Integrate using a for loop and a fixed time-step. More...

Inheritance diagram for dg::SinglestepTimeloop< ContainerType >:

Public Types
using	container_type = ContainerType

using	value_type = dg::get_value_type< ContainerType >

Public Types inherited from dg::aTimeloop< ContainerType >
using	value_type = dg::get_value_type< ContainerType >

using	container_type = ContainerType

Public Member Functions
	SinglestepTimeloop ()=default
	no allocation More...

	SinglestepTimeloop (std::function< void(value_type, const ContainerType &, value_type &, ContainerType &, value_type)> step, value_type dt=0)
	Construct using a `std::function`. More...

template<class Stepper , class ODE >
	SinglestepTimeloop (Stepper &&stepper, ODE &&ode, value_type dt=0)
	Bind the step function of a single step stepper. More...

template<class ... Params>
void	construct (Params &&...ps)
	Perfect forward parameters to one of the constructors. More...

void	set_dt (value_type dt)
	Set the constant timestep to be used in the integrate functions. More...

void	integrate_steps (value_type t0, const container_type &u0, value_type t1, container_type &u1, unsigned steps)
	Integrate differential equation with a fixed number of steps. More...

virtual SinglestepTimeloop *	clone () const
	Abstract copy method that returns a copy of *this on the heap. More...

Public Member Functions inherited from dg::aTimeloop< ContainerType >
void	integrate (value_type t0, const ContainerType &u0, value_type t1, ContainerType &u1)
	Integrate a differential equation between given bounds. More...

void	integrate (value_type &t0, const ContainerType &u0, value_type t1, ContainerType &u1, enum to mode)
	Build your own timeloop. More...

value_type	get_dt () const
	The current timestep. More...

virtual aTimeloop *	clone () const =0
	Abstract copy method that returns a copy of *this on the heap. More...

virtual	~aTimeloop ()

Additional Inherited Members
Protected Member Functions inherited from dg::aTimeloop< ContainerType >
	aTimeloop ()
	empty More...

	aTimeloop (const aTimeloop &)
	empty More...

aTimeloop &	operator= (const aTimeloop &)
	return *this More...

Detailed Description

template<class ContainerType>
struct dg::SinglestepTimeloop< ContainerType >

Integrate using a for loop and a fixed time-step.

The implementation (of integrate) is equivalent to

dg::blas1::copy( u0, u1);
unsigned N = round((t1 - t0)/dt);
for( unsigned i=0; i<N; i++)
    step( t0, u1, t0, u1, dt);

where dt is a given constant. If t1 needs to be matched exactly, the last timestep is shortened accordingly.

See also: AdaptiveTimeloop, MultistepTimeloop

Template Parameters

ContainerType

Any class for which a specialization of TensorTraits exists and which fulfills the requirements of the there defined data and execution policies derived from AnyVectorTag and AnyPolicyTag. Among others

dg::HVec (serial), dg::DVec (cuda / omp), dg::MHVec (mpi + serial) or dg::MDVec (mpi + cuda / omp)
std::vector<dg::DVec> (vector of shared device vectors), std::array<double, 4> (array of 4 doubles) or std::map < std::string, dg::DVec> ( a map of named vectors)
double (scalar) and other primitive types ...

If there are several ContainerTypes in the argument list, then TensorTraits must exist for all of them

See also: See The dg dispatch system for a detailed explanation of our type dispatch system

Member Typedef Documentation

◆ container_type

template<class ContainerType >

using dg::SinglestepTimeloop< ContainerType >::container_type = ContainerType

◆ value_type

template<class ContainerType >

using dg::SinglestepTimeloop< ContainerType >::value_type = dg::get_value_type<ContainerType>

Constructor & Destructor Documentation

◆ SinglestepTimeloop() [1/3]

template<class ContainerType >

dg::SinglestepTimeloop< ContainerType >::SinglestepTimeloop ( )

default

no allocation

◆ SinglestepTimeloop() [2/3]

template<class ContainerType >

dg::SinglestepTimeloop< ContainerType >::SinglestepTimeloop	(	std::function< void(value_type, const ContainerType &, value_type &, ContainerType &, value_type)>	step,
		value_type	dt = `0`
	)

inline

Construct using a std::function.

Parameters

step	Called in the timeloop as `step( t0, u1, t0, u1, dt)` . Has to advance the ode in-place by `dt`
dt	The constant timestep. Can be set later with `set_dt`. Can be negative.

◆ SinglestepTimeloop() [3/3]

template<class ContainerType >

template<class Stepper , class ODE >

dg::SinglestepTimeloop< ContainerType >::SinglestepTimeloop	(	Stepper &&	stepper,
		ODE &&	ode,
		value_type	dt = `0`
	)

inline

Bind the step function of a single step stepper.

Construct a lambda function that calls the step function of stepper with given parameters and stores it internally in a std::function

Template Parameters

Stepper possible steppers are for example dg::RungeKutta, dg::ShuOsher and dg::ImplicitRungeKutta

Parameters

stepper If constructed in-place (rvalue), will be copied into the lambda. If an lvalue, then the lambda stores a reference

Attention: If stepper is an lvalue then you need to make sure that stepper remains valid to avoid a "dangling reference"

Template Parameters

ODE	The ExplicitRHS or tuple type that corresponds to what is inserted into the step member of the Stepper

Parameters

ode	rhs or tuple
dt	The constant timestep. Can be set later with `set_dt`. Can be negative.

Member Function Documentation

◆ clone()

template<class ContainerType >

virtual SinglestepTimeloop * dg::SinglestepTimeloop< ContainerType >::clone ( ) const

inlinevirtual

Abstract copy method that returns a copy of *this on the heap.

Returns: a copy of *this on the heap

See also: dg::ClonePtr

Implements dg::aTimeloop< ContainerType >.

◆ construct()

template<class ContainerType >

template<class ... Params>

void dg::SinglestepTimeloop< ContainerType >::construct ( Params &&... ps )

inline

Perfect forward parameters to one of the constructors.

Template Parameters

Params deduced by the compiler

Parameters

ps	parameters forwarded to constructors

◆ integrate_steps()

template<class ContainerType >

void dg::SinglestepTimeloop< ContainerType >::integrate_steps	(	value_type	t0,
		const container_type &	u0,
		value_type	t1,
		container_type &	u1,
		unsigned	steps
	)

inline

Integrate differential equation with a fixed number of steps.

Equivalent to

set_dt( (t1-t0)/(value_type)steps );

integrate( t0, u0, t1, u1);

dg::SinglestepTimeloop::set_dt

void set_dt(value_type dt)

Set the constant timestep to be used in the integrate functions.

Definition: runge_kutta.h:1046

dg::SinglestepTimeloop::value_type

dg::get_value_type< ContainerType > value_type

Definition: runge_kutta.h:992

dg::aTimeloop::integrate

void integrate(value_type t0, const ContainerType &u0, value_type t1, ContainerType &u1)

Integrate a differential equation between given bounds.

Definition: ode.h:83

Parameters

t0	initial time
u0	initial condition
t1	final time
u1	(write-only) contains solution at `t1` on return (may alias `u0`)
steps	number of steps

◆ set_dt()

template<class ContainerType >

void dg::SinglestepTimeloop< ContainerType >::set_dt ( value_type dt )

inline

Set the constant timestep to be used in the integrate functions.

Parameters

dt	new timestep to use in integrate functions. Can be negative.

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

runge_kutta.h

Public Types

Public Member Functions

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ container_type

◆ value_type

Constructor & Destructor Documentation

◆ SinglestepTimeloop() [1/3]

◆ SinglestepTimeloop() [2/3]

◆ SinglestepTimeloop() [3/3]

Member Function Documentation

◆ clone()

◆ construct()

◆ integrate_steps()

◆ set_dt()