After a classifier is done training/testing, how do I apply a selection cut afterwards and save the selected events using the response of the classifier?

I’m currently running a mlp neural network. After the training is finished, I can plot the response to the classifier with the TMVAGUI, which shows the separation strength for the signal/background events in my root file. Now, I want to apply a selection cut, and save these events based on the response plot (for example, the background events from 0.6 to 0.9 in this plot). How do I save these events?

Also, for all my events, there’s an event ID assigned as a separate variable, but I obviously cannot use it as a branch in my Tree when doing the ML training as the event ID numbers are useless for training. Is there a way to check the event IDs for the variables I’ve used for the training after its done? I hope this question makes sense…

Hi @abayyari,
welcome to the ROOT forum!
I think that @moneta can help you with this.