ROC Curves

Hello everyone! it's my first day with Knime and after surfing on it, I've discovered that it's not yet possible to build Roc curves, is this right? I've tried building a decission tree, but it doesn't output probabilities. So it's not possible to build the Roc Cruve. I guess you haven't included Roc node if it's not possible to use it, isn't it? So, what I'm doing wrong?
thanks!!
cheers,
Luciana

Hi Luciana,

You are right, not every predictor node in KNIME currently outputs class probabilities. Nodes that do are all Weka nodes and the Bayes-Predictor (and maybe some of the neural network nodes, but I'm not 100% sure). You may have to enable this in the nodes dialog. In the future all predictor nodes should output probabilities.

Regards,

Thorsten

It is the future (has been for some time, I guess) and most predictor nodes do have an option to output class probabilites. 

Is there any way to access the class probabilites of the KNN?E.g. how many neighbors considered belonged to the one class or the other class?

 

Best,

Sarah