Aloha all,

The attached patch adds tikzDevice support to ob-R.  It requires that
the tikzDevice package be available to R, so it must be installed and
loaded.  Something like the following code in .Rprofile will load the
package by default:

old <- getOption("defaultPackages")
options(defaultPackages = c(old, "tikzDevice"))

Then, specify a .tex file in the :file header argument of the R source
code block, e.g., :file intervals.tex, and the graphic will be produced
by tikzDevice.

The advantage of this for LaTeX export is that the resulting file will
be set with the fonts of its surrounding document.

Something like this works for me, where the \sffamily command uses the
document's sans serif font and the file is called intervals.tex:

\begin{figure}[htb!]
  \centering
  \sffamily
  \input{../figure/intervals}
  \caption[Elapsed time between Polynesian colonization of Hawai`i and fire-pit use]{Elapsed time between Polynesian colonization of Hawai`i and fire-pit use.}
  \label{fig:elapsed-time}
\end{figure}
 
All the best,
Tom