Package org.apache.commons.math3.ode.sampling

Class NordsieckStepInterpolator

java.lang.Object
org.apache.commons.math3.ode.sampling.AbstractStepInterpolator
org.apache.commons.math3.ode.sampling.NordsieckStepInterpolator
All Implemented Interfaces:
Externalizable, Serializable, StepInterpolator
public class NordsieckStepInterpolator extends AbstractStepInterpolator
This class implements an interpolator for integrators using Nordsieck representation.

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

Since:
2.0
See Also:

  • Field Details

    • stateVariation

      protected double[] stateVariation
      State variation.

  • Constructor Details

  • Method Details

    • doCopy

      protected StepInterpolator doCopy()
      Really copy the finalized instance.

      This method is called by AbstractStepInterpolator.copy() after the step has been finalized. It must perform a deep copy to have an new instance completely independent for the original instance.

      Specified by:
      doCopy in class AbstractStepInterpolator
      Returns:
      a copy of the finalized instance

    • reinitialize

      public void reinitialize(double[] y, boolean forward, EquationsMapper primaryMapper, EquationsMapper[] secondaryMappers)
      Reinitialize the instance.

      Beware that all arrays must be references to integrator arrays, in order to ensure proper update without copy.

      Overrides:
      reinitialize in class AbstractStepInterpolator
      Parameters:
      y - reference to the integrator array holding the state at the end of the step
      forward - integration direction indicator
      primaryMapper - equations mapper for the primary equations set
      secondaryMappers - equations mappers for the secondary equations sets

    • reinitialize

      public void reinitialize(double time, double stepSize, double[] scaledDerivative, Array2DRowRealMatrix nordsieckVector)
      Reinitialize the instance.

      Beware that all arrays must be references to integrator arrays, in order to ensure proper update without copy.

      Parameters:
      time - time at which all arrays are defined
      stepSize - step size used in the scaled and Nordsieck arrays
      scaledDerivative - reference to the integrator array holding the first scaled derivative
      nordsieckVector - reference to the integrator matrix holding the Nordsieck vector

    • rescale

      public void rescale(double stepSize)
      Rescale the instance.

      Since the scaled and Nordsieck arrays are shared with the caller, this method has the side effect of rescaling this arrays in the caller too.

      Parameters:
      stepSize - new step size to use in the scaled and Nordsieck arrays

    • getInterpolatedStateVariation

      public double[] getInterpolatedStateVariation() throws MaxCountExceededException
      Get the state vector variation from current to interpolated state.

      This method is aimed at computing y(tinterpolation) -y(tcurrent) accurately by avoiding the cancellation errors that would occur if the subtraction were performed explicitly.

      The returned vector is a reference to a reused array, so it should not be modified and it should be copied if it needs to be preserved across several calls.

      Returns:
      state vector at time AbstractStepInterpolator.getInterpolatedTime()
      Throws:
      MaxCountExceededException - if the number of functions evaluations is exceeded
      See Also:

    • computeInterpolatedStateAndDerivatives

      protected void computeInterpolatedStateAndDerivatives(double theta, 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 AbstractStepInterpolator
      Parameters:
      theta - normalized interpolation abscissa within the step (theta is zero at the previous time step and one at the current time step)
      oneMinusThetaH - time gap between the interpolated time and the current time

    • writeExternal

      public void writeExternal(ObjectOutput out) throws IOException
      Specified by:
      writeExternal in interface Externalizable
      Specified by:
      writeExternal in class AbstractStepInterpolator
      Throws:
      IOException

    • readExternal

      public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException
      Specified by:
      readExternal in interface Externalizable
      Specified by:
      readExternal in class AbstractStepInterpolator
      Throws:
      IOException
      ClassNotFoundException