title: histogram in jfreechart
body: <p>I'm trying to use <a href="http://www.jfree.org/jfreechart/" rel="noreferrer">JfreeChart</a> to create a chart for the histogram of an image , but I don't fully understand how to provide the input data for the histogram .The function I am suppose to use is this:</p>
  
  <pre><code>addSeries(java.lang.Comparable key, double[] values, int bins) 
  </code></pre>
  
  <p>I find that documentation is really unclear. I have a 256-element array filled with the number of pixels of each intensity which I want to be able to use as an input, but I don't know how.  Has someone encountered this problem before ? </p>