title: Numpy splitting multidimensional arrays
body: <p>I have a multidimensional numpy array that I want to split based on a particular column.</p>
  
  <p>Ex. <code>[[1,0,2,3],[1,2,3,4],[2,3,4,5]]</code>
  Say I want to split this array by the 2nd column with the expression <code>x &lt;=2</code>. Then I would get two arrays <code>[[1,0,2,3],[1,2,3,4]]</code> and <code>[[2,3,4,5]]</code>.</p>
  
  <p>I am currently using this statement, which I don't  think is correct.</p>
  
  <pre><code>splits = np.split(S, np.where(S[:, a] &lt;= t)[0][:1]) #splits S based on t
  
  #a is the column number
  </code></pre>