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 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 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 ---------------------------------------------------------------------
This archive was generated by hypermail 2b29 : Sat Jan 04 2003 - 23:51:16 MET