[ROOT] drawing histos with null y-errors

From: David d'Enterria (denterria@nevis.columbia.edu)
Date: Sat Feb 14 2004 - 11:39:56 MET


Hi ROOT team,

I want to plot (for graphical purposes only) a histogram which has been 
filled manually and has null y-errors. The default drawing option for 
histos in this case produces a "blank" output in the canvas:

TH1D* h = new TH1D("h","h",100,0,100);
h->FillRandom("pol1",5000);
h.Draw(); // no problem here the histo has non-null y-errors
for (int i=0;i<h->GetNbinsX()+1;i++){h->SetBinError(i,0.);};
h.Draw(); // the histo "disappears"
h.Draw("h"); // OK the histo is back there ...

Is this is a bug or a feature ? Why doesn't THistPainter::Paint 
<http://root.cern.ch/root/htmldoc/THistPainter.html#THistPainter:Paint>(Option_t 
*option) set the default (empty) draw option to "h" in this case ?

Thanks.

PS: Using root_v4.00.01.Linux.RH7.3.gcc296 binaries (same feature in 
root_v3.10.01.Linux.RH7.3.gcc296)

-- 
 David d'Enterria                         Nevis Labs, Columbia University
 http://www.nevis.columbia.edu/~denterria      538 W. 120th St., NY 10027
 mailto:denterria@nevis.columbia.edu        tel/fax: +1 212 854 5199/3379
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 PHENIX Collaboration                             Brookhaven National Lab
 http://www.phenix.bnl.gov/~enterria           Bldg 510C, Upton, NY 11973
 mailto:denterri@bnl.gov                    tel/fax: +1 631 344 7053/3253
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