title: perl: How to calculate difference for consecutive two numbers in second column only in a text file
body: <p>For example: 32.44 and 30.97 then 30.97 and 29.77 so on for n number for using perl</p>
  
  <pre><code>Col1      Col2   Col3    Col4
  ------------------------------
  0000     32.44   37.88   39.47
  0001     30.97   37.87   39.49
  0002     29.77   37.69   39.39
  0003     28.26   37.43   39.23
  </code></pre>