i have a root file which only contains TH2F histograms, and i need to know how many entries there are for a subset of one of the axis.
in my case, the range of the histogram is x=(0,100), y=(0,7), but i only want to know how many entries there are in x=(20,30), y=(0,7).
i’ve tried many combinations of GetEntries(), SetLimits(), Integrate(), but nothing has worked (and the latter is not so useful for me, as the entries have weights != 1)
is there a simple way (e.g., an argument in GetEntries()), which i can use to return the number of entries for a sub-range? please note that i do not have access to the program which created the histograms, so i cannot re-fill them in the range that i would like.
many thanks in advance,