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 **************************************************************************/
16 //-------------------------------------------------------------------------
17 // Implementation of the ITS tracker class
19 // Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
20 //-------------------------------------------------------------------------
26 #include "AliITSgeom.h"
27 #include "AliITSRecPoint.h"
28 #include "AliTPCtrack.h"
29 #include "AliITSclusterV2.h"
30 #include "AliITStrackerV2.h"
38 extern TRandom *gRandom;
40 AliITStrackerV2::AliITSlayer AliITStrackerV2::fLayers[kMaxLayer]; // ITS layers
43 AliITStrackerV2(const AliITSgeom *geom) throw (const Char_t *) {
44 //--------------------------------------------------------------------
45 //This is the AliITStracker constructor
46 //It also reads clusters from a root file
47 //--------------------------------------------------------------------
50 AliITSgeom *g=(AliITSgeom*)geom;
54 for (i=1; i<kMaxLayer+1; i++) {
55 Int_t nlad=g->GetNladders(i);
56 Int_t ndet=g->GetNdetectors(i);
58 g->GetTrans(i,1,1,x,y,z);
59 Double_t r=TMath::Sqrt(x*x + y*y);
60 Double_t poff=TMath::ATan2(y,x);
63 g->GetTrans(i,1,2,x,y,z);
64 r += TMath::Sqrt(x*x + y*y);
65 g->GetTrans(i,2,1,x,y,z);
66 r += TMath::Sqrt(x*x + y*y);
67 g->GetTrans(i,2,2,x,y,z);
68 r += TMath::Sqrt(x*x + y*y);
71 new (fLayers+i-1) AliITSlayer(r,poff,zoff,nlad,ndet);
73 for (Int_t j=1; j<nlad+1; j++) {
74 for (Int_t k=1; k<ndet+1; k++) { //Fill this layer with detectors
75 Float_t x,y,zshift; g->GetTrans(i,j,k,x,y,zshift);
76 Double_t rot[9]; g->GetRotMatrix(i,j,k,rot);
78 Double_t r =-x*rot[1] + y*rot[0]; if (i==1) r=-r;
79 Double_t phi=TMath::ATan2(rot[1],rot[0]); if (i==1) phi-=3.1415927;
81 AliITSdetector &det=fLayers[i-1].GetDetector((j-1)*ndet + k-1);
83 if (phi<0) phi += 2*TMath::Pi();
85 new(&det) AliITSdetector(r,phi);
93 TTree *cTree=(TTree*)gDirectory->Get("cTree");
95 ("AliITStrackerV2::AliITStrackerV2 can't get cTree !\n");
97 TBranch *branch=cTree->GetBranch("Clusters");
99 ("AliITStrackerV2::AliITStrackerV2 can't get Clusters branch !\n");
101 TClonesArray dummy("AliITSclusterV2",10000), *clusters=&dummy;
102 branch->SetAddress(&clusters);
104 Int_t nentr=(Int_t)cTree->GetEntries();
105 for (i=0; i<nentr; i++) {
106 if (!cTree->GetEvent(i)) continue;
107 //Int_t lay,lad,det; g->GetModuleId(i-1,lay,lad,det);
108 Int_t lay,lad,det; g->GetModuleId(i,lay,lad,det);
109 Int_t ncl=clusters->GetEntriesFast();
111 AliITSclusterV2 *c=(AliITSclusterV2*)clusters->UncheckedAt(ncl);
114 if (c->GetLabel(2)!=LAB)
115 if (c->GetLabel(1)!=LAB)
116 if (c->GetLabel(0)!=LAB) continue;
117 cout<<lay-1<<' '<<lad-1<<' '<<det-1<<' '<<c->GetY()<<' '<<c->GetZ()<<endl;
120 AliITSdetector &det=fLayers[lay-1].GetDetector(c->GetDetectorIndex());
121 Double_t r=det.GetR(); r=TMath::Sqrt(r*r + c->GetY()*c->GetY());
122 if (r > TMath::Abs(c->GetZ())-0.5)
123 fLayers[lay-1].InsertCluster(new AliITSclusterV2(*c));
128 catch (const Char_t *msg) {
140 Int_t AliITStrackerV2::Clusters2Tracks(const TFile *inp, TFile *out) {
141 //--------------------------------------------------------------------
142 //This functions reconstructs ITS tracks
143 //--------------------------------------------------------------------
144 TFile *in=(TFile*)inp;
145 TDirectory *savedir=gDirectory;
148 cerr<<"AliITStrackerV2::Clusters2Tracks(): ";
149 cerr<<"file with TPC tracks is not open !\n";
153 if (!out->IsOpen()) {
154 cerr<<"AliITStrackerV2::Clusters2Tracks(): ";
155 cerr<<"file for ITS tracks is not open !\n";
160 TTree *tpcTree=(TTree*)in->Get("TPCf");
162 cerr<<"AliITStrackerV2::Clusters2Tracks() ";
163 cerr<<"can't get a tree with TPC tracks !\n";
167 AliTPCtrack *itrack=new AliTPCtrack;
168 tpcTree->SetBranchAddress("tracks",&itrack);
171 TTree itsTree("ITSf","Tree with ITS tracks");
172 AliITStrackV2 *otrack=&fBestTrack;
173 itsTree.Branch("tracks","AliITStrackV2",&otrack,32000,0);
177 Int_t nentr=(Int_t)tpcTree->GetEntries();
178 for (Int_t i=0; i<nentr; i++) {
180 if (!tpcTree->GetEvent(i)) continue;
181 Int_t tpcLabel=itrack->GetLabel(); //save the TPC track label
185 if (TMath::Abs(tpcLabel)!=LAB) continue;
186 cout<<tpcLabel<<" *****************\n";
190 ResetTrackToFollow(AliITStrackV2(*itrack));
191 } catch (const Char_t *msg) {
197 fYV=gRandom->Gaus(0.,kSigmaYV); fZV=gRandom->Gaus(0.,kSigmaZV);
199 Double_t r2=fTrackToFollow.GetX()*fTrackToFollow.GetX();
200 Double_t x0=0.082/21.82*2.33*(45*45+40*40)/r2+2.000/41.28*0.03*75*75/r2;
201 fTrackToFollow.Improve(x0,fYV,fZV);
204 fTrackToFollow.PropagateTo(xk,0.,0.); //Ne if it's still there
207 fTrackToFollow.PropagateTo(xk, 0.005/44.77*1.71, 0.005*1.71); //Tedlar
209 fTrackToFollow.PropagateTo(xk, 0.02/44.86*1.45, 0.02*1.45); //Kevlar
211 fTrackToFollow.PropagateTo(xk, 2.0/41.28*0.029, 2.0*0.029);//Nomex
213 fTrackToFollow.PropagateTo(xk, 0.02/44.86*1.45, 0.02*1.45); //Kevlar
215 fTrackToFollow.PropagateTo(xk, 0.005/44.77*1.71, 0.005*1.71); //Tedlar
218 fTrackToFollow.PropagateTo(xk,0.,0.); //C02
221 fTrackToFollow.PropagateTo(xk, 0.005/24.01*2.7, 0.005*2.7); //Al
223 fTrackToFollow.PropagateTo(xk, 0.005/44.77*1.71, 0.005*1.71); //Tedlar
225 fTrackToFollow.PropagateTo(xk, 0.02/44.86*1.45, 0.02*1.45); //Kevlar
227 fTrackToFollow.PropagateTo(xk, 0.5/41.28*.029, 0.5*0.029); //Nomex
229 fTrackToFollow.PropagateTo(xk, 0.02/44.86*1.45, 0.02*1.45); //Kevlar
231 fTrackToFollow.PropagateTo(xk, 0.005/44.77*1.71, 0.005*1.71); //Tedlar
233 fTrackToFollow.PropagateTo(xk, 0.005/24.01*2.7, 0.005*2.7); //Al
236 for (FollowProlongation(); fI<kMaxLayer; fI++) {
237 while (TakeNextProlongation()) FollowProlongation();
241 cout<<fBestTrack.GetNumberOfClusters()<<" number of clusters\n\n";
244 if (fBestTrack.GetNumberOfClusters() >= kMaxLayer-kLayersToSkip) {
245 cerr << ++ntrk << " \r";
246 fBestTrack.SetLabel(tpcLabel);
247 UseClusters(&fBestTrack);
255 cerr<<"Number of TPC tracks: "<<nentr<<endl;
256 cerr<<"Number of prolonged tracks: "<<ntrk<<endl;
263 Int_t AliITStrackerV2::PropagateBack(const TFile *inp, TFile *out) {
264 //--------------------------------------------------------------------
265 //This functions propagates reconstructed ITS tracks back
266 //--------------------------------------------------------------------
267 TFile *in=(TFile*)inp;
268 TDirectory *savedir=gDirectory;
271 cerr<<"AliITStrackerV2::PropagateBack(): ";
272 cerr<<"file with ITS tracks is not open !\n";
276 if (!out->IsOpen()) {
277 cerr<<"AliITStrackerV2::PropagateBack(): ";
278 cerr<<"file for back propagated ITS tracks is not open !\n";
283 TTree *itsTree=(TTree*)in->Get("ITSf");
285 cerr<<"AliITStrackerV2::PropagateBack() ";
286 cerr<<"can't get a tree with ITS tracks !\n";
289 AliITStrackV2 *itrack=new AliITStrackV2;
290 itsTree->SetBranchAddress("tracks",&itrack);
293 TTree backTree("ITSb","Tree with back propagated ITS tracks");
294 AliTPCtrack *otrack=0;
295 backTree.Branch("tracks","AliTPCtrack",&otrack,32000,0);
299 Int_t nentr=(Int_t)itsTree->GetEntries();
300 for (Int_t i=0; i<nentr; i++) {
301 itsTree->GetEvent(i);
302 ResetTrackToFollow(*itrack);
303 fTrackToFollow.ResetCovariance(); fTrackToFollow.ResetClusters();
304 Int_t itsLabel=fTrackToFollow.GetLabel(); //save the ITS track label
307 if (TMath::Abs(itsLabel)!=LAB) continue;
308 cout<<itsLabel<<" *****************\n";
312 Int_t nc=itrack->GetNumberOfClusters();
314 for (Int_t k=0; k<nc; k++) {
315 Int_t index=itrack->GetClusterIndex(k);
316 AliITSclusterV2 *c=(AliITSclusterV2*)GetCluster(index);
317 cout<<c->GetLabel(0)<<' '<<c->GetLabel(1)<<' '<<c->GetLabel(2)<<endl;
321 const AliITSclusterV2 *c=0;
323 idx=itrack->GetClusterIndex(nc); l=(idx&0xf0000000)>>28;
324 c=(AliITSclusterV2*)GetCluster(idx);
326 for (fI=0; fI<kMaxLayer; fI++) {
327 AliITSlayer &layer=fLayers[fI];
328 Double_t r=layer.GetR();
329 if (fI==2 || fI==4) {
330 Double_t rs=0.5*(fLayers[fI-1].GetR() + r);
331 Double_t ds=0.034; if (fI==4) ds=0.039;
332 Double_t dx0r=ds/21.82*2.33, dr=ds*2.33;
333 if (!fTrackToFollow.PropagateTo(rs,1*dx0r,dr)) throw "";
337 if (!fTrackToFollow.GetGlobalXYZat(r,x,y,z))
338 throw "AliITStrackerV2::PropagateBack: failed to estimate track !";
339 Double_t phi=TMath::ATan2(y,x);
340 Double_t d=layer.GetThickness(phi,z);
341 Int_t idet=layer.FindDetectorIndex(phi,z);
343 throw "AliITStrackerV2::PropagateBack: failed to find a detector !\n";
344 const AliITSdetector &det=layer.GetDetector(idet);
345 r=det.GetR(); phi=det.GetPhi();
346 if (!fTrackToFollow.Propagate(phi,r,d/21.82*2.33,d*2.33)) throw "";
348 const AliITSclusterV2 *cl=0;
350 Double_t maxchi2=kMaxChi2;
353 if (idet != c->GetDetectorIndex()) {
354 idet=c->GetDetectorIndex();
355 const AliITSdetector &det=layer.GetDetector(idet);
356 r=det.GetR(); phi=det.GetPhi();
357 if (!fTrackToFollow.Propagate(phi,r,0.,0.)) throw "";
359 Double_t chi2=fTrackToFollow.GetPredictedChi2(c);
361 cl=c; maxchi2=chi2; index=idx;
364 idx=itrack->GetClusterIndex(nc); l=(idx&0xf0000000)>>28;
365 c=(AliITSclusterV2*)GetCluster(idx);
369 if (fTrackToFollow.GetNumberOfClusters()>2) {
370 Double_t dz=3*TMath::Sqrt(fTrackToFollow.GetSigmaZ2()+kSigmaZ2[fI]);
371 Double_t dy=3*TMath::Sqrt(fTrackToFollow.GetSigmaY2()+kSigmaY2[fI]);
372 Double_t zmin=fTrackToFollow.GetZ() - dz;
373 Double_t zmax=fTrackToFollow.GetZ() + dz;
374 Double_t ymin=fTrackToFollow.GetY() + phi*r - dy;
375 Double_t ymax=fTrackToFollow.GetY() + phi*r + dy;
376 layer.SelectClusters(zmin,zmax,ymin,ymax);
378 const AliITSclusterV2 *cc=0; Int_t ci;
379 while ((cc=layer.GetNextCluster(ci))!=0) {
380 if (idet != cc->GetDetectorIndex()) continue;
381 Double_t chi2=fTrackToFollow.GetPredictedChi2(cc);
383 cl=cc; index=(fI<<28)+ci; maxchi2=chi2;
389 if (!fTrackToFollow.Update(cl,maxchi2,index))
390 cerr<<"AliITStrackerV2::PropagateBack: filtering failed !\n";
396 fTrackToFollow.PropagateTo(xk,0.,0.); //Air
399 fTrackToFollow.PropagateTo(xk, 0.005/24.01*2.7, 0.005*2.7); //Al
401 fTrackToFollow.PropagateTo(xk, 0.005/44.77*1.71, 0.005*1.71); //Tedlar
403 fTrackToFollow.PropagateTo(xk, 0.02/44.86*1.45, 0.02*1.45); //Kevlar
405 fTrackToFollow.PropagateTo(xk, 0.5/41.28*.029, 0.5*0.029); //Nomex
407 fTrackToFollow.PropagateTo(xk, 0.02/44.86*1.45, 0.02*1.45); //Kevlar
409 fTrackToFollow.PropagateTo(xk, 0.005/44.77*1.71, 0.005*1.71); //Tedlar
411 fTrackToFollow.PropagateTo(xk, 0.005/24.01*2.7, 0.005*2.7); //Al
414 fTrackToFollow.PropagateTo(xk,0.,0.); //CO2
417 fTrackToFollow.PropagateTo(xk, 0.005/44.77*1.71, 0.005*1.71); //Tedlar
419 fTrackToFollow.PropagateTo(xk, 0.02/44.86*1.45, 0.02*1.45); //Kevlar
421 fTrackToFollow.PropagateTo(xk, 2.0/41.28*0.029, 2.0*0.029);//Nomex
423 fTrackToFollow.PropagateTo(xk, 0.02/44.86*1.45, 0.02*1.45); //Kevlar
425 fTrackToFollow.PropagateTo(xk, 0.005/44.77*1.71, 0.005*1.71); //Tedlar
427 fTrackToFollow.SetLabel(itsLabel);
428 otrack=new AliTPCtrack(fTrackToFollow,fTrackToFollow.GetAlpha());
429 backTree.Fill(); delete otrack;
430 UseClusters(&fTrackToFollow);
431 cerr << ++ntrk << " \r";
433 catch (const Char_t *msg) {
440 cerr<<"Number of ITS tracks: "<<nentr<<endl;
441 cerr<<"Number of back propagated ITS tracks: "<<ntrk<<endl;
448 AliCluster *AliITStrackerV2::GetCluster(Int_t index) const {
449 //--------------------------------------------------------------------
450 // Return pointer to a given cluster
451 //--------------------------------------------------------------------
452 Int_t l=(index & 0xf0000000) >> 28;
453 Int_t c=(index & 0x0fffffff) >> 00;
454 return fLayers[l].GetCluster(c);
458 void AliITStrackerV2::FollowProlongation() {
459 //--------------------------------------------------------------------
460 //This function finds a track prolongation
461 //--------------------------------------------------------------------
462 Int_t tryAgain=kLayersToSkip;
469 AliITSlayer &layer=fLayers[fI];
470 AliITStrackV2 &track=fTracks[fI];
472 Double_t r=layer.GetR();
473 if (fI==3 || fI==1) {
474 Double_t rs=0.5*(fLayers[fI+1].GetR() + r);
475 Double_t ds=0.034; if (fI==3) ds=0.039;
476 Double_t dx0r=ds/21.82*2.33, dr=ds*2.33;
477 fTrackToFollow.Propagate(fTrackToFollow.GetAlpha(),rs,1*dx0r,dr);
482 if (!fTrackToFollow.GetGlobalXYZat(r,x,y,z)) {
483 cerr<<"AliITStrackerV2::FollowProlongation: failed to estimate track !\n";
486 Double_t phi=TMath::ATan2(y,x);
487 Double_t d=layer.GetThickness(phi,z);
488 Int_t idet=layer.FindDetectorIndex(phi,z);
490 cerr<<"AliITStrackerV2::FollowProlongation: failed to find a detector !\n";
494 //propagate to the intersection
495 const AliITSdetector &det=layer.GetDetector(idet);
497 if (!fTrackToFollow.Propagate(phi,det.GetR(),1*d/21.82*2.33,d*2.33)) {
498 cerr<<"AliITStrackerV2::FollowProlongation: propagation failed !\n";
501 fTrackToFollow.SetDetectorIndex(idet);
503 //Select possible prolongations and store the current track estimation
504 track.~AliITStrackV2(); new(&track) AliITStrackV2(fTrackToFollow);
505 Double_t dz=3*TMath::Sqrt(track.GetSigmaZ2() + kSigmaZ2[fI]);
506 if (dz < 0.5*TMath::Abs(track.GetTgl())) dz=0.5*TMath::Abs(track.GetTgl());
507 if (dz > kMaxRoad/4) {
508 //cerr<<"AliITStrackerV2::FollowProlongation: too broad road in Z !\n";
511 Double_t dy=4*TMath::Sqrt(track.GetSigmaY2() + kSigmaY2[fI]);
512 if (dy < 0.5*TMath::Abs(track.GetSnp())) dy=0.5*TMath::Abs(track.GetSnp());
513 if (dy > kMaxRoad/4) {
514 //cerr<<"AliITStrackerV2::FollowProlongation: too broad road in Y !\n";
518 Double_t zmin=track.GetZ() - dz;
519 Double_t zmax=track.GetZ() + dz;
520 Double_t ymin=track.GetY() + r*phi - dy;
521 Double_t ymax=track.GetY() + r*phi + dy;
522 layer.SelectClusters(zmin,zmax,ymin,ymax);
524 //take another prolongation
525 if (!TakeNextProlongation()) if (!tryAgain--) break;
526 tryAgain=kLayersToSkip;
530 //deal with the best track
531 Int_t ncl=fTrackToFollow.GetNumberOfClusters();
532 Int_t nclb=fBestTrack.GetNumberOfClusters();
535 Double_t chi2=fTrackToFollow.GetChi2();
536 if (chi2/ncl < kChi2PerCluster) {
537 if (ncl > nclb || chi2 < fBestTrack.GetChi2()) {
547 Int_t AliITStrackerV2::TakeNextProlongation() {
548 //--------------------------------------------------------------------
549 //This function takes another track prolongation
550 //--------------------------------------------------------------------
552 Double_t d=GetEffectiveThickness(0,0); //Think of this !!!!
554 AliITSlayer &layer=fLayers[fI];
555 AliITStrackV2 &t=fTracks[fI];
557 Double_t dz=4*TMath::Sqrt(t.GetSigmaZ2() + kSigmaZ2[fI]);
558 Double_t dy=4*TMath::Sqrt(t.GetSigmaY2() + kSigmaY2[fI]);
560 const AliITSclusterV2 *c=0; Int_t ci=-1;
561 Double_t chi2=12345.;
562 while ((c=layer.GetNextCluster(ci))!=0) {
566 //if (c->GetLabel(0)!=TMath::Abs(lbl)) continue;
569 Int_t idet=c->GetDetectorIndex();
571 if (t.GetDetectorIndex()!=idet) {
572 const AliITSdetector &det=layer.GetDetector(idet);
573 if (!t.Propagate(det.GetPhi(),det.GetR(),0.,0.)) {
574 cerr<<"AliITStrackerV2::TakeNextProlongation: propagation failed !\n";
577 t.SetDetectorIndex(idet);
580 cout<<fI<<" change detector !\n";
585 if (TMath::Abs(t.GetZ() - c->GetZ()) > dz) continue;
586 if (TMath::Abs(t.GetY() - c->GetY()) > dy) continue;
588 //m[0]=fYV; m[1]=fZV;
589 //chi2=t.GetPredictedChi2(c,m,d/21.82*2.33);
590 chi2=t.GetPredictedChi2(c);
592 if (chi2<kMaxChi2) break;
596 cout<<fI<<" chi2="<<chi2<<' '<<t.GetY()<<' '<<t.GetZ()<<' '<<dy<<' '<<dz<<endl;
599 if (chi2>=kMaxChi2) return 0;
602 ResetTrackToFollow(t);
604 //if (!fTrackToFollow.Update(m,chi2,(fI<<28)+ci)) {
605 if (!fTrackToFollow.Update(c,chi2,(fI<<28)+ci)) {
606 cerr<<"AliITStrackerV2::TakeNextProlongation: filtering failed !\n";
609 fTrackToFollow.Improve(d/21.82*2.33,fYV,fZV);
612 cout<<"accepted lab="<<c->GetLabel(0)<<' '
613 <<fTrackToFollow.GetNumberOfClusters()<<' '
614 <<fTrackToFollow.GetY()<<' '<<fTrackToFollow.GetZ()<<endl<<endl;
623 AliITStrackerV2::AliITSlayer::AliITSlayer() {
624 //--------------------------------------------------------------------
625 //default AliITSlayer constructor
626 //--------------------------------------------------------------------
631 AliITStrackerV2::AliITSlayer::
632 AliITSlayer(Double_t r,Double_t p,Double_t z,Int_t nl,Int_t nd) {
633 //--------------------------------------------------------------------
634 //main AliITSlayer constructor
635 //--------------------------------------------------------------------
636 fR=r; fPhiOffset=p; fZOffset=z;
637 fNladders=nl; fNdetectors=nd;
638 fDetectors=new AliITSdetector[fNladders*fNdetectors];
644 AliITStrackerV2::AliITSlayer::~AliITSlayer() {
645 //--------------------------------------------------------------------
646 // AliITSlayer destructor
647 //--------------------------------------------------------------------
649 for (Int_t i=0; i<fN; i++) delete fClusters[i];
652 Int_t AliITStrackerV2::AliITSlayer::InsertCluster(AliITSclusterV2 *c) {
653 //--------------------------------------------------------------------
654 //This function adds a cluster to this layer
655 //--------------------------------------------------------------------
656 if (fN==kMaxClusterPerLayer) {
657 cerr<<"AliITStrackerV2::AliITSlayer::InsertCluster(): Too many clusters !\n";
661 if (fN==0) {fClusters[fN++]=c; return 0;}
662 Int_t i=FindClusterIndex(c->GetZ());
663 memmove(fClusters+i+1 ,fClusters+i,(fN-i)*sizeof(AliITSclusterV2*));
664 fClusters[i]=c; fN++;
669 Int_t AliITStrackerV2::AliITSlayer::FindClusterIndex(Double_t z) const {
670 //--------------------------------------------------------------------
671 // This function returns the index of the nearest cluster
672 //--------------------------------------------------------------------
674 if (z <= fClusters[0]->GetZ()) return 0;
675 if (z > fClusters[fN-1]->GetZ()) return fN;
676 Int_t b=0, e=fN-1, m=(b+e)/2;
677 for (; b<e; m=(b+e)/2) {
678 if (z > fClusters[m]->GetZ()) b=m+1;
684 void AliITStrackerV2::AliITSlayer::
685 SelectClusters(Double_t zmin,Double_t zmax,Double_t ymin, Double_t ymax) {
686 //--------------------------------------------------------------------
687 // This function sets the "window"
688 //--------------------------------------------------------------------
689 fI=FindClusterIndex(zmin); fZmax=zmax;
690 Double_t circle=2*TMath::Pi()*fR;
691 if (ymax>circle) { ymax-=circle; ymin-=circle; }
692 fYmin=ymin; fYmax=ymax;
695 const AliITSclusterV2 *AliITStrackerV2::AliITSlayer::GetNextCluster(Int_t &ci){
696 //--------------------------------------------------------------------
697 // This function returns clusters within the "window"
698 //--------------------------------------------------------------------
699 const AliITSclusterV2 *cluster=0;
700 for (Int_t i=fI; i<fN; i++) {
701 const AliITSclusterV2 *c=fClusters[i];
702 if (c->GetZ() > fZmax) break;
703 if (c->IsUsed()) continue;
704 const AliITSdetector &det=GetDetector(c->GetDetectorIndex());
705 Double_t y=fR*det.GetPhi() + c->GetY();
707 if (y>2.*fR*TMath::Pi()) y -= 2*fR*TMath::Pi();
708 if (y>1.*fR*TMath::Pi() && fYmax<y) y -= 2*fR*TMath::Pi();
710 if (y<fYmin) continue;
711 if (y>fYmax) continue;
719 Int_t AliITStrackerV2::AliITSlayer::
720 FindDetectorIndex(Double_t phi, Double_t z) const {
721 //--------------------------------------------------------------------
722 //This function finds the detector crossed by the track
723 //--------------------------------------------------------------------
724 Double_t dphi=phi-fPhiOffset;
725 if (dphi < 0) dphi += 2*TMath::Pi();
726 else if (dphi >= 2*TMath::Pi()) dphi -= 2*TMath::Pi();
727 Int_t np=Int_t(dphi*fNladders*0.5/TMath::Pi()+0.5);
729 Double_t dz=fZOffset-z;
730 Int_t nz=Int_t(dz*(fNdetectors-1)*0.5/fZOffset+0.5);
732 if (np>=fNladders) np-=fNladders;
733 if (np<0) np+=fNladders;
736 cout<<np<<' '<<nz<<endl;
739 return np*fNdetectors + nz;
743 AliITStrackerV2::AliITSlayer::GetThickness(Double_t phi, Double_t z) const {
744 //--------------------------------------------------------------------
745 //This function returns the thickness of this layer
746 //--------------------------------------------------------------------
748 if (3 <fR&&fR<8 ) return 1.1*0.096;
749 if (13<fR&&fR<26) return 1.1*0.088;
750 if (37<fR&&fR<41) return 1.1*0.085;
755 Double_t AliITStrackerV2::GetEffectiveThickness(Double_t phi,Double_t z) const
757 //--------------------------------------------------------------------
758 //Returns the thickness between the current layer and the vertex
759 //--------------------------------------------------------------------
763 Double_t xn=fLayers[fI].GetR();
764 for (Int_t i=0; i<fI; i++) {
765 Double_t xi=fLayers[i].GetR();
766 d+=fLayers[i].GetThickness(phi,z)*xi*xi;
770 Double_t xi=0.5*(fLayers[1].GetR()+fLayers[2].GetR());
775 Double_t xi=0.5*(fLayers[3].GetR()+fLayers[4].GetR());
783 Int_t AliITStrackerV2::AliITSlayer::InRoad() const {
784 //--------------------------------------------------------------------
785 // This function returns number of clusters within the "window"
786 //--------------------------------------------------------------------
788 for (Int_t i=fI; i<fN; i++) {
789 const AliITSclusterV2 *c=fClusters[i];
790 if (c->GetZ() > fZmax) break;
791 //if (c->IsUsed()) continue;
792 const AliITSdetector &det=GetDetector(c->GetDetectorIndex());
793 Double_t y=fR*det.GetPhi() + c->GetY();
795 if (y>2.*fR*TMath::Pi()) y -= 2*fR*TMath::Pi();
796 if (y>1.*fR*TMath::Pi() && fYmax<y) y -= 2*fR*TMath::Pi();
798 if (y<fYmin) continue;
799 if (y>fYmax) continue;