title: Converting from coordinate system WGS84 to SWEREF991330
body: <p>I've been looking for a way to convert GPS coordinates in my iOS app (written in Swift) to SWEREF99 (1330 in my case) but it seems impossible to find an "easy" way of doing this. What do I need to know before even trying to write a function on my own?</p>
  
  <p><strong>Example:</strong> </p>
  
  <p>Lat: 56.545414,
  Lon: 13.469853</p>
  
  <p>Should return:</p>
  
  <p>N 6269294,
  E 148146</p>
  
  <p>A Swift func would be really appreciated! Thanks for your help.</p>