title: Google-Maps-for-Rails - How do I set the size of a map image using gmap4rails?
body: <p>Greetings.</p>
  
  <p>I've had trouble with the Cartographer plugin when deploying to Heroku.
  I tried Google-Maps-for-Rails (gmaps4rails gem) and it looks very promising. But I've not been able to figure out how to set the map image size.</p>
  
  <p>With Cartographer, I can set the map image size using markup like the following.</p>
  
  <pre><code>&lt;div id="map-right"&gt;
    &lt;%= raw Cartographer::Header.new.to_s %&gt;
    &lt;%= raw @map.to_html %&gt;
    &lt;div id="map" style="width:658px;height:348px;"&gt;[Map]&lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>How do I get similar behavior using gmaps4rails? I'm trying this.</p>
  
  <pre><code>&lt;div id="map-right"&gt;
    &lt;div id="map" style="width:658px;height:348px;"&gt;&lt;%= gmaps4rails(@events_map) %&gt;&lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>That draws the map but does not set image size. What's a sensible approach?</p>
  
  <p>Thanks.</p>