title: Gnuplot: multiple plots in multiple windows
body: <p>I want to do multiple plots related to differents data columns of the same file but I want a new window for each plot. I don't want attached plots associated to the command <code>set multiplot layout 1,2</code>.
  The idea is represented by the following pseudocode:</p>
  <pre><code>&gt;gnuplot
  
  &gt;plot &quot;myfile.txt&quot; u 1:4
  
  &gt;#make me plot another file without deleting the previous one i.e. open a new window on which data is plotted
  
  &gt;instructions I don't know
  
  &gt;plot &quot;myfile.txt&quot; u: ($3*$3) 
  
  &gt;#I obtain two windows
  </code></pre>