title: gnuplot computing stats over multiple columns
body: <p>I have a simple 9 column file. I wan't to compute certain statistics for each column and then plot it (using gnuplot).</p>
  
  <p><strong>1)</strong> This is how I compute statistics for every column excluding the first one.</p>
  
  <pre><code>stats 'data' every ::2 name "stats"
  </code></pre>
  
  <p><strong>2)</strong> In the output screen I can see that the operation is successful. Note that the number of columns/records is 8</p>
  
  <pre><code>* FILE: 
    Records:      8
    Out of range: 0
    Invalid:      0
    Blank:        0
    Data Blocks:  1
  
  * COLUMNS:
    Mean:          6.5000       491742.6625
    Std Dev:       2.2913          703.4865
    Sum:          52.0000       3.93394e+06
    Sum Sq.:     380.0000       1.93449e+12
  
    Minimum:       3.0000 [0]   490312.0000 [2]
    Maximum:      10.0000 [7]   492643.5000 [7]
    Quartile:      4.5000       491329.5000
    Median:        6.5000       491911.1500
    Quartile:      8.5000       492252.2500
  
    Linear Model: y = 121.8 x + 4.91e+05
    Correlation:  r = 0.3966
    Sum xy:       2.558e+07
  </code></pre>
  
  <p><strong>3)</strong> Now I can access statistics on the first 2 columns by appending _x and _y like this</p>
  
  <pre><code>print stats_median_x
  print stats_median_y
  </code></pre>
  
  <p>My questions are:</p>
  
  <ul>
  <li>How can I access statistics (lets say medians) for the remaining 6 columns?</li>
  <li>How could I plot lets say a line over all medians against some X axis?</li>
  </ul>
  
  <p>I know that I can simply add a python script to pre-compute all this, but I would prefer to avoid it if there is an easy way to do it using gnuplot itself.</p>
  
  <p>Thanks!</p>