Using the BxByBz tracking functions in AliReconstruction, and the corresponding chang...

[u/mrichter/AliRoot.git] / STEER / AliESDtrack.cxx

diff --git a/STEER/AliESDtrack.cxx b/STEER/AliESDtrack.cxx
index 428c17ff8658e79ae1aa32ee85cd2c8740b03856..a405b8971f7708179b19a98a42b9e81eb8893c05 100644 (file)
--- a/STEER/AliESDtrack.cxx
+++ b/STEER/AliESDtrack.cxx
@@ -1893,6 +1893,54 @@ Double_t b, Double_t maxd, AliExternalTrackParam *cParam) {
   return kTRUE;
 }
 
+//_______________________________________________________________________
+Bool_t AliESDtrack::RelateToVertexTPCBxByBz(const AliESDVertex *vtx, 
+Double_t b[3], Double_t maxd, AliExternalTrackParam *cParam) {
+  //
+  // Try to relate the TPC-only track parameters to the vertex "vtx", 
+  // if the (rough) transverse impact parameter is not bigger then "maxd". 
+  //
+  // All three components of the magnetic field ,"b[3]" (kG), 
+  // are taken into account.
+  //
+  // a) The TPC-only paramters are extapolated to the DCA to the vertex.
+  // b) The impact parameters and their covariance matrix are calculated.
+  // c) An attempt to constrain the TPC-only params to the vertex is done.
+  //    The constrained params are returned via "cParam".
+  //
+  // In the case of success, the returned value is kTRUE
+  // otherwise, it's kFALSE)
+  // 
+
+  if (!fTPCInner) return kFALSE;
+  if (!vtx) return kFALSE;
+
+  Double_t dz[2],cov[3];
+  if (!fTPCInner->PropagateToDCABxByBz(vtx, b, maxd, dz, cov)) return kFALSE;
+
+  fdTPC = dz[0];
+  fzTPC = dz[1];  
+  fCddTPC = cov[0];
+  fCdzTPC = cov[1];
+  fCzzTPC = cov[2];
+  
+  Double_t covar[6]; vtx->GetCovMatrix(covar);
+  Double_t p[2]={GetParameter()[0]-dz[0],GetParameter()[1]-dz[1]};
+  Double_t c[3]={covar[2],0.,covar[5]};
+
+  Double_t chi2=GetPredictedChi2(p,c);
+  if (chi2>kVeryBig) return kFALSE;
+
+  fCchi2TPC=chi2;
+
+  if (!cParam) return kTRUE;
+
+  *cParam = *fTPCInner;
+  if (!cParam->Update(p,c)) return kFALSE;
+
+  return kTRUE;
+}
+
 //_______________________________________________________________________
 Bool_t AliESDtrack::RelateToVertex(const AliESDVertex *vtx, 
 Double_t b, Double_t maxd, AliExternalTrackParam *cParam) {
@@ -1948,6 +1996,61 @@ Double_t b, Double_t maxd, AliExternalTrackParam *cParam) {
   return kTRUE;
 }
 
+//_______________________________________________________________________
+Bool_t AliESDtrack::RelateToVertexBxByBz(const AliESDVertex *vtx, 
+Double_t b[3], Double_t maxd, AliExternalTrackParam *cParam) {
+  //
+  // Try to relate this track to the vertex "vtx", 
+  // if the (rough) transverse impact parameter is not bigger then "maxd". 
+  //            Magnetic field is "b" (kG).
+  //
+  // a) The track gets extapolated to the DCA to the vertex.
+  // b) The impact parameters and their covariance matrix are calculated.
+  // c) An attempt to constrain this track to the vertex is done.
+  //    The constrained params are returned via "cParam".
+  //
+  // In the case of success, the returned value is kTRUE
+  // (otherwise, it's kFALSE)
+  //  
+
+  if (!vtx) return kFALSE;
+
+  Double_t dz[2],cov[3];
+  if (!PropagateToDCABxByBz(vtx, b, maxd, dz, cov)) return kFALSE;
+
+  fD = dz[0];
+  fZ = dz[1];  
+  fCdd = cov[0];
+  fCdz = cov[1];
+  fCzz = cov[2];
+  
+  Double_t covar[6]; vtx->GetCovMatrix(covar);
+  Double_t p[2]={GetParameter()[0]-dz[0],GetParameter()[1]-dz[1]};
+  Double_t c[3]={covar[2],0.,covar[5]};
+
+  Double_t chi2=GetPredictedChi2(p,c);
+  if (chi2>kVeryBig) return kFALSE;
+
+  fCchi2=chi2;
+
+
+  //--- Could now these lines be removed ? ---
+  delete fCp;
+  fCp=new AliExternalTrackParam(*this);  
+
+  if (!fCp->Update(p,c)) {delete fCp; fCp=0; return kFALSE;}
+  //----------------------------------------
+
+  fVertexID = vtx->GetID();
+
+  if (!cParam) return kTRUE;
+
+  *cParam = *this;
+  if (!cParam->Update(p,c)) return kFALSE; 
+
+  return kTRUE;
+}
+
 //_______________________________________________________________________
 void AliESDtrack::Print(Option_t *) const {
   // Prints info on the track