ShowerTrackTrajToSpacePoint_tool.cc

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//############################################################################
//### Name:        ShowerTrackTrajToSpacePoint                             ###
//### Author:      Dominic Barker                                          ###
//### Date:        01.10.19                                                ###
//### Description: Tool to associate the initial track trajectory points   ###
//###              to the spacepoints                                      ###
//############################################################################

//Framework Includes
#include "art/Utilities/ToolMacros.h"

//LArSoft Includes
#include "lardataobj/RecoBase/Hit.h"
#include "lardataobj/RecoBase/SpacePoint.h"
#include "lardataobj/RecoBase/Track.h"
#include "larpandora/LArPandoraEventBuilding/LArPandoraShower/Tools/IShowerTool.h"

namespace ShowerRecoTools {

  class ShowerTrackTrajToSpacePoint : public IShowerTool {

  public:
    ShowerTrackTrajToSpacePoint(const fhicl::ParameterSet& pset);

    //Match trajectory points to the spacepoints
    int CalculateElement(const art::Ptr<recob::PFParticle>& pfparticle,
                         art::Event& Event,
                         reco::shower::ShowerElementHolder& ShowerEleHolder) override;

  private:
    float fMaxDist; //Max distance that a spacepoint can be from a trajectory
    //point to be matched
    art::InputTag fPFParticleLabel;
    int fVerbose;

    std::string fInitialTrackSpacePointsOutputLabel;
    std::string fInitialTrackHitsOutputLabel;
    std::string fInitialTrackInputTag;
    std::string fShowerStartPositionInputTag;
    std::string fInitialTrackSpacePointsInputTag;
  };

  ShowerTrackTrajToSpacePoint::ShowerTrackTrajToSpacePoint(const fhicl::ParameterSet& pset)
    : IShowerTool(pset.get<fhicl::ParameterSet>("BaseTools"))
    , fMaxDist(pset.get<float>("MaxDist"))
    , fPFParticleLabel(pset.get<art::InputTag>("PFParticleLabel"))
    , fVerbose(pset.get<int>("Verbose"))
    , fInitialTrackSpacePointsOutputLabel(
        pset.get<std::string>("InitialTrackSpacePointsOutputLabel"))
    , fInitialTrackHitsOutputLabel(pset.get<std::string>("InitialTrackHitsOutputLabel"))
    , fInitialTrackInputTag(pset.get<std::string>("InitialTrackInputTag"))
    , fShowerStartPositionInputTag(pset.get<std::string>("ShowerStartPositionInputTag"))
    , fInitialTrackSpacePointsInputTag(pset.get<std::string>("InitialTrackSpacePointsInputTag"))
  {}

  int
  ShowerTrackTrajToSpacePoint::CalculateElement(const art::Ptr<recob::PFParticle>& pfparticle,
                                                art::Event& Event,
                                                reco::shower::ShowerElementHolder& ShowerEleHolder)
  {

    //Check the Track has been defined
    if (!ShowerEleHolder.CheckElement(fInitialTrackInputTag)) {
      if (fVerbose)
        mf::LogError("ShowerTrackTrajToSpacePoint") << "Initial track not set" << std::endl;
      return 0;
    }

    //Check the start position is set.
    if (!ShowerEleHolder.CheckElement(fShowerStartPositionInputTag)) {
      if (fVerbose)
        mf::LogError("ShowerTrackTrajToSpacePoint")
          << "Start position not set, returning " << std::endl;
      return 0;
    }

    //Check the Track Hits has been defined
    if (!ShowerEleHolder.CheckElement(fInitialTrackSpacePointsInputTag)) {
      if (fVerbose)
        mf::LogError("ShowerTrackTrajToSpacePoint")
          << "Initial track spacepoints not set" << std::endl;
      return 0;
    }

    //Get the start poistion
    TVector3 ShowerStartPosition = {-999, -999, -999};
    ShowerEleHolder.GetElement(fShowerStartPositionInputTag, ShowerStartPosition);

    //Get the initial track hits.
    std::vector<art::Ptr<recob::SpacePoint>> intitaltrack_sp;
    ShowerEleHolder.GetElement(fInitialTrackSpacePointsInputTag, intitaltrack_sp);

    //Get the track
    recob::Track InitialTrack;
    ShowerEleHolder.GetElement(fInitialTrackInputTag, InitialTrack);

    std::vector<art::Ptr<recob::SpacePoint>> new_intitaltrack_sp;
    //Loop over the trajectory points
    for (unsigned int traj = 0; traj < InitialTrack.NumberTrajectoryPoints(); ++traj) {

      //ignore bogus info.
      auto flags = InitialTrack.FlagsAtPoint(traj);
      if (flags.isSet(recob::TrajectoryPointFlagTraits::NoPoint)) { continue; }

      geo::Point_t TrajPositionPoint = InitialTrack.LocationAtPoint(traj);
      TVector3 TrajPosition = {TrajPositionPoint.X(), TrajPositionPoint.Y(), TrajPositionPoint.Z()};

      geo::Point_t TrajPositionStartPoint = InitialTrack.LocationAtPoint(0);
      TVector3 TrajPositionStart = {
        TrajPositionStartPoint.X(), TrajPositionStartPoint.Y(), TrajPositionStartPoint.Z()};

      //Ignore values with 0 mag from the start position
      if ((TrajPosition - TrajPositionStart).Mag() == 0) { continue; }
      if ((TrajPosition - ShowerStartPosition).Mag() == 0) { continue; }

      float MinDist = 9999;
      unsigned int index = 999;
      for (unsigned int sp = 0; sp < intitaltrack_sp.size(); ++sp) {
        //Find the spacepoint closest to the trajectory point.
        art::Ptr<recob::SpacePoint> spacepoint = intitaltrack_sp[sp];
        TVector3 pos =
          IShowerTool::GetLArPandoraShowerAlg().SpacePointPosition(spacepoint) - TrajPosition;
        if (pos.Mag() < MinDist && pos.Mag() < fMaxDist) {
          MinDist = pos.Mag();
          index = sp;
        }
      }

      if (index == 999) { continue; }
      //Add the spacepoint to the track spacepoints.
      new_intitaltrack_sp.push_back(intitaltrack_sp[index]);

      //Delete the spacepoint so it can not be used again.
      intitaltrack_sp.erase(intitaltrack_sp.begin() + index);
    }

    // Get the spacepoints
    auto const spHandle = Event.getValidHandle<std::vector<recob::SpacePoint>>(fPFParticleLabel);

    // Get the hits associated with the space points
    const art::FindOneP<recob::Hit>& fohsp =
      ShowerEleHolder.GetFindOneP<recob::Hit>(spHandle, Event, fPFParticleLabel);

    //Save the corresponding hits
    std::vector<art::Ptr<recob::Hit>> trackHits;
    for (auto const& spacePoint : new_intitaltrack_sp) {
      //Get the hits
      const art::Ptr<recob::Hit> hit = fohsp.at(spacePoint.key());
      trackHits.push_back(hit);
    }

    //Save the spacepoints.
    ShowerEleHolder.SetElement(new_intitaltrack_sp, fInitialTrackSpacePointsOutputLabel);
    ShowerEleHolder.SetElement(trackHits, fInitialTrackHitsOutputLabel);

    return 0;
  }

}

DEFINE_ART_CLASS_TOOL(ShowerRecoTools::ShowerTrackTrajToSpacePoint)