Class AdamsFieldIntegrator<T extends CalculusFieldElement<T>>

Type Parameters:
T - the type of the field elements
All Implemented Interfaces:
FieldODEIntegrator<T>
Direct Known Subclasses:
AdamsBashforthFieldIntegrator, AdamsMoultonFieldIntegrator

public abstract class AdamsFieldIntegrator<T extends CalculusFieldElement<T>> extends MultistepFieldIntegrator<T>
Base class for Adams-Bashforth and Adams-Moulton integrators.
  • Constructor Details

    • AdamsFieldIntegrator

      public AdamsFieldIntegrator(Field<T> field, String name, int nSteps, int order, double minStep, double maxStep, double scalAbsoluteTolerance, double scalRelativeTolerance) throws MathIllegalArgumentException
      Build an Adams integrator with the given order and step control parameters.
      Parameters:
      field - field to which the time and state vector elements belong
      name - name of the method
      nSteps - number of steps of the method excluding the one being computed
      order - order of the method
      minStep - minimal step (sign is irrelevant, regardless of integration direction, forward or backward), the last step can be smaller than this
      maxStep - maximal step (sign is irrelevant, regardless of integration direction, forward or backward), the last step can be smaller than this
      scalAbsoluteTolerance - allowed absolute error
      scalRelativeTolerance - allowed relative error
      Throws:
      MathIllegalArgumentException - if order is 1 or less
    • AdamsFieldIntegrator

      public AdamsFieldIntegrator(Field<T> field, String name, int nSteps, int order, double minStep, double maxStep, double[] vecAbsoluteTolerance, double[] vecRelativeTolerance) throws IllegalArgumentException
      Build an Adams integrator with the given order and step control parameters.
      Parameters:
      field - field to which the time and state vector elements belong
      name - name of the method
      nSteps - number of steps of the method excluding the one being computed
      order - order of the method
      minStep - minimal step (sign is irrelevant, regardless of integration direction, forward or backward), the last step can be smaller than this
      maxStep - maximal step (sign is irrelevant, regardless of integration direction, forward or backward), the last step can be smaller than this
      vecAbsoluteTolerance - allowed absolute error
      vecRelativeTolerance - allowed relative error
      Throws:
      IllegalArgumentException - if order is 1 or less
  • Method Details

    • integrate

      public FieldODEStateAndDerivative<T> integrate(FieldExpandableODE<T> equations, FieldODEState<T> initialState, T finalTime) throws MathIllegalArgumentException, MathIllegalStateException
      Integrate the differential equations up to the given time.

      This method solves an Initial Value Problem (IVP).

      Since this method stores some internal state variables made available in its public interface during integration (FieldODEIntegrator.getCurrentSignedStepsize()), it is not thread-safe.

      Parameters:
      equations - differential equations to integrate
      initialState - initial state (time, primary and secondary state vectors)
      finalTime - target time for the integration (can be set to a value smaller than t0 for backward integration)
      Returns:
      final state, its time will be the same as finalTime if integration reached its target, but may be different if some FieldODEEventHandler stops it at some point.
      Throws:
      MathIllegalArgumentException - if integration step is too small
      MathIllegalStateException - if the number of functions evaluations is exceeded
    • initializeHighOrderDerivatives

      protected Array2DRowFieldMatrix<T> initializeHighOrderDerivatives(T h, T[] t, T[][] y, T[][] yDot)
      Initialize the high order scaled derivatives at step start.
      Specified by:
      initializeHighOrderDerivatives in class MultistepFieldIntegrator<T extends CalculusFieldElement<T>>
      Parameters:
      h - step size to use for scaling
      t - first steps times
      y - first steps states
      yDot - first steps derivatives
      Returns:
      Nordieck vector at first step (h2/2 y''n, h3/6 y'''n ... hk/k! y(k)n)
    • updateHighOrderDerivativesPhase1

      public Array2DRowFieldMatrix<T> updateHighOrderDerivativesPhase1(Array2DRowFieldMatrix<T> highOrder)
      Update the high order scaled derivatives for Adams integrators (phase 1).

      The complete update of high order derivatives has a form similar to: \[ r_{n+1} = (s_1(n) - s_1(n+1)) P^{-1} u + P^{-1} A P r_n \] this method computes the P-1 A P rn part.

      Parameters:
      highOrder - high order scaled derivatives (h2/2 y'', ... hk/k! y(k))
      Returns:
      updated high order derivatives
      See Also:
    • updateHighOrderDerivativesPhase2

      public void updateHighOrderDerivativesPhase2(T[] start, T[] end, Array2DRowFieldMatrix<T> highOrder)
      Update the high order scaled derivatives Adams integrators (phase 2).

      The complete update of high order derivatives has a form similar to: \[ r_{n+1} = (s_1(n) - s_1(n+1)) P^{-1} u + P^{-1} A P r_n \] this method computes the (s1(n) - s1(n+1)) P-1 u part.

      Phase 1 of the update must already have been performed.

      Parameters:
      start - first order scaled derivatives at step start
      end - first order scaled derivatives at step end
      highOrder - high order scaled derivatives, will be modified (h2/2 y'', ... hk/k! y(k))
      See Also:
    • errorEstimation

      protected abstract double errorEstimation(T[] previousState, T predictedTime, T[] predictedState, T[] predictedScaled, FieldMatrix<T> predictedNordsieck)
      Estimate error.
      Parameters:
      previousState - state vector at step start
      predictedTime - time at step end
      predictedState - predicted state vector at step end
      predictedScaled - predicted value of the scaled derivatives at step end
      predictedNordsieck - predicted value of the Nordsieck vector at step end
      Returns:
      estimated normalized local discretization error
      Since:
      2.0
    • finalizeStep

      protected abstract org.hipparchus.ode.nonstiff.AdamsFieldStateInterpolator<T> finalizeStep(T stepSize, T[] predictedState, T[] predictedScaled, Array2DRowFieldMatrix<T> predictedNordsieck, boolean isForward, FieldODEStateAndDerivative<T> globalPreviousState, FieldODEStateAndDerivative<T> globalCurrentState, FieldEquationsMapper<T> equationsMapper)
      Finalize the step.
      Parameters:
      stepSize - step size used in the scaled and Nordsieck arrays
      predictedState - predicted state at end of step
      predictedScaled - predicted first scaled derivative
      predictedNordsieck - predicted 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
      Returns:
      step interpolator
      Since:
      2.0