title: Find the closest two numbers and its the distance
body: <p>I have a file like:</p>
  
  <pre><code>0.000000
  0.000051
  0.000076
  0.000102
  0.000152
  0.000178
  0.000203
  0.000229
  0.000254
  0.000279
  0.000305
  0.000356
  0.000381
  0.000406
  </code></pre>
  
  <p>And I wanna find the two numbers and its closest distance.
  I'm using shell script. At the time I have:</p>
  
  <pre><code>points.dat cat | cut-f1 | sort | uniq
  </code></pre>
  
  <p>In next case I would like to consider two columns. So would a column for the x-axis and one for the y axis.
  It's like the Closest pair of points problem.
  I would like help in that too.</p>
  
  <p>Thank you for helping!</p>