In using root_pandas and root_numpy, how can the elements of a vector be read in as separate columns in a DataFrame?

ROOT
1

I’ve got a tree in a ROOT file that contains some vector variables, such as jet_pt. For jet_pt, the first element is the pT of the first jet in an event, the second element is the pT of the second jet in an event and so on. I would like to read in such values such that they become separate columns in a resulting DataFrame, such as jet_pt[0], jet_pt[1] or jet_pt_1, jet_pt_2. Currently, there seems to be a flattening process happening. How should I read in the ROOT file?

import root_pandas

df = root_pandas.read_root("data.root", "nominal", flatten = ["jet_pt"], ignore = ["truth_blah_info"])
2

Hi, root_pandas is a third party package, not maintained by the ROOT project. I am not sure whether the root_pandas developers hang out here. You might have more luck checking their github page for their favourite communication channel.

Cheers,
Enrico