title: square root of sum of square of columns in multidimensional array
body: <p>I am using multidimensional list with numpy</p>
  
  <p>I have a list.</p>
  
  <pre><code>l = [[0 2 8] [0 2 7] [0 2 5] [2 4 5] [ 8 4 7]]
  </code></pre>
  
  <p>I need to find square root of sum of square of columns.</p>
  
  <pre><code>0 2 8
  0 2 7
  0 2 5
  2 4 5
  8 4 7
  </code></pre>
  
  <p>output as,</p>
  
  <pre><code>l = [sqrt((square(0) + square(0) + square(0) + square(2) + square(8))  sqrt((square(2) + square(2) + square(2) + square(4) + square(4)) sqrt((square(8) + square(7) + square(5)) + square(5) + square(7))]
  </code></pre>