xarray lecture

[gregordecristoforo]

This is my suggestion for the outline of the Xarray lecture. The biggest questions for me are the following:

1. Shall we include exercises in this lectures or shall we use all allocated 30 minutes for the lecture. In the latter case we can still include the exercises so that people can do them in their own time.
2. Is this outline to dense? If yes, which topic has the lowest priority?
3. Which example dataset shall we use? We can use the one showed below. Personally, I would prefer one that doesn't use a a custom datatype for the time coordinates.

from pythia_datasets import DATASETS

filepath = DATASETS.fetch('CESM2_sst_data.nc')
ds = xr.open_dataset(filepath)

Feedback of any kind is very welcome!

[wmvanvliet]

How about using NARR_19930313_0000 instead? Is has temperature at different heights of the atmosphere (measured as isobaric pressure). It doesn't have a time component.

[wmvanvliet]

I've made an image that I hope will be enlightening of how xarray annotates a numpy array in dimensions, coordinates and units.

[gregordecristoforo]

Great, thank you for creating the figure! Let's use the NARR_19930313_0000.nc dataset then. Just one question, shouldn't the isobaric pressure decrease with height?
And out of interest, do the coordinates shown in the figure actually refer to the right lon and lat in Colorado as the image suggests? That would be really cool, but no problem if they don't. For illustrative purposes that is more than enough.

[gregordecristoforo]

In the upcoming days and weeks I will start working on the lecture material. Is there a part that you want to lead during the lecture, @wmvanvliet? Shall I work the whole markdown document or is there a part you want to take over?

[wmvanvliet]

shouldn't the isobaric pressure decrease with height?

Oh yeah :)

[wmvanvliet]

do the coordinates shown in the figure actually refer to the right lon and lat in Colorado as the image suggests? That would be really cool, but no problem if they don't.

I think somewhere in that region, but the image is not precise. I could make it precise if I have a little time.

[wmvanvliet]

In the upcoming days and weeks I will start working on the lecture material. Is there a part that you want to lead during the lecture, @wmvanvliet? Shall I work the whole markdown document or is there a part you want to take over?

With only 30mins, I'm fine with you taking the lead during the entire lecture. Of course I want to help with putting the lecture materials together.

[gregordecristoforo]

I think somewhere in that region, but the image is not precise. I could make it precise if I have a little time.

Don't worry about it, the picture (with the corrected hPA values) is very useful for the lecture material :) Thanks again for creating it.

With only 30mins, I'm fine with you taking the lead during the entire lecture. Of course I want to help with putting the lecture materials together.

Sounds good, I will start with creating the lecture material then. I will let you know when I have a section ready for review. Your feedback would be very much appreciated!

[wmvanvliet]

I've updated the image. The actual coordinates of the cube are drawn on this map: https://framacarte.org/en/map/anonymous-edit/196572:0w7b-sUXFbHgfyUZYs7kGu1VLe7nLL2NzzthvtWdGhQ which is used as the floor of the image now.

[gregordecristoforo]

Thanks a lot, that looks perfect!

[gregordecristoforo]

It seems like I am unable to download the image of the dataset. Can you forward me the image @wmvanvliet? I will use a screenshot with lower resolution in the meantime. My email is [email protected]

[gregordecristoforo]

This is the first version of the Xarray lecture. It is still a bit rough around the edges and I will add the two exercises tomorrow. @wmvanvliet If you have any comments or ideas for improvement, please let me know.

[rkdarst]

I invited Gregor to the repo for independent merging and pushing as needed. For whatever makes sense, go ahead and do it!

[gregordecristoforo]

The exercises are now included. Please let me know, what you think about them.

[gregordecristoforo]

The sphinx build also breaks for the last commit (commit 188a462) before anything is added in this PR

[rkdarst]

I'm working on the problem. I found it this morning (but not the solution), and haven't had time to do a proper fix. I plan to do any fix to get it working asap.

[gregordecristoforo]

Thx no stress! One can build the xarray lecture with sphinx-autobuild content _build if anyone wants to have a look at the lecture.

[rkdarst]

Now it builds. The files list has some warnings saying that some of the image files are missing. And a lot of other warnings from other files but I'd ignore them and merge, we can figure them out later.

[wmvanvliet]

Really nice work @gregordecristoforo!

[wmvanvliet]

Suggested change

	{
	data_vars = {

Let's make it super clear that these are the Data Variables.

[gregordecristoforo]

Thanks for the feedback! I included most of your suggestions. I'll get to the remaining ones probably tomorrow.

[bast]

I moved the two remaining suggestions to a new follow-up issue: #295

I did this because I want to merge this now so that it can get some exposure/visibility for other instructors/helpers/organizers.

Thank you for the great lesson addition!