DTrackCandidate_factory_THROWN.cc

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// $Id$
//
//    File: DTrackCandidate_factory_THROWN.cc
// Created: Tue Dec 12 12:42:57 EST 2006
// Creator: davidl (on Darwin swire-b241.jlab.org 8.8.0 powerpc)
//

#include <cmath>
using namespace std;

#include <JANA/JEventLoop.h>
#include <DANA/DApplication.h>

#include <CDC/DCDCTrackHit.h>
#include <FDC/DFDCPseudo.h>

#include "DTrackCandidate_factory_THROWN.h"
#include <TRACKING/DMCThrown.h>
#include <TRACKING/DReferenceTrajectory.h>
#include <TRACKING/DTrackFitter.h>
#include <TRACKING/DTrackHitSelector.h>
#include <DRandom.h>
#include <DMatrix.h>

//------------------
// Constructor
//------------------
DTrackCandidate_factory_THROWN::DTrackCandidate_factory_THROWN()
{
   fitter = NULL;
   hitselector = NULL;
   bfield = NULL;
}

//------------------
// brun
//------------------
jerror_t DTrackCandidate_factory_THROWN::brun(jana::JEventLoop *loop, int32_t runnumber)
{
   DApplication* dapp=dynamic_cast<DApplication*>(eventLoop->GetJApplication());
   bfield = dapp->GetBfield(runnumber);

   // Get pointer to DTrackFitter object that actually fits a track
   vector<const DTrackFitter *> fitters;
   loop->Get(fitters);
   if(fitters.size()<1){
      _DBG_<<"Unable to get a DTrackFitter object! NO Charged track fitting will be done!"<<endl;
      return RESOURCE_UNAVAILABLE;
   }
   
   // Drop the const qualifier from the DTrackFitter pointer (I'm surely going to hell for this!)
   fitter = const_cast<DTrackFitter*>(fitters[0]);

   // Warn user if something happened that caused us NOT to get a fitter object pointer
   if(!fitter){
      _DBG_<<"ERROR: Unable to get a DTrackFitter object! Chisq for DTrackCandidate:THROWN will NOT be calculated!"<<endl;
      return RESOURCE_UNAVAILABLE;
   }

   // Get pointer to DTrackHitSelector object
   vector<const DTrackHitSelector *> hitselectors;
   loop->Get(hitselectors);
   if(hitselectors.size()<1){
      _DBG_<<"ERROR: Unable to get a DTrackHitSelector object! NO DTrackCandidate:THROWN objects will be created!"<<endl;
      return RESOURCE_UNAVAILABLE;
   }
   hitselector = hitselectors[0];

   // Get the particle ID algorithms
   loop->GetSingle(dParticleID);

   return NOERROR;
}

//------------------
// evnt
//------------------
jerror_t DTrackCandidate_factory_THROWN::evnt(JEventLoop *loop, uint64_t eventnumber)
{
   vector<const DMCThrown*> mcthrowns;
   vector<const DCDCTrackHit*> cdctrackhits;
   vector<const DFDCPseudo*> fdcpseudos;
   loop->Get(mcthrowns);
   loop->Get(cdctrackhits);
   loop->Get(fdcpseudos);

   for(unsigned int i=0; i< mcthrowns.size(); i++){
      const DMCThrown *thrown = mcthrowns[i];
      const DKinematicData *kd_thrown = thrown;

      if(fabs(thrown->charge())<1)continue;

      // First, copy over the DKinematicData part
      DTrackCandidate *candidate = new DTrackCandidate;
      DKinematicData *kd_candidate = candidate;
      *kd_candidate = *kd_thrown;
      
      // Add DMCThrown as associated object
      candidate->AddAssociatedObject(thrown);

      // We need to swim a reference trajectory here. To avoid the overhead
      // of allocating/deallocating them every event, we keep a pool and
      // re-use them. If the pool is not big enough, then add one to the
      // pool.
      unsigned int locNumInitialReferenceTrajectories = rt_pool.size();
      if(rt_pool.size()<=_data.size()){
         // This is a little ugly, but only gets called a few times throughout the life of the process
         // Note: these never get deleted, even at the end of process.
         rt_pool.push_back(new DReferenceTrajectory(bfield));
      }
      DReferenceTrajectory *rt = rt_pool[_data.size()];
      if(locNumInitialReferenceTrajectories == rt_pool.size()) //didn't create a new one
        rt->Reset();
      rt->q = candidate->charge();
      candidate->rt = rt;
      DVector3 pos = candidate->position();
      DVector3 mom = candidate->momentum();
      rt->Swim(pos, mom, candidate->charge());

      // Find hits that should be on this track and add them as associated objects
      vector<const DCDCTrackHit*> cdchits;
      vector<const DFDCPseudo*> fdchits;
      if(hitselector)hitselector->GetCDCHits(DTrackHitSelector::kHelical, rt, cdctrackhits, cdchits);
      if(hitselector)hitselector->GetFDCHits(DTrackHitSelector::kHelical, rt, fdcpseudos, fdchits);
      for(unsigned int i=0; i<cdchits.size(); i++)candidate->AddAssociatedObject(cdchits[i]);
      for(unsigned int i=0; i<fdchits.size(); i++)candidate->AddAssociatedObject(fdchits[i]);

      // We want to get chisq and Ndof values for this track using the hits from above.
      // We do this using the DTrackFitter object. This more or less guarantees that the
      // chisq calculation is done in the same way as it is for track fitting. Note
      // that no fitting is actually done here so this should be reasonably fast
      if(fitter){
         fitter->Reset();
         fitter->AddHits(cdchits);
         fitter->AddHits(fdchits);
         double chisq;
         int Ndof;
         fitter->ChiSq(DTrackFitter::kTimeBased, rt, &chisq, &Ndof);
         candidate->chisq = chisq;
         candidate->Ndof = Ndof;
      }else{
         candidate->chisq = 0.0;
         candidate->Ndof = 0;
      }

      _data.push_back(candidate);
   }

  // Set CDC ring & FDC plane hit patterns
  for(size_t loc_i = 0; loc_i < _data.size(); ++loc_i)
  {
    vector<const DCDCTrackHit*> locCDCTrackHits;
    _data[loc_i]->Get(locCDCTrackHits);

    vector<const DFDCPseudo*> locFDCPseudos;
    _data[loc_i]->Get(locFDCPseudos);

    _data[loc_i]->dCDCRings = dParticleID->Get_CDCRingBitPattern(locCDCTrackHits);
    _data[loc_i]->dFDCPlanes = dParticleID->Get_FDCPlaneBitPattern(locFDCPseudos);
  }

   return NOERROR;
}