Is there a way to implement a weighted average using the groupby function?

[franlane94]

Hi all,

I was wondering whether there is a neat way to implement a weighted mean when using the groupby function. I would achieve this in Pandas by applying a function when grouping. However, I can't see a way to do this using datatable.

Thanks!

[st-pasha]

Formula dt.sum(f.X * f.weight) / dt.sum(f.weight) will compute weighted average of a column X, and you can use it either with or without a groupby.