uproot3-methods

import uproot3 import numpy as np # Installing uproot3-methods automatically adds methods to uproot3 arrays. # No explicit import of uproot3_methods is needed for the methods to be available on arrays. # Example: Create a dummy ROOT file with four-vectors using uproot3 with uproot3.recreate('test_tree.root') as file: file['tree'] = { 'px': np.array([10.0, 20.0, 30.0]), 'py': np.array([5.0, 10.0, 15.0]), 'pz': np.array([1.0, 2.0, 3.0]), 'energy': np.array([11.22, 22.45, 33.67]) } # Open the file and access the branches as a 'Momentum4D' object with uproot3.open('test_tree.root') as file: tree = file['tree'] # uproot3-methods automatically provides a 'Momentum4D' accessor # if the 'px', 'py', 'pz', 'energy' branches are present. # This assumes 'Momentum4D' is enabled by default or via configuration. # For a direct example, let's load specific branches and construct. vectors = uproot3.allbranches(file, filter_name=['px', 'py', 'pz', 'energy']) # Assuming uproot3-methods is installed, it enhances the awkward0 array with methods # You might need to explicitly wrap or configure, but typically it's auto-applied. # For direct usage or clarity, we can use the class directly. from uproot3_methods.vector.lorentz import TLorentzVector # Example: create TLorentzVector objects from numpy arrays p4_vectors = TLorentzVector.from_pxyzm( vectors['px'], vectors['py'], vectors['pz'], np.zeros_like(vectors['px']) # mass=0 for simplicity ) print(f"First vector pt: {p4_vectors.pt[0]:.2f}") print(f"All vectors eta: {p4_vectors.eta}") # Example for histograms # from uproot3_methods.hist import TH1F # hist = TH1F(bins=np.array([0, 1, 2, 3]), values=np.array([10, 20, 30])) # print(f"Histogram integral: {hist.integral}")