README for TMVATrainer/TMVATester --------------------------------- This README file explains how a TMVA training can be performed on a TTree containing signal and background events with a simple set of two macros. The TMVATester macro shows the performance as well as writes a file containing a TNtuple with the network output, which can be added as a friend to the original TTree. When using some root-file 'input.root' with a ttree 'ntp' containing signal and background, you can train a BDT (boosted decision tree) TMVA with root [0] .x TMVATrainer.C+("input.root", "ntp", , , [precut]) where is the cut separating good from bad candidates, and is a blank separated list of the variables which should be used for the training. Also an opional precut can be applied. To test and write out a friend tree 'tf' to a file 'input_tmvaout.root' with the network output, execute: root [0] .x TMVATester.C+("input.root", "ntp", , , [precut]) Here, is the output of the training process, in our example in the new created subfolder weights/ named input_ntp_BDT.weights.xml. If a precut was used for training, the same should be applied here. The tester shows the network output for signal and background and a ROC curve. It can be used interactively by this commands: root [0] TFile f("input.root") root [1] ntp.AddFriend("tf","input_tmvaout.root") root [2] ntp.Draw(,"tmvaout>0");