Nest a tibble using a grouping specification

Nest a tibble using a grouping specification

group_nest(.tbl, ..., .key = "data", keep = FALSE)

Arguments

.tbl	A tbl
...	Grouping specification, forwarded to group_by()
.key	the name of the list column
keep	Should the grouping columns be kept in the list column.

Value

A tbl with one row per unique combination of the grouping variables. The first columns are the grouping variables, followed by a list column of tibbles with matching rows of the remaining columns.

Details

Grouped data frames

The primary use case for group_nest() is with already grouped data frames, typically a result of group_by(). In this case group_nest() only uses the first argument, the grouped tibble, and warns when ... is used.

Ungrouped data frames

When used on ungrouped data frames, group_nest() forwards the ... to group_by() before nesting, therefore the ... are subject to the data mask.

See also

Other grouping functions: group_by_all, group_by, group_indices, group_keys, group_map, group_rows, group_size, group_trim, groups

Examples

#----- use case 1: a grouped data frame
iris %>%
  group_by(Species) %>%
  group_nest()
#> # A tibble: 3 x 2
#>   Species    data             
#>   <fct>      <list>           
#> 1 setosa     <tibble [50 × 4]>
#> 2 versicolor <tibble [50 × 4]>
#> 3 virginica  <tibble [50 × 4]>

# this can be useful if the grouped data has been altered before nesting
iris %>%
  group_by(Species) %>%
  filter(Sepal.Length > mean(Sepal.Length)) %>%
  group_nest()
#> # A tibble: 3 x 2
#>   Species    data             
#>   <fct>      <list>           
#> 1 setosa     <tibble [22 × 4]>
#> 2 versicolor <tibble [24 × 4]>
#> 3 virginica  <tibble [22 × 4]>

#----- use case 2: using group_nest() on a ungrouped data frame with
#                  a grouping specification that uses the data mask
starwars %>%
  group_nest(species, homeworld)
#> # A tibble: 58 x 3
#>    species  homeworld   data             
#>    <chr>    <chr>       <list>           
#>  1 Aleena   Aleen Minor <tibble [1 × 11]>
#>  2 Besalisk Ojom        <tibble [1 × 11]>
#>  3 Cerean   Cerea       <tibble [1 × 11]>
#>  4 Chagrian Champala    <tibble [1 × 11]>
#>  5 Clawdite Zolan       <tibble [1 × 11]>
#>  6 Droid    Naboo       <tibble [1 × 11]>
#>  7 Droid    Tatooine    <tibble [2 × 11]>
#>  8 Droid    <NA>        <tibble [2 × 11]>
#>  9 Dug      Malastare   <tibble [1 × 11]>
#> 10 Ewok     Endor       <tibble [1 × 11]>
#> # … with 48 more rows