title: When using GPX in Xcode to simulate location changes, is there a way to control the speed?
body: <p>I'm using the following GPX file in Xcode 4.2 to simulate a location change. It works well, but I can't control the speed of the location change.  stamp seems to be not working. Does anyone have a solution for this?</p>
  
  <pre><code>&lt;?xml version="1.0"?&gt;
  &lt;gpx version="1.1" creator="Xcode"&gt; 
      &lt;wpt lat="37.331705" lon="-122.030237"&gt;&lt;/wpt&gt;
      &lt;wpt lat="37.331705" lon="-122.030337"&gt;&lt;/wpt&gt;
      &lt;wpt lat="37.331705" lon="-122.030437"&gt;&lt;/wpt&gt;
      &lt;wpt lat="37.331705" lon="-122.030537"&gt;&lt;/wpt&gt;
  &lt;/gpx&gt;
  </code></pre>