title: Set height and width of entire ggvis plot, including axes and axis labels
body: <p>I want my ggvis plots to have a specific height and width.</p>
  
  <p>Adding <code>%&gt;% set_options(height = 480, width = 480)</code> sizes only the actual plot, i.e. the grid with the data is 480x480. I want to be able to specify the dimensions of the entire image, including axes, ticks and labels. </p>
  
  <p>Any suggestions?</p>
  
  <p><strong>EDIT:</strong> A full example:</p>
  
  <pre><code>library(ggvis)
  mtcars %&gt;% 
      ggvis(~hp,~wt) %&gt;% 
      layer_points() %&gt;% 
      set_options(height = 480, width = 480)
  </code></pre>