I’m struggling with the “GetChisquare” method when using the Levenberg-Marquardth Algorithm for the minimization when I limit a parameter within an certain interval with “SetParLimits”.
Although the fitted curve looks quite nice when plotted, the Chi-square is way to big when compared with TMinuitMinimizer. I’ve realized that without the “SetParLimits” everything looks normal, however I’m fitting a lot of spectra with a given function and I need to limit one of the function parameters, otherwise for some spectra the fit does not converge.
Does anyone knows what may be the reason?
Thank you in advance,