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animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF > Struct Template Reference

#include <explicit_stepper.h>

Inheritance diagram for animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >:

List of all members.

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Detailed Description

template<class SolverF, class HSmallerF, class HLargerF, class IsDifferentF>
struct animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >

Adaptive stepsize control for explicit integration methods.

This straightforward technique take each step twice, once as a full step, and, independently, as two half steps.

The difference between the two final state estimates is a convenient indicator of error. It is this difference that we shall endeavor to keep to a desired degree of accuracy, neither too large nor too small. We do this by adjusting time step value.

Declaration/Definition file: animal/integration/stepper.h (creation date: March 28, 2000).

Author:

David Bourguignon

iMAGIS/GRAVIR, 2000

Definition at line 39 of file explicit_stepper.h.

Public Member Functions
	Step_Doubling ()
	Default constructor, does nothing.
	Step_Doubling (const SolverF &slf, const HSmallerF &hsf, const HLargerF &hlf, const IsDifferentF &isdf)
	Constructor.
void	resize (const typename Derivative::sizeype size)
	To take dynamic modifications of the model into account.
Call operator
void	operator() (const Model &M, State &S, const Real t, const Real htry, Real &hdid, Real &hnext)
void	operator() (const Model &M, const State &initial_S, State &final_S, const Real t, const Real htry, Real &hdid, Real &hnext)
Public Attributes
State	initial_S_copy
	Copy of the initial state.
State	final_S_eval
	Value at final state.
Derivative	initial_D
	Derivative first evaluation.
unsigned int	ngood
	number of "good" steps taken
unsigned int	nbad
	number of "bad" (but retried and fixed) steps taken

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Constructor & Destructor Documentation

template<class SolverF, class HSmallerF, class HLargerF, class IsDifferentF> animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::Step_Doubling (   )  [inline]

Default constructor, does nothing. Definition at line 52 of file explicit_stepper.h.

template<class SolverF, class HSmallerF, class HLargerF, class IsDifferentF> animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::Step_Doubling (  const SolverF &  slf, const HSmallerF &  hsf, const HLargerF &  hlf, const IsDifferentF &  isdf )  [inline]

Constructor. Definition at line 57 of file explicit_stepper.h.

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Member Function Documentation

template<class SolverF, class HSmallerF, class HLargerF, class IsDifferentF> void animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::operator() (  const Model &  M, const State &  initial_S, State &  final_S, const Real  t, const Real  htry, Real &  hdid, Real &  hnext )  [inline]

Reimplemented from animal::integration::Stepper_Function< SolverF, HSmallerF, HLargerF, IsDifferentF >. Reimplemented in animal::integration::Step_Back_And_Forth< SolverF, HSmallerF, HLargerF, IsDifferentF >. Definition at line 96 of file explicit_stepper.h. References animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::final_S_eval, animal::integration::Stepper_Function< SolverF, HSmallerF, HLargerF, IsDifferentF >::hlarger, animal::integration::Stepper_Function< SolverF, HSmallerF, HLargerF, IsDifferentF >::hsmaller, animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::initial_D, animal::integration::Stepper_Function< SolverF, HSmallerF, HLargerF, IsDifferentF >::isDifferent, animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::nbad, animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::ngood, and animal::integration::Stepper_Function< SolverF, HSmallerF, HLargerF, IsDifferentF >::solve.

template<class SolverF, class HSmallerF, class HLargerF, class IsDifferentF> void animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::operator() (  const Model &  M, State &  S, const Real  t, const Real  htry, Real &  hdid, Real &  hnext )  [inline]

Reimplemented from animal::integration::Stepper_Function< SolverF, HSmallerF, HLargerF, IsDifferentF >. Reimplemented in animal::integration::Step_Back_And_Forth< SolverF, HSmallerF, HLargerF, IsDifferentF >. Definition at line 88 of file explicit_stepper.h. References animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::initial_S_copy.

template<class SolverF, class HSmallerF, class HLargerF, class IsDifferentF> void animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::resize (  const typename Derivative::sizeype  size  )  [inline]

To take dynamic modifications of the model into account. Definition at line 77 of file explicit_stepper.h. References animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::final_S_eval, animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::initial_D, and animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::initial_S_copy.

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Member Data Documentation

template<class SolverF, class HSmallerF, class HLargerF, class IsDifferentF> State animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::final_S_eval

Value at final state. Definition at line 43 of file explicit_stepper.h. Referenced by animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::operator()(), and animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::resize().

template<class SolverF, class HSmallerF, class HLargerF, class IsDifferentF> Derivative animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::initial_D

Derivative first evaluation. Definition at line 46 of file explicit_stepper.h. Referenced by animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::operator()(), and animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::resize().

template<class SolverF, class HSmallerF, class HLargerF, class IsDifferentF> State animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::initial_S_copy

Copy of the initial state. Definition at line 42 of file explicit_stepper.h. Referenced by animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::operator()(), and animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::resize().

template<class SolverF, class HSmallerF, class HLargerF, class IsDifferentF> unsigned int animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::nbad

number of "bad" (but retried and fixed) steps taken Definition at line 49 of file explicit_stepper.h. Referenced by animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::operator()().

template<class SolverF, class HSmallerF, class HLargerF, class IsDifferentF> unsigned int animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::ngood

number of "good" steps taken Definition at line 48 of file explicit_stepper.h. Referenced by animal::integration::Step_Doubling< SolverF, HSmallerF, HLargerF, IsDifferentF >::operator()().

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

• explicit_stepper.h

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