I seem to have a problem using graphical cuts with the ntuple.
I have two cuts in a file CUTS.root and an ntuple in another file.
Contrary to what the TCutG.html says, I cannot use the cut
as an argument to the ntuple.
The TCutG.html says that:
A graphical cut can be used in a TTree selection expression:
Root > T.Draw("fEtot","cutg1")
where "cutg1" is the name of an existing graphical cut.
I am trying to do just that, and I am getting an error message
"EMPTY STRING".
Any suggestion, why TCutG is not working?
*********** protons->Print()
x[0]=0.667727, y[0]=5.36767
x[1]=0.667727, y[1]=4.0679
..... etc.... --> so the cut was read from the file
*ERROR 4 :
Empty String
*ERROR 4 :
Empty String
total num counts in the ptofH_TB_p histo 0
The macro looks like this:
TFile *fil = new TFile ("CUTS.root");
fil->cd();
fil->ls();
TCutG *protons = (TCutG *) fil->Get("protons");
cout<<" \n \n *********** protons->Print()" <<endl;
protons->Print();
// =======================================================
// projecting histograms from ntuple
// =======================================================
ntFile.cd(); // without this the ntuple NT is unknown
// 2d plot of TOF vs momentum, inside the cut
NT->Draw("tof1:momentum>>ptofH_TB_p","protons");
c1->Update();
total = ptofH_TB_p ->GetEntries();
cout<<"total num counts in the ptofH_TB_p histo " << total <<endl;
Wojtek Skulski skulski@pas.rochester.edu
This archive was generated by hypermail 2b29 : Sat Jan 04 2003 - 23:50:46 MET