I want to draw several histograms with several different binnings from a tree using TTree:Draw(). For some reason, I want to pipe the output of Draw into a histogram (say “htemp”) and then add this histogram to an empty one later on. So first I need to make sure that this htemp has the proper binning; i need to rebin it. But that only works if I first give a general binning (e.g. per integer or half integer of the variable that I plot, e.g. 1000 bins from 0 to 1000) to the htemp. That I can do in the draw command with “htemp(1000,0,1000)”. However, as I want to have a general code and - in general - the binning of the final histogram may be not uniform, I need to rebin every histogram using an array rather than xmin and xmax. But ROOT ignores this case, i.e. I cannot rebin a histogram using an array if this histogram was initialized with xmin,xmax. Is there still a clever way to do this?