I wish to identify groups representing different treatments, but to plot them and do a regression using a continuous variable ("cover") ignoring the groupings.
d$year <- NA d$year <-c(rep(2007,12), rep(2008,12)) d$treatment <- c(rep("A",4),rep("B",4),rep("C",4), rep("A",4), rep("B",4), rep("C",4)) d$cover <- rnorm(24) d$variable <- rnorm(24) xyplot(variable ~ cover | year, d, type=c("p","r"), groups=treatment ) As it stands, a different regression line is plotted for each treatment. Oh, and how do I display the actual numeric value of year (e.g., "2007") in the strip, rather than the word "year"? --Seth Dr. Seth W. Bigelow Biologist, USDA-FS Pacific Southwest Research Station 1731 Research Park Drive, Davis California [[alternative HTML version deleted]] ______________________________________________ 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.