title: update your xcode error for installing gnuplot on mac
body: <p>trying to install gnuplot using this command on terminal</p>
  
  <pre><code>Mac:~ Amar$ brew install gnuplot --with-xll
  Error: Your Xcode (7.3.1) is too outdated.
  Please update to Xcode 8.2 (or delete it).
  Xcode can be updated from the App Store
  </code></pre>
  
  <p>but, when in checked if xcode needs to be updated , i get following </p>
  
  <pre><code>Mac:~ Amar$ softwareupdate --install xcode
  Software Update Tool
  Copyright 2002-2015 Apple Inc.
  
  xcode: No such update
  No updates are available.
  </code></pre>
  
  <p>Please let me know how to get this problem solved.</p>