title: Is it possible to let gnuplot calculate the average value from a column?
body: <p>I want to create with Gnuplot a diagram from the columns 4 and 10 of my input file. </p>
  
  <p>The input data file looks this way (the <code>^^^^^</code> symbols only highlight the relevant columns).</p>
  
  <pre><code>                           ^^^^^                               ^^^^^
  2017-05-29 15:41:29 10 512 0.215 4.332 0.430 1.451 1.158 0.199 7.785
  2017-05-29 15:41:44 10 512 0.201 1.206 0.304 1.186 1.068 0.196 4.161
  2017-05-29 15:42:00 10 512 0.195 1.223 0.301 1.206 1.055 0.204 4.184
  2017-05-29 15:42:15 10 512 0.191 1.234 0.302 1.157 1.102 0.191 4.177
  2017-05-29 15:42:30 10 512 0.196 1.233 0.297 1.246 1.129 0.206 4.307
  ...
  </code></pre>
  
  <p>I want two bars. One shows the average value of columns 4 and the other one the avarage value of columns 10.</p>
  
  <p>Is it possible to let gnuplot calculate the average value of a column?</p>