Defines the grouping variables for LOQ imputation in [do_preprocess.pk()].
Usage
stat_loq_group(...)
Value
A list of expressions. This is added to the `pk` object.
Arguments
...
A set of unquoted variables whose unique combinations define
a group with which to impute missing LOQ values (using the
minimum non-missing LOQ value in the group multiplied by `calc_loq_factor`).
Default is `Chemical, Species, Reference, Media`.