title: NVD3, Clear svg before loading new chart
body: <p>I have several different <code>NVD3</code> charts that I call upon in the same svg.
  I use buttons to call functions, each containing a new chart that uses its own data.</p>
  
  <p>Is there a way to clear my single svg without deleting it?
  I wish to press a button to call my chart, but clear the svg before the new chart is loaded.</p>
  
  <p>It's not an issue when using the kind of chart... calling two <code>multibarhorizontal</code> charts, for example, just updates the shapes, which is fine.
  The problem is loading two different charts, like a line and a bar.</p>
  
  <p>Thanks in advance</p>
  
  <p><strong>EDIT</strong> - The answers must be something like d<code>3.select("svg").remove()</code> but that just deletes the svg. I only want to clear it.</p>