[R] a question about levelplot

[Jason Turner]

See the FAQ

http://cran.r-project.org/doc/FAQ/R-FAQ.html#Why%20do%20lattice%2ftrellis%20graphics%20not%20work%3f

????? wrote:

> Hello everyone
> 
> I met a strange problem when I call "levelplot" in another function
> 
> 
>>library(lattice)
>>mat = matrix(1:9, nrow=3)
>>mylevelplot = function() {
> 
> +    png('test.png')
> +    levelplot(mat)
> +    dev.off()
> +}
> 
>>mylevelplot()
> 
> null device
>                1