title: Math.abs function in Select statement in Scala
body: <p>I have the following code in Scala:</p>
  
  <pre><code>val FilteredPSPDF = PSPDF.select("accountname","amount", "currency", "datestamp","orderid","transactiontype")
  </code></pre>
  
  <p>However, I have some values in column "amount" which are negative and I need to change them to positive values.  Is it possible to do this arithmetic function within the Select statement? How do I go about this?</p>