explain ROC graph

Dhiii12Dhiii12 Member Posts: 7 Learner I
edited April 19 in Help
Help me,

can anyone explain about this ROC graph on rapidminer, I'm just learning? how to get the AUC 7.511 value on this ROC chart



Thank you for your time and help!

dhiya

Best Answer

  • BalazsBaranyBalazsBarany Administrator, Moderator, Employee, RapidMiner Certified Analyst, RapidMiner Certified Expert Posts: 788 Unicorn
    Solution Accepted
    Hi!

    ROC (Receiver Operator Characteristics) charts are described in the help of the Compare ROCs operator.
    https://docs.rapidminer.com/latest/studio/operators/validation/visual/compare_rocs.html

    For drawing this chart, the predictions are sorted descending by confidence. At each confidence level, the red line goes up for every correct prediction and to the right for every wrong prediction. The ideal "curve" would always go up because every decision would be right with a 100 % confidence. 

    The Area Under the Curve is calculated by literally determining the area under the red curve. It can be 1 as the maximum (the area of a square going from (0, 0) to (1, 1) and theoretically 0 as the minimum. 0.5 is like tossing coins: Random true or false results.

    Regards,
    Balázs
    lionelderkrikormschmitzDhiii12

Answers

  • Dhiii12Dhiii12 Member Posts: 7 Learner I
    Hello @BalazsBarany

    thanks for the answer it was very helpful
    @BalazsBarany
  • Dhiii12Dhiii12 Member Posts: 7 Learner I
    two question please, 
    what is the difference between blue line and red line, 
    what is the shadow blue and red behind the line?

    Thank you for your time and help!

    @BalazsBarany
  • BalazsBaranyBalazsBarany Administrator, Moderator, Employee, RapidMiner Certified Analyst, RapidMiner Certified Expert Posts: 788 Unicorn
    Hi!

    As you can see in the charts, the blue line is called "ROC (Thresholds)". These are the confidence levels as described.

    The areas are the variance resulting from cross validation iterations.

    Regards,
    Balázs
    Dhiii12
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