I created a RootTalk thread on this (http://root.cern.ch/phpBB3/viewtopic.php?f=15&amp;t=15448), but got no replies.
I demonstrate in the simple script attached that RooFit's RooDataSet reduce(Cut(mycut)) and tree->Draw(myvar, mycut) give different numbers of entries, and also a binned version of the same RooDataSet give yet different numbers of entries. I would expect there might be a slight binning effect for the RooDataSet.
It seems fishy that there would be different answers for the same binning, though.
Have I done something terribly wrong?