I have a question about what is the principle to set the weight of the training Trees in TMVA.
In TMVA we have factory->AddBackgroundTree(*Tree, weight).
I was woundering if the following logic and using is correct:
suppose we have ttbar and multijet background, and the cross-sections before passing thourgh the MVA are A and B respectively. Also I assume the number of entries in each background trees are equal, then I can use:
If the above is correct, then is the following statement is correct:
when training, the number of ttbar events used is 1000A/(A+B) and the number of multijet events used is 1000B/(A+B).
Really appreciate if anyone could help me with the problem.