title: gnuplot how to set tics format by power of 10
body: <p>I have a plot with:</p>
  
  <pre><code>xtics = {0, 2000, 4000, ..., 20000}
  </code></pre>
  
  <p>and I would like them to be shown as:</p>
  
  <pre><code>0 2 4 ... 20
        x 10^3
  </code></pre>
  
  <p>Is there any way to do so?</p>