On Fri, Feb 20, 2009 at 01:34:02AM -0800, Chris Bennett wrote: > I want to add a dashed vertical line to a number of xyplots. > > Here is a simple script of the type of plot I have but then I want to add a > reference line to 1995 on each of the panels. I have tried panel.abline and > other suggestions on the forum but can't get it to work. > > plot<-rep(letters[1:3],each=10) > year<-rep(1991:2000,times=3) > matter<-rep(seq(2,6.5,0.5),times=3) > xyplot(matter~year|plot,type="l")
The panel function is the way to go: xyplot( matter~year|plot, type="l", panel=function(...){ panel.xyplot(...) panel.abline(v=1995) } ) BTW: it is not a good idea to use the name of builting functions as a variable name (plot). cu Philipp -- Dr. Philipp Pagel Lehrstuhl für Genomorientierte Bioinformatik Technische Universität München Wissenschaftszentrum Weihenstephan 85350 Freising, Germany http://mips.gsf.de/staff/pagel ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.