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, Int_t eventn) throw (const Char_t *) {
44 //--------------------------------------------------------------------
45 //This is the AliITStracker constructor
46 //It also reads clusters from a root file
47 //--------------------------------------------------------------------
49 fEventN = eventn; //MI change add event number - used to generate identifier
52 AliITSgeom *g=(AliITSgeom*)geom;
56 for (i=1; i<kMaxLayer+1; i++) {
57 Int_t nlad=g->GetNladders(i);
58 Int_t ndet=g->GetNdetectors(i);
60 g->GetTrans(i,1,1,x,y,z);
61 Double_t r=TMath::Sqrt(x*x + y*y);
62 Double_t poff=TMath::ATan2(y,x);
65 g->GetTrans(i,1,2,x,y,z);
66 r += TMath::Sqrt(x*x + y*y);
67 g->GetTrans(i,2,1,x,y,z);
68 r += TMath::Sqrt(x*x + y*y);
69 g->GetTrans(i,2,2,x,y,z);
70 r += TMath::Sqrt(x*x + y*y);
73 new (fLayers+i-1) AliITSlayer(r,poff,zoff,nlad,ndet);
75 for (Int_t j=1; j<nlad+1; j++) {
76 for (Int_t k=1; k<ndet+1; k++) { //Fill this layer with detectors
77 Float_t x,y,zshift; g->GetTrans(i,j,k,x,y,zshift);
78 Double_t rot[9]; g->GetRotMatrix(i,j,k,rot);
80 Double_t r =-x*rot[1] + y*rot[0]; if (i==1) r=-r;
81 Double_t phi=TMath::ATan2(rot[1],rot[0]); if (i==1) phi-=3.1415927;
83 AliITSdetector &det=fLayers[i-1].GetDetector((j-1)*ndet + k-1);
85 if (phi<0) phi += 2*TMath::Pi();
87 new(&det) AliITSdetector(r,phi);
97 sprintf(cname,"TreeC_ITS_%d",eventn);
98 TTree *cTree=(TTree*)gDirectory->Get(cname);
101 ("AliITStrackerV2::AliITStrackerV2 can't get cTree !\n");
103 TBranch *branch=cTree->GetBranch("Clusters");
105 ("AliITStrackerV2::AliITStrackerV2 can't get Clusters branch !\n");
107 TClonesArray dummy("AliITSclusterV2",10000), *clusters=&dummy;
108 branch->SetAddress(&clusters);
110 Int_t nentr=(Int_t)cTree->GetEntries();
111 for (i=0; i<nentr; i++) {
112 if (!cTree->GetEvent(i)) continue;
113 Int_t lay,lad,det; g->GetModuleId(i,lay,lad,det);
114 Int_t ncl=clusters->GetEntriesFast();
116 AliITSclusterV2 *c=(AliITSclusterV2*)clusters->UncheckedAt(ncl);
119 if (c->GetLabel(2)!=LAB)
120 if (c->GetLabel(1)!=LAB)
121 if (c->GetLabel(0)!=LAB) continue;
122 cout<<lay-1<<' '<<lad-1<<' '<<det-1<<' '<<c->GetY()<<' '<<c->GetZ()<<endl;
125 AliITSdetector &det=fLayers[lay-1].GetDetector(c->GetDetectorIndex());
126 Double_t r=det.GetR(); r=TMath::Sqrt(r*r + c->GetY()*c->GetY());
127 if (r > TMath::Abs(c->GetZ())-0.5)
128 fLayers[lay-1].InsertCluster(new AliITSclusterV2(*c));
132 delete cTree; //Thanks to Mariana Bondila
134 catch (const Char_t *msg) {
146 Int_t AliITStrackerV2::Clusters2Tracks(const TFile *inp, TFile *out) {
147 //--------------------------------------------------------------------
148 //This functions reconstructs ITS tracks
149 //--------------------------------------------------------------------
150 TFile *in=(TFile*)inp;
151 TDirectory *savedir=gDirectory;
154 cerr<<"AliITStrackerV2::Clusters2Tracks(): ";
155 cerr<<"file with TPC tracks is not open !\n";
159 if (!out->IsOpen()) {
160 cerr<<"AliITStrackerV2::Clusters2Tracks(): ";
161 cerr<<"file for ITS tracks is not open !\n";
168 sprintf(tname,"TreeT_TPC_%d",fEventN);
169 TTree *tpcTree=(TTree*)in->Get(tname);
172 cerr<<"AliITStrackerV2::Clusters2Tracks() ";
173 cerr<<"can't get a tree with TPC tracks !\n";
177 AliTPCtrack *itrack=new AliTPCtrack;
178 tpcTree->SetBranchAddress("tracks",&itrack);
181 TTree itsTree("ITSf","Tree with ITS tracks");
182 AliITStrackV2 *otrack=&fBestTrack;
183 itsTree.Branch("tracks","AliITStrackV2",&otrack,32000,0);
187 Int_t nentr=(Int_t)tpcTree->GetEntries();
188 for (Int_t i=0; i<nentr; i++) {
190 if (!tpcTree->GetEvent(i)) continue;
191 Int_t tpcLabel=itrack->GetLabel(); //save the TPC track label
195 if (TMath::Abs(tpcLabel)!=LAB) continue;
196 cout<<tpcLabel<<" *****************\n";
200 ResetTrackToFollow(AliITStrackV2(*itrack));
201 } catch (const Char_t *msg) {
207 fYV=gRandom->Gaus(0.,kSigmaYV); fZV=gRandom->Gaus(0.,kSigmaZV);
209 Double_t r2=fTrackToFollow.GetX()*fTrackToFollow.GetX();
210 Double_t x0=0.082/21.82*2.33*(45*45+40*40)/r2+2.000/41.28*0.03*75*75/r2;
211 fTrackToFollow.Improve(x0,fYV,fZV);
214 fTrackToFollow.PropagateTo(xk,0.,0.); //Ne if it's still there
217 fTrackToFollow.PropagateTo(xk, 0.005/44.77*1.71, 0.005*1.71); //Tedlar
219 fTrackToFollow.PropagateTo(xk, 0.02/44.86*1.45, 0.02*1.45); //Kevlar
221 fTrackToFollow.PropagateTo(xk, 2.0/41.28*0.029, 2.0*0.029);//Nomex
223 fTrackToFollow.PropagateTo(xk, 0.02/44.86*1.45, 0.02*1.45); //Kevlar
225 fTrackToFollow.PropagateTo(xk, 0.005/44.77*1.71, 0.005*1.71); //Tedlar
228 fTrackToFollow.PropagateTo(xk,0.,0.); //C02
231 fTrackToFollow.PropagateTo(xk, 0.005/24.01*2.7, 0.005*2.7); //Al
233 fTrackToFollow.PropagateTo(xk, 0.005/44.77*1.71, 0.005*1.71); //Tedlar
235 fTrackToFollow.PropagateTo(xk, 0.02/44.86*1.45, 0.02*1.45); //Kevlar
237 fTrackToFollow.PropagateTo(xk, 0.5/41.28*.029, 0.5*0.029); //Nomex
239 fTrackToFollow.PropagateTo(xk, 0.02/44.86*1.45, 0.02*1.45); //Kevlar
241 fTrackToFollow.PropagateTo(xk, 0.005/44.77*1.71, 0.005*1.71); //Tedlar
243 fTrackToFollow.PropagateTo(xk, 0.005/24.01*2.7, 0.005*2.7); //Al
246 for (FollowProlongation(); fI<kMaxLayer; fI++) {
247 while (TakeNextProlongation()) FollowProlongation();
251 cout<<fBestTrack.GetNumberOfClusters()<<" number of clusters\n\n";
254 if (fBestTrack.GetNumberOfClusters() >= kMaxLayer-kLayersToSkip) {
255 cerr << ++ntrk << " \r";
256 fBestTrack.SetLabel(tpcLabel);
257 UseClusters(&fBestTrack);
262 sprintf(tname,"TreeT_ITS_%d",fEventN);
263 itsTree.Write(tname);
265 cerr<<"Number of TPC tracks: "<<nentr<<endl;
266 cerr<<"Number of prolonged tracks: "<<ntrk<<endl;
268 delete tpcTree; //Thanks to Mariana Bondila
275 Int_t AliITStrackerV2::PropagateBack(const TFile *inp, TFile *out) {
276 //--------------------------------------------------------------------
277 //This functions propagates reconstructed ITS tracks back
278 //--------------------------------------------------------------------
279 TFile *in=(TFile*)inp;
280 TDirectory *savedir=gDirectory;
283 cerr<<"AliITStrackerV2::PropagateBack(): ";
284 cerr<<"file with ITS tracks is not open !\n";
288 if (!out->IsOpen()) {
289 cerr<<"AliITStrackerV2::PropagateBack(): ";
290 cerr<<"file for back propagated ITS tracks is not open !\n";
295 TTree *itsTree=(TTree*)in->Get("TreeT_ITS_0");
297 cerr<<"AliITStrackerV2::PropagateBack() ";
298 cerr<<"can't get a tree with ITS tracks !\n";
301 AliITStrackV2 *itrack=new AliITStrackV2;
302 itsTree->SetBranchAddress("tracks",&itrack);
305 TTree backTree("TreeT_ITSb_0","Tree with back propagated ITS tracks");
306 AliTPCtrack *otrack=0;
307 backTree.Branch("tracks","AliTPCtrack",&otrack,32000,0);
311 Int_t nentr=(Int_t)itsTree->GetEntries();
312 for (Int_t i=0; i<nentr; i++) {
313 itsTree->GetEvent(i);
314 ResetTrackToFollow(*itrack);
315 fTrackToFollow.ResetCovariance(); fTrackToFollow.ResetClusters();
316 Int_t itsLabel=fTrackToFollow.GetLabel(); //save the ITS track label
319 if (TMath::Abs(itsLabel)!=LAB) continue;
320 cout<<itsLabel<<" *****************\n";
324 Int_t nc=itrack->GetNumberOfClusters();
326 for (Int_t k=0; k<nc; k++) {
327 Int_t index=itrack->GetClusterIndex(k);
328 AliITSclusterV2 *c=(AliITSclusterV2*)GetCluster(index);
329 cout<<c->GetLabel(0)<<' '<<c->GetLabel(1)<<' '<<c->GetLabel(2)<<endl;
333 const AliITSclusterV2 *c=0;
335 idx=itrack->GetClusterIndex(nc); l=(idx&0xf0000000)>>28;
336 c=(AliITSclusterV2*)GetCluster(idx);
338 for (fI=0; fI<kMaxLayer; fI++) {
339 AliITSlayer &layer=fLayers[fI];
340 Double_t r=layer.GetR();
341 if (fI==2 || fI==4) {
342 Double_t rs=0.5*(fLayers[fI-1].GetR() + r);
343 Double_t ds=0.034; if (fI==4) ds=0.039;
344 Double_t dx0r=ds/21.82*2.33, dr=ds*2.33;
345 if (!fTrackToFollow.PropagateTo(rs,1*dx0r,dr)) throw "";
349 if (!fTrackToFollow.GetGlobalXYZat(r,x,y,z))
350 throw "AliITStrackerV2::PropagateBack: failed to estimate track !";
351 Double_t phi=TMath::ATan2(y,x);
352 Double_t d=layer.GetThickness(phi,z);
353 Int_t idet=layer.FindDetectorIndex(phi,z);
355 throw "AliITStrackerV2::PropagateBack: failed to find a detector !\n";
356 const AliITSdetector &det=layer.GetDetector(idet);
357 r=det.GetR(); phi=det.GetPhi();
358 if (!fTrackToFollow.Propagate(phi,r,d/21.82*2.33,d*2.33)) throw "";
360 const AliITSclusterV2 *cl=0;
362 Double_t maxchi2=kMaxChi2;
365 if (idet != c->GetDetectorIndex()) {
366 idet=c->GetDetectorIndex();
367 const AliITSdetector &det=layer.GetDetector(idet);
368 r=det.GetR(); phi=det.GetPhi();
369 if (!fTrackToFollow.Propagate(phi,r,0.,0.)) throw "";
371 Double_t chi2=fTrackToFollow.GetPredictedChi2(c);
373 cl=c; maxchi2=chi2; index=idx;
376 idx=itrack->GetClusterIndex(nc); l=(idx&0xf0000000)>>28;
377 c=(AliITSclusterV2*)GetCluster(idx);
381 if (fTrackToFollow.GetNumberOfClusters()>2) {
382 Double_t dz=3*TMath::Sqrt(fTrackToFollow.GetSigmaZ2()+kSigmaZ2[fI]);
383 Double_t dy=3*TMath::Sqrt(fTrackToFollow.GetSigmaY2()+kSigmaY2[fI]);
384 Double_t zmin=fTrackToFollow.GetZ() - dz;
385 Double_t zmax=fTrackToFollow.GetZ() + dz;
386 Double_t ymin=fTrackToFollow.GetY() + phi*r - dy;
387 Double_t ymax=fTrackToFollow.GetY() + phi*r + dy;
388 layer.SelectClusters(zmin,zmax,ymin,ymax);
390 const AliITSclusterV2 *cc=0; Int_t ci;
391 while ((cc=layer.GetNextCluster(ci))!=0) {
392 if (idet != cc->GetDetectorIndex()) continue;
393 Double_t chi2=fTrackToFollow.GetPredictedChi2(cc);
395 cl=cc; index=(fI<<28)+ci; maxchi2=chi2;
401 if (!fTrackToFollow.Update(cl,maxchi2,index))
402 cerr<<"AliITStrackerV2::PropagateBack: filtering failed !\n";
408 fTrackToFollow.PropagateTo(xk,0.,0.); //Air
411 fTrackToFollow.PropagateTo(xk, 0.005/24.01*2.7, 0.005*2.7); //Al
413 fTrackToFollow.PropagateTo(xk, 0.005/44.77*1.71, 0.005*1.71); //Tedlar
415 fTrackToFollow.PropagateTo(xk, 0.02/44.86*1.45, 0.02*1.45); //Kevlar
417 fTrackToFollow.PropagateTo(xk, 0.5/41.28*.029, 0.5*0.029); //Nomex
419 fTrackToFollow.PropagateTo(xk, 0.02/44.86*1.45, 0.02*1.45); //Kevlar
421 fTrackToFollow.PropagateTo(xk, 0.005/44.77*1.71, 0.005*1.71); //Tedlar
423 fTrackToFollow.PropagateTo(xk, 0.005/24.01*2.7, 0.005*2.7); //Al
426 fTrackToFollow.PropagateTo(xk,0.,0.); //CO2
429 fTrackToFollow.PropagateTo(xk, 0.005/44.77*1.71, 0.005*1.71); //Tedlar
431 fTrackToFollow.PropagateTo(xk, 0.02/44.86*1.45, 0.02*1.45); //Kevlar
433 fTrackToFollow.PropagateTo(xk, 2.0/41.28*0.029, 2.0*0.029);//Nomex
435 fTrackToFollow.PropagateTo(xk, 0.02/44.86*1.45, 0.02*1.45); //Kevlar
437 fTrackToFollow.PropagateTo(xk, 0.005/44.77*1.71, 0.005*1.71); //Tedlar
439 fTrackToFollow.SetLabel(itsLabel);
440 otrack=new AliTPCtrack(fTrackToFollow,fTrackToFollow.GetAlpha());
441 backTree.Fill(); delete otrack;
442 UseClusters(&fTrackToFollow);
443 cerr << ++ntrk << " \r";
445 catch (const Char_t *msg) {
452 cerr<<"Number of ITS tracks: "<<nentr<<endl;
453 cerr<<"Number of back propagated ITS tracks: "<<ntrk<<endl;
457 delete itsTree; //Thanks to Mariana Bondila
462 AliCluster *AliITStrackerV2::GetCluster(Int_t index) const {
463 //--------------------------------------------------------------------
464 // Return pointer to a given cluster
465 //--------------------------------------------------------------------
466 Int_t l=(index & 0xf0000000) >> 28;
467 Int_t c=(index & 0x0fffffff) >> 00;
468 return fLayers[l].GetCluster(c);
472 void AliITStrackerV2::FollowProlongation() {
473 //--------------------------------------------------------------------
474 //This function finds a track prolongation
475 //--------------------------------------------------------------------
476 Int_t tryAgain=kLayersToSkip;
483 AliITSlayer &layer=fLayers[fI];
484 AliITStrackV2 &track=fTracks[fI];
486 Double_t r=layer.GetR();
487 if (fI==3 || fI==1) {
488 Double_t rs=0.5*(fLayers[fI+1].GetR() + r);
489 Double_t ds=0.034; if (fI==3) ds=0.039;
490 Double_t dx0r=ds/21.82*2.33, dr=ds*2.33;
491 fTrackToFollow.Propagate(fTrackToFollow.GetAlpha(),rs,1*dx0r,dr);
496 if (!fTrackToFollow.GetGlobalXYZat(r,x,y,z)) {
497 cerr<<"AliITStrackerV2::FollowProlongation: failed to estimate track !\n";
500 Double_t phi=TMath::ATan2(y,x);
501 Double_t d=layer.GetThickness(phi,z);
502 Int_t idet=layer.FindDetectorIndex(phi,z);
504 cerr<<"AliITStrackerV2::FollowProlongation: failed to find a detector !\n";
508 //propagate to the intersection
509 const AliITSdetector &det=layer.GetDetector(idet);
511 if (!fTrackToFollow.Propagate(phi,det.GetR(),1*d/21.82*2.33,d*2.33)) {
512 cerr<<"AliITStrackerV2::FollowProlongation: propagation failed !\n";
515 fTrackToFollow.SetDetectorIndex(idet);
517 //Select possible prolongations and store the current track estimation
518 track.~AliITStrackV2(); new(&track) AliITStrackV2(fTrackToFollow);
519 Double_t dz=3*TMath::Sqrt(track.GetSigmaZ2() + kSigmaZ2[fI]);
520 if (dz < 0.5*TMath::Abs(track.GetTgl())) dz=0.5*TMath::Abs(track.GetTgl());
521 if (dz > kMaxRoad/4) {
522 //cerr<<"AliITStrackerV2::FollowProlongation: too broad road in Z !\n";
525 Double_t dy=4*TMath::Sqrt(track.GetSigmaY2() + kSigmaY2[fI]);
526 if (dy < 0.5*TMath::Abs(track.GetSnp())) dy=0.5*TMath::Abs(track.GetSnp());
527 if (dy > kMaxRoad/4) {
528 //cerr<<"AliITStrackerV2::FollowProlongation: too broad road in Y !\n";
532 Double_t zmin=track.GetZ() - dz;
533 Double_t zmax=track.GetZ() + dz;
534 Double_t ymin=track.GetY() + r*phi - dy;
535 Double_t ymax=track.GetY() + r*phi + dy;
536 layer.SelectClusters(zmin,zmax,ymin,ymax);
538 //take another prolongation
539 if (!TakeNextProlongation()) if (!tryAgain--) break;
540 tryAgain=kLayersToSkip;
544 //deal with the best track
545 Int_t ncl=fTrackToFollow.GetNumberOfClusters();
546 Int_t nclb=fBestTrack.GetNumberOfClusters();
549 Double_t chi2=fTrackToFollow.GetChi2();
550 if (chi2/ncl < kChi2PerCluster) {
551 if (ncl > nclb || chi2 < fBestTrack.GetChi2()) {
561 Int_t AliITStrackerV2::TakeNextProlongation() {
562 //--------------------------------------------------------------------
563 //This function takes another track prolongation
564 //--------------------------------------------------------------------
566 Double_t d=GetEffectiveThickness(0,0); //Think of this !!!!
568 AliITSlayer &layer=fLayers[fI];
569 AliITStrackV2 &t=fTracks[fI];
571 Double_t dz=4*TMath::Sqrt(t.GetSigmaZ2() + kSigmaZ2[fI]);
572 Double_t dy=4*TMath::Sqrt(t.GetSigmaY2() + kSigmaY2[fI]);
574 const AliITSclusterV2 *c=0; Int_t ci=-1;
575 Double_t chi2=12345.;
576 while ((c=layer.GetNextCluster(ci))!=0) {
580 //if (c->GetLabel(0)!=TMath::Abs(lbl)) continue;
583 Int_t idet=c->GetDetectorIndex();
585 if (t.GetDetectorIndex()!=idet) {
586 const AliITSdetector &det=layer.GetDetector(idet);
587 if (!t.Propagate(det.GetPhi(),det.GetR(),0.,0.)) {
588 cerr<<"AliITStrackerV2::TakeNextProlongation: propagation failed !\n";
591 t.SetDetectorIndex(idet);
594 cout<<fI<<" change detector !\n";
599 if (TMath::Abs(t.GetZ() - c->GetZ()) > dz) continue;
600 if (TMath::Abs(t.GetY() - c->GetY()) > dy) continue;
602 //m[0]=fYV; m[1]=fZV;
603 //chi2=t.GetPredictedChi2(c,m,d/21.82*2.33);
604 chi2=t.GetPredictedChi2(c);
606 if (chi2<kMaxChi2) break;
610 cout<<fI<<" chi2="<<chi2<<' '<<t.GetY()<<' '<<t.GetZ()<<' '<<dy<<' '<<dz<<endl;
613 if (chi2>=kMaxChi2) return 0;
616 ResetTrackToFollow(t);
618 //if (!fTrackToFollow.Update(m,chi2,(fI<<28)+ci)) {
619 if (!fTrackToFollow.Update(c,chi2,(fI<<28)+ci)) {
620 cerr<<"AliITStrackerV2::TakeNextProlongation: filtering failed !\n";
623 fTrackToFollow.Improve(d/21.82*2.33,fYV,fZV);
626 cout<<"accepted lab="<<c->GetLabel(0)<<' '
627 <<fTrackToFollow.GetNumberOfClusters()<<' '
628 <<fTrackToFollow.GetY()<<' '<<fTrackToFollow.GetZ()<<endl<<endl;
637 AliITStrackerV2::AliITSlayer::AliITSlayer() {
638 //--------------------------------------------------------------------
639 //default AliITSlayer constructor
640 //--------------------------------------------------------------------
643 for (Int_t i=0; i<kMaxClusterPerLayer; i++) fClusters[i]=0;
646 AliITStrackerV2::AliITSlayer::
647 AliITSlayer(Double_t r,Double_t p,Double_t z,Int_t nl,Int_t nd) {
648 //--------------------------------------------------------------------
649 //main AliITSlayer constructor
650 //--------------------------------------------------------------------
651 fR=r; fPhiOffset=p; fZOffset=z;
652 fNladders=nl; fNdetectors=nd;
653 fDetectors=new AliITSdetector[fNladders*fNdetectors];
654 for (Int_t i=0; i<kMaxClusterPerLayer; i++) fClusters[i]=0;
660 AliITStrackerV2::AliITSlayer::~AliITSlayer() {
661 //--------------------------------------------------------------------
662 // AliITSlayer destructor
663 //--------------------------------------------------------------------
665 for (Int_t i=0; i<fN; i++) delete fClusters[i];
668 Int_t AliITStrackerV2::AliITSlayer::InsertCluster(AliITSclusterV2 *c) {
669 //--------------------------------------------------------------------
670 //This function adds a cluster to this layer
671 //--------------------------------------------------------------------
672 if (fN==kMaxClusterPerLayer) {
673 cerr<<"AliITStrackerV2::AliITSlayer::InsertCluster(): Too many clusters !\n";
677 if (fN==0) {fClusters[fN++]=c; return 0;}
678 Int_t i=FindClusterIndex(c->GetZ());
679 memmove(fClusters+i+1 ,fClusters+i,(fN-i)*sizeof(AliITSclusterV2*));
680 fClusters[i]=c; fN++;
685 Int_t AliITStrackerV2::AliITSlayer::FindClusterIndex(Double_t z) const {
686 //--------------------------------------------------------------------
687 // This function returns the index of the nearest cluster
688 //--------------------------------------------------------------------
690 if (z <= fClusters[0]->GetZ()) return 0;
691 if (z > fClusters[fN-1]->GetZ()) return fN;
692 Int_t b=0, e=fN-1, m=(b+e)/2;
693 for (; b<e; m=(b+e)/2) {
694 if (z > fClusters[m]->GetZ()) b=m+1;
700 void AliITStrackerV2::AliITSlayer::
701 SelectClusters(Double_t zmin,Double_t zmax,Double_t ymin, Double_t ymax) {
702 //--------------------------------------------------------------------
703 // This function sets the "window"
704 //--------------------------------------------------------------------
705 fI=FindClusterIndex(zmin); fZmax=zmax;
706 Double_t circle=2*TMath::Pi()*fR;
707 if (ymax>circle) { ymax-=circle; ymin-=circle; }
708 fYmin=ymin; fYmax=ymax;
711 const AliITSclusterV2 *AliITStrackerV2::AliITSlayer::GetNextCluster(Int_t &ci){
712 //--------------------------------------------------------------------
713 // This function returns clusters within the "window"
714 //--------------------------------------------------------------------
715 const AliITSclusterV2 *cluster=0;
716 for (Int_t i=fI; i<fN; i++) {
717 const AliITSclusterV2 *c=fClusters[i];
718 if (c->GetZ() > fZmax) break;
719 if (c->IsUsed()) continue;
720 const AliITSdetector &det=GetDetector(c->GetDetectorIndex());
721 Double_t y=fR*det.GetPhi() + c->GetY();
723 if (y>2.*fR*TMath::Pi()) y -= 2*fR*TMath::Pi();
724 if (y>1.*fR*TMath::Pi() && fYmax<y) y -= 2*fR*TMath::Pi();
726 if (y<fYmin) continue;
727 if (y>fYmax) continue;
735 Int_t AliITStrackerV2::AliITSlayer::
736 FindDetectorIndex(Double_t phi, Double_t z) const {
737 //--------------------------------------------------------------------
738 //This function finds the detector crossed by the track
739 //--------------------------------------------------------------------
740 Double_t dphi=phi-fPhiOffset;
741 if (dphi < 0) dphi += 2*TMath::Pi();
742 else if (dphi >= 2*TMath::Pi()) dphi -= 2*TMath::Pi();
743 Int_t np=Int_t(dphi*fNladders*0.5/TMath::Pi()+0.5);
745 Double_t dz=fZOffset-z;
746 Int_t nz=Int_t(dz*(fNdetectors-1)*0.5/fZOffset+0.5);
748 if (np>=fNladders) np-=fNladders;
749 if (np<0) np+=fNladders;
752 cout<<np<<' '<<nz<<endl;
755 return np*fNdetectors + nz;
759 AliITStrackerV2::AliITSlayer::GetThickness(Double_t phi, Double_t z) const {
760 //--------------------------------------------------------------------
761 //This function returns the thickness of this layer
762 //--------------------------------------------------------------------
764 if (3 <fR&&fR<8 ) return 2.2*0.096;
765 if (13<fR&&fR<26) return 1.1*0.088;
766 if (37<fR&&fR<41) return 1.1*0.085;
771 Double_t AliITStrackerV2::GetEffectiveThickness(Double_t phi,Double_t z) const
773 //--------------------------------------------------------------------
774 //Returns the thickness between the current layer and the vertex
775 //--------------------------------------------------------------------
779 Double_t xn=fLayers[fI].GetR();
780 for (Int_t i=0; i<fI; i++) {
781 Double_t xi=fLayers[i].GetR();
782 d+=fLayers[i].GetThickness(phi,z)*xi*xi;
786 Double_t xi=0.5*(fLayers[1].GetR()+fLayers[2].GetR());
791 Double_t xi=0.5*(fLayers[3].GetR()+fLayers[4].GetR());
799 Int_t AliITStrackerV2::AliITSlayer::InRoad() const {
800 //--------------------------------------------------------------------
801 // This function returns number of clusters within the "window"
802 //--------------------------------------------------------------------
804 for (Int_t i=fI; i<fN; i++) {
805 const AliITSclusterV2 *c=fClusters[i];
806 if (c->GetZ() > fZmax) break;
807 //if (c->IsUsed()) continue;
808 const AliITSdetector &det=GetDetector(c->GetDetectorIndex());
809 Double_t y=fR*det.GetPhi() + c->GetY();
811 if (y>2.*fR*TMath::Pi()) y -= 2*fR*TMath::Pi();
812 if (y>1.*fR*TMath::Pi() && fYmax<y) y -= 2*fR*TMath::Pi();
814 if (y<fYmin) continue;
815 if (y>fYmax) continue;