,2) = fSumPolY[4];
4035 (*fCovarPolY)(1,0) = (*fCovarPolY)(0,1) = fSumPolY[1];
4036 (*fCovarPolY)(2,0) = (*fCovarPolY)(0,2) = fSumPolY[2];
4037 (*fCovarPolY)(2,1) = (*fCovarPolY)(1,2) = fSumPolY[3];
4038 fCovarPolY->Invert();
4039 (*fCovarPolZ)(0,0) = fSumPolZ[0]; (*fCovarPolZ)(1,1) = fSumPolZ[2];
4040 (*fCovarPolZ)(1,0) = (*fCovarPolZ)(0,1) = fSumPolZ[1];
4041 fCovarPolZ->Invert();
4042 return fTrackFitter->GetChisquare() / fTrackFitter->GetNpoints();
4043}
4044
4045//_____________________________________________________________________________
4046void AliTRDtrackerV1::AliTRDtrackFitterRieman::UpdateFitters(AliTRDseedV1 * const tracklet){
4047 //
4048 // Does the transformations and updates the fitters
4049 // The following transformation is applied
4050 //
4051 AliTRDcluster *cl = NULL;
4052 Double_t x, y, z, dx, t, w, we, yerr, zerr;
4053 Double_t uvt[4];
4054 if(!tracklet || !tracklet->IsOK()) return;
4055 Double_t tilt = tracklet->GetTilt();
4056 for(Int_t itb = 0; itb < AliTRDseedV1::kNclusters; itb++){
4057 if(!(cl = tracklet->GetClusters(itb))) continue;
4058 if(!cl->IsInChamber()) continue;
4059 if (!tracklet->IsUsable(itb)) continue;
4060 x = cl->GetX();
4061 y = cl->GetY();
4062 z = cl->GetZ();
4063 dx = x - fXref;
4064 // Transformation
4065 t = 1./(x*x + y*y);
4066 uvt[0] = 2. * x * t;
4067 uvt[1] = t;
4068 uvt[2] = 2. * tilt * t;
4069 uvt[3] = 2. * tilt * dx * t;
4070 w = 2. * (y + tilt*z) * t;
4071 // error definition changes for the different calls
4072 we = 2. * t;
4073 we *= TMath::Sqrt(cl->GetSigmaY2()+tilt*tilt*cl->GetSigmaZ2());
4074 // Update sums for error calculation
4075 yerr = 1./(TMath::Sqrt(cl->GetSigmaY2()) + fSysClusterError);
4076 yerr *= yerr;
4077 zerr = 1./cl->GetSigmaZ2();
4078 for(Int_t ipol = 0; ipol < 5; ipol++){
4079 fSumPolY[ipol] += yerr;
4080 yerr *= x;
4081 if(ipol < 3){
4082 fSumPolZ[ipol] += zerr;
4083 zerr *= x;
4084 }
4085 }
4086 fTrackFitter->AddPoint(uvt, w, we);
4087 fZfitter->AddPoint(&x, z, static_cast<Double_t>(TMath::Sqrt(cl->GetSigmaZ2())));
4088 }
4089}
4090
4091//_____________________________________________________________________________
4092Bool_t AliTRDtrackerV1::AliTRDtrackFitterRieman::CheckAcceptable(Double_t offset, Double_t slope){
4093 //
4094 // Check whether z-results are acceptable
4095 // Definition: Distance between tracklet fit and track fit has to be
4096 // less then half a padlength
4097 // Point of comparision is at the anode wire
4098 //
4099 Bool_t acceptablez = kTRUE;
4100 Double_t zref = 0.0;
4101 for (Int_t iLayer = 0; iLayer < kNPlanes; iLayer++) {
4102 if(!fTracklets[iLayer]->IsOK()) continue;
4103 zref = offset + slope * (fTracklets[iLayer]->GetX0() - fXref);
4104 if (TMath::Abs(fTracklets[iLayer]->GetZfit(0) - zref) > fTracklets[iLayer]->GetPadLength() * 0.5 + 1.0)
4105 acceptablez = kFALSE;
4106 }
4107 return acceptablez;
4108}
4109
4110//_____________________________________________________________________________
4111Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::GetYat(Double_t x) const {
4112 //
4113 // Calculate y position out of the track parameters
4114 // y: R^2 = (x - x0)^2 + (y - y0)^2
4115 // => y = y0 +/- Sqrt(R^2 - (x - x0)^2)
4116 // R = Sqrt() = 1/Curvature
4117 // => y = y0 +/- Sqrt(1/Curvature^2 - (x - x0)^2)
4118 //
4119 Double_t y = 0;
4120 Double_t disc = (x * fParameters[0] + fParameters[1]);
4121 disc = 1 - fParameters[0]*fParameters[2] + fParameters[1]*fParameters[1] - disc*disc;
4122 if (disc >= 0) {
4123 disc = TMath::Sqrt(disc);
4124 y = (1.0 - disc) / fParameters[0];
4125 }
4126 return y;
4127}
4128
4129//_____________________________________________________________________________
4130Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::GetZat(Double_t x) const {
4131 //
4132 // Return z position for a given x position
4133 // Simple linear function
4134 //
4135 return fParameters[3] + fParameters[4] * (x - fXref);
4136}
4137
4138//_____________________________________________________________________________
4139Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::GetDyDxAt(Double_t x) const {
4140 //
4141 // Calculate dydx at a given radial position out of the track parameters
4142 // dy: R^2 = (x - x0)^2 + (y - y0)^2
4143 // => y = +/- Sqrt(R^2 - (x - x0)^2) + y0
4144 // => dy/dx = (x - x0)/Sqrt(R^2 - (x - x0)^2)
4145 // Curvature: cr = 1/R = a/Sqrt(1 + b^2 - c*a)
4146 // => dy/dx = (x - x0)/(1/(cr^2) - (x - x0)^2)
4147 //
4148 Double_t x0 = -fParameters[1] / fParameters[0];
4149 Double_t curvature = GetCurvature();
4150 Double_t dy = 0;
4151 if (-fParameters[2] * fParameters[0] + fParameters[1] * fParameters[1] + 1 > 0) {
4152 if (1.0/(curvature * curvature) - (x - x0) * (x - x0) > 0.0) {
4153 Double_t yderiv = (x - x0) / TMath::Sqrt(1.0/(curvature * curvature) - (x - x0) * (x - x0));
4154 if (fParameters[0] < 0) yderiv *= -1.0;
4155 dy = yderiv;
4156 }
4157 }
4158 return dy;
4159}
4160
4161//_____________________________________________________________________________
4162Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::GetCurvature() const {
4163 //
4164 // Calculate track curvature
4165 //
4166 //
4167 Double_t curvature = 1.0 + fParameters[1]*fParameters[1] - fParameters[2]*fParameters[0];
4168 if (curvature > 0.0)
4169 curvature = fParameters[0] / TMath::Sqrt(curvature);
4170 return curvature;
4171}
4172
4173//_____________________________________________________________________________
4174void AliTRDtrackerV1::AliTRDtrackFitterRieman::GetCovAt(Double_t x, Double_t *cov) const {
4175 //
4176 // Error Definition according to gauss error propagation
4177 //
4178 TMatrixD transform(3,3);
4179 transform(0,0) = transform(1,1) = transform(2,2) = 1;
4180 transform(0,1) = transform(1,2) = x;
4181 transform(0,2) = x*x;
4182 TMatrixD covariance(transform, TMatrixD::kMult, *fCovarPolY);
4183 covariance *= transform.T();
4184 cov[0] = covariance(0,0);
4185 TMatrixD transformZ(2,2);
4186 transformZ(0,0) = transformZ(1,1) = 1;
4187 transformZ(0,1) = x;
4188 TMatrixD covarZ(transformZ, TMatrixD::kMult, *fCovarPolZ);
4189 covarZ *= transformZ.T();
4190 cov[1] = covarZ(0,0);
4191 cov[2] = 0;
4192}
4193
4194//____________________________________________________________________
4195Double_t AliTRDtrackerV1::AliTRDtrackFitterRieman::CalculateReferenceX(){
4196 //
4197 // Calculates the reference x-position for the tilted Rieman fit defined as middle
4198 // of the stack (middle between layers 2 and 3). For the calculation all the tracklets
4199 // are taken into account
4200 //
4201 // Parameters: - Array of tracklets(AliTRDseedV1)
4202 //
4203 // Output: - The reference x-position(Float_t)
4204 //
4205 Int_t nDistances = 0;
4206 Float_t meanDistance = 0.;
4207 Int_t startIndex = 5;
4208 for(Int_t il =5; il > 0; il--){
4209 if(fTracklets[il]->IsOK() && fTracklets[il -1]->IsOK()){
4210 Float_t xdiff = fTracklets[il]->GetX0() - fTracklets[il -1]->GetX0();
4211 meanDistance += xdiff;
4212 nDistances++;
4213 }
4214 if(fTracklets[il]->IsOK()) startIndex = il;
4215 }
4216 if(fTracklets[0]->IsOK()) startIndex = 0;
4217 if(!nDistances){
4218 // We should normally never get here
4219 Float_t xpos[2]; memset(xpos, 0, sizeof(Float_t) * 2);
4220 Int_t iok = 0, idiff = 0;
4221 // This attempt is worse and should be avoided:
4222 // check for two chambers which are OK and repeat this without taking the mean value
4223 // Strategy avoids a division by 0;
4224 for(Int_t il = 5; il >= 0; il--){
4225 if(fTracklets[il]->IsOK()){
4226 xpos[iok] = fTracklets[il]->GetX0();
4227 iok++;
4228 startIndex = il;
4229 }
4230 if(iok) idiff++; // to get the right difference;
4231 if(iok > 1) break;
4232 }
4233 if(iok > 1){
4234 meanDistance = (xpos[0] - xpos[1])/idiff;
4235 }
4236 else{
4237 // we have do not even have 2 layers which are OK? The we do not need to fit at all
4238 return 331.;
4239 }
4240 }
4241 else{
4242 meanDistance /= nDistances;
4243 }
4244 return fTracklets[startIndex]->GetX0() + (2.5 - startIndex) * meanDistance - 0.5 * (AliTRDgeometry::AmThick() + AliTRDgeometry::DrThick());
4245}