title: Reshape Data frame variables into list
body: <p>I'm havin an issue with R.</p>
  
  <p>I have the following dataframe:</p>
  
  <pre><code>FirstName LastName Exercice1 Exercice2
     Eric       A        15        12
     Eric       A        14        14
     Eric       A        12        15
     Paul       B        12        14
     Paul       B        14        14
     Joe        C        15        12
     Joe        C        15        17
     Joe        C        16        17
     Joe        C        18        19
  </code></pre>
  
  <p>And I want to change it into the following:</p>
  
  <pre><code>FirstName   LastName            Mark
                           Exercice1 Exercice2
     Eric         A            15        12
                               14        14
                               12        15
                           Exercice1 Exercice2
     Paul        B             12        14
                               14        14
                           Exercice1 Exercice2
     Joe        C              15        12
                               15        17
                               16        17
                               18        19
  </code></pre>
  
  <p>In short I would like to group for each students their marks for every test into a single variable that is a data frame.</p>
  
  <p>Do you have any ideas if that is possible and how I should do?</p>