title: filling under step functions in gnuplot
body: <p>I am using Gnuplot to draw step functions from an input file: </p>
  
  <pre><code>plot 'myFile' using 1:2 with steps
  </code></pre>
  
  <p>I want to fill underneath the plot. something like </p>
  
  <pre><code>plot 'myFile' using 1:2 with filledcurves 
  </code></pre>
  
  <p>But Gnuplot fill underneath the diagram by drawing a line between consecutive points. </p>
  
  <p>How can I fill in underneath the step function?</p>