]> git.uio.no Git - u/mrichter/AliRoot.git/blobdiff - ITS/AliITStrackerV2.cxx
Extracting AliITStrackMI from AliITStrackV2. Reverting AliITStrackerV2 to the version...
[u/mrichter/AliRoot.git] / ITS / AliITStrackerV2.cxx
index fb72a090dfa4d142794bbd4347dee11adbda41c9..e57517be4ce8c5d961aa9751e5f0c454bf8fc9ac 100644 (file)
 
 //-------------------------------------------------------------------------
 //               Implementation of the ITS tracker class
-//
+//    It reads AliITSclusterV2 clusters and creates AliITStrackV2 tracks
+//                   and fills with them the ESD
 //          Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch
 //     dEdx analysis by: Boris Batyunya, JINR, Boris.Batiounia@cern.ch
 //-------------------------------------------------------------------------
 
+#include <new>
+
 #include <TFile.h>
 #include <TTree.h>
 #include <TRandom.h>
 
 #include "AliITSgeom.h"
 #include "AliITSRecPoint.h"
-#include "AliTPCtrack.h"
 #include "AliESD.h"
 #include "AliITSclusterV2.h"
 #include "AliITStrackerV2.h"
 
 ClassImp(AliITStrackerV2)
 
-AliITStrackerV2::AliITSlayer AliITStrackerV2::fLayers[kMaxLayer]; // ITS layers
+AliITStrackerV2::AliITSlayer AliITStrackerV2::fgLayers[kMaxLayer]; // ITS layers
 
 AliITStrackerV2::AliITStrackerV2(const AliITSgeom *geom) : AliTracker() {
   //--------------------------------------------------------------------
@@ -60,7 +62,7 @@ AliITStrackerV2::AliITStrackerV2(const AliITSgeom *geom) : AliTracker() {
     r += TMath::Sqrt(x*x + y*y);
     r*=0.25;
 
-    new (fLayers+i-1) AliITSlayer(r,poff,zoff,nlad,ndet);
+    new (fgLayers+i-1) AliITSlayer(r,poff,zoff,nlad,ndet);
 
     for (Int_t j=1; j<nlad+1; j++) {
       for (Int_t k=1; k<ndet+1; k++) { //Fill this layer with detectors
@@ -73,7 +75,7 @@ AliITStrackerV2::AliITStrackerV2(const AliITSgeom *geom) : AliTracker() {
         Double_t cp=TMath::Cos(phi), sp=TMath::Sin(phi);
         Double_t r=x*cp+y*sp;
 
-        AliITSdetector &det=fLayers[i-1].GetDetector((j-1)*ndet + k-1); 
+        AliITSdetector &det=fgLayers[i-1].GetDetector((j-1)*ndet + k-1); 
         new(&det) AliITSdetector(r,phi); 
       } 
     }  
@@ -83,7 +85,7 @@ AliITStrackerV2::AliITStrackerV2(const AliITSgeom *geom) : AliTracker() {
   fI=kMaxLayer;
 
   fPass=0;
-  fConstraint[0]=1; fConstraint[1]=0;
+  fConstraint[0]=1; fConstraint[1]=0;//-1;
 
   Double_t xyz[]={kXV,kYV,kZV}, ers[]={kSigmaXV,kSigmaYV,kSigmaZV}; 
   SetVertex(xyz,ers);
@@ -115,18 +117,18 @@ Int_t AliITStrackerV2::LoadClusters(TTree *cTree) {
 
   Int_t j=0;
   for (Int_t i=0; i<kMaxLayer; i++) {
-    Int_t ndet=fLayers[i].GetNdetectors();
-    Int_t jmax = j + fLayers[i].GetNladders()*ndet;
+    Int_t ndet=fgLayers[i].GetNdetectors();
+    Int_t jmax = j + fgLayers[i].GetNladders()*ndet;
     for (; j<jmax; j++) {           
       if (!cTree->GetEvent(j)) continue;
       Int_t ncl=clusters->GetEntriesFast();
       while (ncl--) {
         AliITSclusterV2 *c=(AliITSclusterV2*)clusters->UncheckedAt(ncl);
-        fLayers[i].InsertCluster(new AliITSclusterV2(*c));
+        fgLayers[i].InsertCluster(new AliITSclusterV2(*c));
       }
       clusters->Delete();
     }
-    fLayers[i].ResetRoad(); //road defined by the cluster density
+    fgLayers[i].ResetRoad(); //road defined by the cluster density
   }
 
   return 0;
@@ -136,7 +138,7 @@ void AliITStrackerV2::UnloadClusters() {
   //--------------------------------------------------------------------
   //This function unloads ITS clusters
   //--------------------------------------------------------------------
-  for (Int_t i=0; i<kMaxLayer; i++) fLayers[i].ResetClusters();
+  for (Int_t i=0; i<kMaxLayer; i++) fgLayers[i].ResetClusters();
 }
 
 static Int_t CorrectForDeadZoneMaterial(AliITStrackV2 *t) {
@@ -164,7 +166,7 @@ static Int_t CorrectForDeadZoneMaterial(AliITStrackV2 *t) {
      //Double_t x,y,z; t->GetGlobalXYZat(rr,x,y,z);
      //if (TMath::Abs(y)<yyr) t->PropagateTo(rr,-dr,x0r); 
      if (!t->PropagateTo(rcd,-dcd,x0cd)) return 1;
-     if (!t->PropagateTo(riw,-diw,x0iw)) return 1;
+     if (!t->PropagateTo(riw+0.001,-diw,x0iw)) return 1;
   } else {
   ::Error("CorrectForDeadZoneMaterial","track is already in the dead zone !");
     return 1;
@@ -186,7 +188,9 @@ Int_t AliITStrackerV2::Clusters2Tracks(AliESD *event) {
     while (nentr--) {
       AliESDtrack *esd=event->GetTrack(nentr);
 
-      if (esd->GetStatus() != AliESDtrack::kTPCin) continue;
+      if ((esd->GetStatus()&AliESDtrack::kTPCin)==0) continue;
+      if (esd->GetStatus()&AliESDtrack::kTPCout) continue;
+      if (esd->GetStatus()&AliESDtrack::kITSin) continue;
 
       AliITStrackV2 *t=0;
       try {
@@ -196,7 +200,10 @@ Int_t AliITStrackerV2::Clusters2Tracks(AliESD *event) {
         delete t;
         continue;
       }
-      if (TMath::Abs(t->GetD())>4) continue;
+      if (TMath::Abs(t->GetD())>4) {
+       delete t;
+       continue;
+      }
 
       if (CorrectForDeadZoneMaterial(t)!=0) {
          Warning("Clusters2Tracks",
@@ -251,95 +258,6 @@ Int_t AliITStrackerV2::Clusters2Tracks(AliESD *event) {
   return 0;
 }
 
-Int_t AliITStrackerV2::Clusters2Tracks(TTree *tpcTree, TTree *itsTree) {
-  //--------------------------------------------------------------------
-  // This functions reconstructs ITS tracks
-  // The clusters must be already loaded !
-  //--------------------------------------------------------------------
-  Int_t nentr=0; TObjArray itsTracks(15000);
-
-  {/* Read TPC tracks */ 
-    AliTPCtrack *itrack=new AliTPCtrack; 
-    TBranch *branch=tpcTree->GetBranch("tracks");
-    if (!branch) {
-       Error("Clusters2Tracks","Can't get the branch !");
-       return 1;
-    }
-    tpcTree->SetBranchAddress("tracks",&itrack);
-    nentr=(Int_t)tpcTree->GetEntries();
-
-    Info("Clusters2Tracks","Number of TPC tracks: %d\n",nentr);
-
-    for (Int_t i=0; i<nentr; i++) {
-       tpcTree->GetEvent(i);
-       AliITStrackV2 *t=0;
-       try {
-           t=new AliITStrackV2(*itrack);
-       } catch (const Char_t *msg) {
-           Warning("Clusters2Tracks",msg);
-           delete t;
-           continue;
-       }
-       if (TMath::Abs(t->GetD())>4) continue;
-
-       if (CorrectForDeadZoneMaterial(t)!=0) {
-        Warning("Clusters2Tracks",
-                 "failed to correct for the material in the dead zone !\n");
-         continue;
-       }
-
-       itsTracks.AddLast(t);
-    }
-    delete itrack;
-  }
-  itsTracks.Sort();
-  nentr=itsTracks.GetEntriesFast();
-
-
-  AliITStrackV2 *otrack=&fBestTrack;
-  TBranch *branch=itsTree->GetBranch("tracks");
-  if (!branch) itsTree->Branch("tracks","AliITStrackV2",&otrack,32000,3);
-  else branch->SetAddress(&otrack);
-
-  for (fPass=0; fPass<2; fPass++) {
-     Int_t &constraint=fConstraint[fPass]; if (constraint<0) continue;
-     for (Int_t i=0; i<nentr; i++) {
-       AliITStrackV2 *t=(AliITStrackV2*)itsTracks.UncheckedAt(i);
-       if (t==0) continue;           //this track has been already tracked
-       Int_t tpcLabel=t->GetLabel(); //save the TPC track label
-
-       ResetTrackToFollow(*t);
-       ResetBestTrack();
-
-       for (FollowProlongation(); fI<kMaxLayer; fI++) {
-          while (TakeNextProlongation()) FollowProlongation();
-       }
-
-       if (fBestTrack.GetNumberOfClusters() == 0) continue;
-
-       if (fConstraint[fPass]) {
-          ResetTrackToFollow(*t);
-         if (!RefitAt(3.7, &fTrackToFollow, &fBestTrack)) continue;
-          ResetBestTrack();
-       }
-
-       fBestTrack.SetLabel(tpcLabel);
-       fBestTrack.CookdEdx();
-       CookLabel(&fBestTrack,0.); //For comparison only
-       itsTree->Fill();
-       UseClusters(&fBestTrack);
-       delete itsTracks.RemoveAt(i);
-     }
-  }
-
-  nentr=(Int_t)itsTree->GetEntries();
-  Info("Clusters2Tracks","Number of prolonged tracks: %d\n",nentr);
-
-  itsTracks.Delete();
-
-  return 0;
-}
-
 Int_t AliITStrackerV2::PropagateBack(AliESD *event) {
   //--------------------------------------------------------------------
   // This functions propagates reconstructed ITS tracks back
@@ -352,7 +270,8 @@ Int_t AliITStrackerV2::PropagateBack(AliESD *event) {
   for (Int_t i=0; i<nentr; i++) {
      AliESDtrack *esd=event->GetTrack(i);
 
-     if (esd->GetStatus()!=(AliESDtrack::kTPCin|AliESDtrack::kITSin)) continue;
+     if ((esd->GetStatus()&AliESDtrack::kITSin)==0) continue;
+     if (esd->GetStatus()&AliESDtrack::kITSout) continue;
 
      AliITStrackV2 *t=0;
      try {
@@ -366,12 +285,13 @@ Int_t AliITStrackerV2::PropagateBack(AliESD *event) {
      ResetTrackToFollow(*t);
 
      // propagete to vertex [SR, GSI 17.02.2003]
-     fTrackToFollow.PropagateTo(3.,0.0028,65.19);
-     fTrackToFollow.PropagateToVertex();
-
-     // Start Time measurement [SR, GSI 17.02.2003]
-     fTrackToFollow.StartTimeIntegral();
-     fTrackToFollow.PropagateTo(3.,-0.0028,65.19);
+     // Start Time measurement [SR, GSI 17.02.2003], corrected by I.Belikov
+     if (fTrackToFollow.PropagateTo(3.,0.0028,65.19)) {
+       if (fTrackToFollow.PropagateToVertex()) {
+          fTrackToFollow.StartTimeIntegral();
+       }
+       fTrackToFollow.PropagateTo(3.,-0.0028,65.19);
+     }
 
      fTrackToFollow.ResetCovariance(); fTrackToFollow.ResetClusters();
      if (RefitAt(49.,&fTrackToFollow,t)) {
@@ -382,7 +302,7 @@ Int_t AliITStrackerV2::PropagateBack(AliESD *event) {
           continue;
         }
         fTrackToFollow.SetLabel(t->GetLabel());
-        fTrackToFollow.CookdEdx();
+        //fTrackToFollow.CookdEdx();
         CookLabel(&fTrackToFollow,0.); //For comparison only
         fTrackToFollow.UpdateESDtrack(AliESDtrack::kITSout);
         UseClusters(&fTrackToFollow);
@@ -396,94 +316,6 @@ Int_t AliITStrackerV2::PropagateBack(AliESD *event) {
   return 0;
 }
 
-Int_t AliITStrackerV2::PropagateBack(TTree *inp, TTree *out) {
-  //--------------------------------------------------------------------
-  //This functions propagates reconstructed ITS tracks back
-  //--------------------------------------------------------------------
-  Error("PropagateBack","This method is not converted to NewIO yet (Args: %x , %x )\n",inp,out);
-  return 1;
-  /*
-  TFile *in=(TFile*)inp;
-  TDirectory *savedir=gDirectory; 
-
-  if (LoadClusters()!=0) return 1;
-
-  if (!in->IsOpen()) {
-    Error("PropagateBack","file with ITS tracks is not open !\n");
-    return 1;
-  }
-
-  if (!out->IsOpen()) {
-  Error("PropagateBack","file for back propagated ITS tracks is not open !\n");
-  return 2;
-  }
-
-  in->cd();
-
-  Char_t tname[100];
-  sprintf(tname,"TreeT_ITS_%d",GetEventNumber());
-  TTree *itsTree=(TTree*)in->Get(tname);
-  if (!itsTree) {
-    Error("PropagateBack","can't get a tree with ITS tracks !\n");
-    return 3;
-  }
-  AliITStrackV2 *itrack=new AliITStrackV2; 
-  itsTree->SetBranchAddress("tracks",&itrack);
-
-  out->cd();
-
-  sprintf(tname,"TreeT_ITSb_%d",GetEventNumber());
-  TTree backTree(tname,"Tree with back propagated ITS tracks");
-  AliTPCtrack *otrack=0;
-  backTree.Branch("tracks","AliTPCtrack",&otrack,32000,2);
-
-  Int_t nentr=(Int_t)itsTree->GetEntries();
-  Int_t i;
-  for (i=0; i<nentr; i++) {
-    itsTree->GetEvent(i);
-    Int_t itsLabel=itrack->GetLabel(); //save the ITS track label
-    ResetTrackToFollow(*itrack);
-
-    // propagete to vertex [SR, GSI 17.02.2003]
-    fTrackToFollow.PropagateTo(3.,0.0028,65.19);
-    fTrackToFollow.PropagateToVertex();
-
-    // Start Time measurement [SR, GSI 17.02.2003]
-    fTrackToFollow.StartTimeIntegral();
-    fTrackToFollow.PropagateTo(3.,-0.0028,65.19);
-    //
-
-    fTrackToFollow.ResetCovariance(); fTrackToFollow.ResetClusters();
-    if (!RefitAt(49.,&fTrackToFollow,itrack)) continue;
-
-    if (CorrectForDeadZoneMaterial(&fTrackToFollow)!=0) {
-       Warning("PropagateBack",
-               "failed to correct for the material in the dead zone !\n");
-       continue;
-    }
-   
-    fTrackToFollow.SetLabel(itsLabel);
-    otrack=new AliTPCtrack(fTrackToFollow,fTrackToFollow.GetAlpha()); 
-    backTree.Fill(); delete otrack;
-    UseClusters(&fTrackToFollow);
-  }
-  i=(Int_t)backTree.GetEntries();
-  backTree.Write();
-
-  Info("PropagateBack","Number of ITS tracks: %d\n",nentr);
-  Info("PropagateBack","Number of back propagated ITS tracks: %d\n",i);
-
-  delete itrack;
-  delete itsTree; //Thanks to Mariana Bondila
-
-  UnloadClusters();
-
-  savedir->cd();
-
-  return 0;
-  */
-}
-
 Int_t AliITStrackerV2::RefitInward(AliESD *event) {
   //--------------------------------------------------------------------
   // This functions refits ITS tracks using the 
@@ -497,10 +329,10 @@ Int_t AliITStrackerV2::RefitInward(AliESD *event) {
   for (Int_t i=0; i<nentr; i++) {
     AliESDtrack *esd=event->GetTrack(i);
 
-    ULong_t flags = AliESDtrack::kITSin | AliESDtrack::kTPCrefit;
-
-    if ( (esd->GetStatus() & flags) != flags ) continue;
-    if ( esd->GetStatus() & AliESDtrack::kITSrefit) continue;
+    if ((esd->GetStatus()&AliESDtrack::kITSout) == 0) continue;
+    if (esd->GetStatus()&AliESDtrack::kITSrefit) continue;
+    if (esd->GetStatus()&AliESDtrack::kTPCout)
+    if ((esd->GetStatus()&AliESDtrack::kTPCrefit)==0) continue;
 
     AliITStrackV2 *t=0;
     try {
@@ -526,9 +358,37 @@ Int_t AliITStrackerV2::RefitInward(AliESD *event) {
        fTrackToFollow.SetLabel(t->GetLabel());
        fTrackToFollow.CookdEdx();
        CookLabel(&fTrackToFollow,0.); //For comparison only
-       fTrackToFollow.UpdateESDtrack(AliESDtrack::kITSrefit);
-       UseClusters(&fTrackToFollow);
-       ntrk++;
+
+       if (fTrackToFollow.PropagateTo(3.,0.0028,65.19)) {//The beam pipe    
+         Double_t a=fTrackToFollow.GetAlpha();
+         Double_t cs=TMath::Cos(a),sn=TMath::Sin(a);
+         Double_t xv= GetX()*cs + GetY()*sn;
+         Double_t yv=-GetX()*sn + GetY()*cs;
+         
+         Double_t c=fTrackToFollow.GetC(), snp=fTrackToFollow.GetSnp();
+         Double_t x=fTrackToFollow.GetX(), y=fTrackToFollow.GetY();
+         Double_t tgfv=-(c*(x-xv)-snp)/(c*(y-yv) + TMath::Sqrt(1.-snp*snp));
+         Double_t fv=TMath::ATan(tgfv);
+
+         cs=TMath::Cos(fv); sn=TMath::Sin(fv);
+         x = xv*cs + yv*sn;
+         yv=-xv*sn + yv*cs; xv=x;
+
+        if (fTrackToFollow.Propagate(fv+a,xv)) {
+            fTrackToFollow.UpdateESDtrack(AliESDtrack::kITSrefit);
+            UseClusters(&fTrackToFollow);
+            {
+            AliITSclusterV2 c; c.SetY(yv); c.SetZ(GetZ());
+            c.SetSigmaY2(GetSigmaY()*GetSigmaY());
+            c.SetSigmaZ2(GetSigmaZ()*GetSigmaZ());
+            Double_t chi2=fTrackToFollow.GetPredictedChi2(&c);
+            if (chi2<kMaxChi2)
+              if (fTrackToFollow.Update(&c,-chi2,0))
+                   fTrackToFollow.SetConstrainedESDtrack(chi2);            
+            }
+            ntrk++;
+         }
+       }
     }
     delete t;
   }
@@ -538,151 +398,13 @@ Int_t AliITStrackerV2::RefitInward(AliESD *event) {
   return 0;
 }
 
-Int_t AliITStrackerV2::RefitInward(TTree *in, TTree *out) {
-  //--------------------------------------------------------------------
-  // This functions refits ITS tracks using the 
-  // "inward propagated" TPC tracks
-  //--------------------------------------------------------------------
-  Error("RefitInward","This method is not converted to NewIO yet (Args: %x , %x )\n",in,out);
-  return 1;
-  /*
-  TFile *in=(TFile*)inp;
-  TDirectory *savedir=gDirectory; 
-
-  if (LoadClusters()!=0) return 1;
-
-  if (!inSeeds->IsOpen()) {
-    Error("RefitInward","file with inward TPC tracks is not open !\n");
-    return 2;
-  }
-
-  if (!in->IsOpen()) {
-    Error("RefitInward","file with ITS tracks is not open !\n");
-    return 2;
-  }
-
-  if (!out->IsOpen()) {
-    Error("RefitInward","file for inward ITS tracks is not open !\n");
-    return 3;
-  }
-
-  Int_t i;
-
-  //LUT used for the track matching (S.Radomski's idea)
-  const Int_t nLab = 400000; // limit on the number of track labels
-  Int_t lut[nLab];
-  for(i=0; i<nLab; i++) lut[i] = -1;
-
-  Char_t tname[100];
-
-  TObjArray itsTracks(15000);
-  {// Read the ITS tracks  
-    sprintf(tname,"TreeT_ITS_%d",GetEventNumber());
-    TTree *itsTree=(TTree*)in->Get(tname);
-    if (!itsTree) {
-      Error("RefitInward","can't get a tree with ITS tracks !\n");
-      return 3;
-    }
-    AliITStrackV2 *itrack=new AliITStrackV2; 
-    itsTree->SetBranchAddress("tracks",&itrack);
-    Int_t nits=(Int_t)itsTree->GetEntries();
-
-    Info("RefitInward","Number of ITS tracks: %d\n",nits);
-
-    for (Int_t i=0; i<nits; i++) {
-       itsTree->GetEvent(i);
-       Int_t lab=TMath::Abs(itrack->GetLabel());
-       if (lab < nLab) {
-         if (lut[lab]>=0) Warning("RefitInward","double track %d\n",lab);
-         lut[lab]=i;
-       } else {
-         Warning("RefitInward","Too big ITS track label: %d\n!",lab);
-         continue;
-       } 
-       itsTracks.AddLast(new AliITStrackV2(*itrack));
-    }
-    delete itsTree;
-    delete itrack;
-  }
-
-  //Get the input seeds tree
-  inSeeds->cd();
-  sprintf(tname,"tracksTPC_%d",GetEventNumber());
-  TTree *tpcTree=(TTree*)inSeeds->Get(tname);
-  if (!tpcTree) {
-     Error("RefitInward","can't get a tree with TPC tracks !\n");
-     return 3;
-  }
-  AliTPCtrack *itrack=new AliTPCtrack; 
-  tpcTree->SetBranchAddress("tracks",&itrack);
-  Int_t ntpc=(Int_t)tpcTree->GetEntries();
-
-  Info("RefitInward","Number of TPC tracks: %d\n",ntpc);
-
-  //Create the output tree
-  out->cd();
-  sprintf(tname,"TreeT_ITSinward_%d",GetEventNumber());
-  TTree outTree(tname,"Tree with inward refitted ITS tracks");
-  AliITStrackV2 *otrack=0;
-  outTree.Branch("tracks","AliITStrackV2",&otrack,32000,0);
-
-  for (i=0; i<ntpc; i++) {
-    tpcTree->GetEvent(i);
-    try {
-      otrack=new AliITStrackV2(*itrack);
-    } catch (const Char_t *msg) {
-      Warning("RefitInward",msg);
-      delete otrack;
-      continue;
-    }
-    //check if this track was reconstructed in the ITS
-    Int_t lab=TMath::Abs(otrack->GetLabel());
-    if (lab >= nLab) {
-      Warning("RefitInward","Too big TPC track label: %d\n!",lab); 
-      continue;
-    }
-    Int_t idx=lut[lab];
-    if (idx<0) continue; //no prolongation in the ITS for this track
-    
-    if (CorrectForDeadZoneMaterial(otrack)!=0) {
-       Warning("RefitInward",
-               "failed to correct for the material in the dead zone !\n");
-       continue;
-    }
-
-    //Refitting...
-    {
-    AliITStrackV2 *ctrack=(AliITStrackV2*)itsTracks.UncheckedAt(idx);
-    if (!RefitAt(3.7, otrack, ctrack)) continue;
-    }
-    otrack->SetLabel(itrack->GetLabel()); //For comparison only
-    otrack->CookdEdx();
-    CookLabel(otrack,0.); //For comparison only
-    outTree.Fill();
-    delete otrack;
-  }
-  i=(Int_t)outTree.GetEntries();
-  Info("RefitInward","Number of inward refitted ITS tracks: %d\n",i);
-  outTree.Write();
-
-  delete tpcTree;
-  delete itrack;
-  UnloadClusters();
-  itsTracks.Delete();
-
-  savedir->cd();
-
-  return 0;
-  */
-}
-
 AliCluster *AliITStrackerV2::GetCluster(Int_t index) const {
   //--------------------------------------------------------------------
   //       Return pointer to a given cluster
   //--------------------------------------------------------------------
   Int_t l=(index & 0xf0000000) >> 28;
   Int_t c=(index & 0x0fffffff) >> 00;
-  return fLayers[l].GetCluster(c);
+  return fgLayers[l].GetCluster(c);
 }
 
 
@@ -693,13 +415,13 @@ void AliITStrackerV2::FollowProlongation() {
   while (fI>fLastLayerToTrackTo) {
     Int_t i=fI-1;
 
-    AliITSlayer &layer=fLayers[i];
+    AliITSlayer &layer=fgLayers[i];
     AliITStrackV2 &track=fTracks[i];
 
     Double_t r=layer.GetR();
 
     if (i==3 || i==1) {
-       Double_t rs=0.5*(fLayers[i+1].GetR() + r);
+       Double_t rs=0.5*(fgLayers[i+1].GetR() + r);
        Double_t d=0.0034, x0=38.6;
        if (i==1) {rs=9.; d=0.0097; x0=42;}
        if (!fTrackToFollow.PropagateTo(rs,d,x0)) {
@@ -791,7 +513,7 @@ Int_t AliITStrackerV2::TakeNextProlongation() {
   //
   //  dEdx analysis by: Boris Batyunya, JINR, Boris.Batiounia@cern.ch 
   //--------------------------------------------------------------------
-  AliITSlayer &layer=fLayers[fI];
+  AliITSlayer &layer=fgLayers[fI];
   ResetTrackToFollow(fTracks[fI]);
 
   Double_t dz=7*TMath::Sqrt(fTrackToFollow.GetSigmaZ2() + kSigmaZ2[fI]);
@@ -1104,10 +826,10 @@ Double_t AliITStrackerV2::GetEffectiveThickness(Double_t y,Double_t z) const
   Double_t d=0.0028*3*3; //beam pipe
   Double_t x0=0;
 
-  Double_t xn=fLayers[fI].GetR();
+  Double_t xn=fgLayers[fI].GetR();
   for (Int_t i=0; i<fI; i++) {
-    Double_t xi=fLayers[i].GetR();
-    d+=fLayers[i].GetThickness(y,z,x0)*xi*xi;
+    Double_t xi=fgLayers[i].GetR();
+    d+=fgLayers[i].GetThickness(y,z,x0)*xi*xi;
   }
 
   if (fI>1) {
@@ -1116,7 +838,7 @@ Double_t AliITStrackerV2::GetEffectiveThickness(Double_t y,Double_t z) const
   }
 
   if (fI>3) {
-    Double_t xi=0.5*(fLayers[3].GetR()+fLayers[4].GetR());
+    Double_t xi=0.5*(fgLayers[3].GetR()+fgLayers[4].GetR());
     d+=0.0034*xi*xi;
   }
 
@@ -1170,13 +892,13 @@ AliITStrackerV2::RefitAt(Double_t xx,AliITStrackV2 *t,const AliITStrackV2 *c) {
   }
 
   for (Int_t i=from; i != to; i += step) {
-     AliITSlayer &layer=fLayers[i];
+     AliITSlayer &layer=fgLayers[i];
      Double_t r=layer.GetR();
  
      {
      Double_t hI=i-0.5*step; 
      if (TMath::Abs(hI-1.5)<0.01 || TMath::Abs(hI-3.5)<0.01) {             
-        Double_t rs=0.5*(fLayers[i-step].GetR() + r);
+        Double_t rs=0.5*(fgLayers[i-step].GetR() + r);
         Double_t d=0.0034, x0=38.6; 
         if (TMath::Abs(hI-1.5)<0.01) {rs=9.; d=0.0097; x0=42;}
         if (!t->PropagateTo(rs,-step*d,x0)) {