Internal helper for getBiomass() and for the calibration and matching
functions. Returns the <to>_cutoff column of the species parameters, with
any NAs replaced by the smallest weight in the model. If the model has no
such column at all, the smallest weight is used for every species, so that
the whole size range is counted.
cutoff_min_w(params, to = c("biomass", "number"))A numeric vector with one minimum weight for each species.
A MizerParams object.
The type of observation, either "biomass" or "number".