title: A region of my ROC curve is below the random line, how to modify the confusion matrix?
body: <p>In the following roc curve when the threshold is low the roc_curve goes below the random line why does this happen?
  The confusion matrix looks like this,
  my question is which of the following elements (TP,FP,TN,FN) in the confusion matrix should be increased or decreased in order to get the roc_curve over the random line?</p>
  
  <p><a href="https://i.stack.imgur.com/zh1H2.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zh1H2.png" alt="ROC Curve"></a></p>
  
  <pre><code>            Predicted
              Neg   Pos
  
  Actual Neg  1656  860
  Actual Pos  145  331
  </code></pre>