Add QSFit.jl and GModelFit.jl packages

[gcalderone]

No description provided.

[icweaver]

Hi Giorgio, thanks for the PR!

Could you describe a little bit about how these packages compare to similar ones like MINPACK.jl and LsqFit.jl?

The reason that I ask is because AFAICT it seems like there is a shift towards moving these kinds of things under the SciML umbrella (larger bus factor, more infra support, etc.)

I have little experience in this domain though, so apologies if I am misunderstanding. Happy to hear from other folks too about the best ways to curate our ecosystem pages

[gcalderone]

Hi @icweaver ,
sure... sorry I did not know how much details should I add, and where is best to put such descriptions.

Also, I agree that SciML umbrella is probably a better choice, but I am currently unable to perform extensive tests to check for superpositions between CMPFit and GModelFit on one side, and the SciML ones on the other hand, or to compare functionalities and performance.
I know I should devote some effort to this but it really is beyond my scope for the moment...

Finally, although I no longer consider myself a newbie in Julia, I definitely am a newbie when it comes to Julia organizations such as Astro or SciML. Hence any guidance or suggestion is really really highly appreciated!!!

Pragmatically:

• Please guide me on where it is best to add package descriptions;
• I can drop my PR to include CMPFit in JuliaAstro, but if you agree I would like to keep GModelFit. The reason is that the latter represents the "fitting engine" for another package of mine, QSFit, which is explicitly devoted to spectral fitting of AGN/QSO spectra at optical/IR wavelengths.

[icweaver]

Hi Giorgio, thanks for the additional context, it's really helpful!

Ok, how's this sound?

1. Have this PR just include entries for GModelFit and QSFit (really cool package btw, I'm still reading more)
2. Update README and description field of GModelFit to show connection to QSFit, similarly to how QSFit already links to GModelFit
3. Optional: If applicable, update README and description of QSFit to show connection to our other spectral fitting package: fjebaker/SpectralFitting.jl. Perhaps Fergus has some thoughts on this if y'all haven't coordinated already @fjebaker?

Abhro and I have just updated the contributor docs (you now edit the ecosystem page markdown and comparison page markdown directly), so please try giving it a go when you can. Sorry for the change out from under you

Also happy to give any assistance to help get this PR across the finish line. Any feedback is appreciated as we work towards a smoother system for adding docs!

[icweaver]

Here's a quick example showing how GModelFit might be added

Howdy again @gcalderone. With #84 now in, adding your edits should be even easier (the markdown files will now automatically build from the original JuliaAstroDocs.jl source file). I've updated your PR to include an example with GModelFit for your review

[gcalderone]

Hi Ian,
I'm deeply sorry for the delay in replying...
I have been in contact with @fjebaker and a number of interesting ideas arose which I was eager to implement in GModelFit before making the packages publicly visible in JuliaAstro. Now all the code is written, I only need to update the documentation.
I'll do it within this week, and be back to finalize this PR.
Sorry again, and thanks for your support!

[icweaver]

Hi Giorgio, totally no rush on my end. That's great to hear about the GModelFit developments! Happy to help get things in whenever you are ready