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    f5da09b2
    Golden track. · f5da09b2
    Zafar authored
      Goldent track is moved to THcHallCSpectrometer::TrackCalc()
      if  fSelUsingScin == 0 then golden track is calculated just
      like podd. i.e. it is the first track with minimum chi2/ndf
      with sorting ON
    
      if fSelUsingScin == 1 then golden track is calculetd just like
      engine/HTRACKING/h_select_best_track_using_scin.h. This method
      gives the best track with minimum value of chi2/ndf but with
      additional cuts on the tracks. These cuts are on dedx, beta
      and on energy.
    
      This commit also corrects and modifies the beta code written
      in the THcHodoscope::FineProcess
    
      At this point we have godlend track and in additoion to
      previous vlues the following values are set to a track:
      Energy, beta, chi2 of beta and dedx[track][first hit].
    
    NOTE: For some tracks we have large differences in value of chi
          square between ENGINE and hcana and this is already
          discussed in the last group meeting. Following emails are
          exchanged regarding this difference of chisquare.
    
    email to Mark:
    
    Hi Mark,
    I tried to trace the origin of difference of the chi square value between
    ENGINE and hcana. Please see the attached file, it has long table which I
    cannot present in this email. Or you can see the file at the following
    link, thanks.
    
    https://userweb.jlab.org/~zahmed/chi2diff.txt
    
    Ahmed
    
    Mark's reply:
    Ahmed,
            Thanks. I agree with what you see, but there is also another reason
    for the difference. For the space point in ch2 the engine and hcana
    choose different left/right combinations. That is why you see the large
    jump in the summed chi2 from planes 9 and 10. The two codes pick
    different left/right because there is a cut on the difference between the
    measured stub xp and an expected xp = sp->GetX()/875  and one code has a combination
    slightly below the cut value and the other slightly above. I do not see a way
    to make the codes agree more exactly since the stub fitting involves a matrix
    inversion.
    
                    Cheers,
                           Mark
    
    ---------------------------------------------------------------------------------------
    f5da09b2
    History
    Golden track.
    Zafar authored
      Goldent track is moved to THcHallCSpectrometer::TrackCalc()
      if  fSelUsingScin == 0 then golden track is calculated just
      like podd. i.e. it is the first track with minimum chi2/ndf
      with sorting ON
    
      if fSelUsingScin == 1 then golden track is calculetd just like
      engine/HTRACKING/h_select_best_track_using_scin.h. This method
      gives the best track with minimum value of chi2/ndf but with
      additional cuts on the tracks. These cuts are on dedx, beta
      and on energy.
    
      This commit also corrects and modifies the beta code written
      in the THcHodoscope::FineProcess
    
      At this point we have godlend track and in additoion to
      previous vlues the following values are set to a track:
      Energy, beta, chi2 of beta and dedx[track][first hit].
    
    NOTE: For some tracks we have large differences in value of chi
          square between ENGINE and hcana and this is already
          discussed in the last group meeting. Following emails are
          exchanged regarding this difference of chisquare.
    
    email to Mark:
    
    Hi Mark,
    I tried to trace the origin of difference of the chi square value between
    ENGINE and hcana. Please see the attached file, it has long table which I
    cannot present in this email. Or you can see the file at the following
    link, thanks.
    
    https://userweb.jlab.org/~zahmed/chi2diff.txt
    
    Ahmed
    
    Mark's reply:
    Ahmed,
            Thanks. I agree with what you see, but there is also another reason
    for the difference. For the space point in ch2 the engine and hcana
    choose different left/right combinations. That is why you see the large
    jump in the summed chi2 from planes 9 and 10. The two codes pick
    different left/right because there is a cut on the difference between the
    measured stub xp and an expected xp = sp->GetX()/875  and one code has a combination
    slightly below the cut value and the other slightly above. I do not see a way
    to make the codes agree more exactly since the stub fitting involves a matrix
    inversion.
    
                    Cheers,
                           Mark
    
    ---------------------------------------------------------------------------------------