Class of Runge-Kutta 4 formula (classic Runge-Kutta method). More...

Inheritance diagram for num_collect::ode::runge_kutta::rk4_formula< Problem >:

Collaboration diagram for num_collect::ode::runge_kutta::rk4_formula< Problem >:

Public Types
using	base_type = formula_base<rk4_formula<Problem>, Problem>
	Type of base class.

Public Types inherited from num_collect::ode::formula_base< rk4_formula< Problem >, Problem >
using	problem_type
	Type of problem.

using	scalar_type
	Type of scalars.

using	variable_type
	Type of variables.

Public Member Functions
void	step (scalar_type time, scalar_type step_size, const variable_type &current, variable_type &estimate)
	Compute the next variable.

Public Member Functions inherited from num_collect::ode::formula_base< rk4_formula< Problem >, Problem >
	formula_base (const problem_type &problem=problem_type())
	Constructor.

auto	problem () -> problem_type &
	Get the problem.

auto	problem () const -> const problem_type &
	Get the problem.

void	step (scalar_type time, scalar_type step_size, const variable_type &current, variable_type &estimate)
	Compute the next variable.

Static Public Attributes
static constexpr auto	log_tag
	Log tag.

static constexpr index_type	order = 4
	Order of this formula.

static constexpr index_type	stages = 4
	Number of stages of this formula.

Coefficients in Butcher array.
`a` is coefficients of intermidiate variables in calculation of intermidiate variables. `b` is coefficients of time in calculation of intermidiate variables. `c` is coefficients of intermidiate variables in calculation of estimates of next variables.
static constexpr scalar_type	a21 = coeff(1, 2)

static constexpr scalar_type	a32 = coeff(1, 2)

static constexpr scalar_type	a43 = coeff(1)

static constexpr scalar_type	b1 = coeff(0)

static constexpr scalar_type	b2 = coeff(1, 2)

static constexpr scalar_type	b3 = coeff(1, 2)

static constexpr scalar_type	b4 = coeff(1)

static constexpr scalar_type	c1 = coeff(1, 6)

static constexpr scalar_type	c2 = coeff(1, 3)

static constexpr scalar_type	c3 = coeff(1, 3)

static constexpr scalar_type	c4 = coeff(1, 6)

Additional Inherited Members
Protected Member Functions inherited from num_collect::ode::formula_base< rk4_formula< Problem >, Problem >
auto	derived () const noexcept -> const rk4_formula< Problem > &
	Access derived object.

auto	derived () noexcept -> rk4_formula< Problem > &
	Access derived object.

Static Protected Member Functions inherited from num_collect::ode::formula_base< rk4_formula< Problem >, Problem >
static constexpr auto	coeff (T val) -> scalar_type
	Convert coefficients.

static constexpr auto	coeff (T1 num, T2 den) -> scalar_type
	Create coefficients.

Detailed Description

template<concepts::problem Problem>
class num_collect::ode::runge_kutta::rk4_formula< Problem >

Class of Runge-Kutta 4 formula (classic Runge-Kutta method).

Template Parameters

Problem Type of problem.

Definition at line 38 of file rk4_formula.h.

Member Typedef Documentation

template<concepts::problem Problem>

Type of base class.

Definition at line 41 of file rk4_formula.h.

template<concepts::problem Problem>

void num_collect::ode::runge_kutta::rk4_formula< Problem >::step	(	scalar_type	time,
		scalar_type	step_size,
		const variable_type &	current,
		variable_type &	estimate )