Add Celestial Coords 1 tutorial notebook [new content]

[kakirastern]

Fixes #443.

Fixes #436 due to a new bug in GitHub.

Address #400, though not completely fixing it.

Add new FITS World Coordinate System (WCS) tutorial to guide users on how to building one's own astropy.wcs.WCS object, serving as an intro to WCS using astropy in two ways programmatically. In addition, a simple way to add a scale bar with the matplotlib package has been introduced.

[kakirastern]

@eblur @kelle @stargaser Due to some technical issues I needed to open a new PR for the 1st Celestial Coords tutorial. Will follow up here instead moving forward.

[kakirastern]

All code pushed to repo. PR is ready for a review.

[adrn]

One quick comment: I would suggest renaming this to "Celestial Coordinates with WCS 1: ...". Taking a look at the infrastructure aspects now!

[adrn]

Looks good to me from an infrastructure perspective!

But: for consistency with other notebooks, could you merge the first cell (the title) with the next cell (header info / authors). You can also remove the "**" (bold), because the header will be bold by default.

[kakirastern]

Thanks @adrn Will make the changes suggested by @eblur now

[kakirastern]

Looks good to me from an infrastructure perspective!

But: for consistency with other notebooks, could you merge the first cell (the title) with the next cell (header info / authors). You can also remove the "**" (bold), because the header will be bold by default.

Sure, just merged the first two markdown cells, and removed the bolding effect from the headings.

[stargaser]

I like this version. I've made some suggestions about the file download and access, and the packages in pip-requirements.txt.

[stargaser]

For the file download part, it would also work to do from astropy.utils.data import download_file and then do

fname = download_file('https://zenodo.org/record/3946743/files/tailored_dss.22.29.38.50-20.50.13_60arcmin.fits')
hdulist = fits.open(fname)

which is more lines of code than opening the URL directly, or using requests to write a local file. It would have the advantage of not downloading the file every time the user re-executes the notebook. My own feeling is that using download_file is a best practice for Astropy notebooks, but I would like to solicit more opinions on that.

[kakirastern]

But I do have reservations about using astropy.utils.data.download_file versus requests when it comes to Zenodo, as it makes the assumption of FITS files being hosted necessarily. Other than that I have no major objections.

[eteq]

Very minor note: I think the print functions shouldn't be in there in cases where it's at the end of the cell - instead I'd say just have the output of the cell be the string that's being printed.

[kakirastern]

Very minor note: I think the print functions shouldn't be in there in cases where it's at the end of the cell - instead I'd say just have the output of the cell be the string that's being printed.

Sure, will make the changes soon.

[kakirastern]

Am changing the temporary downloading path to https://github.com/astropy/astropy-data/raw/6d92878d18e970ce6497b70a9253f65c925978bf/tutorials/celestial-coords1/tailored_dss.22.29.38.50-20.50.13_60arcmin.fits before PR is ready to be merged by maintainers.

[kakirastern]

This is ready for another review before the corresponding astropy/astropy-data#95 PR is merged, since the final link from there will be required for maintainers to merge this PR.

[adrn]

I did my main review via pull request to @kakirastern's branch here, so I'm happy with the notebook now! One minor remaining thing: I think we can remove requests from the requirements files?

[kakirastern]

I did my main review via pull request to @kakirastern's branch here, so I'm happy with the notebook now! One minor remaining thing: I think we can remove requests from the requirements files?

Yup, done 👍

[adrn]

🎉 Thanks @kakirastern !

[kakirastern]

Awesome! Appreciate it @adrn 👍