title: AWK sum all values of a column keeping all floats
body: <p>I'm using the following code to grep the lines that im interested in, keep only the last ones and sum over column nine:</p>
  
  <pre><code>grep -n -49 'FINAL BlaBla' output |tail -9 | awk 'BEGIN {SUM=0}; {SUM=SUM+$9}; END {printf "%.3f\n" SUM}.
  </code></pre>
  
  <p>However the sum over column 9 returns 0,000</p>
  
  <p>the selected lines look as follows</p>
  
  <pre><code>84-    C    -3.42056726    +1    -0.82831327    +1    1.52743549    +1    0.5647
  85-    N    -4.78612760    +1    -1.01185554    +1    1.58894854    +1   -0.5837
  86-    C    -5.19047197    +1    -2.20130686    +1    2.06176295    +1    0.3890
  87-    N    -4.42537785    +1    -3.22689397    +1    2.47304603    +1   -0.4775
  88-    C    -3.03532546    +1    -2.98933854    +1    2.38795560    +1    0.3686
  89-    N    -2.51737448    +1    -1.78267672    +1    1.92262528    +1   -0.5526
  90-   Cl    -6.86455806    +1    -2.45050886    +1    2.15229544    +1    0.0934
  91-    N    -2.24043582    +1    -3.93651444    +1    2.76082642    +1    0.0890
  92-    N    -2.94053526    +1     0.36941710    +1    1.06455738    +1   -0.3274
  </code></pre>
  
  <p>I can't find out where the mistake is. </p>
  
  <p>I also tried to sum over $1 and I correctly obtain 792,000 but when I sum over $3 I get 31,000 ...</p>
  
  <p>what's wrong?</p>