Default evaluater of the k_i's and elements of the transport matrix D of the RKN4 stepping. This is a pure implementation by textbook. More...

#include <acts/blob/master/Core/include/Acts/Propagator/DefaultExtension.hpp>

Public Member Functions
	DefaultExtension ()=default
	Default constructor.

template<typename propagator_state_t , typename stepper_t >
int	bid (const propagator_state_t &, const stepper_t &) const
	Control function if the step evaluation would be valid.

template<typename propagator_state_t , typename stepper_t >
bool	k (const propagator_state_t &state, const stepper_t &stepper, Vector3D &knew, const Vector3D &bField, std::array< double, 4 > &kQoP, const int i=0, const double h=0., const Vector3D &kprev=Vector3D())
	Evaluater of the k_i's of the RKN4. For the case of i = 0 this step sets up qop, too.

template<typename propagator_state_t , typename stepper_t >
bool	finalize (propagator_state_t &state, const stepper_t &stepper, const double h) const
	Veto function after a RKN4 step was accepted by judging on the error of the step. Since the textbook does not deliver further vetos, this is a dummy function.

template<typename propagator_state_t , typename stepper_t >
bool	finalize (propagator_state_t &state, const stepper_t &stepper, const double h, FreeMatrix &D) const
	Veto function after a RKN4 step was accepted by judging on the error of the step. Since the textbook does not deliver further vetos, this is just for the evaluation of the transport matrix.

Private Member Functions
template<typename propagator_state_t , typename stepper_t >
void	propagateTime (propagator_state_t &state, const stepper_t &stepper, const double h) const
	Propagation function for the time coordinate.

template<typename propagator_state_t , typename stepper_t >
bool	transportMatrix (propagator_state_t &state, const stepper_t &stepper, const double h, FreeMatrix &D) const
	Calculates the transport matrix D for the jacobian.

Detailed Description

Default evaluater of the k_i's and elements of the transport matrix D of the RKN4 stepping. This is a pure implementation by textbook.

Definition at line 17 of file DefaultExtension.hpp.

View newest version in sPHENIX GitHub at line 17 of file DefaultExtension.hpp

Constructor & Destructor Documentation

Acts::DefaultExtension::DefaultExtension ( )

default

Default constructor.

Member Function Documentation

template<typename propagator_state_t , typename stepper_t >

int Acts::DefaultExtension::bid	(	const propagator_state_t &	,
		const stepper_t &
	)		const

inline

Control function if the step evaluation would be valid.

Template Parameters

propagator_state_t	Type of the state of the propagator
stepper_t	Type of the stepper

Returns: Boolean flag if the step would be valid

Definition at line 27 of file DefaultExtension.hpp.

View newest version in sPHENIX GitHub at line 27 of file DefaultExtension.hpp

template<typename propagator_state_t , typename stepper_t >

bool Acts::DefaultExtension::finalize	(	propagator_state_t &	state,
		const stepper_t &	stepper,
		const double	h
	)		const

inline

Veto function after a RKN4 step was accepted by judging on the error of the step. Since the textbook does not deliver further vetos, this is a dummy function.

Template Parameters

propagator_state_t	Type of the state of the propagator
stepper_t	Type of the stepper

Parameters

[in]	state	State of the propagator
[in]	stepper	Stepper of the propagation
[in]	h	Step size

Returns: Boolean flag if the calculation is valid

Definition at line 75 of file DefaultExtension.hpp.

View newest version in sPHENIX GitHub at line 75 of file DefaultExtension.hpp

References propagateTime().

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template<typename propagator_state_t , typename stepper_t >

bool Acts::DefaultExtension::finalize	(	propagator_state_t &	state,
		const stepper_t &	stepper,
		const double	h,
		FreeMatrix &	D
	)		const

inline

Veto function after a RKN4 step was accepted by judging on the error of the step. Since the textbook does not deliver further vetos, this is just for the evaluation of the transport matrix.

Template Parameters

propagator_state_t	Type of the state of the propagator
stepper_t	Type of the stepper

Parameters

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

Returns: Boolean flag if the calculation is valid

Definition at line 93 of file DefaultExtension.hpp.

View newest version in sPHENIX GitHub at line 93 of file DefaultExtension.hpp

References propagateTime(), and transportMatrix().

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template<typename propagator_state_t , typename stepper_t >

bool Acts::DefaultExtension::k	(	const propagator_state_t &	state,
		const stepper_t &	stepper,
		Vector3D &	knew,
		const Vector3D &	bField,
		std::array< double, 4 > &	kQoP,
		const int	i = `0`,
		const double	h = `0.`,
		const Vector3D &	kprev = `Vector3D()`
	)

inline

Evaluater of the k_i's of the RKN4. For the case of i = 0 this step sets up qop, too.

Template Parameters

propagator_state_t	Type of the state of the propagator
stepper_t	Type of the stepper

Parameters

[in]	state	State of the propagator
[in]	stepper	Stepper of the propagation
[out]	knew	Next k_i that is evaluated
[in]	bField	B-Field at the evaluation position
[out]	kQoP	k_i elements of the momenta
[in]	i	Index of the k_i, i = [0, 3]
[in]	h	Step size (= 0. ^ 0.5 * StepSize ^ StepSize)
[in]	kprev	Evaluated k_{i - 1}

Returns: Boolean flag if the calculation is valid

Definition at line 47 of file DefaultExtension.hpp.

View newest version in sPHENIX GitHub at line 47 of file DefaultExtension.hpp

References Acts::VectorHelpers::cross(), and Acts::UnitConstants::h.

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template<typename propagator_state_t , typename stepper_t >

void Acts::DefaultExtension::propagateTime	(	propagator_state_t &	state,
		const stepper_t &	stepper,
		const double	h
	)		const

inlineprivate

Propagation function for the time coordinate.

Template Parameters

propagator_state_t	Type of the state of the propagator
stepper_t	Type of the stepper

Parameters

[in,out]	state	State of the propagator
[in]	stepper	Stepper of the propagation
[in]	h	Step size

This evaluation is based on dt/ds = 1/v = 1/(beta * c) with the velocity v, the speed of light c and beta = v/c. This can be re-written as dt/ds = sqrt(m^2/p^2 + c^{-2}) with the mass m and the momentum p.

Definition at line 108 of file DefaultExtension.hpp.

View newest version in sPHENIX GitHub at line 108 of file DefaultExtension.hpp

Referenced by finalize().

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template<typename propagator_state_t , typename stepper_t >

bool Acts::DefaultExtension::transportMatrix	(	propagator_state_t &	state,
		const stepper_t &	stepper,
		const double	h,
		FreeMatrix &	D
	)		const

inlineprivate

Calculates the transport matrix D for the jacobian.

Template Parameters

propagator_state_t	Type of the state of the propagator
stepper_t	Type of the stepper

Parameters

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

Returns: Boolean flag if evaluation is valid

The calculations are based on ATL-SOFT-PUB-2009-002. The update of the Jacobian matrix is requires only the calculation of eq. 17 and 18. Since the terms of eq. 18 are currently 0, this matrix is not needed in the calculation. The matrix A from eq. 17 consists out of 3 different parts. The first one is given by the upper left 3x3 matrix that are calculated by the derivatives dF/dT (called dFdT) and dG/dT (calles dGdT). The second is given by the top 3 lines of the rightmost column. This is calculated by dFdL and dGdL. The remaining non-zero term is calculated directly. The naming of the variables is explained in eq. 11 and are directly related to the initial problem in eq. 7. The evaluation is based by propagating the parameters T and lambda as given in eq. 16 and evaluating the derivations for matrix A.

Note: The translation for u_{n+1} in eq. 7 is in this case a 3-dimensional vector without a dependency of Lambda or lambda neither in u_n nor in u_n'. The second and fourth eq. in eq. 14 have the constant offset matrices h * Id and Id respectively. This involves that the constant offset does not exist for rectangular matrix dGdu' (due to the missing Lambda part) and only exists for dFdu' in dlambda/dlambda.

Definition at line 131 of file DefaultExtension.hpp.

View newest version in sPHENIX GitHub at line 131 of file DefaultExtension.hpp

References Acts::VectorHelpers::cross(), D(), dir, and Acts::UnitConstants::h.

Referenced by finalize().

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The documentation for this struct was generated from the following file:

acts/blob/master/Core/include/Acts/Propagator/DefaultExtension.hpp

Public Member Functions

Private Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation