Package org.hipparchus.ode.sampling

Class FieldStepNormalizer<T extends CalculusFieldElement<T>>

java.lang.Object

org.hipparchus.ode.sampling.FieldStepNormalizer<T>

Type Parameters:

T - the type of the field elements

All Implemented Interfaces:

FieldODEStepHandler<T>

public class FieldStepNormalizer<T extends CalculusFieldElement<T>>
extends Object
implements FieldODEStepHandler<T>

This class wraps an object implementing FieldODEFixedStepHandler into a FieldODEStepHandler.

This wrapper allows to use fixed step handlers with general integrators which cannot guaranty their integration steps will remain constant and therefore only accept general step handlers.

The stepsize used is selected at construction time. The handleStep method of the underlying FieldODEFixedStepHandler object is called at normalized times. The normalized times can be influenced by the StepNormalizerMode and StepNormalizerBounds.

There is no constraint on the integrator, it can use any time step it needs (time steps longer or shorter than the fixed time step and non-integer ratios are all allowed).

Examples (step size = 0.5)

Start time	End time	Direction	Mode	Bounds	Output
0.3	3.1	forward	INCREMENT	NEITHER	0.8, 1.3, 1.8, 2.3, 2.8
0.3	3.1	forward	INCREMENT	FIRST	0.3, 0.8, 1.3, 1.8, 2.3, 2.8
0.3	3.1	forward	INCREMENT	LAST	0.8, 1.3, 1.8, 2.3, 2.8, 3.1
0.3	3.1	forward	INCREMENT	BOTH	0.3, 0.8, 1.3, 1.8, 2.3, 2.8, 3.1
0.3	3.1	forward	MULTIPLES	NEITHER	0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.3	3.1	forward	MULTIPLES	FIRST	0.3, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.3	3.1	forward	MULTIPLES	LAST	0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.1
0.3	3.1	forward	MULTIPLES	BOTH	0.3, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.1
0.0	3.0	forward	INCREMENT	NEITHER	0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.0	3.0	forward	INCREMENT	FIRST	0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.0	3.0	forward	INCREMENT	LAST	0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.0	3.0	forward	INCREMENT	BOTH	0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.0	3.0	forward	MULTIPLES	NEITHER	0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.0	3.0	forward	MULTIPLES	FIRST	0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.0	3.0	forward	MULTIPLES	LAST	0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.0	3.0	forward	MULTIPLES	BOTH	0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0
3.1	0.3	backward	INCREMENT	NEITHER	2.6, 2.1, 1.6, 1.1, 0.6
3.1	0.3	backward	INCREMENT	FIRST	3.1, 2.6, 2.1, 1.6, 1.1, 0.6
3.1	0.3	backward	INCREMENT	LAST	2.6, 2.1, 1.6, 1.1, 0.6, 0.3
3.1	0.3	backward	INCREMENT	BOTH	3.1, 2.6, 2.1, 1.6, 1.1, 0.6, 0.3
3.1	0.3	backward	MULTIPLES	NEITHER	3.0, 2.5, 2.0, 1.5, 1.0, 0.5
3.1	0.3	backward	MULTIPLES	FIRST	3.1, 3.0, 2.5, 2.0, 1.5, 1.0, 0.5
3.1	0.3	backward	MULTIPLES	LAST	3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.3
3.1	0.3	backward	MULTIPLES	BOTH	3.1, 3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.3
3.0	0.0	backward	INCREMENT	NEITHER	2.5, 2.0, 1.5, 1.0, 0.5, 0.0
3.0	0.0	backward	INCREMENT	FIRST	3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.0
3.0	0.0	backward	INCREMENT	LAST	2.5, 2.0, 1.5, 1.0, 0.5, 0.0
3.0	0.0	backward	INCREMENT	BOTH	3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.0
3.0	0.0	backward	MULTIPLES	NEITHER	2.5, 2.0, 1.5, 1.0, 0.5, 0.0
3.0	0.0	backward	MULTIPLES	FIRST	3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.0
3.0	0.0	backward	MULTIPLES	LAST	2.5, 2.0, 1.5, 1.0, 0.5, 0.0
3.0	0.0	backward	MULTIPLES	BOTH	3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.0

See Also:

• FieldODEStepHandler
• FieldODEFixedStepHandler
• StepNormalizerMode
• StepNormalizerBounds

Constructor Summary

Constructors

Constructor	Description
FieldStepNormalizer(double h, FieldODEFixedStepHandler<T> handler)	Simple constructor.
FieldStepNormalizer(double h, FieldODEFixedStepHandler<T> handler, StepNormalizerBounds bounds)	Simple constructor.
FieldStepNormalizer(double h, FieldODEFixedStepHandler<T> handler, StepNormalizerMode mode)	Simple constructor.
FieldStepNormalizer(double h, FieldODEFixedStepHandler<T> handler, StepNormalizerMode mode, StepNormalizerBounds bounds)	Simple constructor.

Method Summary

Modifier and Type	Method	Description
void	finish(FieldODEStateAndDerivative<T> finalState)	Finalize integration.
void	handleStep(FieldODEStateInterpolator<T> interpolator)	Handle the last accepted step.
void	init(FieldODEStateAndDerivative<T> initialState, T finalTime)	Initialize step handler at the start of an ODE integration.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

FieldStepNormalizer

public FieldStepNormalizer(double h,
 FieldODEFixedStepHandler<T> handler)

Simple constructor. Uses INCREMENT mode, and FIRST bounds setting, for backwards compatibility.

Parameters:

h - fixed time step (sign is not used)

handler - fixed time step handler to wrap

FieldStepNormalizer

public FieldStepNormalizer(double h,
 FieldODEFixedStepHandler<T> handler,
 StepNormalizerMode mode)

Simple constructor. Uses FIRST bounds setting.

Parameters:

h - fixed time step (sign is not used)

handler - fixed time step handler to wrap

mode - step normalizer mode to use

FieldStepNormalizer

public FieldStepNormalizer(double h,
 FieldODEFixedStepHandler<T> handler,
 StepNormalizerBounds bounds)

Simple constructor. Uses INCREMENT mode.

Parameters:

h - fixed time step (sign is not used)

handler - fixed time step handler to wrap

bounds - step normalizer bounds setting to use

FieldStepNormalizer

public FieldStepNormalizer(double h,
 FieldODEFixedStepHandler<T> handler,
 StepNormalizerMode mode,
 StepNormalizerBounds bounds)

Simple constructor.

Parameters:

h - fixed time step (sign is not used)

handler - fixed time step handler to wrap

mode - step normalizer mode to use

bounds - step normalizer bounds setting to use

Method Details

init

public void init(FieldODEStateAndDerivative<T> initialState,
 T finalTime)

Initialize step handler at the start of an ODE integration.

This method is called once at the start of the integration. It may be used by the step handler to initialize some internal data if needed.

The default implementation does nothing.

Specified by:

init in interface FieldODEStepHandler<T extends CalculusFieldElement<T>>

Parameters:

initialState - initial time, state vector and derivative

finalTime - target time for the integration

handleStep

public void handleStep(FieldODEStateInterpolator<T> interpolator)

Handle the last accepted step.

Specified by:

handleStep in interface FieldODEStepHandler<T extends CalculusFieldElement<T>>

Parameters:

interpolator - interpolator for the last accepted step

finish

public void finish(FieldODEStateAndDerivative<T> finalState)

Finalize integration.

Specified by:

finish in interface FieldODEStepHandler<T extends CalculusFieldElement<T>>

Parameters:

finalState - state at integration end