[R] SWeave - can I see output in the source?

[Duncan Murdoch]

I'm working on a Latex document with lots of R code in it, so naturally 
enough it would be a good idea to use SWeave.  But then I don't get to 
see the output as I'm editing.

Or do I?  Is there a tool to process a .Rnw file and incorporate the 
output from the commands into it (in a form that is not used for 
producing the output .tex file, but which is updated each time I process 
the file)?

Duncan Murdoch