title: math on second column of two files
body: <p>I have two files,</p>
  <pre><code>&gt;cat foo.txt
  QGP 1044
  TGP 634
  KGP 616
  DGA 504
  PGP 481
  KGD 465
  QGE 456
  TGD 393
  DGS 367
  TGA 366
  </code></pre>
  <pre><code>&gt;cat bar.txt
  QGP 748.6421
  TGP 564.0048
  KGP 568.7543
  DGA 193.6391
  PGP 405.1929
  KGD 248.7047
  QGE 287.7652
  TGD 246.6278
  DGS 143.6255
  TGA 210.1166
  </code></pre>
  <p>Column 1 is identical in both files.
  I need to do a mathematical operation like so,</p>
  <pre><code>(foo.txt$column2 - bar.txt$column2)/sqrt(bar.txt$column2)
  </code></pre>
  <p>and output column1 and the math-operated column2.
  I can't figure out how to iterate over each row using awk. Really appreciate any help!</p>