Class StepNormalizer
java.lang.Object
org.apache.commons.math3.ode.sampling.StepNormalizer
- All Implemented Interfaces:
StepHandler
This class wraps an object implementing
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 |
- Since:
- 1.2
- See Also:
-
Field Summary
FieldsModifier and TypeFieldDescriptionprivate final StepNormalizerBounds
The step normalizer bounds settings to use.private double
First step time.private boolean
Integration direction indicator.private double
Fixed time step.private final FixedStepHandler
Underlying step handler.private double[]
Last derivatives vector.private double[]
Last state vector.private double
Last step time.private final StepNormalizerMode
The step normalizer mode to use. -
Constructor Summary
ConstructorsConstructorDescriptionStepNormalizer
(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. -
Method Summary
Modifier and TypeMethodDescriptionprivate void
doNormalizedStep
(boolean isLast) Invokes the underlying step handler for the current normalized step.void
handleStep
(StepInterpolator interpolator, boolean isLast) Handle the last accepted stepvoid
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.
-
Field Details
-
h
private double hFixed time step. -
handler
Underlying step handler. -
firstTime
private double firstTimeFirst step time. -
lastTime
private double lastTimeLast step time. -
lastState
private double[] lastStateLast state vector. -
lastDerivatives
private double[] lastDerivativesLast derivatives vector. -
forward
private boolean forwardIntegration direction indicator. -
bounds
The step normalizer bounds settings to use. -
mode
The step normalizer mode to use.
-
-
Constructor Details
-
StepNormalizer
- Parameters:
h
- fixed time step (sign is not used)handler
- fixed time step handler to wrap
-
StepNormalizer
Simple constructor. UsesFIRST
bounds setting.- Parameters:
h
- fixed time step (sign is not used)handler
- fixed time step handler to wrapmode
- step normalizer mode to use- Since:
- 3.0
-
StepNormalizer
Simple constructor. UsesINCREMENT
mode.- Parameters:
h
- fixed time step (sign is not used)handler
- fixed time step handler to wrapbounds
- step normalizer bounds setting to use- Since:
- 3.0
-
StepNormalizer
public StepNormalizer(double h, FixedStepHandler handler, StepNormalizerMode mode, StepNormalizerBounds bounds) Simple constructor.- Parameters:
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 use- Since:
- 3.0
-
-
Method Details
-
init
public void init(double t0, double[] y0, double t) Initialize step handler at the start of an ODE integration.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.
- Specified by:
init
in interfaceStepHandler
- Parameters:
t0
- start value of the independent time variabley0
- array containing the start value of the state vectort
- target time for the integration
-
handleStep
public void handleStep(StepInterpolator interpolator, boolean isLast) throws MaxCountExceededException Handle the last accepted step- Specified by:
handleStep
in interfaceStepHandler
- Parameters:
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 one- Throws:
MaxCountExceededException
- if the interpolator throws one because the number of functions evaluations is exceeded
-
isNextInStep
Returns a value indicating whether the next normalized time is in the current step.- Parameters:
nextTime
- the next normalized timeinterpolator
- interpolator for the last accepted step, to use to get the end time of the current step- Returns:
- value indicating whether the next normalized time is in the current step
-
doNormalizedStep
private void doNormalizedStep(boolean isLast) Invokes the underlying step handler for the current normalized step.- Parameters:
isLast
- true if the step is the last one
-
storeStep
Stores the interpolated information for the given time in the current state.- Parameters:
interpolator
- interpolator for the last accepted step, to use to get the interpolated informationt
- the time for which to store the interpolated information- Throws:
MaxCountExceededException
- if the interpolator throws one because the number of functions evaluations is exceeded
-