T
 the type of the field elementspublic interface FirstOrderFieldIntegrator<T extends RealFieldElement<T>>
The classes which are devoted to solve first order differential
equations should implement this interface. The problems which can
be handled should implement the FirstOrderDifferentialEquations
interface.
FirstOrderFieldDifferentialEquations
Modifier and Type  Method and Description 

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 
getCurrentSignedStepsize()
Get the current signed value of the integration stepsize.

FieldODEStateAndDerivative<T> 
getCurrentStepStart()
Get the current value of the step start time t_{i}.

int 
getEvaluations()
Get the number of evaluations of the differential equations function.

Collection<FieldEventHandler<T>> 
getEventHandlers()
Get all the event handlers that have been added to the integrator.

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.

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

void 
setMaxEvaluations(int maxEvaluations)
Set the maximal number of differential equations function evaluations.

void addStepHandler(FieldStepHandler<T> handler)
The handler will be called by the integrator for each accepted step.
handler
 handler for the accepted stepsgetStepHandlers()
,
clearStepHandlers()
Collection<FieldStepHandler<T>> getStepHandlers()
addStepHandler(FieldStepHandler)
,
clearStepHandlers()
void clearStepHandlers()
void addEventHandler(FieldEventHandler<T> handler, double maxCheckInterval, double convergence, int maxIterationCount)
The default solver is a 5^{th} order FieldBracketingNthOrderBrentSolver
.
handler
 event handlermaxCheckInterval
 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 searchmaxIterationCount
 upper limit of the iteration count in
the event time search events.addEventHandler(FieldEventHandler, double, double, int,
org.apache.commons.math4.analysis.solvers.BracketedRealFieldUnivariateSolver)
,
getEventHandlers()
,
clearEventHandlers()
void addEventHandler(FieldEventHandler<T> handler, double maxCheckInterval, double convergence, int maxIterationCount, BracketedRealFieldUnivariateSolver<T> solver)
handler
 event handlermaxCheckInterval
 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 searchmaxIterationCount
 upper limit of the iteration count in
the event time search events.solver
 solver to use to locate the eventaddEventHandler(FieldEventHandler, double, double, int)
,
getEventHandlers()
,
clearEventHandlers()
Collection<FieldEventHandler<T>> getEventHandlers()
addEventHandler(FieldEventHandler, double, double, int)
,
clearEventHandlers()
void clearEventHandlers()
FieldODEStateAndDerivative<T> getCurrentStepStart()
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
.
T getCurrentSignedStepsize()
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
.
void setMaxEvaluations(int maxEvaluations)
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.
maxEvaluations
 maximal number of function evaluations (negative
values are silently converted to maximal integer value, thus representing
almost unlimited evaluations)int getMaxEvaluations()
int getEvaluations()
The number of evaluations corresponds to the last call to the
integrate
method. It is 0 if the method has not been called yet.
FieldODEStateAndDerivative<T> integrate(FieldExpandableODE<T> equations, FieldODEState<T> initialState, T finalTime) throws NumberIsTooSmallException, MaxCountExceededException, NoBracketingException
This method solves an Initial Value Problem (IVP).
Since this method stores some internal state variables made
available in its public interface during integration (getCurrentSignedStepsize()
), it is not threadsafe.
equations
 differential equations to integrateinitialState
 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)finalTime
if
integration reached its target, but may be different if some FieldEventHandler
stops it at some point.NumberIsTooSmallException
 if integration step is too smallMaxCountExceededException
 if the number of functions evaluations is exceededNoBracketingException
 if the location of an event cannot be bracketedCopyright © 2003–2021 The Apache Software Foundation. All rights reserved.