Error bars for groups

[Kabouik]

Apologies if I missed the function, but I was wondering if it would be possible to plot error bars with ggradar, either (1) using a tibble with the grouping factor and the variables as columns, and one row per observation in each group, or (2) using a tibble with the grouping factor, the variables (means) and the error (standard deviations) as columns, and a single row per group.

The first way seems more straightforward, with maybe an argument in ggradar() to state what kind of error to calculate (using a fun=), but the second way seems closer to the current way ggradar works (one row per group).