hadley/ggplot2 — comment on commit a958384341f7bffdb1e2817f9ea6f4b9f3057e88
File:  line 0
By hadley:

This should detect when the range is (floating point) 0. The constants may need some tweaking, but I don't know exactly what they should be. I tried asking on R-help, but didn't get much help.