Multiple Signal And Background samples in TMVA

TMVA
1

Hi Everyone,

I have 5 root files of signal and 5 root files of background process. Now I want TMVA classification but have no idea how to get started with such multiple files.
can anybody help how to deal with this?

Best Regards

2

Hi,

If your 5 root files contains the same TTree (same name and same branches but different entries), the easiest is to create a TChain and use the TChain as a TTree and input that to TMVA in the DataLoader::AddSignalTree and DataLoader::AddBackgroundTree.
See this simple tutorial as an example how to create a TChain.

Lorenzo

3

Hi,

I am in a similar position with a BDT. I have one question: should I adjust either the weight or the number of events so that all the backgrounds have the same influence on the training or is that not necessary?

For example, I have one background tree with 4000 events and another one with 40000. Can I put them directly in the dataloader or should I adjust the weight of the first one and set it equal to 10 so that each background is considered equally?

Thank you very much,
Santiago