On Fri, Feb 26, 2010 at 8:30 AM, Peng Cai <pengcaimaill...@gmail.com> wrote: > Hi All, > > I'm trying to plot boxplot graph. I tried barchart with "groups=" option and > it worked fine. But when I try to generate same kind of graph using > bwplot(), "groups=" option doesn't seem to work. Though this works, > > yield ~ variety | site * year > > I'm thinking why "groups=" doesn't work in this case, can anyone help > please...
Let's see...you have exactly one observation per site/variety/year combination (otherwise the barchart wouldn't have made sense). So in the boxplot you want (which is supposed to summarize a distribution, not a single point), you only have that single point to plot. For that, you can use dotplot(yield ~ variety | site, data = barley, auto.key = TRUE, groups = year, layout = c(6,1), scales=(x=list(rot=45))) If you try to come up with a more sensible example, you would realize that boxplots are already grouped (the grouping variable is the categorical variable in the formula y ~ x, not the 'groups' argument). Compare ## Is this really what you want? bwplot(yield ~ variety, data = barley, col = 1, pch = 16, panel = panel.superpose, panel.groups = panel.bwplot, groups = year, scales=(x=list(rot=45))) bwplot(yield ~ year | variety, data = barley, scales=(x=list(rot=45)), layout = c(10, 1)) -Deepayan > > #Code: > library(lattice) > barchart(yield ~ variety | site, data = barley, > groups = year, layout = c(1,6), > auto.key = list(points = FALSE, rectangles = TRUE, space = "right")) > > bwplot(yield ~ variety | site, data = barley, > groups = year, layout = c(6,1), scales=(x=list(rot=45)), > auto.key = list(points = FALSE, rectangles = TRUE, space = "right")) ______________________________________________ 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.