title: duplicate vector into matrix r
body: <p>Wondering how to duplicate a vector into a matrix in R. For example</p>
  
  <pre><code>v = 1:10
  dup = duplicate(V,2)
  </code></pre>
  
  <p>where <code>dup</code> looks like <code>rbind(1:10,1:10)</code>. Thanks</p>