How to add a new cold-ammonia model?

[jpinedaf]

I want to add the cold-ammonia model. The implementation of the model is simply

    dT0 = 41.18 # Energy difference between (2,2) and (1,1) in K
    trot = tkin * (1 + (tkin/dT0)*np.log(1 + 0.6*np.exp(-15.7/tkin)))**-1
    return ammonia(xarr, trot=trot, **kwargs)

I guess a new function AmmoniaRunner_cold() should be created, which looks almost the same as AmmoniaRunner_cold(). Anything else?

[autocorr]

Hi Jaime, I've added the Swift approximation as an option in a keyword argument as AmmoniaRunner(..., cold=True). This will convert a prior sampling kinetic temperatures and convert them to rotation temperatures. The rotation temperature is only used locally, so the posterior samples will all be in kinetic as drawn from the prior.

I'm finishing up a major refactor and update, so at the exact time of this writing I still need to test that the cube fitting framework still works, but I should get to that in the next couple days. If you'd like to come back and take a look at using it, I'm just finishing up some testing and validation steps while I write-up the paper. I'd be happy to chat about it over video too, since I'm still working on documentation.