Weighted dotplots

[mjskay]

Occurs to me a simple version of this is dots/ellipses or squares that have different vertical sizes (easier layout problem than circles that have different radii, and more correct anyway). Something like a geom_weighted_dots(). Would need to do a bunch of stuff:

• finally implement use of arbitrary layout algorithms in the binwidth finding algorithm (e.g. a shortcut version of each layout alg that just returns max height)
• possibly allow limited support for shapes (at least ellipses, squares, maybe rounded rectangle or a pill shape, maybe even reimplement all pch shapes manually but allow stretching, or at least use the affine transforms to do it).
• implement a geom_weighted_dots() and stat_weighted_dots() (for rvars at least).
• possibly give a warning (maybe with option to turn it off --- or just tell people to unset the weights aesthetic) if weights are used with geom_dots(), suggesting folks used geom_weighted_dots()?
• also consider if this should be a more visual aesthetic (like "dotheight" or "dotextent" or ???) that weights from a dist could be mapped onto?