hey, On Mon, Sep 14, 2009 at 07:51:42AM -0700, John Kane wrote: > p <- ggplot(bmm, aes(x="age", y="bm", colour="pp", group="pp")) > p <- p + geom_line() remove the quotes and it will work: ggplot(bmm, aes(x=age, y=bm, colour=pp, group=pp))+geom_line() regards, Stefan