X-Git-Url: http://git.uio.no/git/?a=blobdiff_plain;ds=sidebyside;f=ITS%2FAliITStrackerV2.cxx;h=53048c6542153ffc038019a1e14e1b00c4937cb3;hb=8f02666b195fdab9325337e022292dcb0b113d73;hp=e57517be4ce8c5d961aa9751e5f0c454bf8fc9ac;hpb=15dd636fe2589363908aa2f48504ba5fab2d5763;p=u%2Fmrichter%2FAliRoot.git

diff --git a/ITS/AliITStrackerV2.cxx b/ITS/AliITStrackerV2.cxx
index e57517be4ce..53048c65421 100644
--- a/ITS/AliITStrackerV2.cxx
+++ b/ITS/AliITStrackerV2.cxx
@@ -15,7 +15,7 @@
 
 //-------------------------------------------------------------------------
 //               Implementation of the ITS tracker class
-//    It reads AliITSclusterV2 clusters and creates AliITStrackV2 tracks
+//    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
@@ -23,42 +23,113 @@
 
 #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 "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::fgLayers[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];
 
-AliITStrackerV2::AliITStrackerV2(const AliITSgeom *geom) : AliTracker() {
+  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 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;
 
@@ -66,14 +137,16 @@ AliITStrackerV2::AliITStrackerV2(const AliITSgeom *geom) : AliTracker() {
 
     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);
+        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[3]={0.};
+        m.LocalToMaster(txyz,xyz);
+        Double_t r=TMath::Sqrt(xyz[0]*xyz[0] + xyz[1]*xyz[1]);
+        Double_t phi=TMath::ATan2(xyz[1],xyz[0]);
 
-        Double_t phi=TMath::ATan2(rot[1],rot[0])+TMath::Pi();
-        phi+=TMath::Pi()/2;
-        if (i==1) phi+=TMath::Pi();
-        Double_t cp=TMath::Cos(phi), sp=TMath::Sin(phi);
-        Double_t r=x*cp+y*sp;
+        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); 
@@ -82,16 +155,17 @@ AliITStrackerV2::AliITStrackerV2(const AliITSgeom *geom) : AliTracker() {
 
   }
 
-  fI=kMaxLayer;
+  fConstraint[0]=1; fConstraint[1]=0;
 
-  fPass=0;
-  fConstraint[0]=1; fConstraint[1]=0;//-1;
-
-  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);
 
 }
 
@@ -99,32 +173,47 @@ 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];
+  for (Int_t i=0; i<AliITSgeomTGeo::GetNLayers(); i++) fLayersNotToSkip[i]=l[i];
 }
 
 Int_t AliITStrackerV2::LoadClusters(TTree *cTree) {
   //--------------------------------------------------------------------
   //This function loads ITS clusters
   //--------------------------------------------------------------------
-  TBranch *branch=cTree->GetBranch("Clusters");
+  TBranch *branch=cTree->GetBranch("ITSRecPoints");
   if (!branch) { 
     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++) {
+  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);
-        fgLayers[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();
     }
@@ -138,7 +227,7 @@ void AliITStrackerV2::UnloadClusters() {
   //--------------------------------------------------------------------
   //This function unloads ITS clusters
   //--------------------------------------------------------------------
-  for (Int_t i=0; i<kMaxLayer; i++) fgLayers[i].ResetClusters();
+  for (Int_t i=0; i<AliITSgeomTGeo::GetNLayers(); i++) fgLayers[i].ResetClusters();
 }
 
 static Int_t CorrectForDeadZoneMaterial(AliITStrackV2 *t) {
@@ -175,7 +264,7 @@ 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 !
@@ -200,7 +289,7 @@ Int_t AliITStrackerV2::Clusters2Tracks(AliESD *event) {
         delete t;
         continue;
       }
-      if (TMath::Abs(t->GetD())>4) {
+      if (TMath::Abs(t->GetD(GetX(),GetY()))>4) {
 	delete t;
 	continue;
       }
@@ -229,7 +318,7 @@ Int_t AliITStrackerV2::Clusters2Tracks(AliESD *event) {
        ResetTrackToFollow(*t);
        ResetBestTrack();
 
-       for (FollowProlongation(); fI<kMaxLayer; fI++) {
+       for (FollowProlongation(); fI<AliITSgeomTGeo::GetNLayers(); fI++) {
           while (TakeNextProlongation()) FollowProlongation();
        }
 
@@ -258,7 +347,7 @@ Int_t AliITStrackerV2::Clusters2Tracks(AliESD *event) {
   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 !
@@ -287,13 +376,13 @@ Int_t AliITStrackerV2::PropagateBack(AliESD *event) {
      // propagete to vertex [SR, GSI 17.02.2003]
      // Start Time measurement [SR, GSI 17.02.2003], corrected by I.Belikov
      if (fTrackToFollow.PropagateTo(3.,0.0028,65.19)) {
-       if (fTrackToFollow.PropagateToVertex()) {
+       if (fTrackToFollow.PropagateToVertex(event->GetVertex())) {
           fTrackToFollow.StartTimeIntegral();
        }
        fTrackToFollow.PropagateTo(3.,-0.0028,65.19);
      }
 
-     fTrackToFollow.ResetCovariance(); fTrackToFollow.ResetClusters();
+     fTrackToFollow.ResetCovariance(10.); fTrackToFollow.ResetClusters();
      if (RefitAt(49.,&fTrackToFollow,t)) {
         if (CorrectForDeadZoneMaterial(&fTrackToFollow)!=0) {
           Warning("PropagateBack",
@@ -316,7 +405,7 @@ Int_t AliITStrackerV2::PropagateBack(AliESD *event) {
   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
@@ -354,40 +443,18 @@ Int_t AliITStrackerV2::RefitInward(AliESD *event) {
     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
 
-       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++;
-         }
+       if (fTrackToFollow.PropagateTo(3.,0.0028,65.19)) {//The beam pipe 
+         AliESDtrack  *esdTrack =fTrackToFollow.GetESDtrack();
+         esdTrack->UpdateTrackParams(&fTrackToFollow,AliESDtrack::kITSrefit);
+         Float_t r[3]={0.,0.,0.};
+         Double_t maxD=3.;
+	 esdTrack->RelateToVertex(event->GetVertex(),GetBz(r),maxD);
+         ntrk++;
        }
     }
     delete t;
@@ -431,12 +498,11 @@ 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) {
@@ -455,38 +521,39 @@ 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;
 
@@ -498,7 +565,7 @@ 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();
         }
@@ -516,16 +583,17 @@ Int_t AliITStrackerV2::TakeNextProlongation() {
   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();
 
@@ -543,22 +611,29 @@ 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(),fTrackToFollow.GetNumberOfClusters()-1); //b.b.
 
   {
   Double_t x0;
@@ -577,27 +652,43 @@ 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;
+
 }
 
 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;
+
+  for (Int_t i=0; i<AliITSRecoParam::fgkMaxClusterPerLayer; i++) fClusters[i]=0;
 
-  fRoad=2*fR*TMath::Sqrt(3.14/1.);//assuming that there's only one cluster
 }
 
 AliITStrackerV2::AliITSlayer::~AliITSlayer() {
@@ -605,16 +696,20 @@ 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() {
@@ -622,37 +717,57 @@ 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; 
@@ -660,48 +775,80 @@ 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);
@@ -845,37 +992,17 @@ Double_t AliITStrackerV2::GetEffectiveThickness(Double_t y,Double_t z) const
   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 xx,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;
@@ -884,10 +1011,10 @@ AliITStrackerV2::RefitAt(Double_t xx,AliITStrackV2 *t,const AliITStrackV2 *c) {
 
   Int_t from, to, step;
   if (xx > t->GetX()) {
-      from=0; to=kMaxLayer;
+      from=0; to=AliITSgeomTGeo::GetNLayers();
       step=+1;
   } else {
-      from=kMaxLayer-1; to=-1;
+      from=AliITSgeomTGeo::GetNLayers()-1; to=-1;
       step=-1;
   }
 
@@ -914,11 +1041,11 @@ AliITStrackerV2::RefitAt(Double_t xx,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;
@@ -930,12 +1057,12 @@ AliITStrackerV2::RefitAt(Double_t xx,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 (idx>=0) {
+        const AliITSRecPoint *c=(AliITSRecPoint *)GetCluster(idx); 
         if (idet != c->GetDetectorIndex()) {
            idet=c->GetDetectorIndex();
            const AliITSdetector &det=layer.GetDetector(idet);
@@ -952,26 +1079,11 @@ AliITStrackerV2::RefitAt(Double_t xx,AliITStrackV2 *t,const AliITStrackV2 *c) {
 	  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; }
-        }
-     }
-     */
+ 
      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;
        }
@@ -984,6 +1096,36 @@ AliITStrackerV2::RefitAt(Double_t xx,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 *c=0; Int_t ci=-1,cci=-1;
+        Double_t maxchi2=1000.*AliITSReconstructor::GetRecoParam()->GetMaxChi2(), tolerance=0.1;
+        while ((c=layer.GetNextCluster(ci))!=0) {
+           if (idet == c->GetDetectorIndex()) continue;
+
+	   const AliITSdetector &det=layer.GetDetector(c->GetDetectorIndex());
+
+	   if (!tmp.Propagate(det.GetPhi(),det.GetR())) continue;
+           
+	   if (TMath::Abs(tmp.GetZ() - c->GetZ()) > tolerance) continue;
+           if (TMath::Abs(tmp.GetY() - c->GetY()) > tolerance) continue;
+
+           Double_t chi2=tmp.GetPredictedChi2(c);
+           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;
@@ -1006,11 +1148,17 @@ 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();
 
 }