title: Gnuplot: how to only draw xtics without tic lables on top
body: <p>I want to draw xtics on top but without its tic labels:</p>
  
  <p>This is what I want:</p>
  
  <p><img src="https://i.stack.imgur.com/XWm5Q.png" alt="enter image description here"></p>
  
  <p>This is the code I tried:</p>
  
  <pre><code>set xtics mirror;
  set border 2+4;
  plot x;
  </code></pre>
  
  <p>This gave me: </p>
  
  <p><img src="https://i.stack.imgur.com/Us73C.png" alt="enter image description here"></p>
  
  <p>How can I modify the script to get what I want?</p>