[R] lattice panel question

[Deepayan Sarkar]

On 10/13/08, Ferry <fmi.mlist at gmail.com> wrote:
> Dear R users,
>
>  How to change lattice panel label/text from the automatically generated
>  label (based on the conditioning) to our own set of label?
>
>  for example:
>
>  someStuff <- data.frame(area = rep(c("SOUTH", "NORTH", "EAST", "WEST"), each
>  = 25),
>                 group = rep(c("A","B","C","D"), each = 5),
>                 mytime = rep(1:4),
>                 val1 = sample(1:100, size=100, replace=TRUE),
>                 val2 = sample(1:100, size=100, replace=TRUE)
>         )
>
>  xyplot(val1+val2 ~ mytime | area * group, data = someStuff, type = c("a",
>  "p", "g"))
>
>  I want to change each panel label/text from for example D/East or D/North
>  ... into Deriv/From East, Deriv/From North ...
>
>  I know I could change from the data, but is there a way to change it from
>  lattice ?

Using a strip function is the most general way, but can get a bit
complicated with two variables. Changing the labels is really the
easiest way; e.g.,

xyplot(val1+val2 ~ mytime | factor(area, labels = c("From East", ...))
* factor(group, ...))

You could also change the 'dimnames' of the resulting object before plotting:

> p <- xyplot(val1+val2 ~ mytime | area * group, data = someStuff)
> dimnames(p)
$area
[1] "EAST"  "NORTH" "SOUTH" "WEST"

$group
[1] "A" "B" "C" "D"

> dimnames(p)$area <- ...
> plot(p)

-Deepayan