problem with TChain::Merge

Scott Sampson (scott@znev03.desy.de)
Wed, 15 Jul 1998 17:03:09 +0200 (MET DST)


Hi,

I try merging 3 files, each with the same Tree "T":

TChain ch("T");
ch.Add("f1.root");
ch.Add("f2.root");
ch.Add("f3.root");
ch.Draw("x");
ch.Merge("all.root");

Now when I do ch.Draw I get the number of expected entries in the
histogram (the sum of the entries in each of the 3 files), but if I open
the file "all.root" and make a plot, there are too many entries: the total
is greater than expected by the number in f1. Further, the values
themselves look funny. Is there a bug in TChain::Merge? If so, is there an
macro which could be to do the equivalent? I tried writing one myself, but
couldn't get it to work. Thanks,

Scott Sampson