Trk2DDistanceFinder.cxx

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/*
  Copyright (C) 2002-2019 CERN for the benefit of the ATLAS collaboration
*/
 
/*********************************************************************
    Trk2DDistanceFinder.cxx - Description in header file
*********************************************************************/
 
//#define SEEDNEWTONTRKDISTANCEFINDER_DEBUG
 
 
#include "TrkVertexSeedFinderUtils/Trk2DDistanceFinder.h"
#include "EventPrimitives/EventPrimitives.h"
#include "GeoPrimitives/GeoPrimitives.h"
#include "TrkEventPrimitives/ParamDefs.h"
#include "TrkParameters/TrackParameters.h"
#include "TrkParticleBase/TrackParticleBase.h"
#include "TrkTrack/Track.h"
#include "TrkVertexSeedFinderUtils/SeedFinderParamDefs.h"
#include "TrkVertexSeedFinderUtils/Trk2dDistanceSeeder.h"
#include <cmath>
 
 
namespace Trk
{
 
 
  Trk2DDistanceFinder::Trk2DDistanceFinder(const std::string& t, const std::string& n, const IInterface*  p) :
    base_class(t,n,p),
    m_2ddistanceseeder("Trk::Trk2dDistanceSeeder"),
    m_numberOfMinimizationFailures(0)
  {
    declareProperty("Trk2dDistanceSeeder",     m_2ddistanceseeder);
  }
 
  Trk2DDistanceFinder::~Trk2DDistanceFinder() = default;
 
  StatusCode Trk2DDistanceFinder::initialize()
  {
 
    //initialize number of failures to 0
    m_numberOfMinimizationFailures=0;
 
    ATH_CHECK( AlgTool::initialize() );
    ATH_CHECK( m_2ddistanceseeder.retrieve() );
    ATH_MSG_DEBUG( "Initialize successful" );
    return StatusCode::SUCCESS;
  }
 
  StatusCode Trk2DDistanceFinder::finalize()
  {
    ATH_MSG_DEBUG( "Finalize successful. Number of failed minimizations: " << m_numberOfMinimizationFailures << ". Few per events is OK!" );
    return StatusCode::SUCCESS;
  }
 

  std::optional<ITrkDistanceFinder::TwoPoints>
  Trk2DDistanceFinder::CalculateMinimumDistance(const Trk::Perigee & a,
                                                const Trk::Perigee & b) const
  {
    std::pair<PointOnTrack,PointOnTrack> minpoints;
    Trk::TwoPoints points;
 
    try {
      minpoints=m_2ddistanceseeder->GetSeed(TwoTracks(a,b), &points);
    } catch (...) {
      ATH_MSG_WARNING( "Problem with 2d analytic minimum distance finder" );
      m_numberOfMinimizationFailures+=1;
      return std::nullopt;
    }
 
 
#ifdef SEEDNEWTONTRKDISTANCEFINDER_DEBUG
    ATH_MSG_DEBUG( "Returned a_phi " << minpoints.first.getPhiPoint() );
    ATH_MSG_DEBUG( "Returned b_phi " << minpoints.second.getPhiPoint() );
#endif
 
    return points;
 
  }

  std::optional<ITrkDistanceFinder::TwoPoints>
  Trk2DDistanceFinder::CalculateMinimumDistance(const  Trk::Track & a,
                                                const Trk::Track & b) const
  {
    if (std::isnan(a.perigeeParameters()->parameters()[Trk::d0])||std::isnan(b.perigeeParameters()->parameters()[Trk::d0])) {
      ATH_MSG_ERROR( "Nan parameters in tracks. Cannot use them" );
      return std::nullopt;
    }
 
    return CalculateMinimumDistance(*(a.perigeeParameters()),*(b.perigeeParameters()));
  }
 
} // namespace Trk