Hello ROOT team,
After scratching my head a while and looking into my code for the reason
why the size of the error bars of my TH1 projected histograms from TH2
were as large as the bin contents themselves, I very much think that
there is a bug in the latest versions of TH2::ProjectionX, and
TH2::ProjectionY :
Whereas in the TH2 source of ROOT version > 3.01 one can read:
for (Int_t <http://root.cern.ch/root/htmldoc/ListOfTypes.html#Int_t>
biny=firstybin;biny<=lastybin;biny++) {
cont = GetCellContent(binx,biny);
err2 += cont*cont;
...
In ROOT version = 3.01 the same piece of code reads:
for (Int_t <http://root.cern.ch/root/html301/ListOfTypes.html#Int_t>
biny=firstybin;biny<=lastybin;biny++) {
cont = GetCellContent(binx,biny);
err = GetCellError(binx,biny);
err2 += err*err;
...
Or I'm missing something here ?
Best wishes,
--
David D'ENTERRIA PostDoctoral Research Scientist
Nevis Labs http://www.nevis.columbia.edu/~denterria
Columbia University, NY mailto:denterria@nevis.columbia.edu
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PHENIX Group (Bldg 510C) tel: +1 631 344 7053
Brookhaven National Lab, Upton, NY 11973 fax: +1 631 344 3253
http://www.phenix.bnl.gov/~enterria mailto:denterri@bnl.gov
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