public class StepNormalizer extends java.lang.Object implements StepHandler
FixedStepHandler
into a StepHandler
.
This wrapper allows to use fixed step handlers with general integrators which cannot guaranty their integration steps will remain constant and therefore only accept general step handlers.
The stepsize used is selected at construction time. The handleStep
method of the underlying
FixedStepHandler
object is called at normalized times. The
normalized times can be influenced by the StepNormalizerMode
and
StepNormalizerBounds
.
There is no constraint on the integrator, it can use any time step it needs (time steps longer or shorter than the fixed time step and non-integer ratios are all allowed).
Examples (step size = 0.5) | |||||
Start time | End time | Direction | Mode |
Bounds | Output |
0.3 | 3.1 | forward | INCREMENT | NEITHER | 0.8, 1.3, 1.8, 2.3, 2.8 |
0.3 | 3.1 | forward | INCREMENT | FIRST | 0.3, 0.8, 1.3, 1.8, 2.3, 2.8 |
0.3 | 3.1 | forward | INCREMENT | LAST | 0.8, 1.3, 1.8, 2.3, 2.8, 3.1 |
0.3 | 3.1 | forward | INCREMENT | BOTH | 0.3, 0.8, 1.3, 1.8, 2.3, 2.8, 3.1 |
0.3 | 3.1 | forward | MULTIPLES | NEITHER | 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 |
0.3 | 3.1 | forward | MULTIPLES | FIRST | 0.3, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 |
0.3 | 3.1 | forward | MULTIPLES | LAST | 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.1 |
0.3 | 3.1 | forward | MULTIPLES | BOTH | 0.3, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.1 |
0.0 | 3.0 | forward | INCREMENT | NEITHER | 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 |
0.0 | 3.0 | forward | INCREMENT | FIRST | 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 |
0.0 | 3.0 | forward | INCREMENT | LAST | 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 |
0.0 | 3.0 | forward | INCREMENT | BOTH | 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 |
0.0 | 3.0 | forward | MULTIPLES | NEITHER | 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 |
0.0 | 3.0 | forward | MULTIPLES | FIRST | 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 |
0.0 | 3.0 | forward | MULTIPLES | LAST | 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 |
0.0 | 3.0 | forward | MULTIPLES | BOTH | 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 |
3.1 | 0.3 | backward | INCREMENT | NEITHER | 2.6, 2.1, 1.6, 1.1, 0.6 |
3.1 | 0.3 | backward | INCREMENT | FIRST | 3.1, 2.6, 2.1, 1.6, 1.1, 0.6 |
3.1 | 0.3 | backward | INCREMENT | LAST | 2.6, 2.1, 1.6, 1.1, 0.6, 0.3 |
3.1 | 0.3 | backward | INCREMENT | BOTH | 3.1, 2.6, 2.1, 1.6, 1.1, 0.6, 0.3 |
3.1 | 0.3 | backward | MULTIPLES | NEITHER | 3.0, 2.5, 2.0, 1.5, 1.0, 0.5 |
3.1 | 0.3 | backward | MULTIPLES | FIRST | 3.1, 3.0, 2.5, 2.0, 1.5, 1.0, 0.5 |
3.1 | 0.3 | backward | MULTIPLES | LAST | 3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.3 |
3.1 | 0.3 | backward | MULTIPLES | BOTH | 3.1, 3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.3 |
3.0 | 0.0 | backward | INCREMENT | NEITHER | 2.5, 2.0, 1.5, 1.0, 0.5, 0.0 |
3.0 | 0.0 | backward | INCREMENT | FIRST | 3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.0 |
3.0 | 0.0 | backward | INCREMENT | LAST | 2.5, 2.0, 1.5, 1.0, 0.5, 0.0 |
3.0 | 0.0 | backward | INCREMENT | BOTH | 3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.0 |
3.0 | 0.0 | backward | MULTIPLES | NEITHER | 2.5, 2.0, 1.5, 1.0, 0.5, 0.0 |
3.0 | 0.0 | backward | MULTIPLES | FIRST | 3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.0 |
3.0 | 0.0 | backward | MULTIPLES | LAST | 2.5, 2.0, 1.5, 1.0, 0.5, 0.0 |
3.0 | 0.0 | backward | MULTIPLES | BOTH | 3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.0 |
StepHandler
,
FixedStepHandler
,
StepNormalizerMode
,
StepNormalizerBounds
Modifier and Type | Field and Description |
---|---|
private StepNormalizerBounds |
bounds
The step normalizer bounds settings to use.
|
private double |
firstTime
First step time.
|
private boolean |
forward
Integration direction indicator.
|
private double |
h
Fixed time step.
|
private FixedStepHandler |
handler
Underlying step handler.
|
private double[] |
lastDerivatives
Last derivatives vector.
|
private double[] |
lastState
Last state vector.
|
private double |
lastTime
Last step time.
|
private StepNormalizerMode |
mode
The step normalizer mode to use.
|
Constructor and Description |
---|
StepNormalizer(double h,
FixedStepHandler handler)
Simple constructor.
|
StepNormalizer(double h,
FixedStepHandler handler,
StepNormalizerBounds bounds)
Simple constructor.
|
StepNormalizer(double h,
FixedStepHandler handler,
StepNormalizerMode mode)
Simple constructor.
|
StepNormalizer(double h,
FixedStepHandler handler,
StepNormalizerMode mode,
StepNormalizerBounds bounds)
Simple constructor.
|
Modifier and Type | Method and Description |
---|---|
private void |
doNormalizedStep(boolean isLast)
Invokes the underlying step handler for the current normalized step.
|
void |
handleStep(StepInterpolator interpolator,
boolean isLast)
Handle the last accepted step
|
void |
init(double t0,
double[] y0,
double t)
Initialize step handler at the start of an ODE integration.
|
private boolean |
isNextInStep(double nextTime,
StepInterpolator interpolator)
Returns a value indicating whether the next normalized time is in the
current step.
|
private void |
storeStep(StepInterpolator interpolator,
double t)
Stores the interpolated information for the given time in the current
state.
|
private double h
private final FixedStepHandler handler
private double firstTime
private double lastTime
private double[] lastState
private double[] lastDerivatives
private boolean forward
private final StepNormalizerBounds bounds
private final StepNormalizerMode mode
public StepNormalizer(double h, FixedStepHandler handler)
h
- fixed time step (sign is not used)handler
- fixed time step handler to wrappublic StepNormalizer(double h, FixedStepHandler handler, StepNormalizerMode mode)
FIRST
bounds setting.h
- fixed time step (sign is not used)handler
- fixed time step handler to wrapmode
- step normalizer mode to usepublic StepNormalizer(double h, FixedStepHandler handler, StepNormalizerBounds bounds)
INCREMENT
mode.h
- fixed time step (sign is not used)handler
- fixed time step handler to wrapbounds
- step normalizer bounds setting to usepublic StepNormalizer(double h, FixedStepHandler handler, StepNormalizerMode mode, StepNormalizerBounds bounds)
h
- fixed time step (sign is not used)handler
- fixed time step handler to wrapmode
- step normalizer mode to usebounds
- step normalizer bounds setting to usepublic void init(double t0, double[] y0, double t)
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.
init
in interface StepHandler
t0
- start value of the independent time variabley0
- array containing the start value of the state vectort
- target time for the integrationpublic void handleStep(StepInterpolator interpolator, boolean isLast) throws MaxCountExceededException
handleStep
in interface StepHandler
interpolator
- interpolator for the last accepted step. For
efficiency purposes, the various integrators reuse the same
object on each call, so if the instance wants to keep it across
all calls (for example to provide at the end of the integration a
continuous model valid throughout the integration range), it
should build a local copy using the clone method and store this
copy.isLast
- true if the step is the last oneMaxCountExceededException
- if the interpolator throws one because
the number of functions evaluations is exceededprivate boolean isNextInStep(double nextTime, StepInterpolator interpolator)
nextTime
- the next normalized timeinterpolator
- interpolator for the last accepted step, to use to
get the end time of the current stepprivate void doNormalizedStep(boolean isLast)
isLast
- true if the step is the last oneprivate void storeStep(StepInterpolator interpolator, double t) throws MaxCountExceededException
interpolator
- interpolator for the last accepted step, to use to
get the interpolated informationt
- the time for which to store the interpolated informationMaxCountExceededException
- if the interpolator throws one because
the number of functions evaluations is exceededCopyright (c) 2003-2014 Apache Software Foundation