Template Class KalmanFitter

Class Documentation

template<typename propagator_t, typename updater_t = VoidKalmanUpdater, typename smoother_t = VoidKalmanSmoother, typename outlier_finder_t = VoidOutlierFinder, typename calibrator_t = VoidMeasurementCalibrator>
class Acts::KalmanFitter

Kalman fitter implementation of Acts as a plugin.

to the Propgator

The Kalman filter contains an Actor and a Sequencer sub-class. The Sequencer has to be part of the Navigator of the Propagator in order to initialize and provide the measurement surfaces.

Template Parameters

  • propagator_t: Type of the propagation class

  • updater_t: Type of the kalman updater class

  • smoother_t: Type of the kalman smoother class

  • outlier_finder_t: Type of the outlier finder class

  • calibrator_t: Type of the calibrator class

The Actor is part of the Propagation call and does the Kalman update and eventually the smoothing. Updater, Smoother and Calibrator are given to the Actor for further use:

  • The Updater is the implemented kalman updater formalism, it runs via a visitor pattern through the measurements.

  • The Smoother is called at the end of the forward fit by the Actor.

  • The outlier finder is called during the filtering by the Actor. It determines if the measurement is an outlier

  • The Calibrator is a dedicated calibration algorithm that allows to calibrate measurements using track information, this could be e.g. sagging for wires, module deformations, etc.

Measurements are not required to be ordered for the KalmanFilter, measurement ordering needs to be figured out by the navigation of the propagator.

The void components are provided mainly for unit testing.

Public Types

using KalmanNavigator = typename propagator_t::Navigator

The navigator type.

using MeasurementSurfaces = std::multimap<const Layer*, const Surface*>

Shorthand definition.

Public Functions

KalmanFitter() = delete

Default constructor is deleted.

KalmanFitter(propagator_t pPropagator, std::unique_ptr<const Logger> logger = getDefaultLogger("KalmanFilter", Logging::INFO))

Constructor from arguments.

template<typename source_link_t, typename start_parameters_t, typename parameters_t = BoundParameters>
auto fit(const std::vector<source_link_t> &sourcelinks, const start_parameters_t &sParameters, const KalmanFitterOptions<outlier_finder_t> &kfOptions) const -> std::enable_if_t<!isDirectNavigator, Result<KalmanFitterResult<source_link_t>>>

Fit implementation of the foward filter, calls the the forward filter and backward smoother.

Note

The input measurements are given in the form of SourceLinks. It’s calibrator_t's job to turn them into calibrated measurements used in the fit.

Return

the output as an output track

Template Parameters

  • source_link_t: Source link type identifying uncalibrated input measurements.

  • start_parameters_t: Type of the initial parameters

  • parameters_t: Type of parameters used for local parameters

Parameters

  • sourcelinks: The fittable uncalibrated measurements

  • sParameters: The initial track parameters

  • kfOptions: KalmanOptions steering the fit

template<typename source_link_t, typename start_parameters_t, typename parameters_t = BoundParameters>
auto fit(const std::vector<source_link_t> &sourcelinks, const start_parameters_t &sParameters, const KalmanFitterOptions<outlier_finder_t> &kfOptions, const std::vector<const Surface*> &sSequence) const -> std::enable_if_t<isDirectNavigator, Result<KalmanFitterResult<source_link_t>>>

Fit implementation of the foward filter, calls the the forward filter and backward smoother.

Note

The input measurements are given in the form of SourceLinks. It’s calibrator_t's job to turn them into calibrated measurements used in the fit.

Return

the output as an output track

Template Parameters

  • source_link_t: Source link type identifying uncalibrated input measurements.

  • start_parameters_t: Type of the initial parameters

  • parameters_t: Type of parameters used for local parameters

Parameters

  • sourcelinks: The fittable uncalibrated measurements

  • sParameters: The initial track parameters

  • kfOptions: KalmanOptions steering the fit

  • sSequence: surface sequence used to initialize a DirectNavigator

Public Static Attributes

constexpr bool isDirectNavigator = std::is_same<KalmanNavigator, DirectNavigator>::value

The navigator has DirectNavigator type or not.