title: What does numpy.ix_() function do and what is the output used for?
body: <p>Below shows the output from <code>numpy.ix_()</code> function. What is the use of the output? It's structure is quite unique.</p>
  <pre><code>import numpy as np
  
  &gt;&gt;&gt; gfg = np.ix_([1, 2, 3, 4, 5, 6], [11, 12, 13, 14, 15, 16], [21, 22, 23, 24, 25, 26], [31, 32, 33, 34, 35, 36] )
  &gt;&gt;&gt; gfg
  (array([[[[1]]],
          [[[2]]],
          [[[3]]],
          [[[4]]],
          [[[5]]],
          [[[6]]]]), 
   
   array([[[[11]],
           [[12]],
           [[13]],
           [[14]],
           [[15]],
           [[16]]]]), 
   
   array([[[[21],
            [22],
            [23],
            [24],
            [25],
            [26]]]]), 
   
   array([[[[31, 32, 33, 34, 35, 36]]]]))
  </code></pre>