title: R generation of sequences from 2 columns data frame
body: <p>I have a <code>data.frame</code> composed by 2 columns in which the first one represents the starting number of a sequence and the second one is the ending number of the same sequence.</p>
  
  <p>For each row, I want to generate a sequence as I just described.</p>
  
  <p>Data:</p>
  
  <pre><code>structure(list(start = c(3, 6, 9, 12, 15, 18, 21, 24, 27, 30), 
  end = c(7, 10, 13, 16, 19, 22, 25, 28, 31, 34)), .Names = c("start", "end"), row.names = c(NA, -10L), class = "data.frame")
  
  &gt; b
     start end
  1      3   7
  2      6  10
  3      9  13
  4     12  16
  5     15  19
  6     18  22
  7     21  25
  8     24  28
  9     27  31
  10    30  34
  </code></pre>
  
  <p>I thought that a simple</p>
  
  <pre><code>seq(b[,1],b[,2])
  </code></pre>
  
  <p>should work, but it's not.</p>
  
  <p>The result I want is a list of sequences, thus in this case 10 lists (or another container). As example, the first sequence should be: 3,4,5,6,7. Others are the same as I shown.</p>