Phyton wrapper NumericalPropagator castin problem

Orekit Python Wrapper usage
1

Hello,

I’m working with the Orekit Python (version 12.2) to propagate an orbit using a NumericalPropagator with the Dormand-Prince method. However, I’m encountering an issue where the setStepHandler() method isn’t recognized or doesn’t seem to work.

Here’s what I’ve tried:

  1. Using setStepHandler() directly on a NumericalPropagator object, but I get errors indicating that the method is not available.
  2. Attempted casting the NumericalPropagator to Propagator using cast_() to access inherited interface methods (such as setStepHandler()), but I still get errors related to method access.

I have read in an old post in the forum that the point nr 2 (using cast_) could solve the issue but I am not able to make it work. I have tried different formulations, all of them give me error.
As an example of my code:

from org.orekit.propagation.numerical import NumericalPropagator
from org.orekit.propagation import Propagator

Create propagator instance

propagator = NumericalPropagator(integrator)

Attempt to cast propagator to Propagator interface

propagator = propagator.cast_(Propagator)

Now attempt to set step handler

propagator.setStepHandler(step_size, step_handler)

Does someone know how to solve this issue and use setStepHandler method in Python on a NumericalPropagator?

Thanks

2

Hi there,

Try casting as AbstractPropagator. Or maybe AbstractIntegratedPropagator I’ve not checked the code.

Do you know what if you use orekit-jpype for the wrapper you won’t need this cast stuff?

Cheers,
Romain.

3

Hi,

The problem is likely that it should be “Propagator.cast_(propagator)” (the method is on the class not the instance)

See example at: orekit_python_artifacts/test/OrekitStepHandlerTest.py at version-12.2 · petrushy/orekit_python_artifacts · GitHub

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4

Thanks to both Petrus and Romain!
I was able to make my code work by using the correct call for cast_ (which is “Propagator.cast_(propagator)”). The code still was not working because I was using OrekitFixedStepHandler, it is working now that I switched to PythonOrekitFixedStepHandler.
Many thanks

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