Integration of the 'units' and 'errors' packages for a complete quantity
calculus system for R vectors, matrices and arrays, with automatic
propagation, conversion, derivation and simplification of magnitudes and
uncertainties.
Documentation about 'units' and 'errors' is provided in the papers by Pebesma,
Mailund & Hiebert (2016, <doi:10.32614/RJ-2016-061>) and by Ucar, Pebesma &
Azcorra (2018, <doi:10.32614/RJ-2018-075>), included in those packages as
ignettes; see 'citation("quantities")' for details.