Acts::HelicalTrackLinearizer< propagator_t, propagator_options_t > Class Template Reference

#include <acts/blob/sPHENIX/Core/include/Acts/Vertexing/HelicalTrackLinearizer.hpp>

Collaboration diagram for Acts::HelicalTrackLinearizer< propagator_t, propagator_options_t >:

Classes
struct	Config
	Configuration struct. More...
struct	State

Public Types
using	Propagator_t = propagator_t
using	BField_t = typename Propagator_t::Stepper::BField

Public Member Functions
	HelicalTrackLinearizer (const Config &config)
	Constructor.
Result< LinearizedTrack >	linearizeTrack (const BoundTrackParameters &params, const Vector4D &linPoint, const Acts::GeometryContext &gctx, const Acts::MagneticFieldContext &mctx, State &state) const
	Function that linearizes BoundTrackParameters at given linearization point.

Private Attributes
const Config	m_cfg
	Configuration object.

Detailed Description

template<typename propagator_t, typename propagator_options_t = PropagatorOptions<>>
class Acts::HelicalTrackLinearizer< propagator_t, propagator_options_t >

Linearizes the measurement equation (dependance of track parameters on the vertex position and track momentum at vertex) at the vicinity of the user-provided linearization point.

The measurement equation is linearized in the following way:

q_k= A_k (x_k - x_0k) + B_k (p_k - p_0k) + c_k

where q_k are the parameters at perigee nearest to the lin point, x_k is the position of the vertex, p_k the track momentum at the vertex, and c_k is the constant term of expansion. A_k and B_k are matrices of derivatives, denoted hereafter as "positionJacobian" and "momentumJacobian" respectively.

Ref.(1) - CERN-THESIS-2010-027, Giacinto Piacquadio (Freiburg U.)

Template Parameters

propagator_t	Propagator type
propagator_options_t	Propagator options type

Definition at line 44 of file HelicalTrackLinearizer.hpp.

View newest version in sPHENIX GitHub at line 44 of file HelicalTrackLinearizer.hpp

Member Typedef Documentation

template<typename propagator_t , typename propagator_options_t = PropagatorOptions<>>

using Acts::HelicalTrackLinearizer< propagator_t, propagator_options_t >::BField_t = typename Propagator_t::Stepper::BField

Definition at line 47 of file HelicalTrackLinearizer.hpp.

View newest version in sPHENIX GitHub at line 47 of file HelicalTrackLinearizer.hpp

template<typename propagator_t , typename propagator_options_t = PropagatorOptions<>>

using Acts::HelicalTrackLinearizer< propagator_t, propagator_options_t >::Propagator_t = propagator_t

Definition at line 46 of file HelicalTrackLinearizer.hpp.

View newest version in sPHENIX GitHub at line 46 of file HelicalTrackLinearizer.hpp

Constructor & Destructor Documentation

template<typename propagator_t , typename propagator_options_t = PropagatorOptions<>>

Acts::HelicalTrackLinearizer< propagator_t, propagator_options_t >::HelicalTrackLinearizer ( const Config &  config )

inline

Constructor.

Parameters

config

Configuration object

Definition at line 90 of file HelicalTrackLinearizer.hpp.

View newest version in sPHENIX GitHub at line 90 of file HelicalTrackLinearizer.hpp

Member Function Documentation

template<typename propagator_t , typename propagator_options_t >

Acts::Result< Acts::LinearizedTrack > Acts::HelicalTrackLinearizer< propagator_t, propagator_options_t >::linearizeTrack	(	const BoundTrackParameters &	params,
		const Vector4D &	linPoint,
		const Acts::GeometryContext &	gctx,
		const Acts::MagneticFieldContext &	mctx,
		State &	state
	)		const

Function that linearizes BoundTrackParameters at given linearization point.

Parameters

params	Parameters to linearize
linPoint	Linearization point
gctx	The geometry context
mctx	The magnetic field context
state	The state object

Returns

Linearized track

F(V, p_i) at PCA in Billoir paper (see FullBilloirVertexFitter.hpp for paper reference, Page 140, Eq. (2) )

Definition at line 13 of file HelicalTrackLinearizer.ipp.

View newest version in sPHENIX GitHub at line 13 of file HelicalTrackLinearizer.ipp

References kdfinder::abs(), Acts::backward, Acts::IntegrationTest::Bz, cos(), Acts::SingleBoundTrackParameters< charge_t >::covariance(), Acts::eBoundPhi, Acts::eBoundQOverP, Acts::eBoundTheta, Acts::ePos0, Acts::ePos1, Acts::ePos2, Acts::eTime, Acts::eZ, Acts::HelicalTrackLinearizer< propagator_t, propagator_options_t >::State::fieldCache, Acts::SingleBoundTrackParameters< charge_t >::get(), Acts::getDefaultLogger(), INFO, M_PI, Acts::SingleBoundTrackParameters< charge_t >::parameters(), pos(), Acts::SingleBoundTrackParameters< charge_t >::position(), Acts::VectorHelpers::position(), Acts::IntegrationTest::R, and Acts::SingleBoundTrackParameters< charge_t >::time().

Referenced by Acts::Test::BOOST_AUTO_TEST_CASE().

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Member Data Documentation

template<typename propagator_t , typename propagator_options_t = PropagatorOptions<>>

const Config Acts::HelicalTrackLinearizer< propagator_t, propagator_options_t >::m_cfg

private

Configuration object.

Definition at line 110 of file HelicalTrackLinearizer.hpp.

View newest version in sPHENIX GitHub at line 110 of file HelicalTrackLinearizer.hpp

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The documentation for this class was generated from the following files:

• acts/blob/sPHENIX/Core/include/Acts/Vertexing/HelicalTrackLinearizer.hpp
• acts/blob/sPHENIX/Core/include/Acts/Vertexing/HelicalTrackLinearizer.ipp