R help - Oct 2006 - density plot text

Is there any way of adding text to a density plot? I have had a go using the
text() function but I think the error is because this function doesn't work
with densityplot().

Alternatively, I understand I can achieve pretty much the same result if I
plot a density kernel estimate using plot() (which allows text()), but I do
prefer densityplot().


Also, is it possible to specify the dimensions of a graphics device? I don't
mean the x and y limits of a plot, but rather can I change the dimensions of
the default (square) graphics device?

Many thanks
Murray


try <- (rnorm(100, mean = 5, sd = 3))
library(lattice)
trellis.device(col = FALSE, theme = lattice.getOption("col.whitebg"))
densityplot(~try)
normtest <- shapiro.test(try)
normtest
pvalue <- round(normtest$p.value,5)
normtext <- paste(normtest$method,"p-value =",pvalue)
normtext
xcoord <- max(try)*0.6
text(xcoord,0.1,normtext)


# alternative

plot(density(try))
text(0,0.1,normtext)

-- 
Murray Pung
Statistician, Datapharm Australia Pty Ltd
0404 273 283

	[[alternative HTML version deleted]]

On 10/25/06, Murray Pung <mcpung at gmail.com>
wrote:
> Is there any way of adding text to a density plot? I have had a go using
the
> text() function but I think the error is because this function doesn't
work
> with densityplot().
>
> Alternatively, I understand I can achieve pretty much the same result if I
> plot a density kernel estimate using plot() (which allows text()), but I do
> prefer densityplot().
>
>
> Also, is it possible to specify the dimensions of a graphics device? I
don't
> mean the x and y limits of a plot, but rather can I change the dimensions
of
> the default (square) graphics device?
>
> Many thanks
> Murray
>
>
> try <- (rnorm(100, mean = 5, sd = 3))
> library(lattice)
> trellis.device(col = FALSE, theme =
lattice.getOption("col.whitebg"))
> densityplot(~try)
> normtest <- shapiro.test(try)
> normtest
> pvalue <- round(normtest$p.value,5)
> normtext <- paste(normtest$method,"p-value =",pvalue)
> normtext
> xcoord <- max(try)*0.6
> text(xcoord,0.1,normtext)
You have two options: either

trellis.focus("panel", 1, 1)
panel.text(xcoord,0.1,normtext)
trellis.unfocus()

which is analogous to the plot(density()) paradigm, or, what in this
situation is more appropriate IMO (as it will work for multipanel
plots as well):

densityplot(~try,
            panel = function(x, ...) {
                panel.densityplot(x, ...)
                normtest <- shapiro.test(x)
                pvalue <- round(normtest$p.value,5)
                normtext <- paste(normtest$method,"p-value =",
pvalue)
                xcoord <- max(try) * 0.6
                panel.text(xcoord, 0.1, normtext)
            })

There are ways to make a safer choice of the y coordinate than 0.1; see

?current.panel.limits

and

library(grid)
?grid.text

-Deepayan