.data with grouped rows (group_by.ir()) or ungrouped rows
(ungroup.ir()).
Arguments
.data
An object of class ir.
...
In group_by(), variables or computations to group by.
Computations are always done on the ungrouped data frame.
To perform computations on the grouped data, you need to use
a separate mutate() step before the group_by().
Computations are not allowed in nest_by().
In ungroup(), variables to remove from the grouping.
.add
When FALSE, the default, group_by() will
override existing groups. To add to the existing groups, use
.add = TRUE.
This argument was previously called add, but that prevented
creating a new grouping variable called add, and conflicts with
our naming conventions.
.drop
Drop groups formed by factor levels that don't appear in the
data? The default is TRUE except when .data has been previously
grouped with .drop = FALSE. See group_by_drop_default() for details.