Using cat() with R prints R session prompt (>) in results block

[John Hendy <jw.hendy@gmail.com>]

With an older orgmode file, I used a block like shown in this thread
to export multiple plots resulting from some modeling work in my
summary document:
- http://lists.gnu.org/archive/html/emacs-orgmode/2012-08/msg01222.html

The code I used was like so:

#+begin_src R :session model :results output raw :exports results

cat("#+begin_center")
cat("\n")

for() {

output-filename <- something[i]

ggplot code

pdf(output-filename)
print(p)
dev.off()

cat(paste("[[../plots/",output-filename,"]]",sep=""), sep="\n")
cat("\n")

} # end plotting loop

cat("#+end_center")

#+end_src

When I do that now, I'm getting the > prompt from my R session output
with the cat() command. For example:

#+name: test
#+begin_src R :session r :results output raw :exports results

cat(paste("#+end_center"))
cat("\n")

#+end_src

#+RESULTS: test
#+end_center>

How do I stop that?

As a side note... if I remove cat("\n"), nothing gets put into the
#+results block -- it's just empty. I don't understand why.


Thanks,
John