title: Normalized to 100 data within groups
body: <p>I have a dataset that looks like this:</p>
  
  <pre><code>Var Trait   Value
  0   Trait1  42.26
  1   Trait1  41.81
  2   Trait1  41.21
  0   Trait2  47.82
  1   Trait2  51.44
  2   Trait2  51.42
  0   Trait3  10.27
  1   Trait3  10.63
  2   Trait3  10.14
  </code></pre>
  
  <p>I would like to add a forth column with normalized to 100 data calculated like this for each trait and var1:</p>
  
  <p>(42.26/42.26)*100=<strong>100</strong></p>
  
  <p>(41.81/42.26)*100=<strong>98.93</strong></p>
  
  <p>(41.21/42.26)*100=<strong>97.51</strong></p>
  
  <p>For trait 2 and var1=1, Value is larger than var1=0 Value so in this case row 5 will be calculated like this:
  (47.82/51.44)*100=<strong>92.94</strong></p>