(note: I spend a lot of time working on arviz, and just had a lot of coffee)
I would be super excited to port a lot of the arviz plotting to altair, but right now:
- there is not great xarray support for altair (but they aren’t against such support)
- right now altair embeds your data as json in the DOM in notebooks. arviz crashes your computer if you accidentally plot more than like, 100 dimensions of data (which is fairly typical) because of too many axes. arviz on altair with more than, like 100,000 samples (which is super typical) will crash your browser and then maybe your computer.
xarray support would mean the data could live safely on disk, instead of crashing everything you hold dear.
There is also interest in working with bokeh or something like datashader (which seem like good ideas, I just really like writing altair code!) Dash also seems like an exciting project - plotting samples is a pretty funny use case for most libraries, in that you want to plot a lot of modestly shaded or smoothed data, and often want to drill into particular categories or dimensions.
In terms of immediate performance for matplotlib, we could implement Artists ourselves, and do as much calculation on the machine as we can before rendering. This might be a good solution if there is call for really big pair plots or something. I get pretty frustrated at the lack of interaction, and I guess that’s a tradeoff we have to make for now.