Acts::MultiComponentBoundTrackParameters Class Reference

This class is only a light wrapper around a surface and a vector of parameters. More...

#include <Acts/EventData/MultiComponentTrackParameters.hpp>

Public Types
using	ConstructionTuple
	Type alias for construction tuple containing weight, position, direction, q/p, and covariance.
using	CovarianceMatrix = typename Parameters::CovarianceMatrix
	Type alias for covariance matrix.
using	Parameters = BoundTrackParameters
	Type alias for bound track parameters.
using	ParametersVector = typename Parameters::ParametersVector
	Type alias for bound parameters vector.
using	ParticleHypothesis = Parameters::ParticleHypothesis
	Type alias for particle hypothesis.

Public Member Functions
	MultiComponentBoundTrackParameters ()=delete
	Parameters are not default constructible due to the charge type.
	MultiComponentBoundTrackParameters (const MultiComponentBoundTrackParameters &)=default
	Copy constructor.
	MultiComponentBoundTrackParameters (MultiComponentBoundTrackParameters &&)=default
	Move constructor.
	MultiComponentBoundTrackParameters (std::shared_ptr< const Surface > surface, const ParametersVector &params, std::optional< BoundSquareMatrix > cov, ParticleHypothesis particleHypothesis)
	Construct from a parameters vector on the surface and particle charge.
template<typename covariance_t>
	MultiComponentBoundTrackParameters (std::shared_ptr< const Surface > surface, const std::vector< std::tuple< double, ParametersVector, covariance_t > > &cmps, ParticleHypothesis particleHypothesis)
	Construct from multiple components.
	~MultiComponentBoundTrackParameters ()=default
double	absoluteMomentum () const
	Absolute momentum.
double	charge () const
	Particle electric charge.
const auto &	components () const
	Access the parameters.
std::optional< CovarianceMatrix >	covariance () const
	Optional covariance matrix.
Vector3	direction () const
	Unit direction three-vector, i.e.
Vector4	fourPosition (const GeometryContext &geoCtx) const
	Space-time position four-vector.
template<BoundIndices kIndex>
double	get () const
	Access a single parameter value identified by its index.
Vector3	momentum () const
	Momentum three-vector.
MultiComponentBoundTrackParameters &	operator= (const MultiComponentBoundTrackParameters &)=default
	Copy assignment operator.
MultiComponentBoundTrackParameters &	operator= (MultiComponentBoundTrackParameters &&)=default
	Move assignment operator.
std::pair< double, Parameters >	operator[] (std::size_t i) const
	Get the weight and a GenericBoundTrackParameters object for one component.
ParametersVector	parameters () const
	Parameters vector.
const ParticleHypothesis &	particleHypothesis () const
	Particle hypothesis.
double	phi () const
	Phi direction.
Vector3	position (const GeometryContext &geoCtx) const
	Spatial position three-vector.
double	qOverP () const
	Charge over momentum.
const Surface &	referenceSurface () const
	Reference surface onto which the parameters are bound.
double	theta () const
	Theta direction.
double	time () const
	Time coordinate.
MultiComponentBoundTrackParameters	toBound () const
	Comply with bound convertible, in this case return a copy.
double	transverseMomentum () const
	Transverse momentum.

Static Public Member Functions
static MultiComponentBoundTrackParameters	createCurvilinear (const GeometryContext &geoCtx, const std::vector< ConstructionTuple > &curvi, ParticleHypothesis particleHypothesis)
	We need this helper function in order to construct the base class properly.

Detailed Description

This class is only a light wrapper around a surface and a vector of parameters.

Its main purpose is to provide many constructors for the underlying vector. Most accessors are generated from the BoundTrackParameters equivalent and thus may be expensive

Note

This class holds shared ownership on its reference surface.

The accessors for parameters, covariance, position, etc. are the weighted means of the components.

If all covariances are zero, the accessor for the total covariance does return std::nullopt; TODO Add constructor from range and projector maybe?

Member Typedef Documentation

ConstructionTuple

using Acts::MultiComponentBoundTrackParameters::ConstructionTuple

Initial value:

 std::tuple<double, Acts::Vector4, Acts::Vector3,
                                       double, CovarianceMatrix>

Type alias for construction tuple containing weight, position, direction, q/p, and covariance.

CovarianceMatrix

using Acts::MultiComponentBoundTrackParameters::CovarianceMatrix = typename Parameters::CovarianceMatrix

Type alias for covariance matrix.

Parameters

using Acts::MultiComponentBoundTrackParameters::Parameters = BoundTrackParameters

Type alias for bound track parameters.

ParametersVector

using Acts::MultiComponentBoundTrackParameters::ParametersVector = typename Parameters::ParametersVector

Type alias for bound parameters vector.

ParticleHypothesis

using Acts::MultiComponentBoundTrackParameters::ParticleHypothesis = Parameters::ParticleHypothesis

Type alias for particle hypothesis.

Constructor & Destructor Documentation

MultiComponentBoundTrackParameters() [1/5]

template<typename covariance_t>

Acts::MultiComponentBoundTrackParameters::MultiComponentBoundTrackParameters	(	std::shared_ptr< const Surface >	surface,
		const std::vector< std::tuple< double, ParametersVector, covariance_t > > &	cmps,
		ParticleHypothesis	particleHypothesis )

Construct from multiple components.

Parameters

surface	Surface on which the parameters are bound
cmps	Vector of weight, parameters vector, and covariance components
particleHypothesis	Particle hypothesis for the parameters

MultiComponentBoundTrackParameters() [2/5]

Acts::MultiComponentBoundTrackParameters::MultiComponentBoundTrackParameters	(	std::shared_ptr< const Surface >	surface,
		const ParametersVector &	params,
		std::optional< BoundSquareMatrix >	cov,
		ParticleHypothesis	particleHypothesis )

Construct from a parameters vector on the surface and particle charge.

Parameters

surface	Reference surface the parameters are defined on
params	Bound parameters vector
particleHypothesis	Particle hypothesis for these parameters
cov	Bound parameters covariance matrix

In principle, only the charge magnitude is needed her to allow unambiguous extraction of the absolute momentum. The particle charge is required as an input here to be consistent with the other constructors below that that also take the charge as an input. The charge sign is only used in debug builds to check for consistency with the q/p parameter.

MultiComponentBoundTrackParameters() [3/5]

Acts::MultiComponentBoundTrackParameters::MultiComponentBoundTrackParameters ( )

delete

Parameters are not default constructible due to the charge type.

MultiComponentBoundTrackParameters() [4/5]

Acts::MultiComponentBoundTrackParameters::MultiComponentBoundTrackParameters ( const MultiComponentBoundTrackParameters & )

default

Copy constructor.

MultiComponentBoundTrackParameters() [5/5]

Acts::MultiComponentBoundTrackParameters::MultiComponentBoundTrackParameters ( MultiComponentBoundTrackParameters && )

default

Move constructor.

~MultiComponentBoundTrackParameters()

Acts::MultiComponentBoundTrackParameters::~MultiComponentBoundTrackParameters ( )

default

Member Function Documentation

absoluteMomentum()

double Acts::MultiComponentBoundTrackParameters::absoluteMomentum

(

)

const

Absolute momentum.

Returns

Weighted average absolute momentum magnitude

charge()

double Acts::MultiComponentBoundTrackParameters::charge

(

)

const

Particle electric charge.

Returns

Weighted average particle electric charge

components()

const auto & Acts::MultiComponentBoundTrackParameters::components

(

)

const

Access the parameters.

Returns

Reference to the vector of parameter components

covariance()

std::optional< CovarianceMatrix > Acts::MultiComponentBoundTrackParameters::covariance

(

)

const

Optional covariance matrix.

Returns

Optional weighted average covariance matrix, nullopt if all components have zero covariance

createCurvilinear()

MultiComponentBoundTrackParameters Acts::MultiComponentBoundTrackParameters::createCurvilinear ( const GeometryContext & geoCtx, const std::vector< ConstructionTuple > & curvi, ParticleHypothesis particleHypothesis )

static

We need this helper function in order to construct the base class properly.

Parameters

geoCtx	Geometry context for construction
curvi	Vector of construction tuples containing component data
particleHypothesis	Particle hypothesis for the parameters

Returns

Multi-component bound track parameters in curvilinear representation

direction()

Vector3 Acts::MultiComponentBoundTrackParameters::direction

(

)

const

Unit direction three-vector, i.e.

the normalized momentum three-vector.

Returns

Weighted average normalized direction vector

fourPosition()

Vector4 Acts::MultiComponentBoundTrackParameters::fourPosition

(

const GeometryContext &

geoCtx

)

const

Space-time position four-vector.

Parameters

[in]

geoCtx

Geometry context for the local-to-global transformation

Returns

Weighted average four-dimensional position vector

get()

template<BoundIndices kIndex>

double Acts::MultiComponentBoundTrackParameters::get

(

)

const

Access a single parameter value identified by its index.

Template Parameters

kIndex

Track parameter index

Returns

Weighted average of the parameter at the specified index

momentum()

Vector3 Acts::MultiComponentBoundTrackParameters::momentum

(

)

const

Momentum three-vector.

Returns

Weighted average three-dimensional momentum vector

operator=() [1/2]

MultiComponentBoundTrackParameters & Acts::MultiComponentBoundTrackParameters::operator= ( const MultiComponentBoundTrackParameters & )

default

Copy assignment operator.

Returns

Reference to this object after copying

operator=() [2/2]

MultiComponentBoundTrackParameters & Acts::MultiComponentBoundTrackParameters::operator= ( MultiComponentBoundTrackParameters && )

default

Move assignment operator.

Returns

Reference to this object after moving

operator[]()

std::pair< double, Parameters > Acts::MultiComponentBoundTrackParameters::operator[]

(

std::size_t

i

)

const

Get the weight and a GenericBoundTrackParameters object for one component.

Parameters

i	Index of the component to access

Returns

Pair of weight and bound track parameters for the component

parameters()

ParametersVector Acts::MultiComponentBoundTrackParameters::parameters

(

)

const

Parameters vector.

Returns

Weighted average of parameters from all components

particleHypothesis()

const ParticleHypothesis & Acts::MultiComponentBoundTrackParameters::particleHypothesis

(

)

const

Particle hypothesis.

Returns

Reference to the particle hypothesis

phi()

double Acts::MultiComponentBoundTrackParameters::phi

(

)

const

Phi direction.

Returns

Azimuthal angle phi derived from average direction

position()

Vector3 Acts::MultiComponentBoundTrackParameters::position

(

const GeometryContext &

geoCtx

)

const

Spatial position three-vector.

Parameters

[in]

geoCtx

Geometry context for the local-to-global transformation

Returns

Weighted average three-dimensional position vector

qOverP()

double Acts::MultiComponentBoundTrackParameters::qOverP

(

)

const

Charge over momentum.

Returns

Weighted average charge over momentum ratio

referenceSurface()

const Surface & Acts::MultiComponentBoundTrackParameters::referenceSurface

(

)

const

Reference surface onto which the parameters are bound.

Returns

Reference to the bound reference surface

theta()

double Acts::MultiComponentBoundTrackParameters::theta

(

)

const

Theta direction.

Returns

Polar angle theta derived from average direction

time()

double Acts::MultiComponentBoundTrackParameters::time

(

)

const

Time coordinate.

Returns

Weighted average time coordinate

toBound()

MultiComponentBoundTrackParameters Acts::MultiComponentBoundTrackParameters::toBound

(

)

const

Comply with bound convertible, in this case return a copy.

Returns

Copy of this multi-component track parameters

transverseMomentum()

double Acts::MultiComponentBoundTrackParameters::transverseMomentum

(

)

const

Transverse momentum.

Returns

Weighted average transverse momentum magnitude