title: Minimum bounding rectangle of a circle on a sphere
body: <p>What R packages are available to calculate the minimum bounding box for a great circle?</p>
  
  <p>For example:</p>
  
  <pre><code>box &lt;- polycirc( c( longitude, latitude ), distance=35 )
  </code></pre>
  
  <p>This would return the bounding box for the circle with a radius of 35 kilometres from the central point at the given coordinates (on Earth). Where:</p>
  
  <pre><code>box.longitude_min = The longitude of the circle's western-most point.
  box.longitude_max = The longitude of the circle's eastern-most point.
  box.latitude_min = The latitude of the circle's southern-most point.
  box.latitude_max = The latitude of the circle's northern-most point.
  </code></pre>
  
  <p>Something like this should already exist in R, but I cannot find it. The closest I've found (from SO), which I am currently transmogrifying to R, is:</p>
  
  <p><a href="http://janmatuschek.de/LatitudeLongitudeBoundingCoordinates" rel="nofollow noreferrer">http://janmatuschek.de/LatitudeLongitudeBoundingCoordinates</a></p>
  
  <p>Also, what is the word (if any) for <em>minimum bounding rectangle of a circle</em>? (The opposite of <a href="http://en.wikipedia.org/wiki/Circumscribed_circle" rel="nofollow noreferrer">circumscribed</a>.)</p>