We will begin by assuming our ntuples are flat trees in flavour and category from the JetTagMVAExtractor or BTagAnalyzer, one level up from the original AOD/RECO files. The tree files will look like CombinedSVV2NoVertex_DUSG.root with the tree name CombinedSVV2NoVertex.

Below are the subsequent steps for preparing the training samples for the TMVA:

1) Make the trees really flat without vectors and set variables that are not defined for a given vertex category to a default value. For this, run your ntuples through createNewTree.py which will produce sets of new flat ntuples split in event range such as CombinedSVV2NoVertex_DUSG_0_249999.root with the shared tree name “tree”.

2)