title: Getting NLOpt results after optimization failure using Python API
body: <p>I am running an optimization using NLOpt's Python interface. At a certain point, after a number of iterations, I get an nlopt.RoundoffLimited exception. According to the documentation (<a href="http://ab-initio.mit.edu/wiki/index.php/NLopt_Reference#Error_codes_.28negative_return_values.29" rel="nofollow">http://ab-initio.mit.edu/wiki/index.php/NLopt_Reference#Error_codes_.28negative_return_values.29</a>), after such an exception, "the optimization still typically returns a useful result." How do I actually view the intermediate result? I am running code like:</p>
  
  <pre><code>opt = nlopt.opt(...)
  # ... some optimization settings
  try:
      opt_results = opt.optimize(guess)
  except nlopt.RoundoffLimited:
      # How do I get the latest parameters from opt,
      # after the optimization has failed?
  </code></pre>
  
  <p>I can get the objective value just fine using <code>opt.last_optimize_result()</code>, but I can't find the API call to get the parameters that result in this objective value.</p>
  
  <p>Thanks!</p>