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

Class AbstractFieldStepInterpolator<T extends RealFieldElement<T>>

java.lang.Object
org.apache.commons.math3.ode.sampling.AbstractFieldStepInterpolator<T>
Type Parameters:
T - the type of the field elements
All Implemented Interfaces:
FieldStepInterpolator<T>
public abstract class AbstractFieldStepInterpolator<T extends RealFieldElement<T>> extends Object implements FieldStepInterpolator<T>
This abstract class represents an interpolator over the last step during an ODE integration.

The various ODE integrators provide objects extending this class to the step handlers. The handlers can use these objects to retrieve the state vector at intermediate times between the previous and the current grid points (dense output).

Since:
3.6
See Also:

  • Constructor Details

    • AbstractFieldStepInterpolator

      protected AbstractFieldStepInterpolator(boolean isForward, FieldODEStateAndDerivative<T> globalPreviousState, FieldODEStateAndDerivative<T> globalCurrentState, FieldODEStateAndDerivative<T> softPreviousState, FieldODEStateAndDerivative<T> softCurrentState, FieldEquationsMapper<T> equationsMapper)
      Simple constructor.
      Parameters:
      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 Details

    • restrictStep

      public AbstractFieldStepInterpolator<T> restrictStep(FieldODEStateAndDerivative<T> previousState, FieldODEStateAndDerivative<T> currentState)
      Create a new restricted version of the instance.

      The instance is not changed at all.

      Parameters:
      previousState - start of the restricted step
      currentState - end of the restricted step
      Returns:
      restricted version of the instance
      See Also:

    • create

      protected abstract AbstractFieldStepInterpolator<T> create(boolean newForward, FieldODEStateAndDerivative<T> newGlobalPreviousState, FieldODEStateAndDerivative<T> newGlobalCurrentState, FieldODEStateAndDerivative<T> newSoftPreviousState, FieldODEStateAndDerivative<T> newSoftCurrentState, FieldEquationsMapper<T> newMapper)
      Create a new instance.
      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

    • getGlobalPreviousState

      public FieldODEStateAndDerivative<T> getGlobalPreviousState()
      Get the previous global grid point state.
      Returns:
      previous global grid point state

    • getGlobalCurrentState

      public FieldODEStateAndDerivative<T> getGlobalCurrentState()
      Get the current global grid point state.
      Returns:
      current global grid point state

    • getPreviousState

      public FieldODEStateAndDerivative<T> getPreviousState()
      Get the state at previous grid point time.
      Specified by:
      getPreviousState in interface FieldStepInterpolator<T extends RealFieldElement<T>>
      Returns:
      state at previous grid point time

    • getCurrentState

      public FieldODEStateAndDerivative<T> getCurrentState()
      Get the state at current grid point time.
      Specified by:
      getCurrentState in interface FieldStepInterpolator<T extends RealFieldElement<T>>
      Returns:
      state at current grid point time

    • getInterpolatedState

      public FieldODEStateAndDerivative<T> getInterpolatedState(T time)
      Get the state at interpolated time.

      Setting the time outside of the current step is allowed, but should be used with care since the accuracy of the interpolator will probably be very poor far from this step. This allowance has been added to simplify implementation of search algorithms near the step endpoints.

      Specified by:
      getInterpolatedState in interface FieldStepInterpolator<T extends RealFieldElement<T>>
      Parameters:
      time - time of the interpolated point
      Returns:
      state at interpolated time

    • isForward

      public boolean isForward()
      Check if the natural integration direction is forward.

      This method provides the integration direction as specified by the integrator itself, it avoid some nasty problems in degenerated cases like null steps due to cancellation at step initialization, step control or discrete events triggering.

      Specified by:
      isForward in interface FieldStepInterpolator<T extends RealFieldElement<T>>
      Returns:
      true if the integration variable (time) increases during integration

    • computeInterpolatedStateAndDerivatives

      protected abstract FieldODEStateAndDerivative<T> computeInterpolatedStateAndDerivatives(FieldEquationsMapper<T> equationsMapper, T time, T theta, T thetaH, T oneMinusThetaH) throws MaxCountExceededException
      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.
      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
      Throws:
      MaxCountExceededException - if the number of functions evaluations is exceeded