How to retrieve fit parrameter asymmetric errors (Minos)?


I fit a histogram with a TF1 function and use the ‘E’ option. I have a printout with negative and positive errors for the fit parameters. Is there any possibility to retrieve these errors in a program code?
Thanks much in advance.

Best regards,

After your fit, you can get the parameters’ error the following way:
Assuming your function is f1, then the error on the first parameter is
f1->GetParError(0) for symetric errors and double*x = f1->GetParErrors(0) in case of asymetric errors.
In the latter case, x is an array containing the values.