Hi rooters,
After changing from version 2.25-03 to version 3.00-06, one of my macros,
which creates TEventlists by using the TTree::Draw(">>eventlist","some
selection string") method, does not work anymore. With 3.00-06 nothing is
written into the Eventlists if the selection string becomes too long.
I have tried to reproduce the effect with the TTree T in the
$ROOTSYS/test/Event.root file and the following macro. It is not the same
effect, but what happens is also pretty weird:
void testtree(){
gSystem->Load("libEvent.so");
TFile f("Event.root","read");
TTree* tree = (TTree*)f.Get("T");
TCut cut1 = "abs(fTracks.fBx-0.1)<0.2 && fTracks.fPx>1.0 &&
fTracks.fPz-fTracks.fPy>0.0 && !fTracks.fCharge && !fTracks.fValid &&
fTracks.fPz>1.0 && fTracks.fRandom>800";
TCut cut2 = "fTracks.fNpoint>64";
TCut magic = cut1 && cut2;
cerr << "\n\n\n"
<< cut1 << "\n\n"
<< cut2 << "\n\n"
<< magic << endl;
TCanvas* can = new TCanvas("can","",900,300);
can->Divide(3,1);
can->cd(1);
T->Draw("fTracks.fNpoint", cut1);
can->cd(2);
T->Draw("fTracks.fNpoint", cut2);
can->cd(3);
T->Draw("fTracks.fNpoint", magic);
}
It seems that in "T->Draw("fTracks.fNpoint", magic)" the last cut
(cut2 = "fTracks.fNpoint>64") is simply ignored. In the third histogram
I see also entries with fNpoint<=64. If one of the cuts in
cut1 is removed, e.g. "fTracks.fRandom>800", everything looks fine again.
With 2.25-03 these problems don't occur.
Any Idea?
cheers,
Helmut
This archive was generated by hypermail 2b29 : Tue Jan 01 2002 - 17:50:41 MET