How do I create a stacked area plot with many areas, or where the legend "points" at the respective areas?

Example plot:

http://i56.tinypic.com/eagjfn.jpg

Created with:

qplot(score, ..count.., data=df, fill=method, geom='density', position='stack')

Pretty much imp开发者_高级运维ossible to tell what goes with what. Any way to make this better? Ideally the legend draws lines "connecting" the areas to the item in the legend. Alternatively, I'd at least need some very different filling patterns for the areas.

The human eye does not do well distinguishing between more than 7-10 different categories whether they are indicated using color, shading or pattern. Adding lines or shadings here will, I think, only make this graph harder to read.

In situations like this, I often think that it's best to take a step back and rethink what message you intend for the graph to convey. Do you really need to compare all ~23 methods in a single graph, or can the methods be placed into subgroups and compared in multiple plots or facets? Are some of the methods' curves so similar that they could be combined into a single category?

For instance, I see ~3-4 natural groups just based on the similarity of the curves in your plot. You could plot a single, representative, method from each group to illustrate the large scale differences, and then create additional plots that focus in on the differences between methods within groups.