Fitting result printout

[wztbxl]

Hello expert. Now I am using root v6.31 and I found that the output of fitting result changed the format like

---

Minimizer is Minuit2 / Migrad
Chi2 = 0.485843
NDf = 3
Edm = 5.77384e-06
NCalls = 441
p0 = 0.424859 +/- 0.337043 (limited)
p1 = 0.427513 +/- 0.411857 -0.244134 +0.0724874 (Minos) (limited)
p2 = 1.01785e-06 +/- 1.24178e-06
p3 = -6.79909e-07 +/- 4.89988e-07
Why do some parameters show (Minos) behind it? Do we have some file to explain what’s the meaning?

Do we have some way to set the format and let them print like the old version? Something like:
FCN=1.60664 FROM MINOS STATUS=SUCCESSFUL 45 CALLS 340 TOTAL
EDM=1.32174e-07 STRATEGY= 1 ERROR MATRIX ACCURATE
EXT PARAMETER STEP FIRST
NO. NAME VALUE ERROR SIZE DERIVATIVE
1 p0 2.03563e-06 2.68344e-06 -2.78450e-07 -1.41673e-07
2 p1 2.42278e-01 5.62023e-02 5.62023e-02 9.78547e-02

Thanks a lot for your help!

[Danilo]

Hi,

Thank for the question and welcome to the ROOT Community!

I think you were using Minuit and now Minuit2: how did you install and configured ROOT?
In addition I would suggest to move to a released version, such as 6.32.04, the latest stable, moving away from a generic commit of the master predating end 2023 if possible.

Cheers,
Danilo

[jonas]

Indeed, the reason for the different output is the change of the default minimizer from Minuit to Minuit 2 in ROOT 6.30:

https://root.cern/doc/v630/release-notes.html#minuit2-is-now-the-default-minimizer

[wztbxl]

Hello Danilo,

Thanks for your help.
I installed the root by source code and used the default configuration( I did not specify the default setting). I am sorry I forgot why I downloaded the v6.31.
I will try the new version.

Thanks again for your help!
Zhen

[wztbxl]

He Jonas
Thanks! I change it back to the Minuit. Thanks!
Best,
Zhen