Package org.hipparchus.ode.nonstiff.interpolators

Class GraggBulirschStoerStateInterpolator

java.lang.Object

org.hipparchus.ode.sampling.AbstractODEStateInterpolator

org.hipparchus.ode.nonstiff.interpolators.GraggBulirschStoerStateInterpolator

All Implemented Interfaces:

Serializable, ODEStateInterpolator

public class GraggBulirschStoerStateInterpolator
extends AbstractODEStateInterpolator

This class implements an interpolator for the Gragg-Bulirsch-Stoer integrator.

This interpolator compute dense output inside the last step produced by a Gragg-Bulirsch-Stoer integrator.

This implementation is basically a reimplementation in Java of the odex fortran code by E. Hairer and G. Wanner. The redistribution policy for this code is available here, for convenience, it is reproduced below.

Copyright (c) 2004, Ernst Hairer

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

See Also:

GraggBulirschStoerIntegrator, Serialized Form

Constructor Summary

Constructors

Constructor	Description
GraggBulirschStoerStateInterpolator(boolean forward, ODEStateAndDerivative globalPreviousState, ODEStateAndDerivative globalCurrentState, ODEStateAndDerivative softPreviousState, ODEStateAndDerivative softCurrentState, EquationsMapper mapper, double[][] yMidDots, int mu)	Simple constructor.

Method Summary

Modifier and Type	Method	Description
protected ODEStateAndDerivative	computeInterpolatedStateAndDerivatives(EquationsMapper mapper, double time, double theta, double thetaH, double oneMinusThetaH)	Compute the state and derivatives at the interpolated time.
protected GraggBulirschStoerStateInterpolator	create(boolean newForward, ODEStateAndDerivative newGlobalPreviousState, ODEStateAndDerivative newGlobalCurrentState, ODEStateAndDerivative newSoftPreviousState, ODEStateAndDerivative newSoftCurrentState, EquationsMapper newMapper)	Create a new instance.
double	estimateError(double[] scale)	Estimate interpolation error.

Methods inherited from class org.hipparchus.ode.sampling.AbstractODEStateInterpolator

getCurrentState, getGlobalCurrentState, getGlobalPreviousState, getInterpolatedState, getMapper, getPreviousState, isCurrentStateInterpolated, isForward, isPreviousStateInterpolated, restrictStep

Methods inherited from class java.lang.Object

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

Constructor Detail

GraggBulirschStoerStateInterpolator

public GraggBulirschStoerStateInterpolator(boolean forward,
                                           ODEStateAndDerivative globalPreviousState,
                                           ODEStateAndDerivative globalCurrentState,
                                           ODEStateAndDerivative softPreviousState,
                                           ODEStateAndDerivative softCurrentState,
                                           EquationsMapper mapper,
                                           double[][] yMidDots,
                                           int mu)

Simple constructor.

Parameters:

forward - 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

mapper - equations mapper for the all equations

yMidDots - scaled derivatives at the middle of the step $\tau$ (element k is $h^{k} d^{k}y(\tau)/dt^{k}$ where h is step size...)

mu - degree of the interpolation polynomial

Method Detail

create

protected GraggBulirschStoerStateInterpolator create(boolean newForward,
                                                     ODEStateAndDerivative newGlobalPreviousState,
                                                     ODEStateAndDerivative newGlobalCurrentState,
                                                     ODEStateAndDerivative newSoftPreviousState,
                                                     ODEStateAndDerivative newSoftCurrentState,
                                                     EquationsMapper newMapper)

Create a new instance.

Specified by:

create in class AbstractODEStateInterpolator

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

estimateError

public double estimateError(double[] scale)

Estimate interpolation error.

Parameters:

scale - scaling array

Returns:

estimate of the interpolation error

computeInterpolatedStateAndDerivatives

protected ODEStateAndDerivative computeInterpolatedStateAndDerivatives(EquationsMapper mapper,
                                                                       double time,
                                                                       double theta,
                                                                       double thetaH,
                                                                       double 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 AbstractODEStateInterpolator

Parameters:

mapper - 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