Description
apply a Positioning Method to every group. works like ddply from
plyr package, but the grouping column is always called groups, and
the Positioning Method is not necessarily a function (but can be).Usage
gapply(d,
method,
...,
groups = "groups")
Arguments
d
data frame with column groups.
method
Positioning Method to apply to every group separately.
...
additional arguments for FUN.
groups
can also be useful for piece column.
Value
- data frame of results after applying FUN to each group in d.