As some of my friends & colleagues know, I’ve moved nearly all of my experiment analysis and graphing to “R” http://www.r-project.org/. Being no statistician, nor mathematician, this was (still is) uphill work, though with great rewards on the way. These “R2torials” are great – funny, insightful, rapid, and more than the occasional pearl to advance my undeRstanding:
http://www.twotorials.com/