I am starting to use TMVA package and I have a problem to set the right weight for the input file. Better explanation:
I have 2 files where one is completely background, and I set like the following rows:
factory->AddBackgroundTree(my_tree_back1,3); where 3 is the weight.
For the second file the only difference between the background and signal is the weight (due for different energy spectrum).
factory->SetSignalWeightExpression(“weight0”); → because the weight come from a branch.
And for the second background I need to use SetBackgroundWeightExpression, because like the signal come from the inside branch (“weight1”).
Therefore, I cannot use the last expression because I already added the first background.
How I can resolve that problem?
I tried to use MultiBackground (so two different data loader and two different reader in application) but I think is not correct.
Thank you in advance,