title: How to add a radius to a marker in Google-Maps-for-Rails?
body: <p>i am using the Google-Maps-for-Rails gem and I am now trying to display circles.</p>
  
  <p>My Model "Place" consists of:</p>
  
  <ul>
  <li>longitude</li>
  <li>latitude</li>
  <li>radius</li>
  <li>etc</li>
  </ul>
  
  <p>I have no problem to display markers:</p>
  
  <pre><code># Controller: @markers = Place.all.to_gmaps4rails
  gmaps("markers" =&gt; {"data" =&gt; @markers})
  </code></pre>
  
  <p>Unfortunately it doens't include :radius => ..
  I also know that circles can be displayed like:</p>
  
  <pre><code>gmaps(
  "circles" =&gt; { "data" =&gt; '[
                           {"longitude": -122.214897, "latitude": 37.772323, "radius":1000000}
                           ]',
  })
  </code></pre>
  
  <p>Is there any way to include the radius attribute in the markers hash ? Like:</p>
  
  <pre><code>gmaps("circles"     =&gt; { "data" =&gt; @markers })
  </code></pre>
  
  <p>Probably something like:</p>
  
  <pre><code>Place.all.each |place| place.merge!(:radius =&gt; 1000) ...
  </code></pre>
  
  <p>would do, but I think there may be a nicer solution</p>