title: Find indices of rows that x fall into in numpy array
body: <p>I have a numpy array:</p>
  
  <pre><code>import numpy as np
  stm = np.array([[0,1],[1,5],[4,5],[3,6],[7,9]]) 
  x = 3.5
  </code></pre>
  
  <p>I want to find list of indices where: <code>stm[i][0]&lt;= x &lt;=stm[i][1]</code>
  and the result should be <code>[1,3]</code>.</p>
  
  <p>Is there any way to do this in numpy without having to loop through <code>stm</code>?</p>