Class Acts::CombinatorialKalmanFilter

template<typename propagator_t, typename traj_t>
class CombinatorialKalmanFilter

Combinatorial Kalman filter to find tracks.

The CombinatorialKalmanFilter 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.

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 filtering (track finding) by the Actor.

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

The void components are provided mainly for unit testing.

Template Parameters

propagator_t – Type of the propagator

Public Functions

CombinatorialKalmanFilter() = delete

Default constructor is deleted.

inline CombinatorialKalmanFilter(propagator_t pPropagator, std::unique_ptr<const Logger> _logger = getDefaultLogger("CKF", Logging::INFO))

Constructor from arguments.

Combinatorial Kalman Filter implementation, calls the Kalman filter and smoother.


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 track finding.

Template Parameters
  • source_link_iterator_t – Type of the source link iterator

  • start_parameters_container_t – Type of the initial parameters container

  • calibrator_t – Type of the source link calibrator

  • measurement_selector_t – Type of the measurement selector

  • track_container_t – Type of the track container backend

  • holder_t – Type defining track container backend ownership

  • parameters_t – Type of parameters used for local parameters

  • initialParameters – The initial track parameters

  • tfOptions – CombinatorialKalmanFilterOptions steering the track finding

  • trackContainer – Input track container to use


a container of track finding result for all the initial track parameters