Using const pointer to AliKalmanTrack to avoid incorrect update (Yu.Belikov)

diff --git a/STEER/AliESDtrack.cxx b/STEER/AliESDtrack.cxx
index fe331e1ed38452c8d8b2b875350a871bead567ca..bbaf3f1b1175bd7ed6e89dbdc83bb41aec3c85cd 100644 (file)
--- a/STEER/AliESDtrack.cxx
+++ b/STEER/AliESDtrack.cxx
@@ -15,7 +15,7 @@
 //-----------------------------------------------------------------
 //           Implementation of the ESD track class
 //   ESD = Event Summary Data
-//   This is the class to deal with during the phisical analysis of data
+//   This is the class to deal with during the phisics analysis of data
 //      Origin: Iouri Belikov, CERN
 //      e-mail: Jouri.Belikov@cern.ch
 //-----------------------------------------------------------------
@@ -85,8 +85,12 @@ fRICHsignal(-1)
   fPHOSpos[0]=fPHOSpos[1]=fPHOSpos[2]=0.;
   fEMCALpos[0]=fEMCALpos[1]=fEMCALpos[2]=0.;
   Int_t i;
-  for (i=0; i<5; i++)  { fRp[i]=0.; fCp[i]=0.; fIp[i]=0.; fOp[i]=0.; fTp[i]=0.;}
-  for (i=0; i<15; i++) { fRc[i]=0.; fCc[i]=0.; fIc[i]=0.; fOc[i]=0.; fTc[i]=0.;  }
+  for (i=0; i<5; i++)  { 
+    fRp[i]=fCp[i]=fIp[i]=fOp[i]=fXp[i]=fTp[i]=0.;
+  }
+  for (i=0; i<15; i++) { 
+    fRc[i]=fCc[i]=fIc[i]=fOc[i]=fXc[i]=fTc[i]=0.;  
+  }
   for (i=0; i<6; i++)  { fITSindex[i]=0; }
   for (i=0; i<180; i++){ fTPCindex[i]=0; }
   for (i=0; i<130; i++) { fTRDindex[i]=0; }
@@ -221,10 +225,12 @@ Double_t AliESDtrack::GetMass() const {
 }
 
 //_______________________________________________________________________
-Bool_t AliESDtrack::UpdateTrackParams(AliKalmanTrack *t, ULong_t flags) {
+Bool_t AliESDtrack::UpdateTrackParams(const AliKalmanTrack *t, ULong_t flags) {
   //
   // This function updates track's running parameters 
   //
+  Bool_t rc=kTRUE;
+
   SetStatus(flags);
   fLabel=t->GetLabel();
 
@@ -321,25 +327,17 @@ Bool_t AliESDtrack::UpdateTrackParams(AliKalmanTrack *t, ULong_t flags) {
     break;
 
   case kTRDout:
-    { //requested by the PHOS/EMCAL  ("temporary solution")
-      Int_t i;
-      Double_t x=460.,buf[15];
-      if (t->PropagateTo(x,30.,0.)) {  
-         fOalpha=t->GetAlpha();
-         t->GetExternalParameters(x,buf); fOx=x;
-         for (i=0; i<5; i++) fOp[i]=buf[i];
-         t->GetExternalCovariance(buf);
-         for (i=0; i<15; i++) fOc[i]=buf[i];
-      }
-      x=450.;
-      if (t->PropagateTo(x,30.,0.)) {  
-         fXalpha=t->GetAlpha();
-         t->GetExternalParameters(x,buf); fXx=x;
-         for (i=0; i<5; i++) fXp[i]=buf[i];
-         t->GetExternalCovariance(buf);
-         for (i=0; i<15; i++) fXc[i]=buf[i];
-      }
-    }
+    //requested by the PHOS/EMCAL  ("temporary solution")
+    fOalpha=t->GetAlpha();
+    fOx=460.;
+    rc=GetExternalParametersAt(fOx,fOp);
+    t->GetExternalCovariance(fOc); //can be done better
+
+    fXalpha=t->GetAlpha();
+    fXx=450.;
+    rc=GetExternalParametersAt(fXx,fXp);
+    t->GetExternalCovariance(fXc); //can be done better
+
   case kTRDin: case kTRDrefit:
     fTRDLabel = t->GetLabel();
  
@@ -364,7 +362,7 @@ Bool_t AliESDtrack::UpdateTrackParams(AliKalmanTrack *t, ULong_t flags) {
     return kFALSE;
   }
 
-  return kTRUE;
+  return rc;
 }
 
 //_______________________________________________________________________
@@ -392,6 +390,28 @@ void AliESDtrack::GetExternalParameters(Double_t &x, Double_t p[5]) const {
   x=fRx;
   for (Int_t i=0; i<5; i++) p[i]=fRp[i];
 }
+
+//_______________________________________________________________________
+Bool_t AliESDtrack::GetExternalParametersAt(Double_t x, Double_t p[5]) const {
+  //---------------------------------------------------------------------
+  // This function returns external representation of the track parameters
+  // at the position given by the first argument 
+  //---------------------------------------------------------------------
+  Double_t dx=x-fRx;
+  Double_t f1=fRp[2], f2=f1 + dx*fRp[4]/AliKalmanTrack::GetConvConst();
+
+  if (TMath::Abs(f2) >= 0.9999) return kFALSE;
+  
+  Double_t r1=TMath::Sqrt(1.- f1*f1), r2=TMath::Sqrt(1.- f2*f2);
+  p[0] = fRp[0] + dx*(f1+f2)/(r1+r2);
+  p[1] = fRp[1] + dx*(f1+f2)/(f1*r2 + f2*r1)*fRp[3];
+  p[2] = f2;
+  p[3] = fRp[3];
+  p[4] = fRp[4];
+
+  return kTRUE;
+}
+
 //_______________________________________________________________________
 void AliESDtrack::GetExternalCovariance(Double_t cov[15]) const {
   //---------------------------------------------------------------------

diff --git a/STEER/AliESDtrack.h b/STEER/AliESDtrack.h
index 20ce2927688f170f87b89103c41f9ba1898d1aef..378602ae9b2af4a32235575e6e499960132ab5b3 100644 (file)
--- a/STEER/AliESDtrack.h
+++ b/STEER/AliESDtrack.h
@@ -7,7 +7,7 @@
 
 //-------------------------------------------------------------------------
 //                          Class AliESDtrack
-//   This is the class to deal with during the physical analysis of data
+//   This is the class to deal with during the physics analysis of data
 //      
 //         Origin: Iouri Belikov, CERN, Jouri.Belikov@cern.ch 
 //-------------------------------------------------------------------------
@@ -23,7 +23,7 @@ public:
   virtual ~AliESDtrack();  
   void SetStatus(ULong_t flags) {fFlags|=flags;}
   void ResetStatus(ULong_t flags) {fFlags&=~flags;}
-  Bool_t UpdateTrackParams(AliKalmanTrack *t, ULong_t flags);
+  Bool_t UpdateTrackParams(const AliKalmanTrack *t, ULong_t flags);
   void SetIntegratedLength(Double_t l) {fTrackLength=l;}
   void SetIntegratedTimes(const Double_t *times);
   void SetESDpid(const Double_t *p);
@@ -33,6 +33,7 @@ public:
   Int_t GetLabel() const {return fLabel;}
   Double_t GetAlpha() const {return fRalpha;}
   void GetExternalParameters(Double_t &x, Double_t p[5]) const;
+  Bool_t GetExternalParametersAt(Double_t x, Double_t p[5]) const;
   void GetExternalCovariance(Double_t cov[15]) const;
   Double_t GetIntegratedLength() const {return fTrackLength;}
   void GetIntegratedTimes(Double_t *times) const;
@@ -190,16 +191,16 @@ protected:
   Double_t fTc[15];   // external cov. matrix of the track parameters
 
 //Track parameters at the radius of the PHOS
-  Double_t fOalpha;   // Track rotation angle
-  Double_t fOx;       // x-coordinate of the track reference plane
-  Double_t fOp[5];    // external track parameters
-  Double_t fOc[15];   // external cov. matrix of the track parameters
+  Double_t fOalpha;   //! Track rotation angle
+  Double_t fOx;       //! x-coordinate of the track reference plane
+  Double_t fOp[5];    //! external track parameters
+  Double_t fOc[15];   //! external cov. matrix of the track parameters
 
 //Track parameters at the radius of the EMCAL
-  Double_t fXalpha;   // Track rotation angle
-  Double_t fXx;       // x-coordinate of the track reference plane
-  Double_t fXp[5];    // external track parameters
-  Double_t fXc[15];   // external cov. matrix of the track parameters
+  Double_t fXalpha;   //! Track rotation angle
+  Double_t fXx;       //! x-coordinate of the track reference plane
+  Double_t fXp[5];    //! external track parameters
+  Double_t fXc[15];   //! external cov. matrix of the track parameters
 
   // ITS related track information
   Float_t fITSchi2;        // chi2 in the ITS
@@ -249,7 +250,7 @@ protected:
   Float_t fRICHsignal;     // detector's PID signal (beta for RICH)
   Float_t fRICHr[kSPECIES];// "detector response probabilities" (for the PID)
        
-  ClassDef(AliESDtrack,7)  //ESDtrack 
+  ClassDef(AliESDtrack,8)  //ESDtrack 
 };
 
 #endif