Display the knitr code chunk source in document

knitr, latex, r

Solution

This should do it...

1 line in the setup chunk, and 1 extra param in the chunk desired for output...

Console:

`install.packages(devtools)`  
`devtools::install_github("thell/knitliteral")`

For `.Rnw`:

<<"knitr-setup", include=FALSE, cache=FALSE>>=
knitLiteral::kast_on()
@

<<"my_chunk", eval=FALSE, opts.label="literal-literal">>=
# Something that will not be output in the doc.
@

Output:

<<"my_chunk", eval=FALSE>>=
@

For `.Rmd`:

`{r knitr_setup, include=FALSE, cache=FALSE} knitLiteral::kast_on()

`{r my_chunk, opts.label="literal-literal"} # Something that will not be output in the doc.

``

Output:

`{r my_chunk}

``

** The use of 4 backticks keeps syntax highlighting as valid `R` (where used).

From this chunk and what you can see in the source of the example Literal Markdown doc and the rendered doc that there is no need to have a complex chunk.

The sweave example file is also available showing the same examples.

Problem

I'm trying to output the source of a knitr chunk onto a beamer slide. For example, I would like the following code chunk to be displayed as is in the .Rnw: ``` <<code-chunk, echo=TRUE, tidy=TRUE>>= @ ``` I've attempted to recreate this behavior using: ``` <<out-first-code-chunk, echo=FALSE, comment=NA>>= cat(paste("<<example-code-chunk, echo=TRUE, tidy=TRUE>>=","@",sep="\n")) @ ``` This code is legitimate since the cat command in R's console gives: ``` > cat('<<example-code-chunk, echo=TRUE, tidy=TRUE>>=','@',sep='\n') <<code-chunk, echo=TRUE, tidy=TRUE>>= @ ``` However, the resulting latex: ``` \begin{frame} \frametitle{Code Chunk} To incorporate R code into your knitr documents \begin{knitrout} \definecolor{shadecolor}{rgb}{0.969, 0.969, 0.969}\color{fgcolor}\begin{kframe} \begin{verbatim} <<example-code-chunk, echo=TRUE, tidy=TRUE>>= @ \end{verbatim} \end{kframe} \end{knitrout} ``` Throws errors: ``` <<example-code-chunk, echo=TRUE, tidy=TRUE>>= @ \end {verbatim} \end \ETC. ! Paragraph ended before \@xverbatim was complete. <to be read again> \par l.198 \end{frame} I suspect you've forgotten a `}', causing me to apply this control sequence to too much text. How can we recover? My plan is to forget the whole thing and hope for the best. ! LaTeX Error: \begin{verbatim} on input line 198 ended by \end{beamer@framepau ses}. See the LaTeX manual or LaTeX Companion for explanation. Type H <return> for immediate help. ... l.198 \end{frame} Your command was ignored. Type I <command> <return> to replace it with another command, or <return> to continue without it. ! LaTeX Error: \begin{kframe} on input line 198 ended by \end{beamer@frameslide }. ``` Why is the latex environment thinking that verbatim was not closed? Is there a more appropriate way to display a code-chunk in its entirety?

Original source