1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
18 //-------------------------------------------------------
19 // Implementation of the TPC tracker
21 // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
22 //-------------------------------------------------------
23 #include <TObjArray.h>
28 #include "AliESDEvent.h"
29 #include "AliESDtrack.h"
31 #include "AliTPCtracker.h"
32 #include "AliTPCcluster.h"
33 #include "AliTPCParam.h"
34 #include "AliClusters.h"
36 ClassImp(AliTPCtracker)
38 //_____________________________________________________________________________
39 AliTPCtracker::AliTPCtracker():
51 // The default TPC tracker constructor
55 //_____________________________________________________________________________
56 AliTPCtracker::AliTPCtracker(const AliTPCParam *par):
58 fkNIS(par->GetNInnerSector()/2),
59 fInnerSec(new AliTPCSector[fkNIS]),
60 fkNOS(par->GetNOuterSector()/2),
61 fOuterSec(new AliTPCSector[fkNOS]),
64 fParam((AliTPCParam*) par),
67 //---------------------------------------------------------------------
68 // The main TPC tracker constructor
69 //---------------------------------------------------------------------
72 for (i=0; i<fkNIS; i++) fInnerSec[i].Setup(par,0);
73 for (i=0; i<fkNOS; i++) fOuterSec[i].Setup(par,1);
77 //_____________________________________________________________________________
78 AliTPCtracker::~AliTPCtracker() {
79 //------------------------------------------------------------------
80 // TPC tracker destructor
81 //------------------------------------------------------------------
90 //_____________________________________________________________________________
91 Double_t f1(Double_t x1,Double_t y1,
92 Double_t x2,Double_t y2,
93 Double_t x3,Double_t y3)
95 //-----------------------------------------------------------------
96 // Initial approximation of the track curvature
97 //-----------------------------------------------------------------
98 Double_t d=(x2-x1)*(y3-y2)-(x3-x2)*(y2-y1);
99 Double_t a=0.5*((y3-y2)*(y2*y2-y1*y1+x2*x2-x1*x1)-
100 (y2-y1)*(y3*y3-y2*y2+x3*x3-x2*x2));
101 Double_t b=0.5*((x2-x1)*(y3*y3-y2*y2+x3*x3-x2*x2)-
102 (x3-x2)*(y2*y2-y1*y1+x2*x2-x1*x1));
104 Double_t xr=TMath::Abs(d/(d*x1-a)), yr=d/(d*y1-b);
106 return -xr*yr/sqrt(xr*xr+yr*yr);
110 //_____________________________________________________________________________
111 Double_t f2(Double_t x1,Double_t y1,
112 Double_t x2,Double_t y2,
113 Double_t x3,Double_t y3)
115 //-----------------------------------------------------------------
116 // Initial approximation of the track curvature times center of curvature
117 //-----------------------------------------------------------------
118 Double_t d=(x2-x1)*(y3-y2)-(x3-x2)*(y2-y1);
119 Double_t a=0.5*((y3-y2)*(y2*y2-y1*y1+x2*x2-x1*x1)-
120 (y2-y1)*(y3*y3-y2*y2+x3*x3-x2*x2));
121 Double_t b=0.5*((x2-x1)*(y3*y3-y2*y2+x3*x3-x2*x2)-
122 (x3-x2)*(y2*y2-y1*y1+x2*x2-x1*x1));
124 Double_t xr=TMath::Abs(d/(d*x1-a)), yr=d/(d*y1-b);
126 return -a/(d*y1-b)*xr/sqrt(xr*xr+yr*yr);
129 //_____________________________________________________________________________
130 Double_t f3(Double_t x1,Double_t y1,
131 Double_t x2,Double_t y2,
132 Double_t z1,Double_t z2)
134 //-----------------------------------------------------------------
135 // Initial approximation of the tangent of the track dip angle
136 //-----------------------------------------------------------------
137 return (z1 - z2)/sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
140 //_____________________________________________________________________________
141 Int_t AliTPCtracker::LoadClusters(TTree *cTree) {
142 //-----------------------------------------------------------------
143 // This function loads TPC clusters.
144 //-----------------------------------------------------------------
145 TBranch *branch=cTree->GetBranch("Segment");
147 Error("LoadClusters","Can't get the branch !");
151 AliClusters carray, *addr=&carray;
152 addr = new AliClusters("AliTPCcluster");
153 branch->SetAddress(&addr);
155 Int_t nentr=(Int_t)cTree->GetEntries();
157 for (Int_t i=0; i<nentr; i++) {
160 Int_t ncl=carray.GetArray()->GetEntriesFast();
162 Int_t nir=fInnerSec->GetNRows(), nor=fOuterSec->GetNRows();
163 Int_t id=carray.GetID();
164 if ((id<0) || (id>2*(fkNIS*nir + fkNOS*nor))) {
165 Fatal("LoadClusters","Wrong index !");
167 Int_t outindex = 2*fkNIS*nir;
170 Int_t row = id - sec*nir;
172 AliTPCRow &padrow=fInnerSec[sec][row];
174 AliTPCcluster *c=(AliTPCcluster*)carray[ncl];
175 padrow.InsertCluster(c,sec,row);
180 Int_t row = id - sec*nor;
182 AliTPCRow &padrow=fOuterSec[sec][row];
184 AliTPCcluster *c=(AliTPCcluster*)carray[ncl];
185 padrow.InsertCluster(c,sec+fkNIS,row);
188 carray.GetArray()->Clear();
194 //_____________________________________________________________________________
195 void AliTPCtracker::UnloadClusters() {
196 //-----------------------------------------------------------------
197 // This function unloads TPC clusters.
198 //-----------------------------------------------------------------
200 for (i=0; i<fkNIS; i++) {
201 Int_t nr=fInnerSec->GetNRows();
202 for (Int_t n=0; n<nr; n++) fInnerSec[i][n].ResetClusters();
204 for (i=0; i<fkNOS; i++) {
205 Int_t nr=fOuterSec->GetNRows();
206 for (Int_t n=0; n<nr; n++) fOuterSec[i][n].ResetClusters();
210 //_____________________________________________________________________________
211 Int_t AliTPCtracker::FollowProlongation(AliTPCseed& t, Int_t rf) {
212 //-----------------------------------------------------------------
213 // This function tries to find a track prolongation.
214 //-----------------------------------------------------------------
215 Double_t xt=t.GetX();
216 const Int_t kSKIP=(t.GetNumberOfClusters()<10) ? kRowsToSkip :
217 Int_t(0.5*fSectors->GetNRows());
218 Int_t tryAgain=kSKIP;
220 Double_t alpha=t.GetAlpha() - fSectors->GetAlphaShift();
221 if (alpha > 2.*TMath::Pi()) alpha -= 2.*TMath::Pi();
222 if (alpha < 0. ) alpha += 2.*TMath::Pi();
223 Int_t s=Int_t(alpha/fSectors->GetAlpha())%fN;
225 Int_t nrows=fSectors->GetRowNumber(xt)-1;
226 for (Int_t nr=nrows; nr>=rf; nr--) {
227 Double_t x=fSectors->GetX(nr), ymax=fSectors->GetMaxY(nr);
228 if (!t.PropagateTo(x)) return 0;
232 Double_t maxchi2=kMaxCHI2;
233 const AliTPCRow &krow=fSectors[s][nr];
234 Double_t pt=t.GetSignedPt();
235 Double_t sy2=AliTPCcluster::SigmaY2(t.GetX(),t.GetTgl(),pt);
236 Double_t sz2=AliTPCcluster::SigmaZ2(t.GetX(),t.GetTgl());
237 Double_t road=4.*sqrt(t.GetSigmaY2() + sy2), y=t.GetY(), z=t.GetZ();
240 if (t.GetNumberOfClusters()>4)
241 Warning("FindProlongation","Too broad road !");
246 for (Int_t i=krow.Find(y-road); i<krow; i++) {
247 AliTPCcluster *c=(AliTPCcluster*)(krow[i]);
248 if (c->GetY() > y+road) break;
249 if (c->IsUsed()) continue;
250 if ((c->GetZ()-z)*(c->GetZ()-z) > 16.*(t.GetSigmaZ2()+sz2)) continue;
251 Double_t chi2=t.GetPredictedChi2(c);
252 if (chi2 > maxchi2) continue;
255 index=krow.GetIndex(i);
259 Float_t l=fSectors->GetPadPitchWidth();
260 Float_t corr=1.; if (nr>63) corr=0.67; // new (third) pad response !
261 t.SetSampledEdx(cl->GetQ()/l*corr,t.GetNumberOfClusters());
262 if (!t.Update(cl,maxchi2,index)) {
263 if (!tryAgain--) return 0;
264 } else tryAgain=kSKIP;
266 if (tryAgain==0) break;
269 if (!t.Rotate(fSectors->GetAlpha())) return 0;
270 } else if (y <-ymax) {
272 if (!t.Rotate(-fSectors->GetAlpha())) return 0;
280 //_____________________________________________________________________________
282 Int_t AliTPCtracker::FollowRefitInward(AliTPCseed *seed, AliTPCtrack *track) {
284 // This function propagates seed inward TPC using old clusters
287 // Sylwester Radomski, GSI
293 Int_t nRows = fSectors->GetNRows();
294 for (Int_t iRow = nRows-1; iRow >= 0; iRow--) {
296 Double_t x = fSectors->GetX(iRow);
297 if (!seed->PropagateTo(x)) return 0;
299 // try to find an assigned cluster in this row
301 AliTPCcluster* cluster = NULL;
304 for (Int_t iCluster = 0; iCluster < track->GetNumberOfClusters(); iCluster++) {
305 idx = track->GetClusterIndex(iCluster);
306 sec = (idx&0xff000000)>>24;
307 Int_t row = (idx&0x00ff0000)>>16;
308 if (((fSectors == fInnerSec) && (sec >= fkNIS)) ||
309 ((fSectors == fOuterSec) && (sec < fkNIS))) continue;
311 cluster = (AliTPCcluster*) GetCluster(idx);
316 // update the track seed with the found cluster
319 Double_t dAlpha = fParam->GetAngle(sec) - seed->GetAlpha();
320 if (TMath::Abs(dAlpha) > 0.0001) {
321 if (!seed->Rotate(dAlpha)) return 0;
322 if (!seed->PropagateTo(x)) return 0;
325 seed->Update(cluster, seed->GetPredictedChi2(cluster), idx);
332 //_____________________________________________________________________________
333 Int_t AliTPCtracker::FollowBackProlongation
334 (AliTPCseed& seed, const AliTPCtrack &track) {
335 //-----------------------------------------------------------------
336 // This function propagates tracks back through the TPC
337 //-----------------------------------------------------------------
338 Double_t alpha=seed.GetAlpha() - fSectors->GetAlphaShift();
339 if (alpha > 2.*TMath::Pi()) alpha -= 2.*TMath::Pi();
340 if (alpha < 0. ) alpha += 2.*TMath::Pi();
341 Int_t s=Int_t(alpha/fSectors->GetAlpha())%fN;
343 Int_t idx=-1, sec=-1, row=-1;
344 Int_t nc=track.GetNumberOfClusters();
347 idx=track.GetClusterIndex(nc);
348 sec=(idx&0xff000000)>>24; row=(idx&0x00ff0000)>>16;
350 if (fSectors==fInnerSec) { if (sec >= fkNIS) row=-1; }
351 else { if (sec < fkNIS) row=-1; }
353 Int_t nr=fSectors->GetNRows();
354 for (Int_t i=0; i<nr; i++) {
355 Double_t x=fSectors->GetX(i), ymax=fSectors->GetMaxY(i);
357 if (!seed.GetYAt(x,GetBz(),y)) return 0;
361 if (!seed.Rotate(fSectors->GetAlpha())) return 0;
362 } else if (y <-ymax) {
364 if (!seed.Rotate(-fSectors->GetAlpha())) return 0;
367 if (!seed.PropagateTo(x)) return 0;
371 Double_t maxchi2=kMaxCHI2;
372 Double_t pt=seed.GetSignedPt();
373 Double_t sy2=AliTPCcluster::SigmaY2(seed.GetX(),seed.GetTgl(),pt);
374 Double_t sz2=AliTPCcluster::SigmaZ2(seed.GetX(),seed.GetTgl());
375 Double_t road=4.*sqrt(seed.GetSigmaY2() + sy2), z=seed.GetZ();
377 Warning("FollowBackProlongation","Too broad road !");
381 Int_t accepted=seed.GetNumberOfClusters();
383 //try to accept already found cluster
384 AliTPCcluster *c=(AliTPCcluster*)GetCluster(idx);
386 if ((chi2=seed.GetPredictedChi2(c))<maxchi2 || accepted<27) {
387 index=idx; cl=c; maxchi2=chi2;
388 } //else cerr<<"AliTPCtracker::FollowBackProlongation: oulier !\n";
391 idx=track.GetClusterIndex(nc);
392 sec=(idx&0xff000000)>>24; row=(idx&0x00ff0000)>>16;
394 if (fSectors==fInnerSec) { if (sec >= fkNIS) row=-1; }
395 else { if (sec < fkNIS) row=-1; }
399 //try to fill the gap
400 const AliTPCRow &krow=fSectors[s][i];
403 for (Int_t icl=krow.Find(y-road); icl<krow; icl++) {
404 AliTPCcluster *c=(AliTPCcluster*)(krow[icl]);
405 if (c->GetY() > y+road) break;
406 if (c->IsUsed()) continue;
407 if ((c->GetZ()-z)*(c->GetZ()-z)>16.*(seed.GetSigmaZ2()+sz2)) continue;
408 Double_t chi2=seed.GetPredictedChi2(c);
409 if (chi2 > maxchi2) continue;
412 index=krow.GetIndex(icl);
418 Float_t l=fSectors->GetPadPitchWidth();
419 Float_t corr=1.; if (i>63) corr=0.67; // new (third) pad response !
420 seed.SetSampledEdx(cl->GetQ()/l*corr,seed.GetNumberOfClusters());
421 seed.Update(cl,maxchi2,index);
429 //_____________________________________________________________________________
430 void AliTPCtracker::MakeSeeds(Int_t i1, Int_t i2) {
431 //-----------------------------------------------------------------
432 // This function creates track seeds.
433 //-----------------------------------------------------------------
434 Double_t x[5], c[15];
436 Double_t alpha=fSectors->GetAlpha(), shift=fSectors->GetAlphaShift();
437 Double_t cs=cos(alpha), sn=sin(alpha);
439 Double_t x1 =fSectors->GetX(i1);
440 Double_t xx2=fSectors->GetX(i2);
442 for (Int_t ns=0; ns<fN; ns++) {
443 Int_t nl=fSectors[(ns-1+fN)%fN][i2];
444 Int_t nm=fSectors[ns][i2];
445 Int_t nu=fSectors[(ns+1)%fN][i2];
446 const AliTPCRow& kr1=fSectors[ns][i1];
447 for (Int_t is=0; is < kr1; is++) {
448 Double_t y1=kr1[is]->GetY(), z1=kr1[is]->GetZ();
449 for (Int_t js=0; js < nl+nm+nu; js++) {
450 const AliTPCcluster *kcl;
452 Double_t x3=GetX(), y3=GetY(), z3=GetZ();
455 const AliTPCRow& kr2=fSectors[(ns-1+fN)%fN][i2];
457 y2=kcl->GetY(); z2=kcl->GetZ();
462 const AliTPCRow& kr2=fSectors[ns][i2];
464 x2=xx2; y2=kcl->GetY(); z2=kcl->GetZ();
466 const AliTPCRow& kr2=fSectors[(ns+1)%fN][i2];
468 y2=kcl->GetY(); z2=kcl->GetZ();
473 Double_t zz=z1 - (z1-z3)/(x1-x3)*(x1-x2);
474 if (TMath::Abs(zz-z2)>5.) continue;
476 Double_t d=(x2-x1)*(0.-y2)-(0.-x2)*(y2-y1);
478 Warning("MakeSeeds","Straight seed !");
483 x[4]=f1(x1,y1,x2,y2,x3,y3);
484 if (TMath::Abs(x[4]) >= 0.0066) continue;
485 x[2]=f2(x1,y1,x2,y2,x3,y3);
486 //if (TMath::Abs(x[4]*x1-x[2]) >= 0.99999) continue;
487 x[3]=f3(x1,y1,x2,y2,z1,z2);
488 if (TMath::Abs(x[3]) > 1.2) continue;
489 Double_t a=asin(x[2]);
490 Double_t zv=z1 - x[3]/x[4]*(a+asin(x[4]*x1-x[2]));
491 if (TMath::Abs(zv-z3)>10.) continue;
493 Double_t sy1=kr1[is]->GetSigmaY2(), sz1=kr1[is]->GetSigmaZ2();
494 Double_t sy2=kcl->GetSigmaY2(), sz2=kcl->GetSigmaZ2();
495 //Double_t sy3=400*3./12., sy=0.1, sz=0.1;
496 Double_t sy3=25000*x[4]*x[4]+0.1, sy=0.1, sz=0.1;
498 Double_t f40=(f1(x1,y1+sy,x2,y2,x3,y3)-x[4])/sy;
499 Double_t f42=(f1(x1,y1,x2,y2+sy,x3,y3)-x[4])/sy;
500 Double_t f43=(f1(x1,y1,x2,y2,x3,y3+sy)-x[4])/sy;
501 Double_t f20=(f2(x1,y1+sy,x2,y2,x3,y3)-x[2])/sy;
502 Double_t f22=(f2(x1,y1,x2,y2+sy,x3,y3)-x[2])/sy;
503 Double_t f23=(f2(x1,y1,x2,y2,x3,y3+sy)-x[2])/sy;
504 Double_t f30=(f3(x1,y1+sy,x2,y2,z1,z2)-x[3])/sy;
505 Double_t f31=(f3(x1,y1,x2,y2,z1+sz,z2)-x[3])/sz;
506 Double_t f32=(f3(x1,y1,x2,y2+sy,z1,z2)-x[3])/sy;
507 Double_t f34=(f3(x1,y1,x2,y2,z1,z2+sz)-x[3])/sz;
511 c[3]=f20*sy1; c[4]=0.; c[5]=f20*sy1*f20+f22*sy2*f22+f23*sy3*f23;
512 c[6]=f30*sy1; c[7]=f31*sz1; c[8]=f30*sy1*f20+f32*sy2*f22;
513 c[9]=f30*sy1*f30+f31*sz1*f31+f32*sy2*f32+f34*sz2*f34;
514 c[10]=f40*sy1; c[11]=0.; c[12]=f40*sy1*f20+f42*sy2*f22+f43*sy3*f23;
515 c[13]=f30*sy1*f40+f32*sy2*f42;
516 c[14]=f40*sy1*f40+f42*sy2*f42+f43*sy3*f43;
518 Int_t index=kr1.GetIndex(is);
519 AliTPCseed *track=new AliTPCseed(x1, ns*alpha+shift, x, c, index);
520 Float_t l=fSectors->GetPadPitchWidth();
521 track->SetSampledEdx(kr1[is]->GetQ()/l,0);
523 Int_t rc=FollowProlongation(*track, i2);
524 if (rc==0 || track->GetNumberOfClusters()<(i1-i2)/2) delete track;
525 else fSeeds->AddLast(track);
531 //_____________________________________________________________________________
532 Int_t AliTPCtracker::ReadSeeds(const TFile *inp) {
533 //-----------------------------------------------------------------
534 // This function reades track seeds.
535 //-----------------------------------------------------------------
536 TDirectory *savedir=gDirectory;
538 TFile *in=(TFile*)inp;
540 Error("ReadSeeds","Input file has not been open !");
545 TTree *seedTree=(TTree*)in->Get("Seeds");
547 Error("ReadSeeds","Can't get a tree with track seeds !");
550 AliTPCtrack *seed=new AliTPCtrack;
551 seedTree->SetBranchAddress("tracks",&seed);
553 if (fSeeds==0) fSeeds=new TObjArray(15000);
555 Int_t n=(Int_t)seedTree->GetEntries();
556 for (Int_t i=0; i<n; i++) {
557 seedTree->GetEvent(i);
558 seed->ResetClusters();
559 fSeeds->AddLast(new AliTPCseed(*seed));
564 delete seedTree; //Thanks to Mariana Bondila
571 //_____________________________________________________________________________
572 Int_t AliTPCtracker::Clusters2Tracks(AliESDEvent *event) {
573 //-----------------------------------------------------------------
574 // This is a track finder.
575 // The clusters must be already loaded !
576 //-----------------------------------------------------------------
579 Int_t nup=fOuterSec->GetNRows(), nlow=fInnerSec->GetNRows();
580 Int_t nrows=nlow+nup;
582 Int_t gap=Int_t(0.125*nrows), shift=Int_t(0.5*gap);
583 fSectors=fOuterSec; fN=fkNOS;
584 fSeeds=new TObjArray(15000);
585 MakeSeeds(nup-1, nup-1-gap);
586 MakeSeeds(nup-1-shift, nup-1-shift-gap);
590 Int_t nseed=fSeeds->GetEntriesFast();
591 for (Int_t i=0; i<nseed; i++) {
592 //tracking in the outer sectors
593 fSectors=fOuterSec; fN=fkNOS;
595 AliTPCseed *pt=(AliTPCseed*)fSeeds->UncheckedAt(i), &t=*pt;
596 if (!FollowProlongation(t)) {
597 delete fSeeds->RemoveAt(i);
601 //tracking in the inner sectors
602 fSectors=fInnerSec; fN=fkNIS;
604 Double_t alpha=t.GetAlpha() - fInnerSec->GetAlphaShift();
605 if (alpha > 2.*TMath::Pi()) alpha -= 2.*TMath::Pi();
606 if (alpha < 0. ) alpha += 2.*TMath::Pi();
607 Int_t ns=Int_t(alpha/fInnerSec->GetAlpha())%fkNIS;
609 alpha=ns*fInnerSec->GetAlpha()+fInnerSec->GetAlphaShift()-t.GetAlpha();
611 if (t.Rotate(alpha)) {
612 if (FollowProlongation(t)) {
613 if (t.GetNumberOfClusters() >= Int_t(0.4*nrows)) {
615 CookLabel(pt,0.1); //For comparison only
616 pt->PropagateTo(fParam->GetInnerRadiusLow());
618 iotrack.UpdateTrackParams(pt,AliESDtrack::kTPCin);
620 event->AddTrack(&iotrack);
626 delete fSeeds->RemoveAt(i);
629 Info("Clusters2Tracks","Number of found tracks : %d",
630 event->GetNumberOfTracks());
632 fSeeds->Clear(); delete fSeeds; fSeeds=0;
637 //_____________________________________________________________________________
638 Int_t AliTPCtracker::RefitInward(AliESDEvent* event) {
640 // The function propagates tracks throught TPC inward
641 // using already associated clusters.
642 // The clusters must be already loaded !
645 Int_t nTracks = event->GetNumberOfTracks();
648 for (Int_t i = 0; i < nTracks; i++) {
649 AliESDtrack* track = event->GetTrack(i);
650 ULong_t status = track->GetStatus();
652 if ( (status & AliESDtrack::kTPCrefit) != 0 ) continue;
653 if ( (status & AliESDtrack::kTPCout ) == 0 ) continue;
655 if ( (status & AliESDtrack::kTRDout ) != 0 )
656 if ( (status & AliESDtrack::kTRDrefit ) == 0 ) continue;
658 AliTPCtrack* tpcTrack = new AliTPCtrack(*track);
659 AliTPCseed* seed=new AliTPCseed(*tpcTrack); seed->ResetClusters();
661 if ( (status & AliESDtrack::kTRDrefit) == 0 ) seed->ResetCovariance(10.);
663 fSectors = fOuterSec;
665 Int_t res = FollowRefitInward(seed, tpcTrack);
667 Int_t nc = seed->GetNumberOfClusters();
669 fSectors = fInnerSec;
671 res = FollowRefitInward(seed, tpcTrack);
672 UseClusters(seed, nc);
675 seed->PropagateTo(fParam->GetInnerRadiusLow());
676 seed->SetLabel(tpcTrack->GetLabel());
677 seed->SetdEdx(tpcTrack->GetdEdx());
678 track->UpdateTrackParams(seed, AliESDtrack::kTPCrefit);
686 Info("RefitInward","Number of refitted tracks : %d",nRefited);
691 Int_t AliTPCtracker::PropagateBack(AliESDEvent *event) {
692 //-----------------------------------------------------------------
693 // This function propagates tracks back through the TPC.
694 // The clusters must be already loaded !
695 //-----------------------------------------------------------------
696 Int_t nentr=event->GetNumberOfTracks();
697 Info("PropagateBack", "Number of ESD tracks: %d\n", nentr);
700 for (Int_t i=0; i<nentr; i++) {
701 AliESDtrack *esd=event->GetTrack(i);
702 ULong_t status=esd->GetStatus();
704 if ( (status & AliESDtrack::kTPCin ) == 0 ) continue;
705 if ( (status & AliESDtrack::kTPCout) != 0 ) continue;
706 if ( (status & AliESDtrack::kITSin) != 0 )
707 if ( (status & AliESDtrack::kITSout) == 0 ) continue;
709 const AliTPCtrack t(*esd);
710 AliTPCseed s(t); s.ResetClusters();
712 if ( (status & AliESDtrack::kITSout) == 0 ) s.ResetCovariance(10.);
715 fSectors=fInnerSec; fN=fkNIS;
717 Double_t alpha=s.GetAlpha() - fSectors->GetAlphaShift();
718 if (alpha > 2.*TMath::Pi()) alpha -= 2.*TMath::Pi();
719 if (alpha < 0. ) alpha += 2.*TMath::Pi();
720 Int_t ns=Int_t(alpha/fSectors->GetAlpha())%fN;
721 alpha =ns*fSectors->GetAlpha() + fSectors->GetAlphaShift();
724 if (!s.Rotate(alpha)) continue;
725 if (!FollowBackProlongation(s,t)) continue;
730 fSectors=fOuterSec; fN=fkNOS;
732 Int_t nc=s.GetNumberOfClusters();
734 alpha=s.GetAlpha() - fSectors->GetAlphaShift();
735 if (alpha > 2.*TMath::Pi()) alpha -= 2.*TMath::Pi();
736 if (alpha < 0. ) alpha += 2.*TMath::Pi();
737 ns=Int_t(alpha/fSectors->GetAlpha())%fN;
739 alpha =ns*fSectors->GetAlpha() + fSectors->GetAlphaShift();
742 if (!s.Rotate(alpha)) continue;
743 if (!FollowBackProlongation(s,t)) continue;
745 Int_t nrows=fOuterSec->GetNRows()+fInnerSec->GetNRows();
746 if (s.GetNumberOfClusters() < Int_t(0.4*nrows)) continue;
748 s.PropagateTo(fParam->GetOuterRadiusUp());
750 CookLabel(&s,0.1); //For comparison only
752 esd->UpdateTrackParams(&s,AliESDtrack::kTPCout);
755 Info("PropagateBack","Number of back propagated tracks: %d",ntrk);
760 //_________________________________________________________________________
761 AliCluster *AliTPCtracker::GetCluster(Int_t index) const {
762 //--------------------------------------------------------------------
763 // Return pointer to a given cluster
764 //--------------------------------------------------------------------
765 Int_t sec=(index&0xff000000)>>24;
766 Int_t row=(index&0x00ff0000)>>16;
767 Int_t ncl=(index&0x0000ffff)>>00;
769 const AliTPCcluster *cl=0;
772 cl=fInnerSec[sec][row].GetUnsortedCluster(ncl);
775 cl=fOuterSec[sec][row].GetUnsortedCluster(ncl);
778 return (AliCluster*)cl;
781 //__________________________________________________________________________
782 void AliTPCtracker::CookLabel(AliKalmanTrack *t, Float_t wrong) const {
783 //--------------------------------------------------------------------
784 //This function "cooks" a track label. If label<0, this track is fake.
785 //--------------------------------------------------------------------
786 Int_t noc=t->GetNumberOfClusters();
787 Int_t *lb=new Int_t[noc];
788 Int_t *mx=new Int_t[noc];
789 AliCluster **clusters=new AliCluster*[noc];
792 for (i=0; i<noc; i++) {
794 Int_t index=t->GetClusterIndex(i);
795 clusters[i]=GetCluster(index);
799 for (i=0; i<noc; i++) {
800 AliCluster *c=clusters[i];
801 lab=TMath::Abs(c->GetLabel(0));
803 for (j=0; j<noc; j++) if (lb[j]==lab || mx[j]==0) break;
811 for (i=0; i<noc; i++) if (mx[i]>max) {max=mx[i]; lab=lb[i];}
813 for (i=0; i<noc; i++) {
814 AliCluster *c=clusters[i];
815 if (TMath::Abs(c->GetLabel(1)) == lab ||
816 TMath::Abs(c->GetLabel(2)) == lab ) max++;
819 if ((1.- Float_t(max)/noc) > wrong) lab=-lab;
822 Int_t tail=Int_t(0.10*noc);
824 for (i=1; i<=tail; i++) {
825 AliCluster *c=clusters[noc-i];
826 if (lab == TMath::Abs(c->GetLabel(0)) ||
827 lab == TMath::Abs(c->GetLabel(1)) ||
828 lab == TMath::Abs(c->GetLabel(2))) max++;
830 if (max < Int_t(0.5*tail)) lab=-lab;
840 //_________________________________________________________________________
841 void AliTPCtracker::AliTPCSector::Setup(const AliTPCParam *par, Int_t f) {
842 //-----------------------------------------------------------------------
843 // Setup inner sector
844 //-----------------------------------------------------------------------
846 fAlpha=par->GetInnerAngle();
847 fAlphaShift=par->GetInnerAngleShift();
848 fPadPitchWidth=par->GetInnerPadPitchWidth();
849 f1PadPitchLength=par->GetInnerPadPitchLength();
850 f2PadPitchLength=f1PadPitchLength;
852 fN=par->GetNRowLow();
853 fRow=new AliTPCRow[fN];
854 for (Int_t i=0; i<fN; i++) fRow[i].SetX(par->GetPadRowRadiiLow(i));
856 fAlpha=par->GetOuterAngle();
857 fAlphaShift=par->GetOuterAngleShift();
858 fPadPitchWidth=par->GetOuterPadPitchWidth();
859 f1PadPitchLength=par->GetOuter1PadPitchLength();
860 f2PadPitchLength=par->GetOuter2PadPitchLength();
863 fRow=new AliTPCRow[fN];
864 for (Int_t i=0; i<fN; i++){
865 fRow[i].SetX(par->GetPadRowRadiiUp(i));
870 //_________________________________________________________________________
872 AliTPCRow::InsertCluster(const AliTPCcluster* c, Int_t sec, Int_t row) {
873 //-----------------------------------------------------------------------
874 // Insert a cluster into this pad row in accordence with its y-coordinate
875 //-----------------------------------------------------------------------
876 if (fN==kMaxClusterPerRow) {
877 ::Error("InsertCluster","Too many clusters !");
881 Int_t index=(((sec<<8)+row)<<16)+fN;
884 fSize=kMaxClusterPerRow/8;
885 fClusterArray=new AliTPCcluster[fSize];
887 fClusterArray[0]=*c; fClusters[fN++]=fClusterArray;
893 AliTPCcluster *buff=new AliTPCcluster[size];
894 memcpy(buff,fClusterArray,fSize*sizeof(AliTPCcluster));
895 for (Int_t i=0; i<fN; i++)
896 fClusters[i]=buff+(fClusters[i]-fClusterArray);
897 delete[] fClusterArray;
902 Int_t i=Find(c->GetY());
903 memmove(fClusters+i+1 ,fClusters+i,(fN-i)*sizeof(AliTPCcluster*));
904 memmove(fIndex +i+1 ,fIndex +i,(fN-i)*sizeof(UInt_t));
906 fClusters[i]=fClusterArray+fN; fClusterArray[fN++]=*c;
909 //___________________________________________________________________
910 Int_t AliTPCtracker::AliTPCRow::Find(Double_t y) const {
911 //-----------------------------------------------------------------------
912 // Return the index of the nearest cluster
913 //-----------------------------------------------------------------------
915 if (y <= fClusters[0]->GetY()) return 0;
916 if (y > fClusters[fN-1]->GetY()) return fN;
917 Int_t b=0, e=fN-1, m=(b+e)/2;
918 for (; b<e; m=(b+e)/2) {
919 if (y > fClusters[m]->GetY()) b=m+1;
925 //_____________________________________________________________________________
926 void AliTPCtracker::AliTPCseed::CookdEdx(Double_t low, Double_t up) {
927 //-----------------------------------------------------------------
928 // This funtion calculates dE/dX within the "low" and "up" cuts.
929 //-----------------------------------------------------------------
931 Int_t nc=GetNumberOfClusters();
933 Int_t swap;//stupid sorting
936 for (i=0; i<nc-1; i++) {
937 if (fdEdxSample[i]<=fdEdxSample[i+1]) continue;
938 Float_t tmp=fdEdxSample[i];
939 fdEdxSample[i]=fdEdxSample[i+1]; fdEdxSample[i+1]=tmp;
944 Int_t nl=Int_t(low*nc), nu=Int_t(up*nc);
946 for (i=nl; i<=nu; i++) dedx += fdEdxSample[i];