New thor functors for differents types of covariance matrix
Following the discussion in the mattermost https://mattermost.web.cern.ch/lhcb/pl/3rn5ngu8ztbffkm3gafs1z37gy, the existing F.COVARIANCE can only be used to access the track state covariance matrix (x,y,tx,ty,qop), it would also be very interesting to be able to access the posCovMatrix for LHCb vertex, threeMomCovMatrix and momPosCovMatrix for LHCb particle (v1 or v2).
This is indeed useful for computing uncertainty in Run3 early measurement analysis.
The first proposal is to create three different Thor Functors for each type of covariance matrix, like F.THREE_MOM_COV_MATRIX, F.MOM_POS_COV_MATRIX, F.POS_COV_MATRIX and then rename the F.COVARIANCE to F.TRACK_COV_MATRIX.
But maybe it could also be something like:
F.COVARIANCE('posCovMatrix'), F.COVARIANCE('threeMomCovMatrix'), F.COVARIANCE('momPosCovMatrix'), F.COVARIANCE('State')