title: Building a matrix by merging the same row vector multiple times
body: <p>Is there a matlab function which allows me to do the following operation?</p>
  
  <p><code>x = [1 2 2 3];</code></p>
  
  <p>and then based on <code>x</code> I want to build the matrix <code>m = [1 2 2 3; 1 2 2 3; 1 2 2 3; 1 2 2 3]</code></p>