title: merge/match two data frames based on partially overlapping variables
body: <p>I want to merge/match two data frames based on partially overlapping variables.</p>
  
  <p>Inputs (example):</p>
  
  <pre><code>Data.frame_A
  X1          X2  X3
  aaa,bbb,ccc 25  AGF
  ddd,eee,fff 23  BGD
  
  
  Data.frame_B
  Y1  Y2
  aaa 25
  fff 23
  </code></pre>
  
  <p>Results:</p>
  
  <pre><code>Data.frame_C
  Z1  Z2  Z3
  AGF 25  aaa
  BGD 23  fff
  </code></pre>
  
  <p>So far I tried some unix commands and R (e.g. merge), but can't get it to work...</p>