as i understand it, the drilldown data format is something like this:
data: [['foo1', 2], ['foo2', 3], ['foo3', 2]]
i was actually successful in adding data to each array like so:
data: [['foo1', 2, 111], ['foo2', 3, 222], ['foo3', 2, 333]]
but, displaying it is giving me trouble. as i understand it, for the tooltip formatter, data is accessed using this.point.name, this.point.y, this.x, or this.percentage. how does one go about retrieving extra data in the point?
Switch to using a point object instead of an array for the data.
In the formatter your extra value will be under:
Fiddle example.