Check UVData.future_array_shapes when caching ModelData.freqs

[piyanatk]

As in the title.

hera_sim/hera_sim/visibilities/simulators.py

Lines 193 to 196 in 9576e78

	@cached_property
	def freqs(self) -> np.ndarray:
	"""Frequnecies at which data is defined."""
	return self.uvdata.freq_array[0]

These lines assume that current_array_shapes is being used. If the UVData uses future_array_shape, it will break SkyModel evaluation (and maybe at other places.)

hera_sim/hera_sim/visibilities/simulators.py

Line 83 in 9576e78

self.sky_model.at_frequencies(self.freqs * units.Hz)

[r-pascua]

Thanks for making an issue about this. I don't necessarily know if I'd classify this as a bug, but this is something that has been in the back of my mind for a few months now. I chatted with Paul and was informed that the community would receive sufficient notice about when the future array shapes will become the new API, so I decided to put off dealing with it. There are also at least a few places in the Simulator class that need to be updated to accommodate using the future array shape.

I think I might want to make this a milestone for version 3, which I'm envisioning will implement the merger of the Simulator class and the VisibilitySimulation class. Curious to hear thoughts from @steven-murray.

[piyanatk]

It looks like initialize_uvdata_from_params is default to use future array shape from pyuvdata=>2.2.6. I do not see this mentioned in the pyuvdata changelogs though. Maybe @bhazelton can verify this.