title: Transform community data into wide-format for vegan package
body: <p>I am trying to analyze some community data with the <code>vegan</code> package. I have my data in the wrong format, and am looking for ways to change the format.
  What I have is something like this:</p>
  
  <pre><code>Habitat          Species        Abundance
  1                  A                3
  2                  B                2
  3                  C                1
  1                  D                5
  2                  A                8
  3                  F                4
  </code></pre>
  
  <p>And what I think I need is:</p>
  
  <pre><code>Habitat      Species A       Species B       Species C    Species D    Species D
  1                3               0              0              5          0
  2                8               ...... etc
  3                0
  </code></pre>
  
  <p>Or is there any other format that <code>vegan</code> can take? I am trying to calculate similarity in species composition between habitats.</p>