I am not sure if this is an error with ROOT or with the documentation, so I decided to just post it here. I believe there is an error in the code example NumericalMinimization , since it crashes with a nullpointer exception for me. The issue appears to be that ROOT::Math::Factory::CreateMinimizer(min…

I looked a bit more into it with my freshly built root installation, and it turned out to be me not realizing the final output line actually comes from the script, and not the minimizer itself. I had changed the factory parameters to build a Minuit, while leaving the NumericalMinimization parameter …

[image] Using the new Minimizer class on ROOT 5 ROOT Check if your ROOT has “minuit2” enabled: root-config --features If not, you will need to rebuild your ROOT 5 from scratch . Try to run the macro version which comes with your ROOT: ${ROOTSYS}/tutorials/fit/NumericalM…

I don’t see any problem with Minuit2: C:\Users\bellenot\build\release\tutorials\fit>root -l NumericalMinimization.C root [0] Processing NumericalMinimization.C... Minuit2Minimizer: Minimize with max-calls 1000000 convergence for edm < 0.001 strategy 1 Minuit2Minimizer : Valid minimum - status = 0 F…

Ah yes, this is the issue - I do not have Minuit2 enabled. I thought it was working since the output claims to use Minuit2: [image] Comparing with @bellenot ’s output it is obvious that it uses the standard Minuit though. Thanks, I’ll try rebuilding ROOT.

The output explicitly says “Minimizer Minuit2” so you do have it. Check: root-config --has-minuit2

Then I do not understand the "Minimizer Minuit2” output (for sure it does not come from “Minuit”). You can also try: root-config --features | grep -i minuit2

Possible error in NumericalMinimization.C tutorial

Newbie

Wile_E_Coyote February 25, 2021, 8:25pm 2