title: How can I denominate levels of lists in R?
body: <p>I would like to denominate the levels of a list, as with <code>rownames()</code> or <code>colnames()</code> when denominating rows and columns of matrices.</p>
  
  <p>Example:</p>
  
  <pre><code>a&lt;-matrix(rep(1,4),2,2)
  b&lt;-matrix(rep(2,9),3,3)
  list&lt;-list(a,b)
  print(list)
  </code></pre>
  
  <p>Instead of returning <code>[[1]]</code> at the first level I want the list to use some string like 'matrix a' instead. Maybe this is simple to do.</p>