[R] lattice/levelplot: panels with values can be empty

[Deepayan Sarkar]

On Thursday 09 October 2003 05:40, Wolfram Fischer wrote:
> I tried:
> 	library(lattice)
>
> 	F0  <- c( 'A', 'A', 'B', 'B' )
> 	F1  <- c(  1 ,  1 ,  1 ,  2 )
> 	F2  <- c(  8 ,  9 ,  8 ,  9 )
> 	VAL <- c(  20,  50,  10,  60 )
> 	df <- data.frame( F0, F1, F2, VAL )
>
> 	levelplot( VAL ~ F1 * F2 | F0, data=df )
>
> I got an empty field for F0 == 'A'
> and a colored field for F0 == 'B'.
> I expected two colored fields. - What can I do?

Hmm, this seems to be a bug triggered when some panel has only one unique x 
(or y) value. Can't think of a workaround, other than adding some dummy rows 
with VAL = NA, e.g.

F0  <- c( 'A', 'A', 'B', 'B', 'A')
F1  <- c(  1 ,  1 ,  1 ,  2 ,  2 )
F2  <- c(  8 ,  9 ,  8 ,  9 ,  8 )
VAL <- c(  20,  50,  10,  60, NA )
df <- data.frame( F0, F1, F2, VAL )

Deepayan