title: Gnuplot : Histogram - How do i swap x and y axis?
body: <p>I have a data file with a number in every line and need to plot a histogram from that. My problem is that I need to swap the x and the y axis. 
  Until now i used the following Code :</p>
  
  <pre><code>set style data histogram 
  
  plot '4_2.dat' u 1
  </code></pre>
  
  <p>I read about 'set parametric', which did work for functions but I do not know how to use it for files. And I know that I normally can change the ordinate by using a different order in the using operator (u 1:2 / 2:1). Since I just got 1 entry per row, I do not know how to swap the x and y axis.</p>