Select grouping variables

This selection helpers matches grouping variables. It can be used in select() or vars() selections.

group_cols(vars = peek_vars())

Arguments

vars	A character vector of variable names. When called from inside selecting functions like dplyr::select() these are automatically set to the names of the table.

See also

groups() and group_vars() for retrieving the grouping variables outside selection contexts.

Examples

gdf <- iris %>% group_by(Species)

# Select the grouping variables:
gdf %>% select(group_cols())
#> # A tibble: 150 x 1
#> # Groups:   Species [3]
#>    Species
#>    <fct>  
#>  1 setosa 
#>  2 setosa 
#>  3 setosa 
#>  4 setosa 
#>  5 setosa 
#>  6 setosa 
#>  7 setosa 
#>  8 setosa 
#>  9 setosa 
#> 10 setosa 
#> # … with 140 more rows

# Remove the grouping variables from mutate selections:
gdf %>% mutate_at(vars(-group_cols()), `/`, 100)
#> # A tibble: 150 x 5
#> # Groups:   Species [3]
#>    Sepal.Length Sepal.Width Petal.Length Petal.Width Species
#>           <dbl>       <dbl>        <dbl>       <dbl> <fct>  
#>  1        0.051      0.035        0.0140       0.002 setosa 
#>  2        0.049      0.03         0.0140       0.002 setosa 
#>  3        0.047      0.032        0.013        0.002 setosa 
#>  4        0.046      0.031        0.015        0.002 setosa 
#>  5        0.05       0.036        0.0140       0.002 setosa 
#>  6        0.054      0.039        0.017        0.004 setosa 
#>  7        0.046      0.034        0.0140       0.003 setosa 
#>  8        0.05       0.034        0.015        0.002 setosa 
#>  9        0.044      0.0290       0.0140       0.002 setosa 
#> 10        0.049      0.031        0.015        0.001 setosa 
#> # … with 140 more rows