R help - Jun 2012 - add horizontal reference lines in lattice bwplot

I'm plotting a lattice bwplot from a data.frame and would like to add some
horizontal lines indicating some reference values (preferably with text
annotation) as well as a grid of regular log tics.  The following illustrates
the plot:
data(ToothGrowth)
require("lattice")
p = bwplot(exp(len) ~ supp, ToothGrowth,
    panel = function(..., box.ratio) {
        panel.grid(h=-1, col.line="grey")
        panel.violin(..., col = "lightblue", adjust = 1.0,
                     varwidth = FALSE, box.ratio = box.ratio, log = 'y')
        panel.bwplot(..., fill = NULL, box.ratio = .1, log = 'y')
    }, scales=list(y=list(log=TRUE)))

(The actual data I am working with represents bandwidth achieved in a set of
tests at times and a log scale seems appropriate. Also there are many tests).

I've tried the following to add horizontal lines with no success. I get no
abline at all and just two evenly spaced grid lines.
        panel.abline(h=10^13, col.line="red")
        panel.grid(h=2, v=0, y=c(10^11, 10^12), col.line="blue")

Also I have no idea where to start annotating the lines (well panel.text seems
the place to start).

FWIW I tried ggplot2 also, but the violins it produces for my data get lost in
the scale I need as the distributions for some tests are much narrower than for
others (and far from normal).

Gareth Williams
CSIRO

Hello Gareth,

Concerning the lines, you can try :
panel.abline(h=13)
and
panel.grid(h=2, v=0, y=c(11, 12), col.line="blue")

I have no idea for the annotation. Sorry.

Ptit Bleu.


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> -----Original Message-----
> From: PtitBleu [mailto:ptit_bleu at yahoo.fr]
> Sent: Wednesday, 13 June 2012 5:46 PM
> To: r-help at r-project.org
> Subject: Re: [R] add horizontal reference lines in lattice bwplot
> 
> Hello Gareth,
> 
> Concerning the lines, you can try :
> panel.abline(h=13)
> and
> panel.grid(h=2, v=0, y=c(11, 12), col.line="blue")
> 
> I have no idea for the annotation. Sorry.
> 
> Ptit Bleu.
Thanks! I did not understand that I needed to use the log10 of the value for the
grid position to match the log scale.
The panel.abline now works. I could not get the panel.grid to work but just
using abline is fine.

I also figured out how to use panel.text with my new knowledge of the grid
coordinate system.

Gareth
> 
> 
> --
> View this message in context: http://r.789695.n4.nabble.com/add-
> horizontal-reference-lines-in-lattice-bwplot-tp4633214p4633219.html
> Sent from the R help mailing list archive at Nabble.com.
>