Confused about histogram values


I am a newbie in ROOT and trying to make sense of it. I have a tree with 98 objects or branches where each is a vector . I found the max and min value of each branch in my whole tree by converting them to numpy array and using max() method. But these results are different from the value on histogram of each branch. i.e. for branch CaloTower_E I got max value of 3545.59912109375. but the histogram looks like this:

where the max is around 1800.

for other branch max(Jet_Eta)=4.8159 and the hist :

which the max value is almost the same as what I’ve got.How can I interpreted that? I was trying to use “GetUxmax” to find max value and then normalize my data.