title: GraphViz: Windows PATH not set with new installer, issue when calling from R
body: <p>In an R library, I am using the <code>dot</code> program (from GraphViz) to produce some graphics (usually in png format). <code>dot</code> is a usual executable and I execute it through the <code>system</code> R command. Until now, everything was running fine because the GraphViz installer was adding <code>dot</code> to the PATH environment variable. I was just asking users to install GraphViz.</p>
  
  <p>Since version 2.31 (see <a href="http://www.graphviz.org/Download_windows.php">http://www.graphviz.org/Download_windows.php</a>), GraphViz no longer updates the PATH environment variable and, hence, calling <code>dot</code> fails (this is not a surprise). Because the users of the library are usually not computer experts, I cannot ask them to update the PATH in order to include GraphViz. </p>
  
  <p>The library is distributed on the CRAN. For this reason, I cannot distribute executable (or any compiled code). I mainly need a solution for Windows, since this not seems to affect Linux or Mac.</p>
  
  <p>Any idea, on how I can proceed in order to produce the image file? Or find <code>dot</code>?</p>