xtable in pgfSweave (on lyx) : output=tex is invalid?

Question

Many tutorials online say that to include a table in Sweave one should write something like this:

<<output=tex>>=
require(xtable)
stuff
xtable(stuff)
@

That makes sense. But when I do that in LyX 2.1 on Ubuntu 10.04 with texlive-full 2011 installed (and pgfSweave 2.10), I get the following error:

invalid value for 'output' : tex

Answer 1

Should work with results instead of result or output.

<<results=tex>>=

The Sweave documentation may also be helpful.