Hi, I am using Root 3.00.06 on Windows. We have seen some odd behavior. We have a TNtuple - so we are using a simple ROOT file. We find that at times the results of applying a series of TCuts when calling TDraw creates histograms with a varying number of entries. Here is an example: { TFile *f1 = new TFile("backgndavgpdr100000TUP0494.root"); TTree *t1=(TTree*)f1->Get("PDR/t1"); TCut L1V = "((vetoword==0||vetoword>127.)&&(ntothit-nhitsiderow3- nhitsiderow2)<3.)||(Trig_Bits&16)"; TCut L1T = "Trig_Bits>3."; TCut L2T = "(TKR_No_Tracks>0.&&ACD_DOCA>25.)||(Trig_Bits&16)"; } root [1] t1->Draw("ACD_DOCA", L1V&&L1T&&L2T) <TCanvas::MakeDefCanvas>: created default TCanvas with name c1 (Int_t)961 root [2] t1->Draw("ACD_DOCA", L1V&&L1T&&L2T) (Int_t)961 root [3] t1->Draw("ACD_DOCA", L1V&&L1T&&L2T) (Int_t)961 root [4] t1->Draw("ACD_DOCA", L1V&&L1T&&L2T) (Int_t)961 root [5] t1->Draw("ACD_DOCA", L1V&&L1T&&L2T) (Int_t)1210 That last call to t1->Draw, produces a histogram with 1210 entries rather than 961. Please note, I cannot reproduce this odd behavior on Linux. The result of applying these cuts is always the same and correct. It seems as though the L2T cut is truncated sometimes - cutting off the final: "||(Trig_Bits&16)", causing the different results. Is there a limit to the size of the expression that can be passed to TTree::Draw? Thanks, Heather
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