GSFProcessor.cxx

#include "Tracking/Reco/GSFProcessor.h"
 
#include <algorithm>
 
#include "Acts/EventData/SourceLink.hpp"
#include "Tracking/Event/Track.h"
 
namespace tracking {
namespace reco {
 
GSFProcessor::GSFProcessor(const std::string& name, framework::Process& process)
    : TrackingGeometryUser(name, process) {}
 
void GSFProcessor::onNewRun(const ldmx::RunHeader& rh) {
  beam_origin_surface_ = tracking::sim::utils::unboundSurface(-700);
  target_surface_ = tracking::sim::utils::unboundSurface(0.);
  ecal_surface_ = tracking::sim::utils::unboundSurface(240.5);
 
  // Setup a interpolated bfield map
  if (field_map_.empty())
    loadBField();
  else
    loadBField(field_map_);
  const auto map =
      std::static_pointer_cast<InterpolatedMagneticField3>(bField());
 
  auto acts_logging_level = Acts::Logging::FATAL;
 
  if (debug_) acts_logging_level = Acts::Logging::VERBOSE;
 
  // Setup the GSF Fitter
 
  // Stepper
  // Acts::MixtureReductionMethod finalReductionMethod;
  // const auto multi_stepper = Acts::MultiEigenStepperLoop{map};
 
  // Acts::ComponentMergeMethod reductionMethod =
  //    Acts::ComponentMergeMethod::eMaxWeight;
  //  Acts::MultiEigenStepperLoop multi_stepper(
  //      map, reductionMethod,
  //      Acts::getDefaultLogger("GSF_STEP", acts_loggingLevel));
 
  Acts::MultiEigenStepperLoop multi_stepper(map);
  // Detailed Stepper
 
  // Acts::MultiEigenStepperLoop multi_stepper(map, finalReductionMethod);
 
  // Navigator
  Acts::Navigator::Config nav_cfg{geometry().getTG()};
  nav_cfg.resolveMaterial = true;
  nav_cfg.resolvePassive = false;
  nav_cfg.resolveSensitive = true;
  const Acts::Navigator navigator(nav_cfg);
 
  auto gsf_propagator =
      GsfPropagator(std::move(multi_stepper), std::move(navigator),
                    Acts::getDefaultLogger("GSF_PROP", acts_logging_level));
 
  BetheHeitlerApprox bethe_heitler = Acts::makeDefaultBetheHeitlerApprox();
 
  gsf_ = std::make_unique<std::decay_t<decltype(*gsf_)>>(
      std::move(gsf_propagator), std::move(bethe_heitler),
      Acts::getDefaultLogger("GSF", acts_logging_level));
 
  const auto stepper = Acts::EigenStepper<>{map};
  propagator_ = std::make_unique<Propagator>(
      stepper, navigator,
      Acts::getDefaultLogger("GSF_EXTRAP", acts_logging_level));
 
  trk_extrap_ = std::make_shared<std::decay_t<decltype(*trk_extrap_)>>(
      *propagator_, geometryContext(), magneticFieldContext());
}
 
void GSFProcessor::configure(framework::config::Parameters& parameters) {
  out_trk_collection_ =
      parameters.get<std::string>("out_trk_collection", "GSFTracks");
 
  track_collection_ =
      parameters.get<std::string>("track_collection", "TaggerTracks");
  meas_collection_ =
      parameters.get<std::string>("meas_collection", "DigiTaggerSimHits");
 
  track_passname_ = parameters.get<std::string>("track_passname");
  meas_passname_ = parameters.get<std::string>("meas_passname");
  track_collection_event_passname_ =
      parameters.get<std::string>("track_collection_event_passname");
  meas_collection_event_passname_ =
      parameters.get<std::string>("meas_collection_event_passname");
 
  max_components_ = parameters.get<int>("max_components", 4);
  abort_on_error_ = parameters.get<bool>("abort_on_error", false);
  disable_all_material_handling_ =
      parameters.get<bool>("disable_all_material_handling", false);
  weight_cutoff_ = parameters.get<double>("weight_cutoff_", 1.0e-4);
 
  propagator_max_steps_ = parameters.get<int>("propagator_max_steps", 10000);
  propagator_step_size_ = parameters.get<double>("propagator_step_size", 200.);
  field_map_ = parameters.get<std::string>("field_map");
  use_perigee_ = parameters.get<bool>("usePerigee", false);
 
  debug_ = parameters.get<bool>("debug", false);
  tagger_tracking_ = parameters.get<bool>("tagger_tracking", true);
 
  // final_reduction_method_ =
  // parameters.get<double>("finalReductionMethod",);
}  // end of configure()
 
void GSFProcessor::produce(framework::Event& event) {
  // General Setup
 
  auto tg{geometry()};
 
  // Retrieve the tracks
  if (!event.exists(track_collection_, track_collection_event_passname_))
    return;
  const auto& tracks =
      event.getCollection<ldmx::Track>(track_collection_, track_passname_);
 
  // Retrieve the measurements
  if (!event.exists(meas_collection_, meas_collection_event_passname_)) return;
  const auto& measurements =
      event.getCollection<ldmx::Measurement>(meas_collection_, meas_passname_);
 
  tracking::sim::LdmxMeasurementCalibrator calibrator{measurements};
 
  // GSF Setup
  Acts::GainMatrixUpdater updater;
  Acts::GsfExtensions<Acts::VectorMultiTrajectory> gsf_extensions;
  gsf_extensions.updater.connect<
      &Acts::GainMatrixUpdater::operator()<Acts::VectorMultiTrajectory>>(
      &updater);
  gsf_extensions.calibrator
      .connect<&tracking::sim::LdmxMeasurementCalibrator::calibrate1d<
          Acts::VectorMultiTrajectory>>(&calibrator);
 
  // Surface Accessor
  struct SurfaceAccessor {
    const Acts::TrackingGeometry* tracking_geometry_;
 
    const Acts::Surface* operator()(const Acts::SourceLink& sourceLink) const {
      const auto& index_source_link =
          sourceLink.get<acts_examples::IndexSourceLink>();
      return tracking_geometry_->findSurface(index_source_link.geometryId());
    }
  };
 
  SurfaceAccessor m_sl_surface_accessor{tg.getTG().get()};
  // m_slSurfaceAccessor.trackingGeometry = tg.getTG();
  gsf_extensions.surfaceAccessor.connect<&SurfaceAccessor::operator()>(
      &m_sl_surface_accessor);
  gsf_extensions.mixtureReducer.connect<&Acts::reduceMixtureLargestWeights>();
 
  // Propagator Options
 
  // Move this at the start of the producer
  Acts::PropagatorOptions<Acts::StepperPlainOptions,
                          Acts::NavigatorPlainOptions, ActionList, AbortList>
      propagator_options(geometryContext(), magneticFieldContext());
 
  propagator_options.pathLimit = std::numeric_limits<double>::max();
 
  // Activate loop protection at some pt value
  propagator_options.loopProtection = false;
  //(startParameters.transverseMomentum() < cfg.ptLoopers);
 
  // Switch the material interaction on/off & eventually into logging mode
  auto& m_interactor =
      propagator_options.actionList.get<Acts::MaterialInteractor>();
  m_interactor.multipleScattering = true;
  m_interactor.energyLoss = true;
  m_interactor.recordInteractions = false;
 
  // The logger can be switched to sterile, e.g. for timing logging
  auto& s_logger =
      propagator_options.actionList.get<Acts::detail::SteppingLogger>();
  s_logger.sterile = true;
  // Set a maximum step size
  propagator_options.stepping.maxStepSize =
      propagator_step_size_ * Acts::UnitConstants::mm;
  propagator_options.maxSteps = propagator_max_steps_;
 
  // Electron hypothesis
  //  propagator_options.mass = 0.511 * Acts::UnitConstants::MeV;
 
  // GSF options will be configured per-track
  std::shared_ptr<const Acts::Surface> gsf_ref_surface;
  Acts::GsfOptions<Acts::VectorMultiTrajectory> gsf_options{
      geometryContext(), magneticFieldContext(), calibrationContext()};
  gsf_options.extensions = gsf_extensions;
  gsf_options.propagatorPlainOptions = propagator_options;
  gsf_options.maxComponents = max_components_;
  gsf_options.weightCutoff = weight_cutoff_;
  gsf_options.abortOnError = abort_on_error_;
  gsf_options.disableAllMaterialHandling = disable_all_material_handling_;
 
  // Output track container
  std::vector<ldmx::Track> out_tracks;
 
  Acts::VectorTrackContainer vtc;
  Acts::VectorMultiTrajectory mtj;
  Acts::TrackContainer tc{vtc, mtj};
 
  // Loop on tracks
  unsigned int itrk = 0;
  ldmx_log(debug) << "Starting GSF processing of " << tracks.size()
                  << " tracks";
 
  for (auto& track : tracks) {
    ldmx_log(debug) << "Processing track " << itrk << " with "
                    << track.getMeasurementsIdxs().size() << " measurements";
    // Retrieve measurements on track
    std::vector<ldmx::Measurement> meas_on_track;
 
    // std::vector<ActsExamples::IndexSourceLink> fit_trackSourceLinks;
    std::vector<Acts::SourceLink> fit_track_source_links;
 
    for (auto imeas : track.getMeasurementsIdxs()) {
      auto meas = measurements.at(imeas);
      meas_on_track.push_back(meas);
 
      // Retrieve the surface
 
      const Acts::Surface* hit_surface =
          tg.geo::TrackingGeometry::getSurface(meas.getLayerID());
 
      // Store the index_ source link
      acts_examples::IndexSourceLink idx_sl(hit_surface->geometryId(), imeas);
      fit_track_source_links.push_back(Acts::SourceLink(idx_sl));
    }
 
    // Reverse the order of the vectors
    std::reverse(meas_on_track.begin(), meas_on_track.end());
    std::reverse(fit_track_source_links.begin(), fit_track_source_links.end());
 
    for (auto m : meas_on_track) {
      ldmx_log(trace) << "    Measurement:\n" << m << "\n";
    }
 
    ldmx_log(debug) << "  Track bound track parameters preparation:";
 
    // Reconstruct BoundTrackParameters at perigee (target) from stored params.
    // perigee_ is stored in LDMX frame; rotate to ACTS frame for surface
    // creation.
    Acts::Vector3 perigee_acts = tracking::sim::utils::ldmx2Acts(Acts::Vector3(
        track.getPerigeeX(), track.getPerigeeY(), track.getPerigeeZ()));
    std::shared_ptr<Acts::PerigeeSurface> perigee =
        Acts::Surface::makeShared<Acts::PerigeeSurface>(perigee_acts);
 
    Acts::BoundTrackParameters trk_btp =
        tracking::sim::utils::boundTrackParameters(track, perigee);
 
    // GSF starting parameters: for tagger, extrapolate back to beam origin;
    // for recoil, use target parameters directly.
    Acts::BoundTrackParameters trk_btp_fit_start = trk_btp;
 
    if (tagger_tracking_) {
      auto opt_beam_origin =
          trk_extrap_->extrapolate(trk_btp, beam_origin_surface_);
      if (!opt_beam_origin) {
        ldmx_log(warn) << "Failed extrapolating to beam origin for GSF start. "
                          "Skipping..";
        continue;
      }
      trk_btp_fit_start = *opt_beam_origin;
    }
 
    ldmx_log(debug) << "    Perigee surface (acts): (" << track.getPerigeeX()
                    << ", " << track.getPerigeeY() << ", "
                    << track.getPerigeeZ() << ")";
 
    const Acts::BoundVector& trkpars = trk_btp.parameters();
    ldmx_log(debug) << "    Perigee parameters (d0, z0, phi, theta, q/p)= ("
                    << trkpars[Acts::eBoundLoc0] << ", "
                    << trkpars[Acts::eBoundLoc1] << ", "
                    << trkpars[Acts::eBoundPhi] << ", "
                    << trkpars[Acts::eBoundTheta] << ", "
                    << trkpars[Acts::eBoundQOverP] << ")";
 
    const Acts::BoundVector& fit_start_pars = trk_btp_fit_start.parameters();
    ldmx_log(debug) << "    GSF start parameters (d0, z0, phi, theta, q/p)= ("
                    << fit_start_pars[Acts::eBoundLoc0] << ", "
                    << fit_start_pars[Acts::eBoundLoc1] << ", "
                    << fit_start_pars[Acts::eBoundPhi] << ", "
                    << fit_start_pars[Acts::eBoundTheta] << ", "
                    << fit_start_pars[Acts::eBoundQOverP] << ")";
 
    ldmx_log(debug) << "  About to run GSF fit with "
                    << fit_track_source_links.size() << " source links";
 
    // Update GSF reference surface for this track
    if (tagger_tracking_) {
      gsf_ref_surface = beam_origin_surface_;
    } else {
      gsf_ref_surface = target_surface_;
    }
    gsf_options.referenceSurface = &(*gsf_ref_surface);
 
    auto gsf_refit_result =
        gsf_->fit(fit_track_source_links.begin(), fit_track_source_links.end(),
                  trk_btp_fit_start, gsf_options, tc);
 
    if (!gsf_refit_result.ok()) {
      ldmx_log(warn) << "GSF re-fit failed: "
                     << gsf_refit_result.error().message();
      continue;
    }
 
    ldmx_log(debug) << "  GSF fit succeeded, tc.size() = " << tc.size();
 
    if (tc.size() < 1) continue;
 
    auto gsftrk = tc.getTrack(0);
    // calculateTrackQuantities(gsftrk);
 
    const Acts::BoundVector& perigee_pars = gsftrk.parameters();
    const Acts::BoundMatrix& trk_cov = gsftrk.covariance();
    const Acts::Surface& perigee_surface = gsftrk.referenceSurface();
 
    ldmx_log(debug)
        << "    Reference Surface (acts-x, acts-y, acts-z) = ("
        << perigee_surface.transform(geometryContext()).translation()(0) << ", "
        << perigee_surface.transform(geometryContext()).translation()(1) << ", "
        << perigee_surface.transform(geometryContext()).translation()(2) << ")";
 
    ldmx_log(debug) << "    Found track has " << gsftrk.nTrackStates()
                    << " track states";
 
    ldmx_log(debug) << "    Track parameters (d0, z0, phi, theta, q/p)= ("
                    << perigee_pars[Acts::eBoundLoc0] << ", "
                    << perigee_pars[Acts::eBoundLoc1] << ", "
                    << perigee_pars[Acts::eBoundPhi] << ", "
                    << perigee_pars[Acts::eBoundTheta] << ", "
                    << perigee_pars[Acts::eBoundQOverP] << ") ";
 
    ldmx::Track trk;
 
    // Extrapolate GSF track to target surface to get perigee parameters
    auto opt_target = trk_extrap_->extrapolate(gsftrk, target_surface_);
 
    if (opt_target) {
      ldmx_log(debug) << "    GSF target extrapolation succeeded";
      auto ts_at_target = tracking::sim::utils::makeTrackState(
          geometryContext(), *opt_target, ldmx::AtTarget);
      trk.addTrackState(ts_at_target);
 
      trk.setPerigeeParameters(tracking::sim::utils::convertActsToLdmxPars(
          opt_target->parameters()));
      if (opt_target->covariance()) {
        std::vector<double> cov_vec;
        tracking::sim::utils::flatCov(*(opt_target->covariance()), cov_vec);
        trk.setPerigeeCov(cov_vec);
      }
      Acts::Vector3 target_loc_ldmx = tracking::sim::utils::acts2Ldmx(
          target_surface_->transform(geometryContext()).translation());
      trk.setPerigeeLocation(target_loc_ldmx[0], target_loc_ldmx[1],
                             target_loc_ldmx[2]);
 
      ldmx_log(debug)
          << "    GSF target parameters (d0, z0, phi, theta, q/p)= ("
          << opt_target->parameters()[Acts::eBoundLoc0] << ", "
          << opt_target->parameters()[Acts::eBoundLoc1] << ", "
          << opt_target->parameters()[Acts::eBoundPhi] << ", "
          << opt_target->parameters()[Acts::eBoundTheta] << ", "
          << opt_target->parameters()[Acts::eBoundQOverP] << ")";
    } else {
      ldmx_log(debug) << "    GSF target extrapolation failed, using GSF fit "
                         "parameters at reference surface";
      trk.setPerigeeParameters(
          tracking::sim::utils::convertActsToLdmxPars(perigee_pars));
      std::vector<double> v_trk_cov;
      tracking::sim::utils::flatCov(trk_cov, v_trk_cov);
      trk.setPerigeeCov(v_trk_cov);
    }
 
    // Tagger: also add beam-origin state; Recoil: add ECAL state
    if (tagger_tracking_) {
      auto opt_beam_origin =
          trk_extrap_->extrapolate(gsftrk, beam_origin_surface_);
      if (opt_beam_origin)
        trk.addTrackState(tracking::sim::utils::makeTrackState(
            geometryContext(), *opt_beam_origin, ldmx::AtBeamOrigin));
    } else {
      ldmx_log(debug) << "  ECAL extrapolation";
      auto opt_ecal = trk_extrap_->extrapolate(gsftrk, ecal_surface_);
      if (opt_ecal)
        trk.addTrackState(tracking::sim::utils::makeTrackState(
            geometryContext(), *opt_ecal, ldmx::AtECAL));
    }
 
    trk.setChi2(gsftrk.chi2());
    trk.setNhits(gsftrk.nMeasurements());
    trk.setNdf(gsftrk.nMeasurements() - 5);
    trk.setCharge(perigee_pars[Acts::eBoundQOverP] > 0 ? 1 : -1);
 
    // Truth information carried over from input track
    trk.setTrackID(track.getTrackID());
    trk.setPdgID(track.getPdgID());
    trk.setTruthProb(track.getTruthProb());
 
    itrk++;
 
    ldmx_log(debug) << "  Added track to output, total tracks = "
                    << (out_tracks.size() + 1);
 
    out_tracks.push_back(trk);
 
  }  // loop on tracks
 
  event.add(out_trk_collection_, out_tracks);
}  // end of produce()
 
void GSFProcessor::onProcessStart() {};
void GSFProcessor::onProcessEnd() {};
 
}  // namespace reco
}  // namespace tracking
 
DECLARE_PRODUCER(tracking::reco::GSFProcessor)