Vertexer.cxx

#include "Tracking/Reco/Vertexer.h"
 
#include <chrono>
 
#include "TFile.h"
using namespace framework;
 
// This producer takes in input two track collections and forms all possible
// vertices from those It can be used to match the tagger and recoil tracks at
// the target and form the beamspot
 
// TODO Move all the performance monitor to another processor
 
namespace tracking {
namespace reco {
 
Vertexer::Vertexer(const std::string& name, framework::Process& process)
    : framework::Producer(name, process) {}
 
void Vertexer::onProcessStart() {
  // Monitoring plots
 
  double d0min = -2;
  double d0max = 2;
  double z0min = -2;
  double z0max = 2;
 
  h_delta_d0_ = new TH1F("h_delta_d0", "h_delta_d0", 400, d0min, d0max);
  h_delta_z0_ = new TH1F("h_delta_z0", "h_delta_z0", 200, z0min, z0max);
  h_delta_p_ = new TH1F("h_delta_p", "h_delta_p", 200, -1, 4);
  // h_delta_pT_vsP    = new TH2D("h_delta_pT_vs_p","h_delta_pT_v_p",200,)
  h_delta_phi_ = new TH1F("h_delta_phi", "h_delta_phi", 400, -0.2, 0.2);
  h_delta_theta_ = new TH1F("h_delta_theta", "h_delta_theta", 200, -0.1, 0.1);
 
  h_delta_d0_vs_recoil_p_ =
      new TH2F("h_delta_d0_vs_recoil_p", "h_delta_d0_vs_recoil_p", 200, 0, 5,
               400, -1, 1);
  h_delta_z0_vs_recoil_p_ =
      new TH2F("h_delta_z0_vs_recoil_p", "h_delta_z0_vs_recoil_p", 200, 0, 5,
               400, -1, 1);
 
  h_td0_vs_rd0_ =
      new TH2F("h_td0_vs_rd0", "h_td0_vs_rd0", 100, -40, 40, 100, -40, 40);
  h_tz0_vs_rz0_ =
      new TH2F("h_tz0_vs_rz0", "h_tz0_vs_rz0", 100, -40, 40, 100, -40, 40);
 
  gctx_ = Acts::GeometryContext();
  bctx_ = Acts::MagneticFieldContext();
 
  /*
   * This is unused now, should it be?
  auto localToGlobalBin_xyz = [](std::array<size_t, 3> bins,
                                 std::array<size_t, 3> sizes) {
    return (bins[0] * (sizes[1] * sizes[2]) + bins[1] * sizes[2] +
            bins[2]);  // xyz - field space
    // return (bins[1] * (sizes[2] * sizes[0]) + bins[2] * sizes[0] + bins[0]);
    // //zxy
  };
  */
 
  sp_interpolated_b_field_ =
      std::make_shared<InterpolatedMagneticField3>(loadDefaultBField(
          field_map_, defaultTransformPos, defaultTransformBField));
 
  // There is a sign issue between the vertexing and the perigee representation
  Acts::Vector3 b_field(0., 0., -1.5 * Acts::UnitConstants::T);
  b_field_ = std::make_shared<Acts::ConstantBField>(b_field);
 
  std::cout << "Check if nullptr::" << sp_interpolated_b_field_.get()
            << std::endl;
 
  // Set up propagator with void navigator
  // auto&& stepper = Acts::EigenStepper<>{sp_interpolated_bField_};
  // propagator_ = std::make_shared<VoidPropagator>(stepper);
 
  auto&& stepper_const = Acts::EigenStepper<>{b_field_};
  propagator_ = std::make_shared<VoidPropagator>(stepper_const);
}
 
void Vertexer::configure(framework::config::Parameters& parameters) {
  // TODO:: the bfield map should be taken automatically
  field_map_ = parameters.get<std::string>("field_map");
 
  trk_c_name_1_ = parameters.get<std::string>("trk_c_name_1", "TaggerTracks");
  trk_c_name_2_ = parameters.get<std::string>("trk_c_name_2", "RecoilTracks");
  input_pass_name_ = parameters.get<std::string>("input_pass_name");
}
 
void Vertexer::produce(framework::Event& event) {
  nevents_++;
  // auto start = std::chrono::high_resolution_clock::now();
 
  // Track linearizer in the proximity of the vertex location
  using Linearizer = Acts::HelicalTrackLinearizer;
  Linearizer::Config linearizer_config;
  linearizer_config.bField = b_field_;
  linearizer_config.propagator = propagator_;
  Linearizer linearizer(linearizer_config);
 
  // Set up Billoir Vertex Fitter
  using VertexFitter = Acts::FullBilloirVertexFitter;
 
  // Alternatively one can use
  // using VertexFitter =
  //  Acts::FullBilloirVertexFitter<tracking::sim::utils::boundTrackParameters,Linearizer>;
 
  VertexFitter::Config vertex_fitter_cfg;
  VertexFitter billoir_fitter(vertex_fitter_cfg);
  //  mg Aug 2024 .. State doesn't exist in v36 and isn't used here anyway
  //  VertexFitter::State state(sp_interpolated_bField_->makeCache(bctx_));
 
  // Unconstrained fit
  // See
  // https://github.com/acts-project/acts/blob/main/Tests/UnitTests/Core/Vertexing/FullBilloirVertexFitterTests.cpp#L149
  // For constraint implementation
 
  //  Acts::VertexingOptions<Acts::BoundTrackParameters> vfOptions(gctx_,
  //  bctx_);
  // mg Aug 2024 ... VertexingOptions template change in v36
  Acts::VertexingOptions vf_options(gctx_, bctx_);
 
  // Retrive the two track collections
 
  const std::vector<ldmx::Track> tracks_1 =
      event.getCollection<ldmx::Track>(trk_c_name_1_, input_pass_name_);
  const std::vector<ldmx::Track> tracks_2 =
      event.getCollection<ldmx::Track>(trk_c_name_2_, input_pass_name_);
 
  ldmx_log(debug) << "Retrieved track collections" << std::endl
                  << "Track 1 size:" << tracks_1.size() << std::endl
                  << "Track 2 size:" << tracks_2.size() << std::endl;
 
  if (tracks_1.size() < 1 || tracks_2.size() < 1) return;
 
  std::vector<Acts::BoundTrackParameters> billoir_tracks_1, billoir_tracks_2;
 
  // TODO:: The perigee surface should be common between all tracks.
 
  Acts::Vector3 perigee_acts = tracking::sim::utils::ldmx2Acts(Acts::Vector3(
      tracks_1.front().getPerigeeX(), tracks_1.front().getPerigeeY(),
      tracks_1.front().getPerigeeZ()));
  std::shared_ptr<Acts::PerigeeSurface> perigee_surface =
      Acts::Surface::makeShared<Acts::PerigeeSurface>(perigee_acts);
 
  // Monitoring of tagger and recoil tracks
  taggerRecoilMonitoring(tracks_1, tracks_2);
 
  // Start the vertex formation
  // Form a vertex for each combination of tracks found in the same event
  // between the two track collections
 
  for (auto& trk : tracks_1) {
    billoir_tracks_1.push_back(
        tracking::sim::utils::boundTrackParameters(trk, perigee_surface));
  }
 
  for (auto& trk : tracks_2) {
    billoir_tracks_2.push_back(
        tracking::sim::utils::boundTrackParameters(trk, perigee_surface));
  }
 
  //  std::vector<Acts::Vertex<Acts::BoundTrackParameters> > fit_vertices;
  std::vector<Acts::Vertex> fit_vertices;
 
  for (auto& b_trk_1 : billoir_tracks_1) {
    std::vector<const Acts::BoundTrackParameters*> fit_tracks_ptr;
 
    for (auto& b_trk_2 : billoir_tracks_2) {
      fit_tracks_ptr.push_back(&b_trk_1);
      fit_tracks_ptr.push_back(&b_trk_2);
 
      ldmx_log(debug) << "Calling vertex fitter" << std::endl
                      << "Track 1 parameters" << std::endl
                      << b_trk_1 << std::endl
                      << "Track 2 parameters" << std::endl
                      << b_trk_2 << std::endl;
 
      //  std::cout << "Perigee Surface" << std::endl;
      //  perigeeSurface->toStream(gctx_, std::cout);
      //  std::cout << std::endl;
 
    }  // loop on second set of tracks
 
    nreconstructable_++;
    try {
      // Acts::Vertex<Acts::BoundTrackParameters> fitVtx =
      // billoirFitter.fit(fit_tracks_ptr, linearizer, vfOptions,
      // state).value(); fit_vertices.push_back(fitVtx);
      nvertices_++;
 
    } catch (...) {
      ldmx_log(warn) << "Vertex fit failed" << std::endl;
    }
 
  }  // loop on first set
 
  // Convert the vertices in the ldmx EDM and store them
}
 
void Vertexer::onProcessEnd() {
  ldmx_log(info) << "Reconstructed " << nvertices_ << " vertices over "
                 << nreconstructable_ << " reconstructable" << std::endl;
 
  TFile* outfile = new TFile((getName() + ".root").c_str(), "RECREATE");
  outfile->cd();
 
  h_delta_d0_->Write();
  h_delta_z0_->Write();
  h_delta_p_->Write();
  h_delta_phi_->Write();
  h_delta_theta_->Write();
 
  h_delta_d0_vs_recoil_p_->Write();
  h_delta_z0_vs_recoil_p_->Write();
 
  h_td0_vs_rd0_->Write();
  h_tz0_vs_rz0_->Write();
 
  outfile->Close();
  delete outfile;
}
 
void Vertexer::taggerRecoilMonitoring(
    const std::vector<ldmx::Track>& tagger_tracks,
    const std::vector<ldmx::Track>& recoil_tracks) {
  // For the moment only check that I have 1 tagger track and one recoil track
  // To avoid trying to match them
  // TODO update this logic
 
  if (tagger_tracks.size() != 1 || recoil_tracks.size() != 1) return;
 
  ldmx::Track t_trk = tagger_tracks.at(0);
  ldmx::Track r_trk = recoil_tracks.at(0);
 
  double t_p, r_p;
  // these are unsed, should they be? FIXME
  // double t_d0, r_d0;
  // double tt_p_phi, r_phi;
  // double t_theta, r_theta;
  // double t_z0, r_z0;
 
  t_p = t_trk.getCharge() / t_trk.getQoP();
  r_p = r_trk.getCharge() / r_trk.getQoP();
 
  h_delta_d0_->Fill(t_trk.getD0() - r_trk.getD0());
  h_delta_z0_->Fill(t_trk.getZ0() - r_trk.getZ0());
  h_delta_p_->Fill(t_p - r_p);
  h_delta_phi_->Fill(t_trk.getPhi() - r_trk.getPhi());
  h_delta_theta_->Fill(t_trk.getTheta() - r_trk.getTheta());
 
  // differential plots
 
  h_delta_d0_vs_recoil_p_->Fill(r_p, t_trk.getD0() - r_trk.getD0());
  h_delta_z0_vs_recoil_p_->Fill(r_p, t_trk.getZ0() - r_trk.getZ0());
 
  //"beamspot"
  h_td0_vs_rd0_->Fill(r_trk.getD0(), t_trk.getD0());
  h_tz0_vs_rz0_->Fill(r_trk.getZ0(), t_trk.getZ0());
 
  //"pT"
  // TODO Transverse momentum should obtained orthogonal to the B-Field
  // direction This assumes to be along Z (which is not very accurate)
 
  // std::vector<double> r_mom = r_trk.getMomentum();
  // std::vector<double> t_mom = t_trk.getMomentum();
 
  // I assume to have a single photon being emitted in the target: I use
  // momentum conservation p_photon = p_beam - p_recoil
 
  // h_gamma_px->Fill(t_mom[0] - r_mom[0]);
  // h_gamma_py->Fill(t_mom[1] - r_mom[1]);
  // h_gamma_pz->Fill(t_mom[2] - r_mom[2]);
}
 
}  // namespace reco
}  // namespace tracking
 
DECLARE_PRODUCER(tracking::reco::Vertexer)