Acts::GenericBoundTrackParameters< particle_hypothesis_t > Class Template Reference

Track parameters bound to a reference surface for a single track. More...

#include <Acts/EventData/GenericBoundTrackParameters.hpp>

Inheritance diagram for Acts::GenericBoundTrackParameters< particle_hypothesis_t >:

Public Types
using	CovarianceMatrix = BoundSquareMatrix
	Type alias for bound track covariance matrix.
using	ParametersVector = BoundVector
	Type alias for bound track parameters vector.
using	ParticleHypothesis = particle_hypothesis_t
	Type alias for particle hypothesis used in reconstruction.

Public Member Functions
template<typename other_particle_hypothesis_t>
	GenericBoundTrackParameters (const GenericBoundTrackParameters< other_particle_hypothesis_t > &other)
	Converts a bound track parameter with a different hypothesis.
	GenericBoundTrackParameters (std::shared_ptr< const Surface > surface, const ParametersVector &params, std::optional< CovarianceMatrix > cov, ParticleHypothesis particleHypothesis)
	Construct from a parameters vector on the surface and particle charge.
double	absoluteMomentum () const
	Absolute momentum.
double	charge () const
	Particle electric charge.
std::optional< CovarianceMatrix > &	covariance ()
	Optional covariance matrix.
const 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.
std::optional< ActsSquareMatrix< 3 > >	impactParameterCovariance () const
	Covariance matrix of the spatial and temporal impact parameters (i.e., of d0, z0, and t).
Vector3	impactParameters () const
	Vector of spatial and temporal impact parameters (i.e., d0, z0, and t).
Vector2	localPosition () const
	Local spatial position two-vector.
Vector3	momentum () const
	Momentum three-vector.
ParametersVector &	parameters ()
	Parameters vector.
const 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.
RotationMatrix3	referenceFrame (const GeometryContext &geoCtx) const
	Reference frame in which the local error is defined.
const Surface &	referenceSurface () const
	Reference surface onto which the parameters are bound.
GenericBoundTrackParameters< ParticleHypothesis >	reflect () const
	Reflect the parameters.
void	reflectInPlace ()
	Reflect the parameters in place.
std::optional< ActsSquareMatrix< 2 > >	spatialImpactParameterCovariance () const
	Covariance matrix of the spatial impact parameters (i.e., of d0 and z0).
Vector2	spatialImpactParameters () const
	Vector of spatial impact parameters (i.e., d0 and z0).
double	theta () const
	Theta direction.
double	time () const
	Time coordinate.
GenericBoundTrackParameters< Acts::ParticleHypothesis >	toBound () const
	Convert this track parameter object to the general type-erased one.
double	transverseMomentum () const
	Transverse momentum.

Static Public Member Functions
static Result< GenericBoundTrackParameters >	create (const GeometryContext &geoCtx, std::shared_ptr< const Surface > surface, const Vector4 &pos4, const Vector3 &dir, double qOverP, std::optional< CovarianceMatrix > cov, ParticleHypothesis particleHypothesis, double tolerance=s_onSurfaceTolerance)
	Factory to construct from four-position, direction, absolute momentum, and charge.
static GenericBoundTrackParameters	createCurvilinear (const Vector4 &pos4, const Vector3 &dir, double qOverP, std::optional< CovarianceMatrix > cov, ParticleHypothesis particleHypothesis)
	Construct from four-position, direction, and qOverP.
static GenericBoundTrackParameters	createCurvilinear (const Vector4 &pos4, double phi, double theta, double qOverP, std::optional< CovarianceMatrix > cov, ParticleHypothesis particleHypothesis)
	Construct from four-position, angles, and qOverP.

Detailed Description

template<class particle_hypothesis_t>
class Acts::GenericBoundTrackParameters< particle_hypothesis_t >

Track parameters bound to a reference surface for a single track.

Template Parameters

particle_hypothesis_t

Helper type to interpret the particle charge/momentum

This is intended as a user-facing data class that adds additional accessors and charge/momentum interpretation on top of the pure parameters vector. All parameters and their corresponding covariance matrix are stored in bound parametrization. The specific definition of the local spatial parameters is defined by the associated surface.

Note

This class holds shared ownership on its reference surface.

Member Typedef Documentation

CovarianceMatrix

template<class particle_hypothesis_t>

using Acts::GenericBoundTrackParameters< particle_hypothesis_t >::CovarianceMatrix = BoundSquareMatrix

Type alias for bound track covariance matrix.

ParametersVector

template<class particle_hypothesis_t>

using Acts::GenericBoundTrackParameters< particle_hypothesis_t >::ParametersVector = BoundVector

Type alias for bound track parameters vector.

ParticleHypothesis

template<class particle_hypothesis_t>

using Acts::GenericBoundTrackParameters< particle_hypothesis_t >::ParticleHypothesis = particle_hypothesis_t

Type alias for particle hypothesis used in reconstruction.

Constructor & Destructor Documentation

GenericBoundTrackParameters() [1/2]

template<class particle_hypothesis_t>

Acts::GenericBoundTrackParameters< particle_hypothesis_t >::GenericBoundTrackParameters	(	std::shared_ptr< const Surface >	surface,
		const ParametersVector &	params,
		std::optional< CovarianceMatrix >	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
cov	Bound parameters covariance matrix
particleHypothesis	Particle hypothesis

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.

GenericBoundTrackParameters() [2/2]

template<class particle_hypothesis_t>

template<typename other_particle_hypothesis_t>

Acts::GenericBoundTrackParameters< particle_hypothesis_t >::GenericBoundTrackParameters ( const GenericBoundTrackParameters< other_particle_hypothesis_t > & other )

explicit

Converts a bound track parameter with a different hypothesis.

Parameters

other

The other bound track parameters to convert from

Member Function Documentation

absoluteMomentum()

template<class particle_hypothesis_t>

double Acts::GenericBoundTrackParameters< particle_hypothesis_t >::absoluteMomentum

(

)

const

Absolute momentum.

Returns

The absolute momentum magnitude

charge()

template<class particle_hypothesis_t>

double Acts::GenericBoundTrackParameters< particle_hypothesis_t >::charge

(

)

const

Particle electric charge.

Returns

The particle electric charge

covariance() [1/2]

template<class particle_hypothesis_t>

std::optional< CovarianceMatrix > & Acts::GenericBoundTrackParameters< particle_hypothesis_t >::covariance

(

)

Optional covariance matrix.

Returns

Mutable reference to the optional covariance matrix

covariance() [2/2]

template<class particle_hypothesis_t>

const std::optional< CovarianceMatrix > & Acts::GenericBoundTrackParameters< particle_hypothesis_t >::covariance

(

)

const

Optional covariance matrix.

Returns

Const reference to the optional covariance matrix

create()

template<class particle_hypothesis_t>

Result< GenericBoundTrackParameters > Acts::GenericBoundTrackParameters< particle_hypothesis_t >::create ( const GeometryContext & geoCtx, std::shared_ptr< const Surface > surface, const Vector4 & pos4, const Vector3 & dir, double qOverP, std::optional< CovarianceMatrix > cov, ParticleHypothesis particleHypothesis, double tolerance = s_onSurfaceTolerance )

static

Factory to construct from four-position, direction, absolute momentum, and charge.

Parameters

geoCtx	Geometry context for the local-to-global transformation
surface	Reference surface the parameters are defined on
pos4	Track position/time four-vector
dir	Track direction three-vector; normalization is ignored
qOverP	Charge over momentum
cov	Bound parameters covariance matrix
particleHypothesis	Particle hypothesis
tolerance	Tolerance used for globalToLocal

Returns

Result containing the constructed bound track parameters or error

Note

The returned result indicates whether the free parameters could successfully be converted to on-surface parameters.

createCurvilinear() [1/2]

template<class particle_hypothesis_t>

GenericBoundTrackParameters Acts::GenericBoundTrackParameters< particle_hypothesis_t >::createCurvilinear ( const Vector4 & pos4, const Vector3 & dir, double qOverP, std::optional< CovarianceMatrix > cov, ParticleHypothesis particleHypothesis )

static

Construct from four-position, direction, and qOverP.

Parameters

pos4	Track position/time four-vector
dir	Track direction three-vector; normalization is ignored.
qOverP	Charge over momentum
cov	Curvilinear bound parameters covariance matrix
particleHypothesis	Particle hypothesis

Returns

Curvilinear bound track parameters

createCurvilinear() [2/2]

template<class particle_hypothesis_t>

GenericBoundTrackParameters Acts::GenericBoundTrackParameters< particle_hypothesis_t >::createCurvilinear ( const Vector4 & pos4, double phi, double theta, double qOverP, std::optional< CovarianceMatrix > cov, ParticleHypothesis particleHypothesis )

static

Construct from four-position, angles, and qOverP.

Parameters

pos4	Track position/time four-vector
phi	Transverse track direction angle
theta	Longitudinal track direction angle
qOverP	Charge over momentum
cov	Curvilinear bound parameters covariance matrix
particleHypothesis	Particle hypothesis

Returns

Curvilinear bound track parameters

direction()

template<class particle_hypothesis_t>

Vector3 Acts::GenericBoundTrackParameters< particle_hypothesis_t >::direction

(

)

const

Unit direction three-vector, i.e.

the normalized momentum three-vector.

Returns

Normalized direction vector

fourPosition()

template<class particle_hypothesis_t>

Vector4 Acts::GenericBoundTrackParameters< particle_hypothesis_t >::fourPosition

(

const GeometryContext &

geoCtx

)

const

Space-time position four-vector.

Parameters

[in]

geoCtx

Geometry context for the local-to-global transformation

Returns

Four-dimensional position vector (x, y, z, t) in global coordinates

This uses the associated surface to transform the local position on the surface to globalcoordinates. This requires a geometry context to select the appropriate transformation and might be a computationally expensive operation.

get()

template<class particle_hypothesis_t>

template<BoundIndices kIndex>

double Acts::GenericBoundTrackParameters< particle_hypothesis_t >::get

(

)

const

Access a single parameter value identified by its index.

Template Parameters

kIndex

Track parameter index

Returns

The parameter value at the specified index

impactParameterCovariance()

template<class particle_hypothesis_t>

std::optional< ActsSquareMatrix< 3 > > Acts::GenericBoundTrackParameters< particle_hypothesis_t >::impactParameterCovariance

(

)

const

Covariance matrix of the spatial and temporal impact parameters (i.e., of d0, z0, and t).

Returns

Optional 3x3 covariance matrix of impact parameters

impactParameters()

template<class particle_hypothesis_t>

Vector3 Acts::GenericBoundTrackParameters< particle_hypothesis_t >::impactParameters

(

)

const

Vector of spatial and temporal impact parameters (i.e., d0, z0, and t).

Returns

Three-dimensional vector of impact parameters

localPosition()

template<class particle_hypothesis_t>

Vector2 Acts::GenericBoundTrackParameters< particle_hypothesis_t >::localPosition

(

)

const

Local spatial position two-vector.

Returns

Two-dimensional local position vector on the reference surface

momentum()

template<class particle_hypothesis_t>

Vector3 Acts::GenericBoundTrackParameters< particle_hypothesis_t >::momentum

(

)

const

Momentum three-vector.

Returns

Three-dimensional momentum vector

parameters() [1/2]

template<class particle_hypothesis_t>

ParametersVector & Acts::GenericBoundTrackParameters< particle_hypothesis_t >::parameters

(

)

Parameters vector.

Returns

Mutable reference to the parameters vector

parameters() [2/2]

template<class particle_hypothesis_t>

const ParametersVector & Acts::GenericBoundTrackParameters< particle_hypothesis_t >::parameters

(

)

const

Parameters vector.

Returns

Const reference to the parameters vector

particleHypothesis()

template<class particle_hypothesis_t>

const ParticleHypothesis & Acts::GenericBoundTrackParameters< particle_hypothesis_t >::particleHypothesis

(

)

const

Particle hypothesis.

Returns

Reference to the particle hypothesis

phi()

template<class particle_hypothesis_t>

double Acts::GenericBoundTrackParameters< particle_hypothesis_t >::phi

(

)

const

Phi direction.

Returns

The azimuthal angle phi in radians

position()

template<class particle_hypothesis_t>

Vector3 Acts::GenericBoundTrackParameters< particle_hypothesis_t >::position

(

const GeometryContext &

geoCtx

)

const

Spatial position three-vector.

Parameters

[in]

geoCtx

Geometry context for the local-to-global transformation

Returns

Three-dimensional position vector in global coordinates

This uses the associated surface to transform the local position on the surface to globalcoordinates. This requires a geometry context to select the appropriate transformation and might be a computationally expensive operation.

qOverP()

template<class particle_hypothesis_t>

double Acts::GenericBoundTrackParameters< particle_hypothesis_t >::qOverP

(

)

const

Charge over momentum.

Returns

The charge over momentum ratio

referenceFrame()

template<class particle_hypothesis_t>

RotationMatrix3 Acts::GenericBoundTrackParameters< particle_hypothesis_t >::referenceFrame

(

const GeometryContext &

geoCtx

)

const

Reference frame in which the local error is defined.

Parameters

[in]

geoCtx

Geometry context for the local-to-global transformation

Returns

The reference frame rotation matrix

For planar surfaces, this is the transformation local-to-global rotation matrix. For non-planar surfaces, it is the local-to-global rotation matrix of the tangential plane at the track position.

referenceSurface()

template<class particle_hypothesis_t>

const Surface & Acts::GenericBoundTrackParameters< particle_hypothesis_t >::referenceSurface

(

)

const

Reference surface onto which the parameters are bound.

Returns

Reference to the bound reference surface

reflect()

template<class particle_hypothesis_t>

GenericBoundTrackParameters< ParticleHypothesis > Acts::GenericBoundTrackParameters< particle_hypothesis_t >::reflect

(

)

const

Reflect the parameters.

Returns

Reflected parameters.

reflectInPlace()

template<class particle_hypothesis_t>

void Acts::GenericBoundTrackParameters< particle_hypothesis_t >::reflectInPlace

(

)

Reflect the parameters in place.

spatialImpactParameterCovariance()

template<class particle_hypothesis_t>

std::optional< ActsSquareMatrix< 2 > > Acts::GenericBoundTrackParameters< particle_hypothesis_t >::spatialImpactParameterCovariance

(

)

const

Covariance matrix of the spatial impact parameters (i.e., of d0 and z0).

Returns

Optional 2x2 covariance matrix of spatial impact parameters

spatialImpactParameters()

template<class particle_hypothesis_t>

Vector2 Acts::GenericBoundTrackParameters< particle_hypothesis_t >::spatialImpactParameters

(

)

const

Vector of spatial impact parameters (i.e., d0 and z0).

Returns

Two-dimensional vector of spatial impact parameters

theta()

template<class particle_hypothesis_t>

double Acts::GenericBoundTrackParameters< particle_hypothesis_t >::theta

(

)

const

Theta direction.

Returns

The polar angle theta in radians

time()

template<class particle_hypothesis_t>

double Acts::GenericBoundTrackParameters< particle_hypothesis_t >::time

(

)

const

Time coordinate.

Returns

The time coordinate value

toBound()

template<class particle_hypothesis_t>

GenericBoundTrackParameters< Acts::ParticleHypothesis > Acts::GenericBoundTrackParameters< particle_hypothesis_t >::toBound

(

)

const

Convert this track parameter object to the general type-erased one.

Returns

Type-erased bound track parameters

transverseMomentum()

template<class particle_hypothesis_t>

double Acts::GenericBoundTrackParameters< particle_hypothesis_t >::transverseMomentum

(

)

const

Transverse momentum.

Returns

The transverse momentum magnitude