title: Convert R data.frame to Javascript array
body: <p>I want to save some columns of my data frame into a specific format (JavaScript format). I've tried to use <code>toJSON()</code> from <code>rjson</code> package but that doesn't work.</p>
  <p>My result should looks like : <a href="http://leaflet.github.io/Leaflet.markercluster/example/realworld.388.js" rel="nofollow noreferrer">http://leaflet.github.io/Leaflet.markercluster/example/realworld.388.js</a></p>