Acts::EigenStepperDenseExtension Struct Reference

Evaluator of the k_i's and elements of the transport matrix D of the RKN4 stepping. More...

#include <Acts/Propagator/EigenStepperDenseExtension.hpp>

Collaboration diagram for Acts::EigenStepperDenseExtension:

Public Member Functions
template<typename stepper_t>
bool	finalize (typename stepper_t::State &state, const stepper_t &stepper, const IVolumeMaterial *volumeMaterial, const double h) const
	After a RKN4 step was accepted by the stepper this method has an additional veto on the quality of the step.
template<typename stepper_t>
bool	finalize (typename stepper_t::State &state, const stepper_t &stepper, const IVolumeMaterial *volumeMaterial, const double h, FreeMatrix &D) const
	After a RKN4 step was accepted by the stepper this method has an additional veto on the quality of the step.
template<int i, typename stepper_t> requires (i >= 0 && i <= 3)
bool	k (const typename stepper_t::State &state, const stepper_t &stepper, const IVolumeMaterial *volumeMaterial, Vector3 &knew, const Vector3 &bField, std::array< double, 4 > &kQoP, const double h=0., const Vector3 &kprev=Vector3::Zero())
	Evaluator of the k_i's of the RKN4.

Public Attributes
double	currentMomentum = 0.
	Momentum at a certain point.
EigenStepperDefaultExtension	defaultExtension
	Fallback extension.
double	dgdqopValue = 0.
	Derivative d(dEds)d(q/p) evaluated at the initial point.
std::array< double, 4 >	dLdl {}
	Derivatives dLambda''dlambda at each sub-step point.
std::array< double, 4 >	dPds {}
	Derivatives dPds at each sub-step.
std::array< double, 4 >	energy {}
	Energy at each sub-step.
double	g = 0.
	Derivative dEds at the initial point.
double	initialMomentum = 0.
	Particles momentum at k1.
std::array< double, 4 >	Lambdappi {}
	Lambda''_i.
Material	material = Material::Vacuum()
	Material that will be passed TODO : Might not be needed anymore.
std::array< double, 4 >	qop {}
	q/p at each sub-step
std::array< double, 4 >	tKi {}
	k_i equivalent for the time propagation

Detailed Description

Evaluator of the k_i's and elements of the transport matrix D of the RKN4 stepping.

This implementation involves energy loss due to ionisation, bremsstrahlung, pair production and photonuclear interaction in the propagation and the Jacobian. These effects will only occur if the propagation is in a TrackingVolume with attached material.

Member Function Documentation

finalize() [1/2]

template<typename stepper_t>

bool Acts::EigenStepperDenseExtension::finalize	(	typename stepper_t::State &	state,
		const stepper_t &	stepper,
		const IVolumeMaterial *	volumeMaterial,
		const double	h ) const

After a RKN4 step was accepted by the stepper this method has an additional veto on the quality of the step.

The veto lies in evaluation of the energy loss and the therewith constrained to keep the momentum after the step in reasonable values.

Template Parameters

stepper_t

Type of the stepper

Parameters

[in]	state	State of the stepper
[in]	stepper	Stepper of the propagator
[in]	volumeMaterial	Material of the volume
[in]	h	Step size

Returns

Boolean flag if the calculation is valid

finalize() [2/2]

template<typename stepper_t>

bool Acts::EigenStepperDenseExtension::finalize	(	typename stepper_t::State &	state,
		const stepper_t &	stepper,
		const IVolumeMaterial *	volumeMaterial,
		const double	h,
		FreeMatrix &	D ) const

After a RKN4 step was accepted by the stepper this method has an additional veto on the quality of the step.

The veto lies in the evaluation of the energy loss, the therewith constrained to keep the momentum after the step in reasonable values and the evaluation of the transport matrix.

Template Parameters

stepper_t

Type of the stepper

Parameters

[in]	state	State of the stepper
[in]	stepper	Stepper of the propagator
[in]	volumeMaterial	Material of the volume
[in]	h	Step size
[out]	D	Transport matrix

Returns

Boolean flag if the calculation is valid

k()

template<int i, typename stepper_t>
requires (i >= 0 && i <= 3)

bool Acts::EigenStepperDenseExtension::k	(	const typename stepper_t::State &	state,
		const stepper_t &	stepper,
		const IVolumeMaterial *	volumeMaterial,
		Vector3 &	knew,
		const Vector3 &	bField,
		std::array< double, 4 > &	kQoP,
		const double	h = 0.,
		const Vector3 &	kprev = Vector3::Zero() )

Evaluator of the k_i's of the RKN4.

For the case of i = 0 this step sets up member parameters, too.

Template Parameters

i	Index of the k_i, i = [0, 3]
stepper_t	Type of the stepper

Parameters

[in]	state	State of the stepper
[in]	stepper	Stepper of the propagator
[in]	volumeMaterial	Material of the volume
[out]	knew	Next k_i that is evaluated
[out]	kQoP	k_i elements of the momenta
[in]	bField	B-Field at the evaluation position
[in]	h	Step size (= 0. ^ 0.5 * StepSize ^ StepSize)
[in]	kprev	Evaluated k_{i - 1}

Returns

Boolean flag if the calculation is valid

Member Data Documentation

currentMomentum

double Acts::EigenStepperDenseExtension::currentMomentum = 0.

Momentum at a certain point.

defaultExtension

EigenStepperDefaultExtension Acts::EigenStepperDenseExtension::defaultExtension

Fallback extension.

dgdqopValue

double Acts::EigenStepperDenseExtension::dgdqopValue = 0.

Derivative d(dEds)d(q/p) evaluated at the initial point.

dLdl

std::array<double, 4> Acts::EigenStepperDenseExtension::dLdl {}

Derivatives dLambda''dlambda at each sub-step point.

dPds

std::array<double, 4> Acts::EigenStepperDenseExtension::dPds {}

Derivatives dPds at each sub-step.

energy

std::array<double, 4> Acts::EigenStepperDenseExtension::energy {}

Energy at each sub-step.

g

double Acts::EigenStepperDenseExtension::g = 0.

Derivative dEds at the initial point.

initialMomentum

double Acts::EigenStepperDenseExtension::initialMomentum = 0.

Particles momentum at k1.

Lambdappi

std::array<double, 4> Acts::EigenStepperDenseExtension::Lambdappi {}

Lambda''_i.

material

Material Acts::EigenStepperDenseExtension::material = Material::Vacuum()

Material that will be passed TODO : Might not be needed anymore.

qop

std::array<double, 4> Acts::EigenStepperDenseExtension::qop {}

q/p at each sub-step

tKi

std::array<double, 4> Acts::EigenStepperDenseExtension::tKi {}

k_i equivalent for the time propagation