Created attachment 202483 [details] Poster with a variable-slice-radius doughnut chart At the moment, a pie/doughnut chart section carries numeric information only through one aspect: Its angular extent (and, granted, some category information by its color). Sometimes, we want to express _two_ numeric aspects for each item/element. Only few chart types offer this (e.g. X-Y scatter). For pies and doughnuts to offer this capability, the natural aspect to utilize is the one that's uniform for all of them: The radius. Attached is an example graphic - revolving around a 2D-varying doughnut chart - to illustrate the dramatic effect this can have.
I like this. It could maybe be done with no interface changes. Currently only the first data series for a pie or doughnut chart is used. That could change to use the second series, if present, for the radius. For a ring (doughnut) chart, these values could be negative. The first series (category axis) data would still have to be non-negative, of course.