Fix efficiencies computation in presence of corrections. #12
Description
Currently efficiencies are computed with the ratio of MC events, which is the real efficiency if there is no event level weight correction.
- Change to ratios of
y.central. - For the errors there is no clear way to obtain the real uncertanties without having access at least to lumi and xsec. Maybe we can just use the #MC events for that, it will not make a huge difference
- Should we display and save also variated efficiency for every variation? [proposal]