TrackerHowto < Sandbox

<div class="patternContent"><div class="patternTopic"> <h2><a name="Track_refit"></a> Tracker Examples </h2>
In this page you will find some instructions to get the measured rigidty,  to load the alignment of outer layers on existing root data and compute residuals.
<p />
<strong><em>v5 (aka PGTRACK)</em></strong> 
<p />
Details and current status of the alignment parameters can be found at <a href="/twiki/bin/view/AMS/TDVCalibrationNews" class="twikiLink">TDVCalibrationNews</a>.
<p />
Details of use of tracker external planes alignment are at <a href="http://ams.cern.ch/AMS/Analysis/hpl3itp1/root02_v5/html/B584_patches/html/classTrExtAlignDB.html" class="twikiLink">TrExtAlignDB</a>
<p />
Details of track refit method are at <a href="http://ams.cern.ch/AMS/TkTemp/doc.pgtrack/html/classTrTrackR.html#644fad804e6e8d3a4b33049553615795" target="_top">TrTrackR::iTrTrackPar</a>
<p />

<h2><a name="Track_refit"></a> Getting the rigidity </h2>
<p />

<pre>
{
   // event loop
   for (int entry = 0; entry < nentry; entry++) { 
   
      AMSEventR *ev = amschain->GetEvent(entry);

      //
      // Here you put some event selection
      // 

      ParticleR *part = ev->pParticle(0);
      TrTrackR *track = part->pTrTrack();
      //Fitting with INNER pattern and the Choutko Algorithm
      int id = track.iTrTrackPar(1 ,  3,   1);
      if(id<0) continue;

      //----------------------------------------------------------------------------
      //----------------------------------------------------------------------------


      ParticleR *part = ev->pParticle(0);
      TrTrackR *track = part->pTrTrack();
      //Fitting with INNER pattern and the Alcaraz Algorithm
      int id = track.iTrTrackPar(1 ,  3,   2);
      if(id<0) continue;

      //----------------------------------------------------------------------------
      //----------------------------------------------------------------------------

      ParticleR *part = ev->pParticle(0);
      TrTrackR *track = part->pTrTrack();
      //Fitting with INNER pattern and the Chikanian Algorithm
      int id = track.iTrTrackPar(1 ,  3,   3);
      if(id<0) continue;

      //----------------------------------------------------------------------------
      //----------------------------------------------------------------------------

      //Fitting with Maximum span pattern, the Choutko Algorithm
      //and the Perugia alignment stored in the root file
      int id = track.iTrTrackPar(1 ,  0,   1);
      if(id<0) continue;

      //----------------------------------------------------------------------------
      //----------------------------------------------------------------------------

      //Fitting with Maximum span pattern, the Choutko Algorithm
      //and the Madrid alignment stored in the root file
      int id = track.iTrTrackPar(1 ,  0,   11);
      if(id<0) continue;

      //----------------------------------------------------------------------------
      //----------------------------------------------------------------------------

      // Retrieve the rigidity 
      RigidityArray=track->GetPar(id).Rigidity;
      RigidityErr=track->GetPar(id).ErrRinv;
      // Retrieve the Chisq and the Number of degrees of freedom in Y/X
      LogChisqYArray=log10(track->GetPar(id).ChisqY);
      NdofYArray=track.GetPar(id)->NdofY;
      LogChisqXArray=log10(track->GetPar(id).ChisqX);
      NdofXArray=track.GetPar(id)->NdofX;





}
</pre>
<p />

<h2><a name="Track_refit"></a> Load External Alignment </h2>
<p />

<pre>
#include "TrExtAlignDB.h"

{

for (int entry = 0; entry < nentry; entry++) { // event loop
   AMSEventR *event = amschain->GetEvent(entry);

    //
    // Here you put some event selection
    // 
 
   // To Load outer layer alignment :
   //   PG Alignment
   TrExtAlignDB::RecalcAllExtHitCoo(0);    
   //   CIEMAT Alignment
   TrExtAlignDB::RecalcAllExtHitCoo(1);
   //   No Alignment  
   TrExtAlignDB::RecalcAllExtHitCoo(2);
    

}
</pre>
<p />

<h2><a name="Track_refit"></a> Compute Residuals </h2>
<p />

<p />
<pre>
#include "TrExtAlignDB.h"
{

   for (int entry = 0; entry < nentry; entry++) { // event loop
      AMSEventR *ev = amschain->GetEvent(entry);

      //
      // Here you put some event selection
      // 

      ParticleR *part = ev->pParticle(0);
      TrTrackR *track = part->pTrTrack();
      // Loop On Alignments
      for(int i_ext_alig =0; i_ext_alig<2; i_ext_alig++){

           int id = track->iTrTrackPar(algo,pattern,3+i_ext_alig*10);
           if (id<0) return;
           // Load of current Alignment 
           TrExtAlignDB::RecalcAllExtHitCoo(i_ext_alig);
           double Residual[10][2];
           for(int i_layer=1; i_layer<10; i_layer++){
               if( ! track->TestHitLayerJ(i_layer)) continue;    //check if the track has a hit on the layer i_layer   
               AMSPoint Residual_point=track->GetResidualJ(i_layer,id);
               if(   track->TestHitLayerJHasXY(i_layer) )
                   Residual[i_layer][0]=Residual_point.x();    // x residual computed only in case of XY hit
               else Residual[i_layer][0]=-99999999.;
               Residual[i_layer][1]=Residual_point.y();    // y residual 
           }
       }
   }

}
</pre>
<p />

-- Main.DomenicoDurso - 04-Jul-2012
Topic revision: r7 - 2012-07-18 - DomenicoDurso
Account
- Log In
- Cern Search
- TWiki Search
- Google Search
Sandbox All webs
Edit
Attach
Copyright &© 2008-2021 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
or Ideas, requests, problems regarding TWiki? use Discourse or Send feedback