group_data: Grouping metadata

In hadley/dplyr: A Grammar of Data Manipulation

Grouping metadata

Description

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.

Usage

group_data(.data)

group_keys(.tbl, ...)

group_rows(.data)

group_indices(.data, ...)

group_vars(x)

groups(x)

group_size(x)

n_groups(x)

Arguments

.data, .tbl, x	A data frame or extension (like a tibble or grouped tibble).
...	Use of ... is now deprecated; please use group_by() first instead.

Examples

df <- tibble(x = c(1,1,2,2))
group_vars(df)
group_rows(df)
group_data(df)
group_indices(df)

gf <- group_by(df, x)
group_vars(gf)
group_rows(gf)
group_data(gf)
group_indices(gf)

hadley/dplyr documentation built on Nov. 6, 2024, 4:48 p.m.