In order to find the best limits to use for fitting one histogram, I’d like to make a minimization of the chi^2 while the limit bins vary.
So I tried to put the limit bins as parameters of my FCN in Minuit. My FCN works very well. However, the Minuit minimization doesn’t work since I don’t know how to tell Minuit that some parameters in my FCN (the bins’ numbers) are integer.
Hence, it starts to move the bins’ numbers but after one step, the step sizes become less than 1 and the bins don’t change anymore.
This problem is, for sure, linked to the fact that the Minuit step size are not integer and vary.
Does someone know how to tell Minuit to keep integer values for some of the parameters ? Or do you know a better way to do what I want ? (except doing the minimization by varying the limits and finding the minimum chi^2 by myself…)
Thank you in advance, Olivier.