1 // $Id: AliHLTTPCCATrackConvertor.cxx 27042 2008-07-02 12:06:02Z richterm $
2 //***************************************************************************
3 // This file is property of and copyright by the ALICE HLT Project *
4 // ALICE Experiment at CERN, All rights reserved. *
6 // Primary Authors: Sergey Gorbunov <sergey.gorbunov@kip.uni-heidelberg.de> *
7 // Ivan Kisel <kisel@kip.uni-heidelberg.de> *
8 // for The ALICE HLT Project. *
10 // Permission to use, copy, modify and distribute this software and its *
11 // documentation strictly for non-commercial purposes is hereby granted *
12 // without fee, provided that the above copyright notice appears in all *
13 // copies and that both the copyright notice and this permission notice *
14 // appear in the supporting documentation. The authors make no claims *
15 // about the suitability of this software for any purpose. It is *
16 // provided "as is" without express or implied warranty. *
17 //***************************************************************************
19 #include "AliHLTTPCCATrackConvertor.h"
20 #include "AliExternalTrackParam.h"
21 #include "AliHLTTPCCATrackParam.h"
22 #include "AliHLTTPCCAMath.h"
25 void AliHLTTPCCATrackConvertor::GetExtParam( const AliHLTTPCCATrackParam &T1, AliExternalTrackParam &T2, Double_t alpha, Double_t Bz )
27 //* Convert from AliHLTTPCCATrackParam to AliExternalTrackParam parameterisation,
28 //* the angle alpha is the global angle of the local X axis
30 Double_t par[5], cov[15];
31 for( Int_t i=0; i<5; i++ ) par[i] = T1.GetPar()[i];
32 for( Int_t i=0; i<15; i++ ) cov[i] = T1.GetCov()[i];
34 if(par[2]>.99 ) par[2]=.99;
35 if(par[2]<-.99 ) par[2]=-.99;
38 const Double_t kCLight = 0.000299792458;
40 if( CAMath::Abs(Bz)>1.e-4 ) c = 1./(Bz*kCLight);
48 if( T1.GetCosPhi()<0 ){ // change direction
49 par[2] = -par[2]; // sin phi
50 par[3] = -par[3]; // DzDs
51 par[4] = -par[4]; // kappa
59 T2.Set( (Double_t) T1.GetX(),alpha,par,cov);
62 void AliHLTTPCCATrackConvertor::SetExtParam( AliHLTTPCCATrackParam &T1, const AliExternalTrackParam &T2, Double_t Bz )
64 //* Convert from AliExternalTrackParam parameterisation
66 for( Int_t i=0; i<5; i++ ) T1.SetPar( i, T2.GetParameter()[i] );
67 for( Int_t i=0; i<15; i++ ) T1.SetCov( i, T2.GetCovariance()[i] );
69 if(T1.SinPhi()>.99 ) T1.SetSinPhi( .99 );
70 if(T1.SinPhi()<-.99 ) T1.SetSinPhi( -.99 );
71 T1.SetCosPhi( CAMath::Sqrt(1.-T1.SinPhi()*T1.SinPhi()));
72 const Double_t kCLight = 0.000299792458;
73 Double_t c = Bz*kCLight;
75 T1.SetPar( 4, T1.Par()[4]*c );
76 T1.SetCov( 10, T1.Cov()[10]*c );
77 T1.SetCov( 11, T1.Cov()[10]*c );
78 T1.SetCov( 12, T1.Cov()[10]*c );
79 T1.SetCov( 13, T1.Cov()[10]*c );
80 T1.SetCov( 14, T1.Cov()[10]*c*c );