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collaborate with xugrid project? #4
Description
Thanks to @clyne for the great talk at the Pangeo Showcase yesterday.
Following up on that, I thought I'd help make contact between this project and the xugrid project:
The project was started by @Huite and includes a few other contributors such as @visr, who originally brought it to my attention.
The scope of xugrid is as follows:
Xarray extension to work with 2D unstructured grids, for data and topology stored according to UGRID conventions.
Compare this to uxarray
Uxarray will provide Xarray styled funtions to better read in and use unstructured grid datasets that follow UGRID conventions.
These scopes are nearly identical.
Hoping to start a conversation about how these teams could potentially work together.
Activity
rajeeja commentedon Nov 11, 2021
Huite commentedon Nov 11, 2021
Hi,
@rabernat Thanks for opening this.
I'd have liked to watch the Pangeo showcase live, but it was slightly late (22:00 local time for me) and (despite vaccinations) I've got a mild case of COVID-19 to contend with. I'm sure I'll be able to check it out sooner rather than later.
@rajeeja Yeah, I haven't gotten to wrapping things up neatly yet, as the README says, it's still very much a work in progress. Haven't managed to get it to
pipyet either, and I have a lot of tests to write still -- I've been mostly figuring out API stuff. I think you'd be best served best by going through some of the built docs to get a high level impression: https://deltares.github.io/xugrid/Background
To give a bit of background, I'm a geohydrologist at the Groundwater Department of Deltares The impulse for this work on unstructured grids has been the release of MODFLOW6 by the USGS: https://www.usgs.gov/software/modflow-6-usgs-modular-hydrologic-model
The MODFLOW versions we worked with before were all structured, and so both input and output data fit right with the (default) netCDF4 and Xarray data structures. I would obviously like to make working with unstructured data as easily as it is with xarray for structured data. I also would like to serve a broader goal, as there are many more potential users in Deltares, since Deltares uses unstructured hydrological models as well (network1d, mesh2d, layered 3d).
Relevant material
For the record, this where most of my previous discussion can be found:
pydata/xarray#4222
https://github.com/NOAA-ORR-ERD/gridded/issues
In general, I ended up going with the approach sketched here for now:
xgcm/xgcm#225
This does means there's a fair amount of forwarding to do. As far as I can tell, the indexes in xarray are not yet flexible enough to do the stuff I'd like to with "default" xarray accessors. I like the accessor approach -- so far -- because I can tell my colleagues to simply write
.ugridwhenever they want to do something with the unstructured topology.Also a number of notes here:
https://github.com/xarray-contrib/xoak/issues
Cooperation
In general: I'd be very happy with an open source community project. I have no demands with regards to name or branding.
Here's a number of questions that come up for me:
I'm still very much figuring things out -- hence the lack of tests.
numba-celltreeshould have decent coverage though and it's on pip. I do feel like doing some benchmarking on the spatial indexes would be rather useful.I do however have a number of obligations to fulfill within my organization, I need to deliver some features on a fairly short time scale. It seems likely to me your roadmap is somewhat different (and can afford to be more ambitious). I don't think should be an issue: I would be happy to contribute, but it also seems likely that at least on the short term I'd need to keep my own thing in the air (read:
xugrid). As time progresses and this package (uxarray) matures, I could start depending on it more and more, slowly disassemblingxugriduntil it's finally just a shell arounduxarray.