Re: [R] adding horizontal lines to a trellis plot

reference: Deepayan Sarkar's new book on lattice graphics. -- Bert Gunter Genentech -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Blanchard, Suzette Sent: Thursday, June 12, 2008 10:52 AM To: r-help@r-project.org Subject: [R] adding horizontal lines

[R] adding horizontal lines to a trellis plot

I would like to add two horizontal lines representing acceptible drug levels to a trellis plot. I tried using abline and I get an error that "plot.new has not been called." See below. xyplot(FK~WEEK|Event1/MRN, data=FKdat.o1) abline(h=5) abline(h=10) Error in int_abline(a = a, b = b, h = h,