CODEWITHSUNDEEP
rlatexknitrsweave
Stéphane Laurent
Stéphane Laurent

Reputation: 84519

Unevaluated chunk in knitr generates a line break

The following Rnw file produces the output shown below. Is there a clean way to prevent the line break in section 2? Of course, this is just a minimal reproducible example; I don't want to remove the unevaluated chunk, which is programatically evaluated or not in my real issue.

\documentclass{article}

<<setup, include=FALSE>>=
knitr::opts_chunk$set(echo = FALSE)
@

\begin{document}

\section{eval TRUE}

<<results='asis'>>=
cat("Hello.")
@
<<eval=TRUE, results='asis'>>=
cat("How are you?")
@
What's your name?


\section{eval FALSE}

<<results='asis'>>=
cat("Hello.")
@
<<eval=FALSE, results='asis'>>=
cat("How are you?")
@
What's your name?

\end{document}

enter image description here

Edit

I have one solution so far:

<<results='asis'>>=
cat("Hello.")
if(FALSE) cat("How are you?")
@
What's your name?

But I'm wondering whether there's a simpler one, which does not require to group the chunks in a single one like this.

Upvotes: 2

Views: 179

Answers (1)

CL.
CL.

Reputation: 14957

Interestingly, regardless of all options, knitr apparently prints at least a newline for each chunk (even if eval = FALSE, echo = FALSE, results = "hide"). Therefore, the following is just a workaround, but probably a cleaner workaround than the one in the question:

Use if in the chunk (in lieu of the chunk option eval) but print % if the chunk is not supposed to be evaluated. This will make TEX ignore the line. 

\documentclass{article}

<<setup, include=FALSE>>=
  knitr::opts_chunk$set(echo = FALSE)
  showIt <- FALSE
@

\begin{document}

\section{eval FALSE}

<<results='asis'>>=
  cat("Hello.")
@
<<results='asis'>>=
  if(showIt) {
    cat("How are you?")
  } else {
    cat("%")
  }
@
What's your name?

\end{document}

Upvotes: 2

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