Class AbstractFieldIntegrator<T extends RealFieldElement<T>>

Method Details

• getField

  public Field<T> getField()

  Get the field to which state vector elements belong.

  Returns:

  field to which state vector elements belong

• getName

  public String getName()

  Get the name of the method.

  Specified by:

  getName in interface FirstOrderFieldIntegrator<T extends RealFieldElement<T>>

  Returns:

  name of the method

• addStepHandler

  public void addStepHandler(FieldStepHandler<T> handler)

  Add a step handler to this integrator.

  The handler will be called by the integrator for each accepted step.

  Specified by:

  addStepHandler in interface FirstOrderFieldIntegrator<T extends RealFieldElement<T>>

  Parameters:

  handler - handler for the accepted steps

  See Also:

  • FirstOrderFieldIntegrator.getStepHandlers()
  • FirstOrderFieldIntegrator.clearStepHandlers()

• getStepHandlers

  public Collection<FieldStepHandler<T>> getStepHandlers()

  Get all the step handlers that have been added to the integrator.

  Specified by:

  getStepHandlers in interface FirstOrderFieldIntegrator<T extends RealFieldElement<T>>

  Returns:

  an unmodifiable collection of the added events handlers

  See Also:

  • FirstOrderFieldIntegrator.addStepHandler(FieldStepHandler)
  • FirstOrderFieldIntegrator.clearStepHandlers()

• clearStepHandlers

  public void clearStepHandlers()

  Remove all the step handlers that have been added to the integrator.

  Specified by:

  clearStepHandlers in interface FirstOrderFieldIntegrator<T extends RealFieldElement<T>>

  See Also:

  • FirstOrderFieldIntegrator.addStepHandler(FieldStepHandler)
  • FirstOrderFieldIntegrator.getStepHandlers()

• addEventHandler

  public void addEventHandler(FieldEventHandler<T> handler, double maxCheckInterval, double convergence, int maxIterationCount)

  Add an event handler to the integrator.

  The default solver is a 5^th order FieldBracketingNthOrderBrentSolver.

  Specified by:

  addEventHandler in interface FirstOrderFieldIntegrator<T extends RealFieldElement<T>>

  Parameters:

  handler - event handler

  maxCheckInterval - maximal time interval between switching function checks (this interval prevents missing sign changes in case the integration steps becomes very large)

  convergence - convergence threshold in the event time search

  maxIterationCount - upper limit of the iteration count in the event time search events.

  See Also:

  • FirstOrderFieldIntegrator.addEventHandler(FieldEventHandler, double, double, int, org.apache.commons.math3.analysis.solvers.BracketedRealFieldUnivariateSolver)
  • FirstOrderFieldIntegrator.getEventHandlers()
  • FirstOrderFieldIntegrator.clearEventHandlers()

• addEventHandler

  public void addEventHandler(FieldEventHandler<T> handler, double maxCheckInterval, double convergence, int maxIterationCount, BracketedRealFieldUnivariateSolver<T> solver)

  Add an event handler to the integrator.

  Specified by:

  addEventHandler in interface FirstOrderFieldIntegrator<T extends RealFieldElement<T>>

  Parameters:

  handler - event handler

  maxCheckInterval - maximal time interval between switching function checks (this interval prevents missing sign changes in case the integration steps becomes very large)

  convergence - convergence threshold in the event time search

  maxIterationCount - upper limit of the iteration count in the event time search events.

  solver - solver to use to locate the event

  See Also:

  • FirstOrderFieldIntegrator.addEventHandler(FieldEventHandler, double, double, int)
  • FirstOrderFieldIntegrator.getEventHandlers()
  • FirstOrderFieldIntegrator.clearEventHandlers()

• getEventHandlers

  public Collection<FieldEventHandler<T>> getEventHandlers()

  Get all the event handlers that have been added to the integrator.

  Specified by:

  getEventHandlers in interface FirstOrderFieldIntegrator<T extends RealFieldElement<T>>

  Returns:

  an unmodifiable collection of the added events handlers

  See Also:

  • FirstOrderFieldIntegrator.addEventHandler(FieldEventHandler, double, double, int)
  • FirstOrderFieldIntegrator.clearEventHandlers()

• clearEventHandlers

  public void clearEventHandlers()

  Remove all the event handlers that have been added to the integrator.

  Specified by:

  clearEventHandlers in interface FirstOrderFieldIntegrator<T extends RealFieldElement<T>>

  See Also:

  • FirstOrderFieldIntegrator.addEventHandler(FieldEventHandler, double, double, int)
  • FirstOrderFieldIntegrator.getEventHandlers()

• getCurrentStepStart

  public FieldODEStateAndDerivative<T> getCurrentStepStart()

  Get the current value of the step start time t_i.

  This method can be called during integration (typically by the object implementing the differential equations problem) if the value of the current step that is attempted is needed.

  The result is undefined if the method is called outside of calls to integrate.

  Specified by:

  getCurrentStepStart in interface FirstOrderFieldIntegrator<T extends RealFieldElement<T>>

  Returns:

  current value of the state at step start time t_i

• getCurrentSignedStepsize

  public T getCurrentSignedStepsize()

  Get the current signed value of the integration stepsize.

  This method can be called during integration (typically by the object implementing the differential equations problem) if the signed value of the current stepsize that is tried is needed.

  The result is undefined if the method is called outside of calls to integrate.

  Specified by:

  getCurrentSignedStepsize in interface FirstOrderFieldIntegrator<T extends RealFieldElement<T>>

  Returns:

  current signed value of the stepsize

• setMaxEvaluations

  public void setMaxEvaluations(int maxEvaluations)

  Set the maximal number of differential equations function evaluations.

  The purpose of this method is to avoid infinite loops which can occur for example when stringent error constraints are set or when lots of discrete events are triggered, thus leading to many rejected steps.

  Specified by:

  setMaxEvaluations in interface FirstOrderFieldIntegrator<T extends RealFieldElement<T>>

  Parameters:

  maxEvaluations - maximal number of function evaluations (negative values are silently converted to maximal integer value, thus representing almost unlimited evaluations)

• getMaxEvaluations

  public int getMaxEvaluations()

  Get the maximal number of functions evaluations.

  Specified by:

  getMaxEvaluations in interface FirstOrderFieldIntegrator<T extends RealFieldElement<T>>

  Returns:

  maximal number of functions evaluations

• getEvaluations

  public int getEvaluations()

  Get the number of evaluations of the differential equations function.

  The number of evaluations corresponds to the last call to the integrate method. It is 0 if the method has not been called yet.

  Specified by:

  getEvaluations in interface FirstOrderFieldIntegrator<T extends RealFieldElement<T>>

  Returns:

  number of evaluations of the differential equations function

• initIntegration

  protected FieldODEStateAndDerivative<T> initIntegration(FieldExpandableODE<T> eqn, T t0, T[] y0, T t)

  Prepare the start of an integration.

  Parameters:

  eqn - equations to integrate

  t0 - start value of the independent time variable

  y0 - array containing the start value of the state vector

  t - target time for the integration

  Returns:

  initial state with derivatives added

• getEquations

  protected FieldExpandableODE<T> getEquations()

  Get the differential equations to integrate.

  Returns:

  differential equations to integrate

• getEvaluationsCounter

  protected IntegerSequence.Incrementor getEvaluationsCounter()

  Get the evaluations counter.

  Returns:

  evaluations counter

• computeDerivatives

  public T[] computeDerivatives(T t, T[] y) throws DimensionMismatchException, MaxCountExceededException, NullPointerException

  Compute the derivatives and check the number of evaluations.

  Parameters:

  t - current value of the independent time variable

  y - array containing the current value of the state vector

  Returns:

  state completed with derivatives

  Throws:

  DimensionMismatchException - if arrays dimensions do not match equations settings

  MaxCountExceededException - if the number of functions evaluations is exceeded

  NullPointerException - if the ODE equations have not been set (i.e. if this method is called outside of a call to integrate

• setStateInitialized

  protected void setStateInitialized(boolean stateInitialized)

  Set the stateInitialized flag.

  This method must be called by integrators with the value false before they start integration, so a proper lazy initialization is done automatically on the first step.

  Parameters:

  stateInitialized - new value for the flag

• acceptStep

  protected FieldODEStateAndDerivative<T> acceptStep(AbstractFieldStepInterpolator<T> interpolator, T tEnd) throws MaxCountExceededException, DimensionMismatchException, NoBracketingException

  Accept a step, triggering events and step handlers.

  Parameters:

  interpolator - step interpolator

  tEnd - final integration time

  Returns:

  state at end of step

  Throws:

  MaxCountExceededException - if the interpolator throws one because the number of functions evaluations is exceeded

  NoBracketingException - if the location of an event cannot be bracketed

  DimensionMismatchException - if arrays dimensions do not match equations settings

• sanityChecks

  protected void sanityChecks(FieldODEState<T> eqn, T t) throws NumberIsTooSmallException, DimensionMismatchException

  Check the integration span.

  Parameters:

  eqn - set of differential equations

  t - target time for the integration

  Throws:

  NumberIsTooSmallException - if integration span is too small

  DimensionMismatchException - if adaptive step size integrators tolerance arrays dimensions are not compatible with equations settings

• resetOccurred

  protected boolean resetOccurred()

  Check if a reset occurred while last step was accepted.

  Returns:

  true if a reset occurred while last step was accepted

• setStepSize

  protected void setStepSize(T stepSize)

  Set the current step size.

  Parameters:

  stepSize - step size to set

• getStepSize

  protected T getStepSize()

  Get the current step size.

  Returns:

  current step size

• setStepStart

  protected void setStepStart(FieldODEStateAndDerivative<T> stepStart)

  Set current step start.

  Parameters:

  stepStart - step start

• getStepStart

  protected FieldODEStateAndDerivative<T> getStepStart()

  Getcurrent step start.

  Returns:

  current step start

• setIsLastStep

  protected void setIsLastStep(boolean isLastStep)

  Set the last state flag.

  Parameters:

  isLastStep - if true, this step is the last one

• isLastStep

  protected boolean isLastStep()

  Check if this step is the last one.

  Returns:

  true if this step is the last one