allpix::RungeKutta

Class to perform arbitrary Runge-Kutta integration. More…

#include <runge_kutta.h>

Public Classes

	Name
class	Step Utility type to return both the value and the error at every step.

Public Types

	Name
using std::function< Eigen::Matrix< T, D, 1 >(T, Eigen::Matrix< T, D, 1 >)>	StepFunction Stepping function to integrate a single step of the equations.

Public Functions

	Name
	RungeKutta(Eigen::Matrix< T, S+2, S > tableau, StepFunction function, T step_size, Eigen::Matrix< T, D, 1 > initial_y, T initial_t =0) Construct a Runge-Kutta integrator.
void	setTimeStep(T step_size) Changes the time step.
T	getTimeStep() const Return the time step.
void	setValue(Eigen::Matrix< T, D, 1 > y) Changes the current value during integration.
Eigen::Matrix< T, D, 1 >	getValue() const Get the value to integrate.
Eigen::Matrix< T, D, 1 >	getError() const Get the total integration error.
T	getTime() const Get the time during integration.
void	advanceTime(double t) Advance the time of the integration.
Step	step() Execute a single time step of the integration.
Step	step(int amount) Execute multiple time steps of the integration.

Detailed Description

template <typename T ,
int S,
int D =3>
class allpix::RungeKutta;

Class to perform arbitrary Runge-Kutta integration.

Class can be provided a Runge-Kutta tableau (optionally with an error function), together with the dimension of the equations and a step function to integrate a step of the equation. Both the result, error and timestep can be retrieved and changed during the integration.

Public Types Documentation

using StepFunction

using allpix::RungeKutta< T, S, D >::StepFunction =  std::function<Eigen::Matrix<T, D, 1>(T, Eigen::Matrix<T, D, 1>)>;

Stepping function to integrate a single step of the equations.

Public Functions Documentation

function RungeKutta

inline RungeKutta(
    Eigen::Matrix< T, S+2, S > tableau,
    StepFunction function,
    T step_size,
    Eigen::Matrix< T, D, 1 > initial_y,
    T initial_t =0
)

Construct a Runge-Kutta integrator.

Parameters:

tableau One of the possible Runge-Kutta tables (see allpix::tableau should be preferred)
function Step function to perform integration
step_size Time step of the integration
initial_y Start values of the vector to perform integration on
initial_t Initial time at the start of the integration

function setTimeStep

inline void setTimeStep(
    T step_size
)

Changes the time step.

Parameters:

step_size New time step of the integration

function getTimeStep

inline T getTimeStep() const

Return the time step.

Return: Current time step of the integration

function setValue

inline void setValue(
    Eigen::Matrix< T, D, 1 > y
)

Changes the current value during integration.

Note: Can be used to add additional processes during the integration

function getValue

inline Eigen::Matrix< T, D, 1 > getValue() const

Get the value to integrate.

Return: Current value

function getError

inline Eigen::Matrix< T, D, 1 > getError() const

Get the total integration error.

Return: Total integrated error

function getTime

inline T getTime() const

Get the time during integration.

Return: Current time

function advanceTime

inline void advanceTime(
    double t
)

Advance the time of the integration.

Parameters:

t Time step to advance the integration by

function step

inline Step step()

Execute a single time step of the integration.

Return: Combination of the current value and the error in this single step

function step

inline Step step(
    int amount
)

Execute multiple time steps of the integration.

Parameters:

amount Number of steps to combine

Return: Combination of the current value and the total error in all the steps

Updated on 2024-12-13 at 08:31:36 +0000