As far as I understand, the square sum of weight information have been stored after calling Sumw2().
According some requirement, I need to copy histograms by setting its contents and errors bin by bin.
In such a case, the sumw2 information is lost. If I do rebin later on, the error I got is wrong.
Am I right?
If so, may I ask how should I do to preserve the sumw2 information to get a reasonable rebinned error?
Thank you in advance!