code: def roc_values(fg_vals, bg_vals):
      
      if len(fg_vals) == 0:
          return 0
      
      y_true, y_score = values_to_labels(fg_vals, bg_vals)
      
      fpr, tpr, _thresholds = roc_curve(y_true, y_score)
       
      return fpr, tpr
docs: Return fpr (x) and tpr (y) of the ROC curve.
  
      Parameters
      ----------
      fg_vals : array_like
          The list of values for the positive set.
  
      bg_vals : array_like
          The list of values for the negative set.
  
      Returns
      -------
      fpr : array
          False positive rate.
      tpr : array
          True positive rate.