ActsTrk::detail::FitterHelperFunctions::ATLASOutlierFinder Struct Reference

Outlier finder using a Chi2 cut. More...

#include <FitterHelperFunctions.h>

Collaboration diagram for ActsTrk::detail::FitterHelperFunctions::ATLASOutlierFinder:

Public Member Functions
template<typename trajectory_t>
bool	operator() (typename Acts::MultiTrajectory< trajectory_t >::ConstTrackStateProxy state) const
	Classify a measurement as a valid one or an outlier.

Public Attributes
double	StateChiSquaredPerNumberDoFCut = std::numeric_limits<double>::max()

Detailed Description

Outlier finder using a Chi2 cut.

Definition at line 49 of file FitterHelperFunctions.h.

Member Function Documentation

operator()()

template<typename trajectory_t>

bool ActsTrk::detail::FitterHelperFunctions::ATLASOutlierFinder::operator() ( typename Acts::MultiTrajectory< trajectory_t >::ConstTrackStateProxy state ) const

inline

Classify a measurement as a valid one or an outlier.

Template Parameters

track_state_t

Type of the track state

Parameters

state

The track state to classify

Return values

False	if the measurement is not an outlier
True	if the measurement is an outlier

Definition at line 58 of file FitterHelperFunctions.h.

                                                                                                {
      // can't determine an outlier w/o a measurement or predicted parameters
      if (not state.hasCalibrated() or not state.hasPredicted()) {
        return false;
      }
      return Acts::visit_measurement(
          state.calibratedSize(),
    [&] (auto N) -> bool {
      constexpr size_t kMeasurementSize = decltype(N)::value;
 
      auto subspaceHelper = state.template projectorSubspaceHelper<kMeasurementSize>();
 
      typename Acts::TrackStateTraits<kMeasurementSize, true>::Calibrated calibrated{
        state.template calibrated<Acts::MultiTrajectoryTraits::MeasurementSizeMax>().data()};
      
      typename Acts::TrackStateTraits<kMeasurementSize, true>::CalibratedCovariance
        calibratedCovariance{state.template calibratedCovariance<Acts::MultiTrajectoryTraits::MeasurementSizeMax>().data()};
      
      // Take the projector (measurement mapping function)
      // TODO use the subspace helper directly
      const auto H = subspaceHelper.projector();
      
      const auto residual = calibrated - H * state.predicted();
      double chi2 = (residual.transpose() * (calibratedCovariance + H * state.predictedCovariance() * H.transpose()).inverse() * residual).value();     
            return (chi2 > StateChiSquaredPerNumberDoFCut * kMeasurementSize);
          });
    }

Member Data Documentation

StateChiSquaredPerNumberDoFCut

double ActsTrk::detail::FitterHelperFunctions::ATLASOutlierFinder::StateChiSquaredPerNumberDoFCut = std::numeric_limits<double>::max()

Definition at line 50 of file FitterHelperFunctions.h.

---

The documentation for this struct was generated from the following file:

• FitterHelperFunctions.h