[R] Sweave: infelicities with lattice graphics

[Deepayan Sarkar]

On Sun, Sep 12, 2010 at 8:47 AM, Duncan Murdoch
<murdoch.duncan at gmail.com> wrote:
> On 12/09/2010 11:41 AM, Michael Friendly wrote:
>>
>> Just a follow-up on this thread, now with R 2.11.1.  I was happy back then
>> to use Deepayan's solution for this, under earlier R versions; but it now
>> gives an error and the Sweave-generated .tex file no longer compiles.
>>
>> <<ortho-xyplot1-code, keep.source=TRUE, eval=FALSE>>=
>> library(nlme)
>> library(lattice)
>> xyplot(distance ~ age|Sex, data=Orthodont, type='b', groups=Subject,
>> pch=15:25,
>>     col=palette(), cex=1.3, main="Orthodont data")
>> @
>> <<ortho-xyplot1,fig=TRUE, include=FALSE, echo=FALSE, width=6, height=6>>=
>> plot(trellis.last.object())
>> @
>>
>> Now, I get the following from Sweave:
>>
>> Error:  chunk 46 (label=ortho-xyplot1)
>> Error in !lattice.getStatus("current.plot.saved", prefix = prefix) :
>>   invalid argument type
>>
>> Did something in lattice change so that plot(trellis.last.object()) no
>> longer works or needs to be specified differently?
>
> I don't know if something in lattice has changed, but that doesn't look as
> though it should work:  the code to do the plot was never evaluated.  I
> think you would need eval=TRUE in the first chunk, or
> <<ortho-xyplot1-code>>
> ahead of the plot command in the second.

Yes. I notice that it was me who introduced the eval=FALSE (I'm not
sure why). Hopefully that should fix it.

However, there _has_ been a recent lattice update, where the internals
have undergone some change, so there is a chance that is to blame. I
won't be able to take a look before day after tomorrow.

-Deepayan