File HelicalTrackLinearizer.hpp¶
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namespace Acts
Set the Geometry Context PLUGIN.
Set the Calibration Context PLUGIN.
Convenience functions to ease creation of and Acts::InterpolatedMaterialMap and to avoid code duplication.
Set the Mangetic Field Context PLUGIN.
Convenience functions to ease creation of and Acts::InterpolatedBFieldMap and to avoid code duplication.
Currently implemented for the two most common formats: rz and xyz.
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template<typename propagator_t, typename propagator_options_t = PropagatorOptions<>>
class HelicalTrackLinearizer - #include <Acts/Vertexing/HelicalTrackLinearizer.hpp>
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.)
- tparam propagator_t
Propagator type
- tparam propagator_options_t
Propagator options type
Public Types
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using Propagator_t = propagator_t
Public Functions
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inline HelicalTrackLinearizer(const Config &config)
Constructor.
- Parameters
config – Configuration object
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Result<LinearizedTrack> linearizeTrack(const BoundTrackParameters ¶ms, const Vector4 &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
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struct Config
- #include <Acts/Vertexing/HelicalTrackLinearizer.hpp>
Configuration struct.
Public Functions
@ Config constructor if magnetic field is present
- Parameters
bIn – The magnetic field
prop – The propagator
Config constructor without B field -> uses NullBField.
- Parameters
prop – The propagator
Public Members
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std::shared_ptr<MagneticFieldProvider> bField
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double maxRho = 1e+15
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double minQoP = 1e-15
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std::shared_ptr<Propagator_t> propagator
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struct State
- #include <Acts/Vertexing/HelicalTrackLinearizer.hpp>
State struct.
Public Functions
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inline State(MagneticFieldProvider::Cache fieldCacheIn)
The state constructor.
- Parameters
fieldCacheIn – The magnetic field cache
Public Members
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MagneticFieldProvider::Cache fieldCache
Magnetic field cache.
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inline State(MagneticFieldProvider::Cache fieldCacheIn)
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template<typename propagator_t, typename propagator_options_t = PropagatorOptions<>>