title: How to multiply a scalar throughout a specific column within a NumPy array?
body: <p>I need to do some analysis on a large dataset from a hydrolgeology field work. I am using NumPy. I want to know how I can:</p>
  
  <ol>
  <li><p>multiply e.g. the 2nd column of my array by a number (e.g. 5.2). And then </p></li>
  <li><p>calculate the cumulative sum of the numbers in that column. </p></li>
  </ol>
  
  <p>As I mentioned I only want to work on a specific column and not the whole array. </p>