Re: [R] geom_hline

From: Jim Lemon <>
Date: Tue, 25 Dec 2007 20:16:06 +1100

Felipe Carrillo wrote:
> Hi all:
> I am trying to draw a horizontal line along the zero
> "Y axis" value but since zero isn't showing therefore
> the line is not drawn. If I set my intercept to 15
> then it'll work but I dont want to hardcode it because
> the Y axis parameters could be different for another
> variable. I would like to alway set my hline along the
> zero as default. Thanks
> p <- ggplot(mtcars, aes(x = wt, y=mpg)) + geom_point()
> p + geom_hline(intercept=0)
Hi Felipe,
It sounds like you want to include zero in the axis. In base graphics, you would use:


where maxy specifies the upper end of the ordinate. I had a quick look at the ggplot2 docs, but I haven't yet found whether this works in that system.

Jim mailing list PLEASE do read the posting guide and provide commented, minimal, self-contained, reproducible code. Received on Tue 25 Dec 2007 - 09:17:38 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Tue 25 Dec 2007 - 22:30:20 GMT.

Mailing list information is available at Please read the posting guide before posting to the list.