BUG: Encoder fails due to numerical issues edge cases

[aasitvora99]

Describe the bug

3931502 pulled to enh/discrete-encoding breaks current encoding solution on Infinity. It couldn't handle cases where to_dict fails due to numerical issues. Reverting to a previous commit works fine and shows output properly.

To Reproduce

• Start Infinity on encoders_official_discretize branch with RPy sourced from enh/discrete-encoding
• Hit this url on any REST client

curl https://api.rocketpy.org/flights/686ac15e6ce2266e7375bc4a/simulate

• Observe a chain of errors show up on infinity console.

Expected behavior

No errors ig

Screenshots

2025-07-06 19:02:42,277 - INFO - Call to repositories.flight.find_by_id completed for {'data_id': '680e2fcd275e75a42aef1aee'}
2025-07-06 19:02:42,277 - INFO - Call to repositories.flight.read_flight_by_id completed for {}
2025-07-06 19:02:42,277 - INFO - Call to _get_model completed for FlightController
/Users/aasitvora/Desktop/chintu/RocketPy/rocketpy/motors/motor.py:990: UserWarning: burn_time argument (0, 4.264) is out of thrust source time range. Using thrust_source boundary times instead: (0.082, 4.264) s.
If you want to change the burn out time of the curve please use the 'reshape_thrust_curve' argument.
  warnings.warn(
/Users/aasitvora/Desktop/chintu/Infinity-API/.venv/lib/python3.13/site-packages/scipy/integrate/_ivp/lsoda.py:161: UserWarning: lsoda: Repeated convergence failures (perhaps bad Jacobian or tolerances).
  solver._y, solver.t = integrator.run(
/Users/aasitvora/Desktop/chintu/RocketPy/rocketpy/mathutils/function.py:1880: RuntimeWarning: invalid value encountered in divide
  vector_b.extend(3 * ((y[2:] - y[1:-1]) / h[1:] - (y[1:-1] - y[:-2]) / h[:-1]))
2025-07-06 19:02:42,639 - ERROR - get_flight_simulation: Unexpected error array must not contain infs or NaNs
Traceback (most recent call last):
  File "/Users/aasitvora/Desktop/chintu/RocketPy/rocketpy/mathutils/function.py", line 3766, in __get__
    val = cache[self.attrname]
          ~~~~~^^^^^^^^^^^^^^^
KeyError: 'ax'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/aasitvora/Desktop/chintu/RocketPy/rocketpy/mathutils/function.py", line 3771, in __get__
    val = self.func(instance).reset(*args, **kwargs)
          ^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'numpy.ndarray' object has no attribute 'reset'. Did you mean: 'repeat'?

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/aasitvora/Desktop/chintu/Infinity-API/src/controllers/interface.py", line 16, in wrapper
    return await method(self, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/aasitvora/Desktop/chintu/Infinity-API/src/controllers/flight.py", line 108, in get_flight_simulation
    return flight_service.get_flight_simulation()
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/Users/aasitvora/Desktop/chintu/Infinity-API/src/services/flight.py", line 61, in get_flight_simulation
    attributes = rocketpy_encoder(self.flight)
  File "/Users/aasitvora/Desktop/chintu/Infinity-API/src/utils.py", line 29, in rocketpy_encoder
    json_str = json.dumps(
        obj,
    ...<4 lines>...
        allow_pickle=False,
    )
  File "/opt/homebrew/Cellar/python@3.13/3.13.5/Frameworks/Python.framework/Versions/3.13/lib/python3.13/json/__init__.py", line 238, in dumps
    **kw).encode(obj)
          ~~~~~~^^^^^
  File "/opt/homebrew/Cellar/python@3.13/3.13.5/Frameworks/Python.framework/Versions/3.13/lib/python3.13/json/encoder.py", line 200, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/opt/homebrew/Cellar/python@3.13/3.13.5/Frameworks/Python.framework/Versions/3.13/lib/python3.13/json/encoder.py", line 261, in iterencode
    return _iterencode(o, 0)
  File "/Users/aasitvora/Desktop/chintu/RocketPy/rocketpy/_encoders.py", line 74, in default
    encoding = o.to_dict(
        include_outputs=self.include_outputs,
        discretize=self.discretize,
        allow_pickle=self.allow_pickle,
    )
  File "/Users/aasitvora/Desktop/chintu/RocketPy/rocketpy/simulation/flight.py", line 3539, in to_dict
    "ax": self.ax,
          ^^^^^^^
  File "/Users/aasitvora/Desktop/chintu/RocketPy/rocketpy/mathutils/function.py", line 3775, in __get__
    val = Function(source, *args, **kwargs)
  File "/Users/aasitvora/Desktop/chintu/RocketPy/rocketpy/mathutils/function.py", line 158, in __init__
    self.set_source(self.source)
    ~~~~~~~~~~~~~~~^^^^^^^^^^^^^
  File "/Users/aasitvora/Desktop/chintu/RocketPy/rocketpy/mathutils/function.py", line 277, in set_source
    self.set_interpolation(self.__interpolation__)
    ~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/aasitvora/Desktop/chintu/RocketPy/rocketpy/mathutils/function.py", line 322, in set_interpolation
    self.__update_interpolation_coefficients(self.__interpolation__)
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/aasitvora/Desktop/chintu/RocketPy/rocketpy/mathutils/function.py", line 337, in __update_interpolation_coefficients
    self.__interpolate_spline__()
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~^^
  File "/Users/aasitvora/Desktop/chintu/RocketPy/rocketpy/mathutils/function.py", line 1883, in __interpolate_spline__
    c = linalg.solve_banded(
        (1, 1), banded_matrix, vector_b, overwrite_ab=True, overwrite_b=True
    )
  File "/Users/aasitvora/Desktop/chintu/Infinity-API/.venv/lib/python3.13/site-packages/scipy/linalg/_basic.py", line 596, in solve_banded
    b1 = _asarray_validated(b, check_finite=check_finite, as_inexact=True)
  File "/Users/aasitvora/Desktop/chintu/Infinity-API/.venv/lib/python3.13/site-packages/scipy/_lib/_util.py", line 537, in _asarray_validated
    a = toarray(a)
  File "/Users/aasitvora/Desktop/chintu/Infinity-API/.venv/lib/python3.13/site-packages/numpy/lib/function_base.py", line 630, in asarray_chkfinite
    raise ValueError(
        "array must not contain infs or NaNs")
ValueError: array must not contain infs or NaNs
2025-07-06 19:02:42,646 - INFO - Call to get_flight_simulation completed for FlightController

Additional context

Add any other context about the problem here.