From f4e9508c6e242ea34c102d337bdf5d1de542c510 Mon Sep 17 00:00:00 2001
From: hristov <hristov@f7af4fe6-9843-0410-8265-dc069ae4e863>
Date: Wed, 13 Oct 2004 12:01:54 +0000
Subject: [PATCH] Storing angle alpha for the tracks stopped at TRD. The stored
 value is used for inward tracking (M.Ivanov)

---
 TRD/AliTRDtrack.cxx   |  4 +++-
 TRD/AliTRDtracker.cxx | 51 +++++++++++++++++++++++++++++--------------
 2 files changed, 38 insertions(+), 17 deletions(-)

diff --git a/TRD/AliTRDtrack.cxx b/TRD/AliTRDtrack.cxx
index c10c52a487b..2a60b2256f9 100644
--- a/TRD/AliTRDtrack.cxx
+++ b/TRD/AliTRDtrack.cxx
@@ -211,7 +211,9 @@ AliTRDtrack::AliTRDtrack(const AliESDtrack& t)
   //Conversion of the covariance matrix
   Double_t c[15]; t.GetExternalCovariance(c);
   if (t.GetStatus()&AliESDtrack::kTRDbackup){
-    t.GetTRDExternalParameters(x,p,c);
+    t.GetTRDExternalParameters(x,fAlpha,p,c);
+    if      (fAlpha < -TMath::Pi()) fAlpha += 2*TMath::Pi();
+    else if (fAlpha >= TMath::Pi()) fAlpha -= 2*TMath::Pi();
   }
 
   fX=x;
diff --git a/TRD/AliTRDtracker.cxx b/TRD/AliTRDtracker.cxx
index a2d3392c33d..d1926b6936a 100644
--- a/TRD/AliTRDtracker.cxx
+++ b/TRD/AliTRDtracker.cxx
@@ -548,10 +548,13 @@ Int_t AliTRDtracker::PropagateBack(AliESD* event) {
     Int_t lbl = seed->GetLabel();
     AliTRDtrack *track = new AliTRDtrack(*seed);
     track->SetSeedLabel(lbl);
+    seed->UpdateTrackParams(track, AliESDtrack::kTRDbackup); //make backup
     fNseeds++;
     Float_t p4 = track->GetC();
     //
     Int_t expectedClr = FollowBackProlongation(*track);
+    /*
+      // only debug purpose
     if (track->GetNumberOfClusters()<expectedClr/3){
       AliTRDtrack *track1 = new AliTRDtrack(*seed);
       track1->SetSeedLabel(lbl);
@@ -562,28 +565,40 @@ Int_t AliTRDtracker::PropagateBack(AliESD* event) {
       delete track1;
       delete track2;
     }
-    if (TMath::Abs(track->GetC()-p4)/TMath::Abs(p4)>0.2) {
+    */
+     if (TMath::Abs(track->GetC()-p4)/TMath::Abs(p4)>0.2) {
       delete track;
       continue; //too big change of curvature - to be checked
     }
+
     Int_t foundClr = track->GetNumberOfClusters();
     if (foundClr >= foundMin) {
-      if(foundClr >= 2) {
-	track->CookdEdx(); 
-	CookLabel(track, 1-fgkLabelFraction);
+      track->CookdEdx(); 
+      CookLabel(track, 1-fgkLabelFraction);
+      if(track->GetChi2()/track->GetNumberOfClusters()<6) {   // sign only gold tracks
 	UseClusters(track);
       }
-      
-      // Propagate to outer reference plane [SR, GSI, 18.02.2003]
-      //      track->PropagateTo(364.8);  why?
-      
-      //seed->UpdateTrackParams(track, AliESDtrack::kTRDout);
-      //found++;
-      if (track->GetNCross()==0) seed->UpdateTrackParams(track, AliESDtrack::kTRDbackup);
-      else{
-	if (track->GetBackupTrack()) seed->UpdateTrackParams(track->GetBackupTrack(), AliESDtrack::kTRDbackup);
+      Bool_t isGold = kFALSE;
+     
+      if (track->GetChi2()/track->GetNumberOfClusters()<5) {  //full gold track
+	seed->UpdateTrackParams(track, AliESDtrack::kTRDbackup);
+	isGold = kTRUE;
+      }
+      if (!isGold && track->GetNCross()==0&&track->GetChi2()/track->GetNumberOfClusters()<7){ //almost gold track
+	seed->UpdateTrackParams(track, AliESDtrack::kTRDbackup);
+	isGold = kTRUE;
+      }
+      if (!isGold && track->GetBackupTrack()){
+	if (track->GetBackupTrack()->GetNumberOfClusters()>foundMin&&
+	    (track->GetBackupTrack()->GetChi2()/(track->GetBackupTrack()->GetNumberOfClusters()+1))<7){	  
+	  seed->UpdateTrackParams(track->GetBackupTrack(), AliESDtrack::kTRDbackup);
+	  isGold = kTRUE;
+	}
       }
     }
+    else{
+      continue;
+    }
 
     //Propagation to the TOF (I.Belikov)
     
@@ -664,12 +679,16 @@ Int_t AliTRDtracker::RefitInward(AliESD* event)
   Int_t n = event->GetNumberOfTracks();
   for (Int_t i=0; i<n; i++) {
     AliESDtrack* seed=event->GetTrack(i);
+    AliTRDtrack* seed2 = new AliTRDtrack(*seed);
+    if (seed2->GetX()<270){
+      seed->UpdateTrackParams(seed2, AliESDtrack::kTRDbackup); // backup TPC track - only update
+      continue;
+    }
+
     ULong_t status=seed->GetStatus();
     if ( (status & AliESDtrack::kTRDout ) == 0 ) continue;
     if ( (status & AliESDtrack::kTRDin) != 0 ) continue;
-    nseed++;
-
-    AliTRDtrack* seed2 = new AliTRDtrack(*seed);
+    nseed++;    
     seed2->ResetCovariance(5.); 
     AliTRDtrack *pt = new AliTRDtrack(*seed2,seed2->GetAlpha());
     UInt_t * indexes2 = seed2->GetIndexes();
-- 
2.31.1