title: Stack sequence of values x number of times
body: <p>I have a vector 'values' of length 'gs', with discrete values. I want to create a column where 'values' is stacked 'gs' times. E.g.:</p>
  
  <pre><code>gs = 3
  
  values = [1, 2, 3]
  
  ### stack output
  
  [,1]
  1
  2
  3
  1
  2
  3
  1
  2
  3
  </code></pre>