I made a small modification of the example macro rf611_weightedfits.C by making the data generation and the fits extended. Doing this the error on the number of events is smaller then 0.1e-3, in case the AsymptoticError flag is used in conjunction with the Extended flag.
The third row shows the fitted number of events and the last one the corresponding error.
You can see the error on the fitted number of events with AsymptoticError flag enbabled in the bottom right corner. Obviously the error is very low (< 0.1e-3).
The error on the number of events with SumW2Error(true) has some outliers but that is not what I’m concerned about here.
Can anybody tell me if this is an issue with the formula itself so that it can not provide correct errors in case of an extended fit or if it could be an issue with the implementation?
Based on my previous experience I can already say thanks for your replies