AbstractFieldIntegrator (Apache Commons Math 3.6.1 API)

java.lang.Object
- org.apache.commons.math3.ode.AbstractFieldIntegrator<T>

Type Parameters:
T - the type of the field elements

All Implemented Interfaces:

FirstOrderFieldIntegrator<T>

Direct Known Subclasses:

AdaptiveStepsizeFieldIntegrator, RungeKuttaFieldIntegrator
```
public abstract class AbstractFieldIntegrator<T extends RealFieldElement<T>>
extends Object
implements FirstOrderFieldIntegrator<T>
```
Base class managing common boilerplate for all integrators.

Since:

3.6

Constructor Summary

Constructors
Modifier Constructor and Description

protected AbstractFieldIntegrator(Field<T> field, String name)
Build an instance.

Constructors
Modifier	Constructor and Description
`protected`	`AbstractFieldIntegrator(Field<T> field, String name)` Build an instance.

Method Summary

Methods
Modifier and Type	Method and Description
`protected FieldODEStateAndDerivative<T>`	`acceptStep(AbstractFieldStepInterpolator<T> interpolator, T tEnd)` Accept a step, triggering events and step handlers.
`void`	`addEventHandler(FieldEventHandler<T> handler, double maxCheckInterval, double convergence, int maxIterationCount)` Add an event handler to the integrator.
`void`	`addEventHandler(FieldEventHandler<T> handler, double maxCheckInterval, double convergence, int maxIterationCount, BracketedRealFieldUnivariateSolver<T> solver)` Add an event handler to the integrator.
`void`	`addStepHandler(FieldStepHandler<T> handler)` Add a step handler to this integrator.
`void`	`clearEventHandlers()` Remove all the event handlers that have been added to the integrator.
`void`	`clearStepHandlers()` Remove all the step handlers that have been added to the integrator.
`T[]`	`computeDerivatives(T t, T[] y)` Compute the derivatives and check the number of evaluations.
`T`	`getCurrentSignedStepsize()` Get the current signed value of the integration stepsize.
`FieldODEStateAndDerivative<T>`	`getCurrentStepStart()` Get the current value of the step start time t_i.
`protected FieldExpandableODE<T>`	`getEquations()` Get the differential equations to integrate.
`int`	`getEvaluations()` Get the number of evaluations of the differential equations function.
`protected IntegerSequence.Incrementor`	`getEvaluationsCounter()` Get the evaluations counter.
`Collection<FieldEventHandler<T>>`	`getEventHandlers()` Get all the event handlers that have been added to the integrator.
`Field<T>`	`getField()` Get the field to which state vector elements belong.
`int`	`getMaxEvaluations()` Get the maximal number of functions evaluations.
`String`	`getName()` Get the name of the method.
`Collection<FieldStepHandler<T>>`	`getStepHandlers()` Get all the step handlers that have been added to the integrator.
`protected T`	`getStepSize()` Get the current step size.
`protected FieldODEStateAndDerivative<T>`	`getStepStart()` Getcurrent step start.
`protected FieldODEStateAndDerivative<T>`	`initIntegration(FieldExpandableODE<T> eqn, T t0, T[] y0, T t)` Prepare the start of an integration.
`protected boolean`	`isLastStep()` Check if this step is the last one.
`protected boolean`	`resetOccurred()` Check if a reset occurred while last step was accepted.
`protected void`	`sanityChecks(FieldODEState<T> eqn, T t)` Check the integration span.
`protected void`	`setIsLastStep(boolean isLastStep)` Set the last state flag.
`void`	`setMaxEvaluations(int maxEvaluations)` Set the maximal number of differential equations function evaluations.
`protected void`	`setStateInitialized(boolean stateInitialized)` Set the stateInitialized flag.
`protected void`	`setStepSize(T stepSize)` Set the current step size.
`protected void`	`setStepStart(FieldODEStateAndDerivative<T> stepStart)` Set current step start.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.commons.math3.ode.FirstOrderFieldIntegrator
integrate

- Constructor Detail
  - AbstractFieldIntegrator
```
protected AbstractFieldIntegrator(Field<T> field,
                       String name)
```
    Build an instance.
    
    Parameters:
    field - field to which the time and state vector elements belong
    name - name of the method
- Method Detail
  - 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

Class AbstractFieldIntegrator<T extends RealFieldElement<T>>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface org.apache.commons.math3.ode.FirstOrderFieldIntegrator

Constructor Detail

AbstractFieldIntegrator

Method Detail

getField

getName

addStepHandler

getStepHandlers

clearStepHandlers

addEventHandler

addEventHandler

getEventHandlers

clearEventHandlers

getCurrentStepStart

getCurrentSignedStepsize

setMaxEvaluations

getMaxEvaluations

getEvaluations

initIntegration

getEquations

getEvaluationsCounter

computeDerivatives

setStateInitialized

acceptStep

sanityChecks

resetOccurred

setStepSize

getStepSize

setStepStart

getStepStart

setIsLastStep

isLastStep