Serializable
, ODEStepHandler
ContinuousOutputModel
public class DenseOutputModel extends Object implements ODEStepHandler, Serializable
This class act as a step handler from the integrator point of
view. It is called iteratively during the integration process and
stores a copy of all steps information in a sorted collection for
later use. Once the integration process is over, the user can use
the getInterpolatedState
method to retrieve this information at any time. It is important
to wait for the integration to be over before attempting to call
getInterpolatedState
because
some internal variables are set only once the last step has been
handled.
This is useful for example if the main loop of the user application should remain independent from the integration process or if one needs to mimic the behaviour of an analytical model despite a numerical model is used (i.e. one needs the ability to get the model value at any time or to navigate through the data).
If problem modeling is done with several separate integration phases for contiguous intervals, the same ContinuousOutputModel can be used as step handler for all integration phases as long as they are performed in order and in the same direction. As an example, one can extrapolate the trajectory of a satellite with one model (i.e. one set of differential equations) up to the beginning of a maneuver, use another more complex model including thrusters modeling and accurate attitude control during the maneuver, and revert to the first model after the end of the maneuver. If the same continuous output model handles the steps of all integration phases, the user do not need to bother when the maneuver begins or ends, he has all the data available in a transparent manner.
An important feature of this class is that it implements the
Serializable
interface. This means that the result of
an integration can be serialized and reused later (if stored into a
persistent medium like a filesystem or a database) or elsewhere (if
sent to another application). Only the result of the integration is
stored, there is no reference to the integrated problem by
itself.
One should be aware that the amount of data stored in a
ContinuousOutputModel instance can be important if the state vector
is large, if the integration interval is long or if the steps are
small (which can result from small tolerance settings in adaptive
step size integrators
).
ODEStepHandler
,
ODEStateInterpolator
,
Serialized FormConstructor | Description |
---|---|
DenseOutputModel() |
Simple constructor.
|
Modifier and Type | Method | Description |
---|---|---|
void |
append(DenseOutputModel model) |
Append another model at the end of the instance.
|
double |
getFinalTime() |
Get the final integration time.
|
double |
getInitialTime() |
Get the initial integration time.
|
ODEStateAndDerivative |
getInterpolatedState(double time) |
Get the state at interpolated time.
|
void |
handleStep(ODEStateInterpolator interpolator,
boolean isLast) |
Handle the last accepted step.
|
void |
init(ODEStateAndDerivative initialState,
double targetTime) |
Initialize step handler at the start of an ODE integration.
|
public DenseOutputModel()
public void append(DenseOutputModel model) throws MathIllegalArgumentException, MathIllegalStateException
model
- model to add at the end of the instanceMathIllegalArgumentException
- if the model to append is not
compatible with the instance (dimension of the state vector,
propagation direction, hole between the dates)MathIllegalStateException
- if the number of functions evaluations is exceeded
during step finalizationpublic void init(ODEStateAndDerivative initialState, double targetTime)
This method is called once at the start of the integration. It may be used by the step handler to initialize some internal data if needed.
The default implementation does nothing
init
in interface ODEStepHandler
initialState
- initial time, state vector and derivativetargetTime
- target time for the integrationpublic void handleStep(ODEStateInterpolator interpolator, boolean isLast) throws MathIllegalStateException
handleStep
in interface ODEStepHandler
interpolator
- interpolator for the last accepted step.isLast
- true if the step is the last oneMathIllegalStateException
- if the number of functions evaluations is exceeded
during step finalizationpublic double getInitialTime()
public double getFinalTime()
public ODEStateAndDerivative getInterpolatedState(double time)
time
- time of the interpolated pointCopyright © 2016–2018 Hipparchus.org. All rights reserved.