plotly.js aggregations by N columns

[jackparmer]

Here for example I've already grouped air pollution measurements by state name, now I would like to get an average over all counties by year:

cc @alexcjohnson

[alexcjohnson]

This should work the same way as SQL GROUP BY COL1, COL2, COL3, ... - gives one output row per unique combination of values in all N columns.

To be clear, this is an extension of a single aggregate transform, and is not possible through chaining N aggregate transforms - in fact it's kind of the opposite effect, as adding more columns to one aggregate transform generates more output rows, whereas chaining can only give fewer output rows.

[gvwilson]

Hi - this issue has been sitting for a while, so as part of our effort to tidy up our public repositories I'm going to close it. If it's still a concern, we'd be grateful if you could open a new issue (with a short reproducible example if appropriate) so that we can add it to our stack. Cheers - @gvwilson