This collection of functions accesses data about grouped data frames in various ways:
group_data() returns a data frame that defines the grouping structure.
The columns give the values of the grouping variables. The last column,
always called .rows, is a list of integer vectors that gives the
location of the rows in each group.
group_keys() returns a data frame describing the groups.
group_rows() returns a list of integer vectors giving the rows that
each group contains.
group_indices() returns an integer vector the same length as .data
that gives the group that each row belongs to.
group_vars() gives names of grouping variables as character vector.
groups() gives the names of the grouping variables as a list of symbols.
group_size() gives the size of each group.
n_groups() gives the total number of groups.
See context for equivalent functions that return values for the current group.
group_data(.data)
group_keys(.tbl, ...)
group_rows(.data)
group_indices(.data, ...)
group_vars(x)
groups(x)
group_size(x)
n_groups(x)A data frame or extension (like a tibble or grouped tibble).
Use of ... is now deprecated; please use group_by() first
instead.
df <- tibble(x = c(1,1,2,2))
group_vars(df)
#> character(0)
group_rows(df)
#> <list_of<integer>[1]>
#> [[1]]
#> [1] 1 2 3 4
#>
group_data(df)
#> # A tibble: 1 × 1
#> .rows
#> <list<int>>
#> 1 [4]
group_indices(df)
#> [1] 1 1 1 1
gf <- group_by(df, x)
group_vars(gf)
#> [1] "x"
group_rows(gf)
#> <list_of<integer>[2]>
#> [[1]]
#> [1] 1 2
#>
#> [[2]]
#> [1] 3 4
#>
group_data(gf)
#> # A tibble: 2 × 2
#> x .rows
#> <dbl> <list<int>>
#> 1 1 [2]
#> 2 2 [2]
group_indices(gf)
#> [1] 1 1 2 2