Fitting results are the same whatever the setting parameters change

ROOT Version: 6.22/08
Platform: Ubuntu20.04

Dear experts,

I would like to fit a 3D histogram created by class “TH3F”; the fitting function is a standard plane equation, the detail is shown in the attachment.
The problem is the fitting plane is the same whatever I changed the initial parameters, I have no idea about this, could you please help me? Thanks very much.
rr.C (489 Bytes)

Best regards,


Is your fit converging fine? E.g. is the output of the fit process indicating success w/o error?


Hi, Danilo,

Thank you for reply.
It’s converging, the value of “Edm” is 9.08704e-12. But the output fitting plane does not match the histogram well. I guess the conflict may be from different axis, but I am not sure.

Best regards,

Hi Jiechen,

The script you attached is not filling a histogram or fit a histogram.

Anyhow, from your title I understand that you are fitting a plane to the data.
That function will be linear in the fit parameters and therefore the final
fit result not dependent on the initial parameter values.

  • Eddy

Hi, Eddy,

Thank you for explanation.

Best regards,

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