X-Git-Url: http://git.uio.no/git/?a=blobdiff_plain;f=ITS%2FAliITStrackerV2.cxx;h=d80e89f8f05dcfcdc408f0a37557d7918f230812;hb=f5e33cc07e8750f569fba3903ce6f387d30d46bf;hp=7bb30ec9369cc82c9d0f6f815327eb40cef8d387;hpb=83d735005d2c279d149e176175f85aed209c9af9;p=u%2Fmrichter%2FAliRoot.git

diff --git a/ITS/AliITStrackerV2.cxx b/ITS/AliITStrackerV2.cxx
index 7bb30ec9369..d80e89f8f05 100644
--- a/ITS/AliITStrackerV2.cxx
+++ b/ITS/AliITStrackerV2.cxx
@@ -12,82 +12,161 @@
  * about the suitability of this software for any purpose. It is          *
  * provided "as is" without express or implied warranty.                  *
  **************************************************************************/
-
+/* $Id$ */
 //-------------------------------------------------------------------------
 //               Implementation of the ITS tracker class
-//
+//    It reads AliITSRecPoint 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 <TError.h>
 #include <TFile.h>
 #include <TTree.h>
 #include <TRandom.h>
+#include <TGeoMatrix.h>
 
-#include "AliITSgeom.h"
+#include "AliITSgeomTGeo.h"
+#include "AliAlignObj.h"
 #include "AliITSRecPoint.h"
-#include "AliTPCtrack.h"
-#include "AliESD.h"
-#include "AliITSclusterV2.h"
+#include "AliESDEvent.h"
+#include "AliESDtrack.h"
+#include "AliITSRecPoint.h"
+#include "AliITSReconstructor.h"
 #include "AliITStrackerV2.h"
 
 ClassImp(AliITStrackerV2)
 
-AliITStrackerV2::AliITSlayer AliITStrackerV2::fLayers[kMaxLayer]; // ITS layers
+AliITStrackerV2::AliITSlayer AliITStrackerV2::fgLayers[AliITSgeomTGeo::kNLayers]; //ITS layers
+
+AliITStrackerV2::AliITStrackerV2(): 
+  AliTracker(), 
+  fI(AliITSgeomTGeo::GetNLayers()),
+  fBestTrack(),
+  fTrackToFollow(),
+  fPass(0),
+  fLastLayerToTrackTo(AliITSRecoParam::GetLastLayerToTrackTo())
+{
+  //--------------------------------------------------------------------
+  //This is the AliITStrackerV2 default constructor
+  //--------------------------------------------------------------------
+
+  for (Int_t i=1; i<AliITSgeomTGeo::GetNLayers()+1; i++) new(fgLayers+i-1) AliITSlayer();
+
+  fConstraint[0]=1; fConstraint[1]=0;
+
+  Double_t xyz[]={AliITSReconstructor::GetRecoParam()->GetXVdef(),
+		  AliITSReconstructor::GetRecoParam()->GetYVdef(),
+		  AliITSReconstructor::GetRecoParam()->GetZVdef()}; 
+  Double_t ers[]={AliITSReconstructor::GetRecoParam()->GetSigmaXVdef(),
+		  AliITSReconstructor::GetRecoParam()->GetSigmaYVdef(),
+		  AliITSReconstructor::GetRecoParam()->GetSigmaZVdef()}; 
+  SetVertex(xyz,ers);
+
+  for (Int_t i=0; i<AliITSgeomTGeo::GetNLayers(); i++) fLayersNotToSkip[i]=AliITSRecoParam::GetLayersNotToSkip(i);
+
+}
+
+AliITStrackerV2::AliITStrackerV2(const AliITStrackerV2 &t): 
+  AliTracker(t), 
+  fI(t.fI),
+  fBestTrack(t.fBestTrack),
+  fTrackToFollow(t.fTrackToFollow),
+  fPass(t.fPass),
+  fLastLayerToTrackTo(t.fLastLayerToTrackTo)
+{
+  //--------------------------------------------------------------------
+  //This is the AliITStrackerV2 copy constructor
+  //--------------------------------------------------------------------
+
+  //for (Int_t i=1; i<AliITSgeomTGeo::GetNLayers()+1; i++) new(fgLayers+i-1) AliITSlayer();
+
+  fConstraint[0]=t.fConstraint[0]; fConstraint[1]=t.fConstraint[1];
+
+  Double_t xyz[]={AliITSReconstructor::GetRecoParam()->GetXVdef(),
+		  AliITSReconstructor::GetRecoParam()->GetYVdef(),
+		  AliITSReconstructor::GetRecoParam()->GetZVdef()}; 
+  Double_t ers[]={AliITSReconstructor::GetRecoParam()->GetSigmaXVdef(),
+		  AliITSReconstructor::GetRecoParam()->GetSigmaYVdef(),
+		  AliITSReconstructor::GetRecoParam()->GetSigmaZVdef()}; 
+  xyz[0]=t.GetX(); xyz[1]=t.GetY(); xyz[2]=t.GetZ(); 
+  ers[0]=t.GetSigmaX(); ers[1]=t.GetSigmaY(); ers[2]=t.GetSigmaZ(); 
+  SetVertex(xyz,ers);
+
+  for (Int_t i=0; i<AliITSgeomTGeo::GetNLayers(); i++) fLayersNotToSkip[i]=t.fLayersNotToSkip[i];
 
-AliITStrackerV2::AliITStrackerV2(const AliITSgeom *geom) : AliTracker() {
+}
+
+AliITStrackerV2::AliITStrackerV2(const Char_t *geom) : 
+  AliTracker(), 
+  fI(AliITSgeomTGeo::GetNLayers()),
+  fBestTrack(),
+  fTrackToFollow(),
+  fPass(0),
+  fLastLayerToTrackTo(AliITSRecoParam::GetLastLayerToTrackTo())
+{
   //--------------------------------------------------------------------
   //This is the AliITStrackerV2 constructor
   //--------------------------------------------------------------------
-  AliITSgeom *g=(AliITSgeom*)geom;
+  if (geom) {
+    AliWarning("\"geom\" is actually a dummy argument !");
+  }
 
-  Float_t x,y,z;
-  Int_t i;
-  for (i=1; i<kMaxLayer+1; i++) {
-    Int_t nlad=g->GetNladders(i);
-    Int_t ndet=g->GetNdetectors(i);
+  for (Int_t i=1; i<AliITSgeomTGeo::GetNLayers()+1; i++) {
+    Int_t nlad=AliITSgeomTGeo::GetNLadders(i);
+    Int_t ndet=AliITSgeomTGeo::GetNDetectors(i);
 
-    g->GetTrans(i,1,1,x,y,z); 
-    Double_t r=TMath::Sqrt(x*x + y*y);
+    Double_t xyz[3], &x=xyz[0], &y=xyz[1], &z=xyz[2];
+    AliITSgeomTGeo::GetOrigTranslation(i,1,1,xyz); 
     Double_t poff=TMath::ATan2(y,x);
     Double_t zoff=z;
+    Double_t r=TMath::Sqrt(x*x + y*y);
 
-    g->GetTrans(i,1,2,x,y,z);
+    AliITSgeomTGeo::GetOrigTranslation(i,1,2,xyz);
     r += TMath::Sqrt(x*x + y*y);
-    g->GetTrans(i,2,1,x,y,z);
+    AliITSgeomTGeo::GetOrigTranslation(i,2,1,xyz);
     r += TMath::Sqrt(x*x + y*y);
-    g->GetTrans(i,2,2,x,y,z);
+    AliITSgeomTGeo::GetOrigTranslation(i,2,2,xyz);
     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
-        Float_t x,y,zshift; g->GetTrans(i,j,k,x,y,zshift); 
-        Double_t rot[9]; g->GetRotMatrix(i,j,k,rot);
-
-        Double_t r =-x*rot[1] + y*rot[0];         if (i==1) r=-r;
-        Double_t phi=TMath::ATan2(rot[1],rot[0]); if (i==1) phi-=3.1415927;
-        phi+=0.5*TMath::Pi(); if (phi<0) phi += 2*TMath::Pi();
-        AliITSdetector &det=fLayers[i-1].GetDetector((j-1)*ndet + k-1); 
-
+        TGeoHMatrix m; AliITSgeomTGeo::GetOrigMatrix(i,j,k,m);
+        const TGeoHMatrix *tm=AliITSgeomTGeo::GetTracking2LocalMatrix(i,j,k);
+        m.Multiply(tm);
+        Double_t txyz[3]={0.}; 
+	xyz[0]=0.; xyz[1]=0.; xyz[2]=0.;
+        m.LocalToMaster(txyz,xyz);
+        r=TMath::Sqrt(xyz[0]*xyz[0] + xyz[1]*xyz[1]);
+        Double_t phi=TMath::ATan2(xyz[1],xyz[0]);
+
+        if (phi<0) phi+=TMath::TwoPi();
+        else if (phi>=TMath::TwoPi()) phi-=TMath::TwoPi();
+
+        AliITSdetector &det=fgLayers[i-1].GetDetector((j-1)*ndet + k-1); 
         new(&det) AliITSdetector(r,phi); 
       } 
     }  
 
   }
 
-  fI=kMaxLayer;
-
-  fPass=0;
   fConstraint[0]=1; fConstraint[1]=0;
 
-  Double_t xyz[]={kXV,kYV,kZV}, ers[]={kSigmaXV,kSigmaYV,kSigmaZV}; 
+  Double_t xyz[]={AliITSReconstructor::GetRecoParam()->GetXVdef(),
+		  AliITSReconstructor::GetRecoParam()->GetYVdef(),
+		  AliITSReconstructor::GetRecoParam()->GetZVdef()}; 
+  Double_t ers[]={AliITSReconstructor::GetRecoParam()->GetSigmaXVdef(),
+		  AliITSReconstructor::GetRecoParam()->GetSigmaYVdef(),
+		  AliITSReconstructor::GetRecoParam()->GetSigmaZVdef()}; 
   SetVertex(xyz,ers);
 
-  for (Int_t i=0; i<kMaxLayer; i++) fLayersNotToSkip[i]=kLayersNotToSkip[i];
-  fLastLayerToTrackTo=kLastLayerToTrackTo;
+  for (Int_t i=0; i<AliITSgeomTGeo::GetNLayers(); i++) fLayersNotToSkip[i]=AliITSRecoParam::GetLayersNotToSkip(i);
 
 }
 
@@ -95,54 +174,52 @@ void AliITStrackerV2::SetLayersNotToSkip(Int_t *l) {
   //--------------------------------------------------------------------
   //This function set masks of the layers which must be not skipped
   //--------------------------------------------------------------------
-  for (Int_t i=0; i<kMaxLayer; i++) fLayersNotToSkip[i]=l[i];
-}
-
-Int_t AliITStrackerV2::LoadClusters() {
-  return LoadClusters(gFile);
+  for (Int_t i=0; i<AliITSgeomTGeo::GetNLayers(); i++) fLayersNotToSkip[i]=l[i];
 }
 
-Int_t AliITStrackerV2::LoadClusters(const TFile *cf) {
+Int_t AliITStrackerV2::LoadClusters(TTree *cTree) {
   //--------------------------------------------------------------------
   //This function loads ITS clusters
   //--------------------------------------------------------------------
-  if (!((TFile *)cf)->IsOpen()) {
-    Error("LoadClusters","file with ITS clusters has not been open !\n");
-    return 1;
-  }
-
-  char   cname[100]; 
-  sprintf(cname,"TreeC_ITS_%d",GetEventNumber());
-  TTree *cTree=(TTree*)((TFile *)cf)->Get(cname);
-  if (!cTree) { 
-    Error("LoadClusters"," can't get cTree !\n");
-    return 1;
-  }
-  TBranch *branch=cTree->GetBranch("Clusters");
+  TBranch *branch=cTree->GetBranch("ITSRecPoints");
   if (!branch) { 
-    Error("LoadClusters"," can't get Clusters branch !\n");
+    Error("LoadClusters"," can't get the branch !\n");
     return 1;
   }
 
-  TClonesArray dummy("AliITSclusterV2",10000), *clusters=&dummy;
+  TClonesArray dummy("AliITSRecPoint",10000), *clusters=&dummy;
   branch->SetAddress(&clusters);
 
   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;
+  for (Int_t i=0; i<AliITSgeomTGeo::GetNLayers(); i++) {
+    Int_t ndet=fgLayers[i].GetNdetectors();
+    Int_t jmax = j + fgLayers[i].GetNladders()*ndet;
+
+    Double_t r=fgLayers[i].GetR();
+    Double_t circ=TMath::TwoPi()*r;
+
     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));
+        AliITSRecPoint *c=(AliITSRecPoint*)clusters->UncheckedAt(ncl);
+
+	if (!c->Misalign()) AliWarning("Can't misalign this cluster !");
+
+        Int_t idx=c->GetDetectorIndex();
+        AliITSdetector &det=fgLayers[i].GetDetector(idx);
+   
+        Double_t y=r*det.GetPhi()+c->GetY();
+        if (y>circ) y-=circ; else if (y<0) y+=circ;
+        c->SetPhiR(y);
+
+        fgLayers[i].InsertCluster(new AliITSRecPoint(*c));
       }
       clusters->Delete();
     }
-    fLayers[i].ResetRoad(); //road defined by the cluster density
+    fgLayers[i].ResetRoad(); //road defined by the cluster density
   }
-  delete cTree; //Thanks to Mariana Bondila
 
   return 0;
 }
@@ -151,7 +228,7 @@ 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<AliITSgeomTGeo::GetNLayers(); i++) fgLayers[i].ResetClusters();
 }
 
 static Int_t CorrectForDeadZoneMaterial(AliITStrackV2 *t) {
@@ -179,7 +256,7 @@ 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;
@@ -188,7 +265,7 @@ static Int_t CorrectForDeadZoneMaterial(AliITStrackV2 *t) {
   return 0;
 }
 
-Int_t AliITStrackerV2::Clusters2Tracks(AliESD *event) {
+Int_t AliITStrackerV2::Clusters2Tracks(AliESDEvent *event) {
   //--------------------------------------------------------------------
   // This functions reconstructs ITS tracks
   // The clusters must be already loaded !
@@ -201,17 +278,16 @@ 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 = new AliITStrackV2(*esd);
 
-      AliITStrackV2 *t=0;
-      try {
-        t=new AliITStrackV2(*esd);
-      } catch (const Char_t *msg) {
-        Warning("Clusters2Tracks",msg);
-        delete t;
-        continue;
+      if (TMath::Abs(t->GetD(GetX(),GetY()))>4) {
+	delete t;
+	continue;
       }
-      if (TMath::Abs(t->GetD())>4) continue;
 
       if (CorrectForDeadZoneMaterial(t)!=0) {
          Warning("Clusters2Tracks",
@@ -237,7 +313,7 @@ Int_t AliITStrackerV2::Clusters2Tracks(AliESD *event) {
        ResetTrackToFollow(*t);
        ResetBestTrack();
 
-       for (FollowProlongation(); fI<kMaxLayer; fI++) {
+       for (FollowProlongation(); fI<AliITSgeomTGeo::GetNLayers(); fI++) {
           while (TakeNextProlongation()) FollowProlongation();
        }
 
@@ -266,121 +342,7 @@ Int_t AliITStrackerV2::Clusters2Tracks(AliESD *event) {
   return 0;
 }
 
-Int_t AliITStrackerV2::Clusters2Tracks(const TFile *inp, TFile *out) {
-  //--------------------------------------------------------------------
-  //This functions reconstructs ITS tracks
-  //--------------------------------------------------------------------
-  TFile *in=(TFile*)inp;
-  TDirectory *savedir=gDirectory; 
-
-  if (LoadClusters()!=0) return 1;
-
-  if (!in->IsOpen()) {
-    Error("Clusters2Tracks","file with TPC tracks is not open !\n");
-    return 1;
-  }
-
-  if (!out->IsOpen()) {
-    Error("Clusters2Tracks","file for ITS tracks is not open !\n");
-    return 2;
-  }
-
-  in->cd();
- 
-  Char_t tname[100];
-  Int_t nentr=0; TObjArray itsTracks(15000);
-
-  {/* Read TPC tracks */ 
-    sprintf(tname,"TreeT_TPC_%d",GetEventNumber());
-    TTree *tpcTree=(TTree*)in->Get(tname);
-    if (!tpcTree) {
-      Error("Clusters2Tracks","can't get a tree with TPC tracks !\n");
-      return 3;
-    }
-    AliTPCtrack *itrack=new AliTPCtrack; 
-    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 tpcTree; //Thanks to Mariana Bondila
-    delete itrack;
-  }
-  itsTracks.Sort();
-  nentr=itsTracks.GetEntriesFast();
-
-  out->cd();
-
-  sprintf(tname,"TreeT_ITS_%d",GetEventNumber());
-  TTree itsTree(tname,"Tree with ITS tracks");
-  AliITStrackV2 *otrack=&fBestTrack;
-  itsTree.Branch("tracks","AliITStrackV2",&otrack,32000,0);
-
-  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);
-
-  itsTree.Write();
-
-  itsTracks.Delete();
-
-  UnloadClusters();
-
-  savedir->cd();
-  return 0;
-}
-
-Int_t AliITStrackerV2::PropagateBack(AliESD *event) {
+Int_t AliITStrackerV2::PropagateBack(AliESDEvent *event) {
   //--------------------------------------------------------------------
   // This functions propagates reconstructed ITS tracks back
   // The clusters must be loaded !
@@ -392,28 +354,26 @@ 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 {
-        t=new AliITStrackV2(*esd);
-     } catch (const Char_t *msg) {
-        Warning("PropagateBack",msg);
-        delete t;
-        continue;
-     }
+     AliITStrackV2 *t = new AliITStrackV2(*esd);
 
      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(event->GetVertex())) {
+          fTrackToFollow.StartTimeIntegral();
+       }
+       Bool_t okProp=fTrackToFollow.PropagateTo(3.,-0.0028,65.19);
+       if(!okProp){
+	 AliWarning("Propagation to beam pipe radius failed");
+       }
+     }
 
-     fTrackToFollow.ResetCovariance(); fTrackToFollow.ResetClusters();
+     fTrackToFollow.ResetCovariance(10.); fTrackToFollow.ResetClusters();
      if (RefitAt(49.,&fTrackToFollow,t)) {
         if (CorrectForDeadZoneMaterial(&fTrackToFollow)!=0) {
           Warning("PropagateBack",
@@ -422,7 +382,7 @@ 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);
@@ -436,91 +396,7 @@ Int_t AliITStrackerV2::PropagateBack(AliESD *event) {
   return 0;
 }
 
-Int_t AliITStrackerV2::PropagateBack(const TFile *inp, TFile *out) {
-  //--------------------------------------------------------------------
-  //This functions propagates reconstructed ITS tracks back
-  //--------------------------------------------------------------------
-  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) {
+Int_t AliITStrackerV2::RefitInward(AliESDEvent *event) {
   //--------------------------------------------------------------------
   // This functions refits ITS tracks using the 
   // "inward propagated" TPC tracks
@@ -533,19 +409,12 @@ 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()&AliESDtrack::kITSout) == 0) continue;
+    if (esd->GetStatus()&AliESDtrack::kITSrefit) continue;
+    if (esd->GetStatus()&AliESDtrack::kTPCout)
+    if ((esd->GetStatus()&AliESDtrack::kTPCrefit)==0) continue;
 
-    if ( (esd->GetStatus() & flags) != flags ) continue;
-    if ( esd->GetStatus() & AliESDtrack::kITSrefit) continue;
-
-    AliITStrackV2 *t=0;
-    try {
-        t=new AliITStrackV2(*esd);
-    } catch (const Char_t *msg) {
-        Warning("RefitInward",msg);
-        delete t;
-        continue;
-    }
+    AliITStrackV2 *t = new AliITStrackV2(*esd);
 
     if (CorrectForDeadZoneMaterial(t)!=0) {
        Warning("RefitInward",
@@ -555,15 +424,22 @@ Int_t AliITStrackerV2::RefitInward(AliESD *event) {
     }
 
     ResetTrackToFollow(*t);
+    fTrackToFollow.ResetClusters();
 
     //Refitting...
-    if (RefitAt(3.7, &fTrackToFollow, t)) {
+    if (RefitAt(3.7, &fTrackToFollow, t, kTRUE)) {
        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 
+	 fTrackToFollow.UpdateESDtrack(AliESDtrack::kITSrefit);
+         AliESDtrack  *esdTrack =fTrackToFollow.GetESDtrack();
+         Double_t r[3]={0.,0.,0.};
+         Double_t maxD=3.;
+	 esdTrack->RelateToVertex(event->GetVertex(),GetBz(r),maxD);
+         ntrk++;
+       }
     }
     delete t;
   }
@@ -573,142 +449,13 @@ Int_t AliITStrackerV2::RefitInward(AliESD *event) {
   return 0;
 }
 
-Int_t AliITStrackerV2::RefitInward(const TFile *inp, TFile *out) {
-  //--------------------------------------------------------------------
-  // This functions refits ITS tracks using the 
-  // "inward propagated" TPC tracks
-  //--------------------------------------------------------------------
-  TFile *in=(TFile*)inp;
-  TDirectory *savedir=gDirectory; 
-
-  if (LoadClusters()!=0) return 1;
-
-  if (!in->IsOpen()) {
-    Error("RefitInward","file with inward TPC 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*)out->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;
-  }
-
-  out->cd();
-  
-  //Create the output tree
-  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);
-
-  //Get the input tree
-  sprintf(tname,"tracksTPC_%d",GetEventNumber());
-  TTree *tpcTree=(TTree*)in->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);
-
-  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);
 }
 
 
@@ -719,13 +466,13 @@ 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)) {
@@ -735,12 +482,12 @@ void AliITStrackerV2::FollowProlongation() {
     }
 
     //find intersection
-    Double_t x,y,z;  
-    if (!fTrackToFollow.GetGlobalXYZat(r,x,y,z)) {
+    Double_t phi,z;  
+    if (!fTrackToFollow.GetPhiZat(r,phi,z)) {
       //Warning("FollowProlongation","failed to estimate track !\n");
       return;
     }
-    Double_t phi=TMath::ATan2(y,x);
+
     Int_t idet=layer.FindDetectorIndex(phi,z);
     if (idet<0) {
       //Warning("FollowProlongation","failed to find a detector !\n");
@@ -758,38 +505,39 @@ void AliITStrackerV2::FollowProlongation() {
 
     //Select possible prolongations and store the current track estimation
     track.~AliITStrackV2(); new(&track) AliITStrackV2(fTrackToFollow);
-    Double_t dz=7*TMath::Sqrt(track.GetSigmaZ2() + kSigmaZ2[i]);
-    Double_t dy=7*TMath::Sqrt(track.GetSigmaY2() + kSigmaY2[i]);
+    Double_t dz=7*TMath::Sqrt(track.GetSigmaZ2() + AliITSReconstructor::GetRecoParam()->GetSigmaZ2(i));
+    Double_t dy=7*TMath::Sqrt(track.GetSigmaY2() + AliITSReconstructor::GetRecoParam()->GetSigmaY2(i));
     Double_t road=layer.GetRoad();
     if (dz*dy>road*road) {
        Double_t dd=TMath::Sqrt(dz*dy), scz=dz/dd, scy=dy/dd;
        dz=road*scz; dy=road*scy;
     } 
 
-    //Double_t dz=4*TMath::Sqrt(track.GetSigmaZ2() + kSigmaZ2[i]);
+    //Double_t dz=4*TMath::Sqrt(track.GetSigmaZ2() + AliITSReconstructor::GetRecoParam()->GetSigmaZ2(i));
     if (dz < 0.5*TMath::Abs(track.GetTgl())) dz=0.5*TMath::Abs(track.GetTgl());
-    if (dz > kMaxRoad) {
+    if (dz > AliITSReconstructor::GetRecoParam()->GetMaxRoad()) {
       //Warning("FollowProlongation","too broad road in Z !\n");
       return;
     }
 
     if (TMath::Abs(fTrackToFollow.GetZ()-GetZ()) > r+dz) return;
 
-    //Double_t dy=4*TMath::Sqrt(track.GetSigmaY2() + kSigmaY2[i]);
+    //Double_t dy=4*TMath::Sqrt(track.GetSigmaY2() + AliITSReconstructor::GetRecoParam()->GetSigmaY2(i));
     if (dy < 0.5*TMath::Abs(track.GetSnp())) dy=0.5*TMath::Abs(track.GetSnp());
-    if (dy > kMaxRoad) {
+    if (dy > AliITSReconstructor::GetRecoParam()->GetMaxRoad()) {
       //Warning("FollowProlongation","too broad road in Y !\n");
       return;
     }
 
+    fI--;
+
     Double_t zmin=track.GetZ() - dz; 
     Double_t zmax=track.GetZ() + dz;
     Double_t ymin=track.GetY() + r*phi - dy;
     Double_t ymax=track.GetY() + r*phi + dy;
-    layer.SelectClusters(zmin,zmax,ymin,ymax); 
-    fI--;
+    if (layer.SelectClusters(zmin,zmax,ymin,ymax)==0) 
+       if (fLayersNotToSkip[fI]) return;  
 
-    //take another prolongation
     if (!TakeNextProlongation()) 
        if (fLayersNotToSkip[fI]) return;
 
@@ -801,7 +549,7 @@ void AliITStrackerV2::FollowProlongation() {
   if (ncl)
   if (ncl >= nclb) {
      Double_t chi2=fTrackToFollow.GetChi2();
-     if (chi2/ncl < kChi2PerCluster) {        
+     if (chi2/ncl < AliITSReconstructor::GetRecoParam()->GetChi2PerCluster()) {        
         if (ncl > nclb || chi2 < fBestTrack.GetChi2()) {
            ResetBestTrack();
         }
@@ -816,19 +564,20 @@ 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]);
-  Double_t dy=7*TMath::Sqrt(fTrackToFollow.GetSigmaY2() + kSigmaY2[fI]);
+  Double_t dz=7*TMath::Sqrt(fTrackToFollow.GetSigmaZ2() + AliITSReconstructor::GetRecoParam()->GetSigmaZ2(fI));
+  Double_t dy=7*TMath::Sqrt(fTrackToFollow.GetSigmaY2() + AliITSReconstructor::GetRecoParam()->GetSigmaY2(fI));
   Double_t road=layer.GetRoad();
   if (dz*dy>road*road) {
      Double_t dd=TMath::Sqrt(dz*dy), scz=dz/dd, scy=dy/dd;
      dz=road*scz; dy=road*scy;
   } 
 
-  const AliITSclusterV2 *c=0; Int_t ci=-1;
-  Double_t chi2=12345.;
+  const AliITSRecPoint *c=0; Int_t ci=-1;
+  const AliITSRecPoint *cc=0; Int_t cci=-1;
+  Double_t chi2=AliITSReconstructor::GetRecoParam()->GetMaxChi2();
   while ((c=layer.GetNextCluster(ci))!=0) {
     Int_t idet=c->GetDetectorIndex();
 
@@ -846,22 +595,29 @@ Int_t AliITStrackerV2::TakeNextProlongation() {
     if (TMath::Abs(fTrackToFollow.GetZ() - c->GetZ()) > dz) continue;
     if (TMath::Abs(fTrackToFollow.GetY() - c->GetY()) > dy) continue;
 
-    chi2=fTrackToFollow.GetPredictedChi2(c); if (chi2<kMaxChi2) break;
+    Double_t ch2=fTrackToFollow.GetPredictedChi2(c); 
+    if (ch2 > chi2) continue;
+    chi2=ch2;
+    cc=c; cci=ci;
+    break;
   }
 
-  if (chi2>=kMaxChi2) return 0;
-  if (!c) return 0;
+  if (!cc) return 0;
 
-  if (!fTrackToFollow.Update(c,chi2,(fI<<28)+ci)) {
+  {// Take into account the mis-alignment
+    Double_t x = fTrackToFollow.GetX() + cc->GetX();
+    if (!fTrackToFollow.PropagateTo(x,0.,0.)) return 0;
+  }
+  if (!fTrackToFollow.Update(cc,chi2,(fI<<28)+cci)) {
      //Warning("TakeNextProlongation","filtering failed !\n");
      return 0;
   }
 
   if (fTrackToFollow.GetNumberOfClusters()>1)
-  if (TMath::Abs(fTrackToFollow.GetD())>4) return 0;
+    if (TMath::Abs(fTrackToFollow.GetD(GetX(),GetY()))>4) return 0;
 
   fTrackToFollow.
-    SetSampledEdx(c->GetQ(),fTrackToFollow.GetNumberOfClusters()-1); //b.b.
+    SetSampledEdx(cc->GetQ(),fI-2); //b.b.
 
   {
   Double_t x0;
@@ -880,27 +636,48 @@ Int_t AliITStrackerV2::TakeNextProlongation() {
 }
 
 
-AliITStrackerV2::AliITSlayer::AliITSlayer() {
+AliITStrackerV2::AliITSlayer::AliITSlayer():
+  fR(0.),
+  fPhiOffset(0.),
+  fNladders(0),
+  fZOffset(0.),
+  fNdetectors(0),
+  fDetectors(0),
+  fNsel(0),
+  fRoad(2*fR*TMath::Sqrt(3.14/1.)) //assuming that there's only one cluster
+{
   //--------------------------------------------------------------------
   //default AliITSlayer constructor
   //--------------------------------------------------------------------
-  fN=0;
-  fDetectors=0;
+  
+  for (Int_t i=0; i<kNsector; i++) fN[i]=0;
+  for (Int_t i=0; i<AliITSRecoParam::kMaxClusterPerLayer; i++){
+    fClusters[i]=0;
+    fIndex[i]=0;
+  }
 }
 
 AliITStrackerV2::AliITSlayer::
-AliITSlayer(Double_t r,Double_t p,Double_t z,Int_t nl,Int_t nd) {
+AliITSlayer(Double_t r,Double_t p,Double_t z,Int_t nl,Int_t nd): 
+  fR(r), 
+  fPhiOffset(p), 
+  fNladders(nl),
+  fZOffset(z),
+  fNdetectors(nd),
+  fDetectors(new AliITSdetector[nl*nd]),
+  fNsel(0),
+  fRoad(2*r*TMath::Sqrt(3.14/1.)) //assuming that there's only one cluster
+{
   //--------------------------------------------------------------------
   //main AliITSlayer constructor
   //--------------------------------------------------------------------
-  fR=r; fPhiOffset=p; fZOffset=z;
-  fNladders=nl; fNdetectors=nd;
-  fDetectors=new AliITSdetector[fNladders*fNdetectors];
 
-  fN=0;
-  fI=0;
+  for (Int_t i=0; i<kNsector; i++) fN[i]=0;
 
-  fRoad=2*fR*TMath::Sqrt(3.14/1.);//assuming that there's only one cluster
+  for (Int_t i=0; i<AliITSRecoParam::kMaxClusterPerLayer; i++){
+    fClusters[i]=0;
+    fIndex[i]=0;
+  }
 }
 
 AliITStrackerV2::AliITSlayer::~AliITSlayer() {
@@ -908,16 +685,20 @@ AliITStrackerV2::AliITSlayer::~AliITSlayer() {
   // AliITSlayer destructor
   //--------------------------------------------------------------------
   delete[] fDetectors;
-  for (Int_t i=0; i<fN; i++) delete fClusters[i];
+  ResetClusters();
 }
 
 void AliITStrackerV2::AliITSlayer::ResetClusters() {
   //--------------------------------------------------------------------
   // This function removes loaded clusters
   //--------------------------------------------------------------------
-  for (Int_t i=0; i<fN; i++) delete fClusters[i];
-  fN=0;
-  fI=0;
+   for (Int_t s=0; s<kNsector; s++) {
+       Int_t &n=fN[s];
+       while (n) {
+          n--;
+          delete fClusters[s*kMaxClusterPerSector+n];
+       }
+   }
 }
 
 void AliITStrackerV2::AliITSlayer::ResetRoad() {
@@ -925,37 +706,57 @@ void AliITStrackerV2::AliITSlayer::ResetRoad() {
   // This function calculates the road defined by the cluster density
   //--------------------------------------------------------------------
   Int_t n=0;
-  for (Int_t i=0; i<fN; i++) {
-     if (TMath::Abs(fClusters[i]->GetZ())<fR) n++;
+  for (Int_t s=0; s<kNsector; s++) {
+    Int_t i=fN[s];
+    while (i--) 
+       if (TMath::Abs(fClusters[s*kMaxClusterPerSector+i]->GetZ())<fR) n++;
   }
   if (n>1) fRoad=2*fR*TMath::Sqrt(3.14/n);
 }
 
-Int_t AliITStrackerV2::AliITSlayer::InsertCluster(AliITSclusterV2 *c) {
+Int_t AliITStrackerV2::AliITSlayer::InsertCluster(AliITSRecPoint *c) {
   //--------------------------------------------------------------------
-  //This function adds a cluster to this layer
+  // This function inserts a cluster to this layer in increasing
+  // order of the cluster's fZ
   //--------------------------------------------------------------------
-  if (fN==kMaxClusterPerLayer) {
-    ::Error("InsertCluster","Too many clusters !\n");
-    return 1;
+  Float_t circ=TMath::TwoPi()*fR;
+  Int_t sec=Int_t(kNsector*c->GetPhiR()/circ);
+  if (sec>=kNsector) {
+     ::Error("InsertCluster","Wrong sector !\n");
+     return 1;
   }
-
-  if (fN==0) {fClusters[fN++]=c; return 0;}
-  Int_t i=FindClusterIndex(c->GetZ());
-  memmove(fClusters+i+1 ,fClusters+i,(fN-i)*sizeof(AliITSclusterV2*));
-  fClusters[i]=c; fN++;
-
+  Int_t &n=fN[sec];
+  if (n>=kMaxClusterPerSector) {
+     ::Error("InsertCluster","Too many clusters !\n");
+     return 1;
+  }
+  if (n==0) fClusters[sec*kMaxClusterPerSector]=c;
+  else {
+     Int_t i=FindClusterIndex(c->GetZ(),sec);
+     Int_t k=n-i+sec*kMaxClusterPerSector;
+     memmove(fClusters+i+1 ,fClusters+i,k*sizeof(AliITSRecPoint*));
+     fClusters[i]=c;
+  }
+  n++;
   return 0;
 }
 
-Int_t AliITStrackerV2::AliITSlayer::FindClusterIndex(Double_t z) const {
+Int_t 
+AliITStrackerV2::AliITSlayer::FindClusterIndex(Float_t z,Int_t s) const {
   //--------------------------------------------------------------------
-  // This function returns the index of the nearest cluster 
+  // For the sector "s", this function returns the index of the first 
+  // with its fZ >= "z". 
   //--------------------------------------------------------------------
-  if (fN==0) return 0;
-  if (z <= fClusters[0]->GetZ()) return 0;
-  if (z > fClusters[fN-1]->GetZ()) return fN;
-  Int_t b=0, e=fN-1, m=(b+e)/2;
+  Int_t nc=fN[s];
+  if (nc==0) return kMaxClusterPerSector*s;
+
+  Int_t b=kMaxClusterPerSector*s;
+  if (z <= fClusters[b]->GetZ()) return b;
+
+  Int_t e=b+nc-1;
+  if (z > fClusters[e]->GetZ()) return e+1;
+
+  Int_t m=(b+e)/2;
   for (; b<e; m=(b+e)/2) {
     if (z > fClusters[m]->GetZ()) b=m+1;
     else e=m; 
@@ -963,48 +764,80 @@ Int_t AliITStrackerV2::AliITSlayer::FindClusterIndex(Double_t z) const {
   return m;
 }
 
-void AliITStrackerV2::AliITSlayer::
-SelectClusters(Double_t zmin,Double_t zmax,Double_t ymin, Double_t ymax) {
+Int_t AliITStrackerV2::AliITSlayer::
+SelectClusters(Float_t zmin,Float_t zmax,Float_t ymin, Float_t ymax) {
   //--------------------------------------------------------------------
-  // This function sets the "window"
+  // This function selects clusters within the "window"
   //--------------------------------------------------------------------
-  fI=FindClusterIndex(zmin); fZmax=zmax;
-  Double_t circle=2*TMath::Pi()*fR;
-  if (ymax>circle) { ymax-=circle; ymin-=circle; }
-  fYmin=ymin; fYmax=ymax;
+    Float_t circ=fR*TMath::TwoPi();
+
+    if (ymin>circ) ymin-=circ; else if (ymin<0) ymin+=circ;
+    if (ymax>circ) ymax-=circ; else if (ymax<0) ymax+=circ;
+
+    Int_t i1=Int_t(kNsector*ymin/circ); if (i1==kNsector) i1--;
+    if (fN[i1]!=0) {
+       Float_t ym = (ymax<ymin) ? ymax+circ : ymax;
+       Int_t i=FindClusterIndex(zmin,i1), imax=i1*kMaxClusterPerSector+fN[i1];
+       for (; i<imax; i++) {
+           AliITSRecPoint *c=fClusters[i];
+           if (c->IsUsed()) continue;
+           if (c->GetZ()>zmax) break;
+           if (c->GetPhiR()<=ymin) continue;
+           if (c->GetPhiR()>ym) continue;
+           fIndex[fNsel++]=i;
+       }
+    }
+
+    Int_t i2=Int_t(kNsector*ymax/circ); if (i2==kNsector) i2--;
+    if (i2==i1) return fNsel;
+
+    if (fN[i2]!=0) {
+       Float_t ym = (ymin>ymax) ? ymin-circ : ymin;
+       Int_t i=FindClusterIndex(zmin,i2), imax=i2*kMaxClusterPerSector+fN[i2];
+       for (; i<imax; i++) {
+           AliITSRecPoint *c=fClusters[i];
+           if (c->IsUsed()) continue;
+           if (c->GetZ()>zmax) break;
+           if (c->GetPhiR()<=ym) continue;
+           if (c->GetPhiR()>ymax) continue;
+           fIndex[fNsel++]=i;
+       }
+    }
+
+    return fNsel;
 }
 
-const AliITSclusterV2 *AliITStrackerV2::AliITSlayer::GetNextCluster(Int_t &ci){
+const AliITSRecPoint *AliITStrackerV2::AliITSlayer::GetNextCluster(Int_t &ci){
   //--------------------------------------------------------------------
   // This function returns clusters within the "window" 
   //--------------------------------------------------------------------
-  const AliITSclusterV2 *cluster=0;
-  for (Int_t i=fI; i<fN; i++) {
-    const AliITSclusterV2 *c=fClusters[i];
-    if (c->GetZ() > fZmax) break;
-    if (c->IsUsed()) continue;
-    const AliITSdetector &det=GetDetector(c->GetDetectorIndex());    
-    Double_t y=fR*det.GetPhi() + c->GetY();
-
-    if (y>2.*fR*TMath::Pi()) y -= 2*fR*TMath::Pi();
-    if (y>1.*fR*TMath::Pi() && fYmax<y) y -= 2*fR*TMath::Pi();
-
-    if (y<fYmin) continue;
-    if (y>fYmax) continue;
-    cluster=c; ci=i;
-    fI=i+1;
-    break; 
+  AliITSRecPoint *c=0;
+  ci=-1;
+  if (fNsel) {
+     fNsel--;
+     ci=fIndex[fNsel]; 
+     c=fClusters[ci];
   }
+  return c; 
+}
 
-  return cluster;
+Int_t AliITStrackerV2::AliITSlayer::GetNumberOfClusters() const {
+  Int_t n=0;
+  for (Int_t s=0; s<kNsector; s++) n+=fN[s];
+  return n; 
 }
 
-Int_t AliITStrackerV2::AliITSlayer::
-FindDetectorIndex(Double_t phi, Double_t z) const {
+Int_t 
+AliITStrackerV2::AliITSlayer::FindDetectorIndex(Double_t phi,Double_t z)const {
   //--------------------------------------------------------------------
   //This function finds the detector crossed by the track
   //--------------------------------------------------------------------
-  Double_t dphi=phi-fPhiOffset;
+  Double_t dphi;
+  if (fZOffset<0)            // old geometry
+    dphi = -(phi-fPhiOffset);
+  else                       // new geometry
+    dphi = phi-fPhiOffset;
+
   if      (dphi <  0) dphi += 2*TMath::Pi();
   else if (dphi >= 2*TMath::Pi()) dphi -= 2*TMath::Pi();
   Int_t np=Int_t(dphi*fNladders*0.5/TMath::Pi()+0.5);
@@ -1129,10 +962,10 @@ 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) {
@@ -1141,44 +974,24 @@ 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;
   }
 
   return d/(xn*xn);
 }
 
-Int_t AliITStrackerV2::AliITSlayer::InRoad() const {
-  //--------------------------------------------------------------------
-  // This function returns number of clusters within the "window" 
-  //--------------------------------------------------------------------
-  Int_t ncl=0;
-  for (Int_t i=fI; i<fN; i++) {
-    const AliITSclusterV2 *c=fClusters[i];
-    if (c->GetZ() > fZmax) break;
-    if (c->IsUsed()) continue;
-    const AliITSdetector &det=GetDetector(c->GetDetectorIndex());    
-    Double_t y=fR*det.GetPhi() + c->GetY();
-
-    if (y>2.*fR*TMath::Pi()) y -= 2*fR*TMath::Pi();
-    if (y>1.*fR*TMath::Pi() && fYmax<y) y -= 2*fR*TMath::Pi();
-
-    if (y<fYmin) continue;
-    if (y>fYmax) continue;
-    ncl++;
-  }
-  return ncl;
-}
-
-Bool_t 
-AliITStrackerV2::RefitAt(Double_t x,AliITStrackV2 *t,const AliITStrackV2 *c) {
+Bool_t AliITStrackerV2::RefitAt(Double_t xx,AliITStrackV2 *t,
+                                const AliITStrackV2 *c, Bool_t extra) {
   //--------------------------------------------------------------------
   // This function refits the track "t" at the position "x" using
   // the clusters from "c"
+  // If "extra"==kTRUE, 
+  //    the clusters from overlapped modules get attached to "t" 
   //--------------------------------------------------------------------
-  Int_t index[kMaxLayer];
+  Int_t index[AliITSgeomTGeo::kNLayers];
   Int_t k;
-  for (k=0; k<kMaxLayer; k++) index[k]=-1;
+  for (k=0; k<AliITSgeomTGeo::GetNLayers(); k++) index[k]=-1;
   Int_t nc=c->GetNumberOfClusters();
   for (k=0; k<nc; k++) { 
     Int_t idx=c->GetClusterIndex(k),nl=(idx&0xf0000000)>>28;
@@ -1186,27 +999,35 @@ AliITStrackerV2::RefitAt(Double_t x,AliITStrackV2 *t,const AliITStrackV2 *c) {
   }
 
   Int_t from, to, step;
-  if (x > t->GetX()) {
-      from=0; to=kMaxLayer;
+  if (xx > t->GetX()) {
+      from=0; to=AliITSgeomTGeo::GetNLayers();
       step=+1;
   } else {
-      from=kMaxLayer-1; to=-1;
+      from=AliITSgeomTGeo::GetNLayers()-1; to=-1;
       step=-1;
   }
 
   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 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)) {
-          return kFALSE;
-        }
+     if (TMath::Abs(hI-1.5)<0.01 || TMath::Abs(hI-3.5)<0.01) {  
+       Int_t iLay = i-step;
+       Double_t rs = 0.;
+       if(iLay<0 || iLay>= AliITSgeomTGeo::kNLayers){
+	 AliError(Form("Invalid layer %d ",iLay));
+	 return kFALSE;
+       }
+       else{
+	 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)) {
+	 return kFALSE;
+       }
      }
      }
 
@@ -1217,11 +1038,11 @@ AliITStrackerV2::RefitAt(Double_t x,AliITStrackV2 *t,const AliITStrackV2 *c) {
      }
      //
 
-     Double_t x,y,z;
-     if (!t->GetGlobalXYZat(r,x,y,z)) { 
+     Double_t phi,z;
+     if (!t->GetPhiZat(r,phi,z)) { 
        return kFALSE;
      }
-     Double_t phi=TMath::ATan2(y,x);
+
      Int_t idet=layer.FindDetectorIndex(phi,z);
      if (idet<0) { 
        return kFALSE;
@@ -1233,48 +1054,37 @@ AliITStrackerV2::RefitAt(Double_t x,AliITStrackV2 *t,const AliITStrackV2 *c) {
      }
      t->SetDetectorIndex(idet);
 
-     const AliITSclusterV2 *cl=0;
-     Double_t maxchi2=kMaxChi2;
+     const AliITSRecPoint *cl=0;
+     Double_t maxchi2=AliITSReconstructor::GetRecoParam()->GetMaxChi2();
 
      Int_t idx=index[i];
-     if (idx>0) {
-        const AliITSclusterV2 *c=(AliITSclusterV2 *)GetCluster(idx); 
-        if (idet != c->GetDetectorIndex()) {
-           idet=c->GetDetectorIndex();
-           const AliITSdetector &det=layer.GetDetector(idet);
-           if (!t->Propagate(det.GetPhi(),det.GetR())) {
+     if (idx>=0) {
+        const AliITSRecPoint *ccc=(AliITSRecPoint *)GetCluster(idx); 
+        if (idet != ccc->GetDetectorIndex()) {
+           idet=ccc->GetDetectorIndex();
+           const AliITSdetector &det2=layer.GetDetector(idet);
+           if (!t->Propagate(det2.GetPhi(),det2.GetR())) {
              return kFALSE;
            }
            t->SetDetectorIndex(idet);
         }
-        Double_t chi2=t->GetPredictedChi2(c);
-        if (chi2<maxchi2) { cl=c; maxchi2=chi2; }
-        else return kFALSE;
-     }
-     /*
-     if (cl==0)
-     if (t->GetNumberOfClusters()>2) {
-        Double_t dz=4*TMath::Sqrt(t->GetSigmaZ2()+kSigmaZ2[i]);
-        Double_t dy=4*TMath::Sqrt(t->GetSigmaY2()+kSigmaY2[i]);
-        Double_t zmin=t->GetZ() - dz;
-        Double_t zmax=t->GetZ() + dz;
-        Double_t ymin=t->GetY() + phi*r - dy;
-        Double_t ymax=t->GetY() + phi*r + dy;
-        layer.SelectClusters(zmin,zmax,ymin,ymax);
-
-        const AliITSclusterV2 *c=0; Int_t ci=-1;
-        while ((c=layer.GetNextCluster(ci))!=0) {
-           if (idet != c->GetDetectorIndex()) continue;
-           Double_t chi2=t->GetPredictedChi2(c);
-           if (chi2<maxchi2) { cl=c; maxchi2=chi2; idx=ci; }
-        }
+        Double_t chi2=t->GetPredictedChi2(ccc);
+        if (chi2<maxchi2) { 
+	  cl=ccc; 
+	  maxchi2=chi2; 
+	} else {
+	  return kFALSE;
+	}
      }
-     */
+ 
      if (cl) {
+       // Take into account the mis-alignment
+       Double_t x=t->GetX()+cl->GetX();
+       if (!t->PropagateTo(x,0.,0.)) return kFALSE;
        if (!t->Update(cl,maxchi2,idx)) {
           return kFALSE;
        }
-       t->SetSampledEdx(cl->GetQ(),t->GetNumberOfClusters()-1);
+       t->SetSampledEdx(cl->GetQ(),i-2);
      }
 
      {
@@ -1283,6 +1093,37 @@ AliITStrackerV2::RefitAt(Double_t x,AliITStrackV2 *t,const AliITStrackV2 *c) {
      t->CorrectForMaterial(-step*d,x0);
      }
                  
+     if (extra) { //search for extra clusters
+        AliITStrackV2 tmp(*t);
+        Double_t dz=4*TMath::Sqrt(tmp.GetSigmaZ2()+AliITSReconstructor::GetRecoParam()->GetSigmaZ2(i));
+        if (dz < 0.5*TMath::Abs(tmp.GetTgl())) dz=0.5*TMath::Abs(tmp.GetTgl());
+        Double_t dy=4*TMath::Sqrt(t->GetSigmaY2()+AliITSReconstructor::GetRecoParam()->GetSigmaY2(i));
+        if (dy < 0.5*TMath::Abs(tmp.GetSnp())) dy=0.5*TMath::Abs(tmp.GetSnp());
+        Double_t zmin=t->GetZ() - dz;
+        Double_t zmax=t->GetZ() + dz;
+        Double_t ymin=t->GetY() + phi*r - dy;
+        Double_t ymax=t->GetY() + phi*r + dy;
+        layer.SelectClusters(zmin,zmax,ymin,ymax);
+
+        const AliITSRecPoint *cx=0; Int_t ci=-1,cci=-1;
+        maxchi2=1000.*AliITSReconstructor::GetRecoParam()->GetMaxChi2();
+	Double_t tolerance=0.1;
+        while ((cx=layer.GetNextCluster(ci))!=0) {
+           if (idet == cx->GetDetectorIndex()) continue;
+
+	   const AliITSdetector &detx=layer.GetDetector(cx->GetDetectorIndex());
+
+	   if (!tmp.Propagate(detx.GetPhi(),detx.GetR())) continue;
+           
+	   if (TMath::Abs(tmp.GetZ() - cx->GetZ()) > tolerance) continue;
+           if (TMath::Abs(tmp.GetY() - cx->GetY()) > tolerance) continue;
+
+           Double_t chi2=tmp.GetPredictedChi2(cx);
+           if (chi2<maxchi2) { maxchi2=chi2; cci=ci; }
+        }
+        if (cci>=0) t->SetExtraCluster(i,(i<<28)+cci);
+     }
+
      // track time update [SR, GSI 17.02.2003]
      if (t->IsStartedTimeIntegral() && step==1) {
         Double_t newX, newY, newZ;
@@ -1295,7 +1136,7 @@ AliITStrackerV2::RefitAt(Double_t x,AliITStrackV2 *t,const AliITStrackV2 *c) {
 
   }
 
-  if (!t->PropagateTo(x,0.,0.)) return kFALSE;
+  if (!t->PropagateTo(xx,0.,0.)) return kFALSE;
   return kTRUE;
 }
 
@@ -1305,11 +1146,17 @@ void AliITStrackerV2::UseClusters(const AliKalmanTrack *t, Int_t from) const {
   //--------------------------------------------------------------------
   AliTracker::UseClusters(t,from);
 
-  AliITSclusterV2 *c=(AliITSclusterV2 *)GetCluster(t->GetClusterIndex(0));
-  //if (c->GetQ()>2) c->Use();
-  if (c->GetSigmaZ2()>0.1) c->Use();
-  c=(AliITSclusterV2 *)GetCluster(t->GetClusterIndex(1));
-  //if (c->GetQ()>2) c->Use();
-  if (c->GetSigmaZ2()>0.1) c->Use();
+  Int_t clusterIndex = t->GetClusterIndex(0);
+  AliITSRecPoint *c= 0x0;
+
+  if (clusterIndex>-1)
+    c = (AliITSRecPoint *)GetCluster(clusterIndex);
+  if (c && c->GetSigmaZ2()>0.1) c->UnUse();
+
+  c = 0x0;
+  clusterIndex = t->GetClusterIndex(1);
+  if (clusterIndex>-1)
+    c=(AliITSRecPoint *)GetCluster(clusterIndex);
+  if (c && c->GetSigmaZ2()>0.1) c->UnUse();
 
 }