Add two universal field in fields.py

[yingchaolu]

Added MM_nuclei_density and El_number_density.

PR Summary

PR Checklist

• [ ] Code passes flake8 checker
• [ ] New features are documented, with docstrings and narrative docs
• [ ] Adds a test for any bugs fixed. Adds tests for new features.

[yingchaolu]

I would also like to add universal fields for multiple temperature. But I did not find it in the naming convention. http://ytep.readthedocs.io/en/latest/YTEPs/YTEP-0003.html#molecular-and-atomic-species-names

[ngoldbaum]

Can you explain a little bit more what multiple temperature means?

[ngoldbaum]

I don't think we thought about species temperature fields at all in YTEP-0003, so in principle we'd need to add to that system if we want to come up with a systematic way of naming these fields.

I think the field naming scheme that goes best with the naming scheme in YTEP-0003 is to associate temperature fields with each species name, e.g. ion_temperature, El_temperature, C_temperature, radiation_temperature, etc. Are there temperatures for individual ionization states or just for the species as a whole?

[yingchaolu]

I think in flash code we only need ion_temperature, El_temperature and radiation_temperature.

[ngoldbaum]

Hi, can you update this to fix the syntax error?

[matthewturk]

@yingchaolu Anything I can do to help this get across the finish line?

[neutrinoceros]

I attempted to salvage this PR by merging from main here are my conclusions:

• the added aliases are no longer necessary
• the three temperature fields could still be added but maybe not universally (lots of fields are now conditionally defined in flash)
• we cannot push to the original branch because the fork has been deleted

Part of the patch may still be salvaged but I think the PR itself can't, so I'd recommend closing it. I can reopen as a different PR with @yingchaolu's commits.

[jzuhone]

I would simply open a new PR with the three temperature fields and that should be sufficient. But I am also not sure how relevant this is anymore. Either way I would say we can close it.

[neutrinoceros]

I am also not sure how relevant this is anymore

@jzuhone ah that's too bad, I was hoping you'd have an idea ! Well, in the future if anyone want to pick this up again, please feel welcome to. In the mean time I will just close it.

[jzuhone]

I mean, I am pretty sure these fields are still used, but no one seems to be in a big hurry to implement them.