Thanks a lot Deepayan, one question:

Is it possible to place these barplots side-by-side instaed of super
imposing? Something like this:
http://www.imachordata.com/wp-content/uploads/2009/09/boxplot.png

library(lattice)
bwplot(yield ~ variety, data = barley, col = 1, pch = 16,
      panel = panel.superpose, panel.groups = panel.bwplot,
      auto.key=list(space="right"),
      groups = year, scales=(x=list(rot=45)))

Thanks,
Peng

On Fri, Feb 26, 2010 at 3:51 AM, Deepayan Sarkar
<deepayan.sarkar@gmail.com>wrote:

> On Fri, Feb 26, 2010 at 8:30 AM, Peng Cai <pengcaimaillist@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"))
>

	[[alternative HTML version deleted]]

