Hi, I am having one histogram that contains 101 bins. I tried rebining it with the TH1::Rebin: Code (C): histogram->Rebin(2.); But I got the warning message that 2 is not an exact divider of 101. I looked in ROOT TH1 Rebin's page, and read this note: I don't understand what the execution of the program actually does to the bins. Is the initial histogram destroyed? I don't think I understand what they mean with the red-highlighted by me phrase.... Does it mean that it grouped the 100 bins together with 2, and it put the last bin events (101st) in the result's last bin (now 50th)? So more like grouping all the 2 bins in 1 and the last 3 in 1?