How do I groupBy() over the filtered set of rows

Features
1

Hi.
In my js-viewer, I’m migrating from manual processing of each cell to the groupBy() feature. But the lack of ability to aggregate over the filtered sub-set of the data limits me. Is that possible to implement it on your side?

2

Indeed this feature was missing, we’ve just added it. Use whereRowMask method to provide the bitset, just like that:

// Aggregations
let demog = grok.data.demo.demog();
demog.selection.init((i) => i % 2);

let avgAgesByRace = demog
    .groupBy(['race', 'sex'])
    .whereRowMask(demog.selection)
    .avg('age')
    .aggregate();

grok.shell.addTableView(avgAgesByRace);
1 Like
3

Absolutely love it! Thanks for the quick feedback!

Can you also help me with How do I get hover filter please?

I just need both of the pieces to get my job done.

4

Yes I remember about the hover filter, I took a stab at it but it turned out to be not trivial. We don’t keep it as a bitset internally (but rather as a predicate function based on the row index), there were performance reasons for that but perhaps it’s time to make it consistent with the selection and filter.

1 Like
5

That’s good to know. I didn’t know you’ve looked into it.