title: How to remove repeated elements in a vector, similar to 'set' in Python
body: <p>I have a vector with repeated elements, and would like to remove them so that each element appears only once.</p>
  
  <p>In Python I could construct a <a href="https://docs.python.org/2/library/sets.html" rel="noreferrer"><code>Set</code></a> from a vector to achieve this, but how can I do this in R?</p>