Kernel Crashes in Jupyter Notebook when fitting a histogram in pyRoot

Newbie
,
1

When fitting a TF1 function to a TH1F histogram within a cell in a jupyter notebook
the kernel crashes, if there is no code below the fit command.
Why does this happen?

Minimal example:

# Cell 1
from ROOT import TH1F, TF1, TRandom3
RNG = TRandom3(42)
hist1 = TH1F("hist1", "Exp;t;N", 10, 0., 10.)
for entry in range(100):
        num = RNG.Exp(2.0)
        hist1.Fill(num)

expFunk1 = TF1("expFunk1", "([1]/[0])*TMath::Exp(-x/[0])", 0.0, 100.0)
expFunk1.SetParameter(0, 2.0)
expFunk1.SetParameter(1, 100)

# Cell 2
hist1.Fit("expFunk1", "LI")

Note: If you include any command below the fit in Cell 2 the kernel will not crash
and the fit works.

ROOT Version: JupyROOT 6.28/02
Compiler: Python 3 (ipykernel)

2

Hi @yann,

Welcome to the ROOT forum.

Can you provide a crash log so that it is easier for us to look into the issue?

Cheers,
Dev

3

Hi Dev! I got to admit I am not quite sure where to search for a proper log file. I am using a Docker Image that was set up for teaching purposes. All I get in the docker-interface log is: “WARNING:root:kernel 825481f0-5c19-4bae-a1c5-df5288c54c3d restarted”.

4

I am unable to reproduce this issue locally. Maybe @jonas can give you some pointers.