I forgot to say I have commented out your function's first line, sistring <- paste(x) It wouldn't cause any problem, it's just not needed. Rui Barradas -- View this message in context: http://r.789695.n4.nabble.com/automatic-SI-prefixes-as-ticklabels-on-axis-tp4266141p4267965.html Sent from the R help mailing list archive at Nabble.com.