Is there an efficient way for filling TH1 histogram with numpy arrays in 2024?

Newbie
1

Is there a better way to fill a TH1 histogram with numpy array than using a ‘for loop’ to loop through the the array.
PS: I have seen the answers which suggests to use root_numpy but the thing is that root_numpy is not compatible with any version of numpy >1.19.5, hence, the question.

ROOT Version: 6.24.6
Platform: Ubuntu 22
Compiler: Not Provided

2

Hi,
The simples and efficient way to fill now a TH1 histogram with a numpy array (1D) is as in this code example:

import numpy as np
import ROOT

# Create a numpy array with 1000 gaussian data with mu=0 and sigma=1 
x = np.random.normal(0, 1, 1000)

# Create a ROOT histogram
hist = ROOT.TH1D("hist", "hist", 50, -3, 3)
# fill ROOT histogram with weights=1
hist.FillN(x.size, x, np.ones(x.size))

Lorenzo

3

Thank you. I was able to get the desired outcome with FillN.