And if you make 'year' a factor with levels '2007' and '2008' you'll get your second wish.
Peter Sundar Dorai-Raj wrote:
I think this ought to work for you: library(lattice) set.seed(42) d <- data.frame(year = c(rep(2007,12), rep(2008,12)), treatment = rep(LETTERS[1:3], each = 4, times = 2)) d$cover <- rnorm(nrow(d)) d$variable <- rnorm(nrow(d)) xyplot(variable ~ cover | year, d, panel = function(x, y, ...) { panel.superpose(x, y, ...) panel.lmline(x, y, ...) }, groups = treatment) HTH, --sundar On Fri, Sep 18, 2009 at 3:42 PM, Seth W Bigelow <sbige...@fs.fed.us> wrote: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.______________________________________________ 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.
______________________________________________ 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.
