nova -c hmatrixejob.fcl -s <sourcefile>.root
It is used to optimize the electron ID efficiency and the pion rejection efficiency, thus defining a chi-squared cut used on Data objects.
It is envisioned that most users will not use
HMatrices should be persistent as long as the detector geometry and physics list remain constant.
MakeHM works if the input hits are deposited energies. The actual energy calibration is not needed since the inputs are all ratios of deposited energy in a bin compared to the total energy of the object. But,
RawDigits can not be used since attenuation could ruin hit energy correlations.