Dear root experts,
I want to make some plots in a no b-tag region of my phase space. I am reading a ‘Jet_btag’ vector from my ntuples, which has the type ‘ROOT::VecOps::RVec’. This vector has a boolean entry for each jet in the event, which is 1 if the jet is btagged and 0 otherwise. So, I would like to sum the elements of this array and filter just the events where this sum is 0. I tried some things like:
df = df.Filter("Jet_btag.Sum() == 0 ", "No b-jet region")
But it looks like there is no such thing for RVec arrays. And i didn’t found anything like in the documentation. I also tried to convert the array to a numpy array, as its done here → https://root.cern/doc/master/classROOT_1_1VecOps_1_1RVec.html:
df = df.Filter("nump.sum(numpy.asarray(Jet_btag)) == 0 ", “No b-jet region”)
But i get the error:
input_line_177:2:8: error: use of undeclared identifier 'numpy'
So, there is a way to do this directly inside the df.Filter() ?