Dear ROOT,
When I want to determine how many entries in my ntuple
satisfy a certain selection, do I have to give an explicit command that
the selection-string has to be processed? I have tried the following:
// Calculate efficiencies:
Float_t Ptcut,Pcut;
Int_t Nr_Selected;
Int_t Nr_NotSelected;
Char_t Cuts[80];
sprintf(Cuts,"sqrt(Px*Px+Py*Py)>0");
TTreeFormula* Selection = new TTreeFormula("selectionform", Cuts,
muontuple);
Nr_NotSelected= muontuple->GetSelectedRows();
for(Ptcut=0;Ptcut<2;Ptcut+=0.1)
{
for(Pcut=0;Pcut<20;Pcut+=1)
{
sprintf(Cuts," sqrt(Px*Px+Py*Py)> %f && sqrt(Px*Px+Py*Py+Pz*Pz) > %f",
Ptcut, Pcut);
Nr_Selected = muontuple->GetSelectedRows();
Efficiencies->Fill(Nr_Selected,Ptcut,Pcut);
}
}
But somehow the NrSelected is always zero. What should I do?
Thanks,
Maarten
**********************************************************************
* Maarten Bruinsma *
**********************************************************************
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