title: Openlayer 3 coordinates
body: <p>I have a latitude and longitude of some point. How to conver its to the OpenLayer <strong>3</strong> map coordinate system?
  My code is:</p>
  
  <pre><code>...requiries...
  
  
      var coord = [55.7522200, 37.61556005];
      //coord =  ol.proj.transform(coord,'EPSG:4326', 'EPSG:3857');
      var vectorSource = new ol.source.GeoJSON(
           ({
            object: {
              'type': 'FeatureCollection',
              'crs': {
                'type': 'name',
                'properties': {
                  'name': 'EPSG:3857'
                }
              },
              'features': [
                {
                  'type': 'Feature',
                  'geometry': {
                    'type': 'Point',
                    'coordinates': coord
                  }
                }
              ]
            }
          }));
  
      ...
      var map = ...
  </code></pre>
  
  <p>Could you gave me an example for converting the <strong>var coords</strong> on <strong>JavaScript</strong>.
  You can see this example of code at link <a href="http://openlayers.org/en/v3.0.0/examples/geojson.html" rel="nofollow">http://openlayers.org/en/v3.0.0/examples/geojson.html</a></p>