Y-axis labels for Bluff Javascript library

So, I'm using the fabulous Bluff library to put up some gr开发者_运维百科aphs from a Rails app. I wanted to customize the Y-axis labels to display fewer decimal digits of precision. Anybody got a clue how to do that? I could try to analyze the "compressed" version of the library and hack it in there, but I'd rather use the API if I can!

TIA,

rw