[R] bwplot [lattice]: how to get different y-axis scales for each row?

[Marius Hofert]

Dear expeRts,

How can I get ...
(1) different y-axis scales for each row 
(2) while having the same y-axis scales for different columns?

I coulnd't manage to do this with relation="free" [which gives (1) but not (2)].
I also tried relation="sliced", but it did not give the same y-axis scales 
within each row (see the fourth row). Further, it "separates" the panels.

Cheers,

Marius

## minimal example:

library(lattice)

## build example data set
dim <- c(100, 6, 2, 3) # n, groups, methods, attributes
dimnames <- list(n=paste("n=", seq_len(100), sep=""),
	         groups=paste("group=", seq_len(6), sep=""),
	         methods=paste("method=", seq_len(2), sep=""),
	         attr=paste("attribute=", seq_len(3), sep=""))
set.seed(1)	
data <- rexp(prod(dim))
arr <- array(data=data, dim=dim, dimnames=dimnames)
arr[,2,,] <- arr[,2,,]*10
arr[,4,2,2] <- arr[,4,2,2]*10
z <- abs(sweep(arr, 3, 1))
df <- as.data.frame.table(z, responseName="error")

## box plot
bwplot(error ~ methods | attr * groups, data=df, 
       as.table=TRUE, notch=TRUE,
       scales=list(alternating=c(1,1), tck=c(1,0)))

## with relation="sliced"
bwplot(error ~ methods | attr * groups, data=df, 
       as.table=TRUE, notch=TRUE,
       scales=list(alternating=c(1,1), tck=c(1,0), relation="sliced"))