I am working with knitr, polymode, ess and I would like to export just the R code from my .Rnw into a .R file. A basic file might look something like this:
\documentclass[a4paper]{article}
My Rnw file
<<>>=
##This is some R code
1+1
@
\end{document}
In the end, I would like an R file with just
##This is some R code
1+1