#include <solver.h>

Inheritance diagram for StepCore::Solver:

Public Types
enum	{ OK = 0, ToleranceError = 2048, InternalError = 2049, CollisionDetected = 4096, IntersectionDetected = 4097, Aborted = 8192, CollisionError = 16384, ConstraintError = 32768 }

typedef int(*	Function )(double t, const double y, const double yvar, double f, double fvar, void *params)

Public Member Functions
	Solver (int dimension=0, Function function=NULL, void *params=NULL, double stepSize=0.001)

	Solver (double stepSize)

virtual	~Solver ()

int	dimension () const

virtual int	doCalcFn (double t, const VectorXd y, const VectorXd yvar=0, VectorXd f=0, VectorXd *fvar=0)=0

virtual int	doEvolve (double t, double t1, VectorXd y, VectorXd *yvar)=0

Function	function () const

double	localError () const

double	localErrorRatio () const

void *	params () const

virtual void	setDimension (int dimension)

virtual void	setFunction (Function function)

virtual void	setParams (void *params)

virtual void	setStepSize (double stepSize)

virtual void	setToleranceAbs (double toleranceAbs)

virtual void	setToleranceRel (double toleranceRel)

QString	solverType () const

double	stepSize () const

double	toleranceAbs () const

double	toleranceRel () const

Public Member Functions inherited from StepCore::Object
	Object (const QString &name=QString())

virtual	~Object ()

const QString &	name () const

void	setName (const QString &name)

Protected Attributes
int	_dimension

Function	_function

double	_localError

double	_localErrorRatio

void *	_params

double	_stepSize

double	_toleranceAbs

double	_toleranceRel

Protected Attributes inherited from StepCore::Object
QString	_name

Detailed Description

Generic Solver interface.

Provides generic interface suitable for large variety of ordinaty differential equations integration algorithms.

It solves system of the first order differential equations:

$\begin{eqnarray*} \frac{dy_i(t)}{dt} &=& f(y_i(t), t) \\ y_i(t_0) &=& y^0_i \end{eqnarray*}$

Dimension of system is provided via setDimension(), function $f$ is provided via setFunction().

It also provides interface for setting allowed local tolerance. It can be defined using two properties: toleranceAbs and toleranceRel.

On each step solver calculates local error estimation (which depends on used integration method) and local error ratio for each variable using the following formula:

$\mbox{localErrorRatio}_i = \frac{|\mbox{localError}_i|} {\mbox{toleranceAbs} + \mbox{toleranceRel} \cdot | y_i |}$

Non-adaptive solvers cancel current step if maximal local error ratio is bigger than 1.1 (exact value depends on solver) and doEvolve() function returns false.

Adaptive solvers use maximal local error ratio to change time step until the ratio becomes almost equal 1. If it can't be made smaller than 1.1 (exact value depends on solver), solvers cancel current step and doEvolve() function returns false.

Maximal (over all variables) error estimation and error ratio from last time step can be obtained using localError() and localErrorRatio() methods.

Definition at line 70 of file solver.h.

Member Typedef Documentation

typedef int(* StepCore::Solver::Function)(double t, const double *y, const double *yvar, double *f, double *fvar, void *params)

Callback function type.

Definition at line 77 of file solver.h.

Member Enumeration Documentation

anonymous enum

Status codes for doCalcFn and doEvolve.

Enumerator
OK
ToleranceError
InternalError
CollisionDetected
IntersectionDetected
Aborted
CollisionError
ConstraintError

Definition at line 142 of file solver.h.

Constructor & Destructor Documentation

StepCore::Solver::Solver	(	int	dimension = `0`,
		Function	function = `NULL`,
		void *	params = `NULL`,
		double	stepSize = `0.001`
	)

inlineexplicit

Cunstructs a solver.

Definition at line 164 of file solver.h.

StepCore::Solver::Solver ( double stepSize )

inline

Cunstructs a solver.

Definition at line 170 of file solver.h.

virtual StepCore::Solver::~Solver ( )

inlinevirtual

Definition at line 86 of file solver.h.

Member Function Documentation

int StepCore::Solver::dimension ( ) const

inline

Get ODE dimension.

Definition at line 92 of file solver.h.

virtual int StepCore::Solver::doCalcFn	(	double *	t,
		const VectorXd *	y,
		const VectorXd *	yvar = `0`,
		VectorXd *	f = `0`,
		VectorXd *	fvar = `0`
	)

pure virtual

Calculate function value.

Implemented in StepCore::GenericEulerSolver.

virtual int StepCore::Solver::doEvolve	(	double *	t,
		double	t1,
		VectorXd *	y,
		VectorXd *	yvar
	)

pure virtual

Integrate.

Parameters

t	Current time (will be updated by the new value)
t1	Target time
y	Function value
yvar	Function variance

Returns: Solver::OK on success, error status on failure

Todo:: Provide error message

Implemented in StepCore::GenericEulerSolver.

Function StepCore::Solver::function ( ) const

inline

Get callback function.

Definition at line 97 of file solver.h.

double StepCore::Solver::localError ( ) const

inline

Get error estimation from last step.

Definition at line 122 of file solver.h.

double StepCore::Solver::localErrorRatio ( ) const

inline

Get local tolerance calculated at last step.

Definition at line 124 of file solver.h.

void* StepCore::Solver::params ( ) const

inline

Get callback function params.

Definition at line 102 of file solver.h.

virtual void StepCore::Solver::setDimension ( int dimension )

inlinevirtual

Set ODE dimension.

Reimplemented in StepCore::GenericEulerSolver.

Definition at line 94 of file solver.h.

virtual void StepCore::Solver::setFunction ( Function function )

inlinevirtual

Set callback function.

Definition at line 99 of file solver.h.

virtual void StepCore::Solver::setParams ( void * params )

inlinevirtual

Set callback function params.

Definition at line 104 of file solver.h.

virtual void StepCore::Solver::setStepSize ( double stepSize )

inlinevirtual

Set step size (solver can adjust it later)

Definition at line 109 of file solver.h.

virtual void StepCore::Solver::setToleranceAbs ( double toleranceAbs )

inlinevirtual

Set absolute allowed local tolerance.

Definition at line 114 of file solver.h.

virtual void StepCore::Solver::setToleranceRel ( double toleranceRel )

inlinevirtual

Set relative allowed local tolerance.

Definition at line 119 of file solver.h.

QString StepCore::Solver::solverType ( ) const

inline

Get solver type.

Definition at line 89 of file solver.h.

double StepCore::Solver::stepSize ( ) const

inline

Get step size.

Definition at line 107 of file solver.h.

double StepCore::Solver::toleranceAbs ( ) const

inline

Get absolute allowed local tolerance.

Definition at line 112 of file solver.h.

double StepCore::Solver::toleranceRel ( ) const

inline

Get relative allowed local tolerance.

Definition at line 117 of file solver.h.

Member Data Documentation

int StepCore::Solver::_dimension

protected

Definition at line 153 of file solver.h.

Function StepCore::Solver::_function

protected

Definition at line 154 of file solver.h.

double StepCore::Solver::_localError

protected

Definition at line 160 of file solver.h.

double StepCore::Solver::_localErrorRatio

protected

Definition at line 161 of file solver.h.

void* StepCore::Solver::_params

protected

Definition at line 155 of file solver.h.

double StepCore::Solver::_stepSize

protected

Definition at line 157 of file solver.h.

double StepCore::Solver::_toleranceAbs

protected

Definition at line 158 of file solver.h.

double StepCore::Solver::_toleranceRel

protected

Definition at line 159 of file solver.h.

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

solver.h

step/stepcore

Public Types

Public Member Functions

Protected Attributes

Detailed Description

Member Typedef Documentation

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

step/stepcore

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