Getting fit function parameters


I’m experiencing some problems in getting the correct parameters of a function after a fit. What I do in my code is:

  • Get the histogram
  • Define function with starting parameters (f1)
  • Fit histogram with MIGRAD
  • Fit again with MINOS

My problem is that when I try to get the parameters using TF1::GetParameter(int) or also printing the TFitResultPtr, I always obtain the results of the first fit from MIGRAD, even if the fit with MINOS was performed and converged successfully. To be clear the parameters I get are different from the standard printout I have after fitting with MINOS.

Is there any advice I can ask to solve this problem?
Thank you very much!

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