Class StepNormalizer

java.lang.Object
org.hipparchus.ode.sampling.StepNormalizer
All Implemented Interfaces:
ODEStepHandler

public class StepNormalizer extends Object implements ODEStepHandler
This class wraps an object implementing ODEFixedStepHandler into a ODEStepHandler.

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 ODEFixedStepHandler 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 timeEnd time DirectionMode BoundsOutput
0.33.1forwardINCREMENTNEITHER0.8, 1.3, 1.8, 2.3, 2.8
0.33.1forwardINCREMENTFIRST0.3, 0.8, 1.3, 1.8, 2.3, 2.8
0.33.1forwardINCREMENTLAST0.8, 1.3, 1.8, 2.3, 2.8, 3.1
0.33.1forwardINCREMENTBOTH0.3, 0.8, 1.3, 1.8, 2.3, 2.8, 3.1
0.33.1forwardMULTIPLESNEITHER0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.33.1forwardMULTIPLESFIRST0.3, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.33.1forwardMULTIPLESLAST0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.1
0.33.1forwardMULTIPLESBOTH0.3, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.1
0.03.0forwardINCREMENTNEITHER0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.03.0forwardINCREMENTFIRST0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.03.0forwardINCREMENTLAST0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.03.0forwardINCREMENTBOTH0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.03.0forwardMULTIPLESNEITHER0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.03.0forwardMULTIPLESFIRST0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.03.0forwardMULTIPLESLAST0.5, 1.0, 1.5, 2.0, 2.5, 3.0
0.03.0forwardMULTIPLESBOTH0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0
3.10.3backwardINCREMENTNEITHER2.6, 2.1, 1.6, 1.1, 0.6
3.10.3backwardINCREMENTFIRST3.1, 2.6, 2.1, 1.6, 1.1, 0.6
3.10.3backwardINCREMENTLAST2.6, 2.1, 1.6, 1.1, 0.6, 0.3
3.10.3backwardINCREMENTBOTH3.1, 2.6, 2.1, 1.6, 1.1, 0.6, 0.3
3.10.3backwardMULTIPLESNEITHER3.0, 2.5, 2.0, 1.5, 1.0, 0.5
3.10.3backwardMULTIPLESFIRST3.1, 3.0, 2.5, 2.0, 1.5, 1.0, 0.5
3.10.3backwardMULTIPLESLAST3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.3
3.10.3backwardMULTIPLESBOTH3.1, 3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.3
3.00.0backwardINCREMENTNEITHER2.5, 2.0, 1.5, 1.0, 0.5, 0.0
3.00.0backwardINCREMENTFIRST3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.0
3.00.0backwardINCREMENTLAST2.5, 2.0, 1.5, 1.0, 0.5, 0.0
3.00.0backwardINCREMENTBOTH3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.0
3.00.0backwardMULTIPLESNEITHER2.5, 2.0, 1.5, 1.0, 0.5, 0.0
3.00.0backwardMULTIPLESFIRST3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.0
3.00.0backwardMULTIPLESLAST2.5, 2.0, 1.5, 1.0, 0.5, 0.0
3.00.0backwardMULTIPLESBOTH3.0, 2.5, 2.0, 1.5, 1.0, 0.5, 0.0
See Also:
  • Constructor Details

    • StepNormalizer

      public StepNormalizer(double h, ODEFixedStepHandler handler)
      Simple constructor. Uses INCREMENT mode, and FIRST bounds setting, for backwards compatibility.
      Parameters:
      h - fixed time step (sign is not used)
      handler - fixed time step handler to wrap
    • StepNormalizer

      public StepNormalizer(double h, ODEFixedStepHandler handler, StepNormalizerMode mode)
      Simple constructor. Uses FIRST bounds setting.
      Parameters:
      h - fixed time step (sign is not used)
      handler - fixed time step handler to wrap
      mode - step normalizer mode to use
    • StepNormalizer

      public StepNormalizer(double h, ODEFixedStepHandler handler, StepNormalizerBounds bounds)
      Simple constructor. Uses INCREMENT mode.
      Parameters:
      h - fixed time step (sign is not used)
      handler - fixed time step handler to wrap
      bounds - step normalizer bounds setting to use
    • StepNormalizer

      public StepNormalizer(double h, ODEFixedStepHandler handler, StepNormalizerMode mode, StepNormalizerBounds bounds)
      Simple constructor.
      Parameters:
      h - fixed time step (sign is not used)
      handler - fixed time step handler to wrap
      mode - step normalizer mode to use
      bounds - step normalizer bounds setting to use
  • Method Details

    • init

      public void init(ODEStateAndDerivative initialState, double finalTime)
      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.

      The default implementation does nothing

      Specified by:
      init in interface ODEStepHandler
      Parameters:
      initialState - initial time, state vector and derivative
      finalTime - target time for the integration
    • handleStep

      public void handleStep(ODEStateInterpolator interpolator)
      Handle the last accepted step.
      Specified by:
      handleStep in interface ODEStepHandler
      Parameters:
      interpolator - interpolator for the last accepted step
    • finish

      public void finish(ODEStateAndDerivative finalState)
      Finalize integration.
      Specified by:
      finish in interface ODEStepHandler
      Parameters:
      finalState - state at integration end