title: Finding max and identify name's cell for another column
body: <p>Hopefully someone can solve me the following problem.</p>
  
  <p>Here I have a data about different birds and their maximum lengths:</p>
  
  <pre><code>a&lt;-c("bird1","bird2","bird1","bird3","bird2","bird2")
  b&lt;-c(32,45,35,25,51,47)
  c&lt;-data.frame(animal=a,max=b)
    animal max
  1  bird1  32
  2  bird2  45
  3  bird1  35
  4  bird3  25
  5  bird2  51
  6  bird2  47
  </code></pre>
  
  <p>My purpose is to identify the name of the animal which has the maximum length. I know that using <code>max()</code>and <code>which.max()</code>is easy to identify the maximum length and the corresponding cell but how can I know the name of the animal? </p>
  
  <p>Any valuable comment will be helpful for me!</p>