title: Yield to maturity / IRR in Power Query M
body: <p>Do you have any ideas about how to calculate YTM / IRR in Microsoft Power Query? 
  For instance, I have a variable called Table and it contains data </p>
  
  <pre><code>    Date        Payment
      2020-01-01  -1000
      2020-02-01  300
      2020-03-01  800
  </code></pre>
  
  <p>and I would like to call some scalar function, which calculates YTM.</p>