Fit with constraints in TMinuit

[atd]

Hi @OrangeCat

maybe a penalty method is better suited? something like

-lnL=Sum_{i=0}^{N} ln W(\xi_i; a1,a2) + lambda * pow( Func(a1, a2) , 2 ) 

This example shows how to add a Gaussian constraint function

ROOT::FIT, parameter error propagation

Dear rooters, I’m still new to the ROOT::FIT classes. In some of the fits, several parameters are kept fix; but they have an associated error. In order to propagate these errors (associated with the fix parameters) to the “free” parameters, I have to perform several fits changing the values of the fixed parameters (a Montecarlo way of propagating errors). So, my question is: is there a way using ROOT::FIT to propagate the errors of the fixed parameters? I spent a while looking for it, but I …

Best,
Alvaro