title: Insert pandas chart into an Excel file using XlsxWriter
body: <p>I use python 3.4, pandas 0.14.1 and XlsxWriter 0.5.6.
  I create a graph called 'graph' using pandas with the following code</p>
  
  <pre><code> graph=data_iter['_DiffPrice'].hist() 
  </code></pre>
  
  <p>, which produces a beautiful histogram. </p>
  
  <p>Now, how do I insert that graph into an Excel file using XlsxWriter? </p>
  
  <p>I tried the XlsxWriter method </p>
  
  <pre><code>workbook.add_chart()
  </code></pre>
  
  <p>but this creates a graph in Excel, not what I want.</p>
  
  <p>Thanks</p>