org.apache.commons.math3.ode.nonstiff

Class AdamsFieldStepInterpolator<T extends RealFieldElement<T>>

java.lang.Object

org.apache.commons.math3.ode.sampling.AbstractFieldStepInterpolator<T>

org.apache.commons.math3.ode.nonstiff.AdamsFieldStepInterpolator<T>

Type Parameters:

T - the type of the field elements

All Implemented Interfaces:

FieldStepInterpolator<T>

 class AdamsFieldStepInterpolator<T extends RealFieldElement<T>>
extends AbstractFieldStepInterpolator<T>

This class implements an interpolator for Adams integrators using Nordsieck representation.

This interpolator computes dense output around the current point. The interpolation equation is based on Taylor series formulas.

Since:

3.6

See Also:

AdamsBashforthFieldIntegrator, AdamsMoultonFieldIntegrator

Field Summary

Fields

Modifier and Type	Field and Description
private Array2DRowFieldMatrix<T>	nordsieck Nordsieck vector.
private FieldODEStateAndDerivative<T>	reference Reference state.
private T[]	scaled First scaled derivative.
private T	scalingH Step size used in the first scaled derivative and Nordsieck vector.

Constructor Summary

Constructors

Modifier	Constructor and Description
(package private)	AdamsFieldStepInterpolator(T stepSize, FieldODEStateAndDerivative<T> reference, T[] scaled, Array2DRowFieldMatrix<T> nordsieck, boolean isForward, FieldODEStateAndDerivative<T> globalPreviousState, FieldODEStateAndDerivative<T> globalCurrentState, FieldEquationsMapper<T> equationsMapper) Simple constructor.
private	AdamsFieldStepInterpolator(T stepSize, FieldODEStateAndDerivative<T> reference, T[] scaled, Array2DRowFieldMatrix<T> nordsieck, boolean isForward, FieldODEStateAndDerivative<T> globalPreviousState, FieldODEStateAndDerivative<T> globalCurrentState, FieldODEStateAndDerivative<T> softPreviousState, FieldODEStateAndDerivative<T> softCurrentState, FieldEquationsMapper<T> equationsMapper) Simple constructor.

Method Summary

Methods

Modifier and Type	Method and Description
protected FieldODEStateAndDerivative<T>	computeInterpolatedStateAndDerivatives(FieldEquationsMapper<T> equationsMapper, T time, T theta, T thetaH, T oneMinusThetaH) Compute the state and derivatives at the interpolated time.
protected AdamsFieldStepInterpolator<T>	create(boolean newForward, FieldODEStateAndDerivative<T> newGlobalPreviousState, FieldODEStateAndDerivative<T> newGlobalCurrentState, FieldODEStateAndDerivative<T> newSoftPreviousState, FieldODEStateAndDerivative<T> newSoftCurrentState, FieldEquationsMapper<T> newMapper) Create a new instance.
static <S extends RealFieldElement<S>> FieldODEStateAndDerivative<S>	taylor(FieldODEStateAndDerivative<S> reference, S time, S stepSize, S[] scaled, Array2DRowFieldMatrix<S> nordsieck) Estimate state by applying Taylor formula.

Methods inherited from class org.apache.commons.math3.ode.sampling.AbstractFieldStepInterpolator

getCurrentState, getGlobalCurrentState, getGlobalPreviousState, getInterpolatedState, getPreviousState, isForward, restrictStep

Methods inherited from class java.lang.Object

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

Field Detail

scalingH

private T extends RealFieldElement<T> scalingH

Step size used in the first scaled derivative and Nordsieck vector.

reference

private final FieldODEStateAndDerivative<T extends RealFieldElement<T>> reference

Reference state.

Sometimes, the reference state is the same as globalPreviousState, sometimes it is the same as globalCurrentState, so we use a separate field to avoid any confusion.

scaled

private final T extends RealFieldElement<T>[] scaled

First scaled derivative.

nordsieck

private final Array2DRowFieldMatrix<T extends RealFieldElement<T>> nordsieck

Nordsieck vector.

Constructor Detail

AdamsFieldStepInterpolator

AdamsFieldStepInterpolator(T stepSize,
                          FieldODEStateAndDerivative<T> reference,
                          T[] scaled,
                          Array2DRowFieldMatrix<T> nordsieck,
                          boolean isForward,
                          FieldODEStateAndDerivative<T> globalPreviousState,
                          FieldODEStateAndDerivative<T> globalCurrentState,
                          FieldEquationsMapper<T> equationsMapper)

Simple constructor.

Parameters:

stepSize - step size used in the scaled and Nordsieck arrays

reference - reference state from which Taylor expansion are estimated

scaled - first scaled derivative

nordsieck - Nordsieck vector

isForward - integration direction indicator

globalPreviousState - start of the global step

globalCurrentState - end of the global step

equationsMapper - mapper for ODE equations primary and secondary components

AdamsFieldStepInterpolator

private AdamsFieldStepInterpolator(T stepSize,
                          FieldODEStateAndDerivative<T> reference,
                          T[] scaled,
                          Array2DRowFieldMatrix<T> nordsieck,
                          boolean isForward,
                          FieldODEStateAndDerivative<T> globalPreviousState,
                          FieldODEStateAndDerivative<T> globalCurrentState,
                          FieldODEStateAndDerivative<T> softPreviousState,
                          FieldODEStateAndDerivative<T> softCurrentState,
                          FieldEquationsMapper<T> equationsMapper)

Simple constructor.

Parameters:

stepSize - step size used in the scaled and Nordsieck arrays

reference - reference state from which Taylor expansion are estimated

scaled - first scaled derivative

nordsieck - Nordsieck vector

isForward - integration direction indicator

globalPreviousState - start of the global step

globalCurrentState - end of the global step

softPreviousState - start of the restricted step

softCurrentState - end of the restricted step

equationsMapper - mapper for ODE equations primary and secondary components

Method Detail

create

protected AdamsFieldStepInterpolator<T> create(boolean newForward,
                                   FieldODEStateAndDerivative<T> newGlobalPreviousState,
                                   FieldODEStateAndDerivative<T> newGlobalCurrentState,
                                   FieldODEStateAndDerivative<T> newSoftPreviousState,
                                   FieldODEStateAndDerivative<T> newSoftCurrentState,
                                   FieldEquationsMapper<T> newMapper)

Create a new instance.

Specified by:

create in class AbstractFieldStepInterpolator<T extends RealFieldElement<T>>

Parameters:

newForward - integration direction indicator

newGlobalPreviousState - start of the global step

newGlobalCurrentState - end of the global step

newSoftPreviousState - start of the restricted step

newSoftCurrentState - end of the restricted step

newMapper - equations mapper for the all equations

Returns:

a new instance

computeInterpolatedStateAndDerivatives

protected FieldODEStateAndDerivative<T> computeInterpolatedStateAndDerivatives(FieldEquationsMapper<T> equationsMapper,
                                                                   T time,
                                                                   T theta,
                                                                   T thetaH,
                                                                   T oneMinusThetaH)

Compute the state and derivatives at the interpolated time. This is the main processing method that should be implemented by the derived classes to perform the interpolation.

Specified by:

computeInterpolatedStateAndDerivatives in class AbstractFieldStepInterpolator<T extends RealFieldElement<T>>

Parameters:

equationsMapper - mapper for ODE equations primary and secondary components

time - interpolation time

theta - normalized interpolation abscissa within the step (theta is zero at the previous time step and one at the current time step)

thetaH - time gap between the previous time and the interpolated time

oneMinusThetaH - time gap between the interpolated time and the current time

Returns:

interpolated state and derivatives

taylor

public static <S extends RealFieldElement<S>> FieldODEStateAndDerivative<S> taylor(FieldODEStateAndDerivative<S> reference,
                                                                   S time,
                                                                   S stepSize,
                                                                   S[] scaled,
                                                                   Array2DRowFieldMatrix<S> nordsieck)

Estimate state by applying Taylor formula.

Type Parameters:

S - the type of the field elements

Parameters:

reference - reference state

time - time at which state must be estimated

stepSize - step size used in the scaled and Nordsieck arrays

scaled - first scaled derivative

nordsieck - Nordsieck vector

Returns:

estimated state