title: How to grep rows that have value less than 0.2 in a specific column?
body: <pre><code>  ID RT      EZ    Z0      Z1      Z2    RHO     PHE 
  
   1889  UN    NA  1.0000  0.0000  0.0000  0.8765  -1  
   1890  UN    NA  1.0000  0.0000  0.0000  0.4567  -1  
   1891  UN    NA  1.0000  0.0000  0.0000  0.0012  -1  
   1892  UN    NA  1.0000  0.0000  0.0000  0.1011  -1  
  </code></pre>
  
  <p>I would like to grep all the IDs that have column 'RHO' with value less than 0.2, and the other columns are included for the selected rows.</p>