foo <- as.numeric(as.character(your_factors) ). It's a common mistake to forget the first conversion, in which case you end up with an integer sequence rather than the desired values. -- View this message in context: http://r.789695.n4.nabble.com/Convert-a-factor-to-a-numeric-tp4677964p4677971.html Sent from the R help mailing list archive at Nabble.com.