RiddersStepper implements the Ridders method for numerical differentiation to compute the Jacobian of the bound to bound transformation. More...

#include <Acts/Propagator/RiddersStepper.hpp>

Classes
struct	Config
	Configuration struct for the RiddersStepper. More...
struct	State
	The state struct for the RiddersStepper. More...

Public Types
using	BoundParameters = BoundTrackParameters
	The bound parameters type used by this stepper.
using	BoundState = std::tuple<BoundParameters, Jacobian, double>
	The type of the bound state returned by the boundState method.
using	Covariance = BoundMatrix
	The covariance type for the bound parameters.
using	Jacobian = BoundMatrix
	The Jacobian type for the bound to bound transformation.
using	Options = typename StepperImpl::Options
	The options type for the RiddersStepper.
using	StepperImpl = stepper_impl_t
	The type of the underlying stepper implementation.

Public Member Functions
	RiddersStepper (const Config &config)
	Construct a RiddersStepper with the given configuration.
	RiddersStepper (std::shared_ptr< const MagneticFieldProvider > bField)
	Construct a RiddersStepper with the given magnetic field provider.
	RiddersStepper (StepperImpl stepperImpl)
	Construct a RiddersStepper with the given stepper implementation.
double	absoluteMomentum (const State &state) const
	Get the absolute momentum of the primary stepper state.
Result< BoundState >	boundState (State &state, const Surface &surface, bool transportCovariance=true, const FreeToBoundCorrection &freeToBoundCorrection=FreeToBoundCorrection(false)) const
	Compute the bound state.
double	charge (const State &state) const
	Get the charge of the primary stepper state.
BoundState	curvilinearState (State &state, bool transportCovariance=true) const
	Compute the curvilinear state.
Vector3	direction (const State &state) const
	Get the direction of the primary stepper state.
Result< Vector3 >	getField (State &state, const Vector3 &position) const
	Get the magnetic field at the given position for the primary stepper state.
double	getStepSize (const State &state, ConstrainedStep::Type stype) const
	Get the step size for the given constrained step type.
void	initialize (State &state, const BoundParameters &boundParameters) const
	Initialize the state of the RiddersStepper based on the given bound parameters.
void	initialize (State &state, const BoundVector &boundVector, const std::optional< BoundMatrix > &covariance, ParticleHypothesis particleHypothesis, const Surface &surface) const
	Initialize the state of the RiddersStepper based on the given bound vector and covariance.
State	makeState (const Options &options) const
	Create a new state for the RiddersStepper based on the given options.
Vector3	momentum (const State &state) const
	Get the momentum vector of the primary stepper state.
std::string	outputStepSize (const State &state) const
	Get a string representation of the step size constraints.
const ParticleHypothesis &	particleHypothesis (const State &state) const
	Get the particle hypothesis of the primary stepper state.
Vector3	position (const State &state) const
	Get the position of the primary stepper state.
bool	prepareCurvilinearState (State &state) const
	Prepare the stepper for the curvilinear transformation.
double	qOverP (const State &state) const
	Get the charge over momentum of the primary stepper state.
void	releaseStepSize (State &state, ConstrainedStep::Type stype) const
	Release the step size for the given constrained step type.
Result< double >	step (State &state, Direction propagationDirection, const IVolumeMaterial *material) const
	Perform a step.
double	time (const State &state) const
	Get the time of the primary stepper state.
void	transportCovarianceToBound (State &state, const Surface &surface, const FreeToBoundCorrection &freeToBoundCorrection=FreeToBoundCorrection(false)) const
	Transport the covariance to bound parameters.
void	transportCovarianceToCurvilinear (State &state) const
	Transport the covariance to curvilinear parameters.
void	update (State &state, const FreeVector &, const BoundVector &boundParams, const BoundMatrix &covariance, const Surface &surface) const
	Update the state of the RiddersStepper.
void	update (State &state, const Vector3 &position, const Vector3 &direction, double qOverP, double time) const
	Update the state of the RiddersStepper.
void	updateStepSize (State &state, const NavigationTarget &target, Direction direction, ConstrainedStep::Type stype) const
	Update the step size based on the given navigation target, direction, and constrained step type.
void	updateStepSize (State &state, double stepSize, ConstrainedStep::Type stype) const
	Update the step size based on the given step size and constrained step type.
IntersectionStatus	updateSurfaceStatus (State &state, const Surface &surface, std::uint8_t index, Direction navDir, const BoundaryTolerance &boundaryTolerance, double surfaceTolerance, ConstrainedStep::Type stype, const Logger &logger=getDummyLogger()) const
	Update the surface status of the primary and secondary stepper states based on the given surface and navigation direction.

Detailed Description

template<Concepts::SingleStepper stepper_impl_t>
class Acts::Experimental::RiddersStepper< stepper_impl_t >

RiddersStepper implements the Ridders method for numerical differentiation to compute the Jacobian of the bound to bound transformation.

It uses a primary stepper to perform the nominal step and multiple secondary steppers with varied initial conditions to compute the Jacobian columns. The variations are generated based on the input covariance and a configurable variation generator.

Template Parameters

stepper_impl_t the type of the underlying stepper implementation

Constructor & Destructor Documentation

◆ RiddersStepper() [1/3]

template<Concepts::SingleStepper stepper_impl_t>

Acts::Experimental::RiddersStepper< stepper_impl_t >::RiddersStepper ( StepperImpl stepperImpl )

explicit

Construct a RiddersStepper with the given stepper implementation.

Parameters

stepperImpl the underlying stepper implementation

◆ RiddersStepper() [2/3]

template<Concepts::SingleStepper stepper_impl_t>

Acts::Experimental::RiddersStepper< stepper_impl_t >::RiddersStepper ( std::shared_ptr< const MagneticFieldProvider > bField )

explicit

Construct a RiddersStepper with the given magnetic field provider.

Parameters

bField the magnetic field provider

◆ RiddersStepper() [3/3]

template<Concepts::SingleStepper stepper_impl_t>

Acts::Experimental::RiddersStepper< stepper_impl_t >::RiddersStepper ( const Config & config )

explicit

Construct a RiddersStepper with the given configuration.

Parameters

config the configuration for the RiddersStepper

Member Function Documentation

◆ absoluteMomentum()

template<Concepts::SingleStepper stepper_impl_t>

double Acts::Experimental::RiddersStepper< stepper_impl_t >::absoluteMomentum ( const State & state ) const

Get the absolute momentum of the primary stepper state.

Parameters

state the state of the RiddersStepper

Returns: the absolute momentum of the primary stepper state

◆ boundState()

template<Concepts::SingleStepper stepper_impl_t>

Result< BoundState > Acts::Experimental::RiddersStepper< stepper_impl_t >::boundState	(	State &	state,
		const Surface &	surface,
		bool	transportCovariance = true,
		const FreeToBoundCorrection &	freeToBoundCorrection = FreeToBoundCorrection(false) ) const

Compute the bound state.

Parameters

state	the state of the RiddersStepper
surface	the surface
transportCovariance	flag indicating whether to transport the covariance to the bound parameters
freeToBoundCorrection	the correction

Returns: the bound state

◆ charge()

template<Concepts::SingleStepper stepper_impl_t>

double Acts::Experimental::RiddersStepper< stepper_impl_t >::charge ( const State & state ) const

Get the charge of the primary stepper state.

Parameters

state the state of the RiddersStepper

Returns: the charge of the primary stepper state

◆ curvilinearState()

template<Concepts::SingleStepper stepper_impl_t>

BoundState Acts::Experimental::RiddersStepper< stepper_impl_t >::curvilinearState	(	State &	state,
		bool	transportCovariance = true ) const

Compute the curvilinear state.

Parameters

state	the state of the RiddersStepper
transportCovariance	flag indicating whether to transport the covariance to the curvilinear parameters

Returns: the curvilinear state

◆ direction()

template<Concepts::SingleStepper stepper_impl_t>

Vector3 Acts::Experimental::RiddersStepper< stepper_impl_t >::direction ( const State & state ) const

Get the direction of the primary stepper state.

Parameters

state the state of the RiddersStepper

Returns: the direction of the primary stepper state

◆ getField()

template<Concepts::SingleStepper stepper_impl_t>

Result< Vector3 > Acts::Experimental::RiddersStepper< stepper_impl_t >::getField	(	State &	state,
		const Vector3 &	position ) const

Get the magnetic field at the given position for the primary stepper state.

Parameters

state	the state of the RiddersStepper
position	the position at which to get the magnetic field

Returns: the magnetic field at the given position for the primary stepper state

◆ getStepSize()

template<Concepts::SingleStepper stepper_impl_t>

double Acts::Experimental::RiddersStepper< stepper_impl_t >::getStepSize	(	const State &	state,
		ConstrainedStep::Type	stype ) const

Get the step size for the given constrained step type.

Parameters

state	the state of the RiddersStepper
stype	the type of the constrained step for which to get the step size

Returns: the step size of the primary stepper state for the given constrained step type

◆ initialize() [1/2]

template<Concepts::SingleStepper stepper_impl_t>

void Acts::Experimental::RiddersStepper< stepper_impl_t >::initialize	(	State &	state,
		const BoundParameters &	boundParameters ) const

Initialize the state of the RiddersStepper based on the given bound parameters.

Parameters

state	the state
boundParameters	the bound parameters to initialize the state with

◆ initialize() [2/2]

template<Concepts::SingleStepper stepper_impl_t>

void Acts::Experimental::RiddersStepper< stepper_impl_t >::initialize	(	State &	state,
		const BoundVector &	boundVector,
		const std::optional< BoundMatrix > &	covariance,
		ParticleHypothesis	particleHypothesis,
		const Surface &	surface ) const

Initialize the state of the RiddersStepper based on the given bound vector and covariance.

Parameters

state	the state
boundVector	the bound vector to initialize the state with
covariance	the covariance of the bound parameters, used to generate the variations for the secondary steppers
particleHypothesis	the particle hypothesis
surface	the surface on which the bound parameters are defined

◆ makeState()

template<Concepts::SingleStepper stepper_impl_t>

State Acts::Experimental::RiddersStepper< stepper_impl_t >::makeState ( const Options & options ) const

Create a new state for the RiddersStepper based on the given options.

Parameters

options the options

Returns: a new state for the RiddersStepper

◆ momentum()

template<Concepts::SingleStepper stepper_impl_t>

Vector3 Acts::Experimental::RiddersStepper< stepper_impl_t >::momentum ( const State & state ) const

Get the momentum vector of the primary stepper state.

Parameters

state the state of the RiddersStepper

Returns: the momentum vector of the primary stepper state

◆ outputStepSize()

template<Concepts::SingleStepper stepper_impl_t>

std::string Acts::Experimental::RiddersStepper< stepper_impl_t >::outputStepSize ( const State & state ) const

Get a string representation of the step size constraints.

Parameters

state the state of the RiddersStepper

Returns: a string representation of the step size constraints

◆ particleHypothesis()

template<Concepts::SingleStepper stepper_impl_t>

const ParticleHypothesis & Acts::Experimental::RiddersStepper< stepper_impl_t >::particleHypothesis ( const State & state ) const

Get the particle hypothesis of the primary stepper state.

Parameters

state the state of the RiddersStepper

Returns: the particle hypothesis of the primary stepper state

◆ position()

template<Concepts::SingleStepper stepper_impl_t>

Vector3 Acts::Experimental::RiddersStepper< stepper_impl_t >::position ( const State & state ) const

Get the position of the primary stepper state.

Parameters

state the state of the RiddersStepper

Returns: the position of the primary stepper state

◆ prepareCurvilinearState()

template<Concepts::SingleStepper stepper_impl_t>

bool Acts::Experimental::RiddersStepper< stepper_impl_t >::prepareCurvilinearState ( State & state ) const

Prepare the stepper for the curvilinear transformation.

Parameters

state the state of the RiddersStepper

Returns: true if the preparation was successful for all stepper states, false otherwise

◆ qOverP()

template<Concepts::SingleStepper stepper_impl_t>

double Acts::Experimental::RiddersStepper< stepper_impl_t >::qOverP ( const State & state ) const

Get the charge over momentum of the primary stepper state.

Parameters

state the state of the RiddersStepper

Returns: the charge over momentum of the primary stepper state

◆ releaseStepSize()

template<Concepts::SingleStepper stepper_impl_t>

void Acts::Experimental::RiddersStepper< stepper_impl_t >::releaseStepSize	(	State &	state,
		ConstrainedStep::Type	stype ) const

Release the step size for the given constrained step type.

Parameters

state	the state of the RiddersStepper
stype	the type of the constrained step for which to release the step size

◆ step()

template<Concepts::SingleStepper stepper_impl_t>

Result< double > Acts::Experimental::RiddersStepper< stepper_impl_t >::step	(	State &	state,
		Direction	propagationDirection,
		const IVolumeMaterial *	material ) const

Perform a step.

Parameters

state	the state of the RiddersStepper
propagationDirection	the direction
material	the material

Returns: a result containing the step length or an error if the step failed

◆ time()

template<Concepts::SingleStepper stepper_impl_t>

double Acts::Experimental::RiddersStepper< stepper_impl_t >::time ( const State & state ) const

Get the time of the primary stepper state.

Parameters

state the state of the RiddersStepper

Returns: the time of the primary stepper state

◆ transportCovarianceToBound()

template<Concepts::SingleStepper stepper_impl_t>

void Acts::Experimental::RiddersStepper< stepper_impl_t >::transportCovarianceToBound	(	State &	state,
		const Surface &	surface,
		const FreeToBoundCorrection &	freeToBoundCorrection = FreeToBoundCorrection(false) ) const

Transport the covariance to bound parameters.

Parameters

state	the state of the RiddersStepper
surface	the surface
freeToBoundCorrection	the correction

◆ transportCovarianceToCurvilinear()

template<Concepts::SingleStepper stepper_impl_t>

void Acts::Experimental::RiddersStepper< stepper_impl_t >::transportCovarianceToCurvilinear ( State & state ) const

Transport the covariance to curvilinear parameters.

Parameters

state the state of the RiddersStepper

◆ update() [1/2]

template<Concepts::SingleStepper stepper_impl_t>

void Acts::Experimental::RiddersStepper< stepper_impl_t >::update	(	State &	state,
		const FreeVector &	,
		const BoundVector &	boundParams,
		const BoundMatrix &	covariance,
		const Surface &	surface ) const

Update the state of the RiddersStepper.

Parameters

state	the state of the RiddersStepper
boundParams	the bound vector
covariance	the covariance of the bound parameters
surface	the surface on which the bound parameters are defined

◆ update() [2/2]

template<Concepts::SingleStepper stepper_impl_t>

void Acts::Experimental::RiddersStepper< stepper_impl_t >::update	(	State &	state,
		const Vector3 &	position,
		const Vector3 &	direction,
		double	qOverP,
		double	time ) const

Update the state of the RiddersStepper.

Parameters

state	the state of the RiddersStepper
position	the position
direction	the direction
qOverP	the charge over momentum
time	the time

◆ updateStepSize() [1/2]

template<Concepts::SingleStepper stepper_impl_t>

void Acts::Experimental::RiddersStepper< stepper_impl_t >::updateStepSize	(	State &	state,
		const NavigationTarget &	target,
		Direction	direction,
		ConstrainedStep::Type	stype ) const

Update the step size based on the given navigation target, direction, and constrained step type.

Parameters

state	the state of the RiddersStepper
target	the navigation target
direction	the direction
stype	the type of the constrained step

◆ updateStepSize() [2/2]

template<Concepts::SingleStepper stepper_impl_t>

void Acts::Experimental::RiddersStepper< stepper_impl_t >::updateStepSize	(	State &	state,
		double	stepSize,
		ConstrainedStep::Type	stype ) const

Update the step size based on the given step size and constrained step type.

Parameters

state	the state of the RiddersStepper
stepSize	the step size
stype	the type of the constrained step

◆ updateSurfaceStatus()

template<Concepts::SingleStepper stepper_impl_t>

IntersectionStatus Acts::Experimental::RiddersStepper< stepper_impl_t >::updateSurfaceStatus	(	State &	state,
		const Surface &	surface,
		std::uint8_t	index,
		Direction	navDir,
		const BoundaryTolerance &	boundaryTolerance,
		double	surfaceTolerance,
		ConstrainedStep::Type	stype,
		const Logger &	logger = getDummyLogger() ) const

Update the surface status of the primary and secondary stepper states based on the given surface and navigation direction.

Parameters

state	the state of the RiddersStepper
surface	the surface
index	the index of the surface
navDir	the navigation direction
boundaryTolerance	the boundary tolerance
surfaceTolerance	the surface tolerance
stype	the type of the constrained step
logger	the logger

Returns: the overall intersection status after updating the surface status for the primary and secondary stepper states

Classes

Public Types

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ RiddersStepper() [1/3]

◆ RiddersStepper() [2/3]

◆ RiddersStepper() [3/3]

Member Function Documentation

◆ absoluteMomentum()

◆ boundState()

◆ charge()

◆ curvilinearState()

◆ direction()

◆ getField()

◆ getStepSize()

◆ initialize() [1/2]

◆ initialize() [2/2]

◆ makeState()

◆ momentum()

◆ outputStepSize()

◆ particleHypothesis()

◆ position()

◆ prepareCurvilinearState()

◆ qOverP()

◆ releaseStepSize()

◆ step()

◆ time()

◆ transportCovarianceToBound()

◆ transportCovarianceToCurvilinear()

◆ update() [1/2]

◆ update() [2/2]

◆ updateStepSize() [1/2]

◆ updateStepSize() [2/2]

◆ updateSurfaceStatus()