title: Double column plot in Gnuplot multiplot
body: <p>I try to create a combination of multiplots (2x2) and a single plot. I am not sure
  what I am making wrong but I can't figure out how to do it. My attempt:</p>
  
  <pre><code>plot sin(x) title "this should be a single plot"
  
  set multiplot layout 2,2 title "Those are the multiplots"
  
  set title "A!"
  plot sin(x)
  
  set title "B!"
  plot cos(x) not
  
  set title "C!"
  tan(x) title "tan"
  
  set title "D"
  tan(0.5*x) not
  </code></pre>
  
  <p>No matter if I put plot after or earlier but I can't visualize it. </p>
  
  <p>Thanks.</p>