Group by a selection of variables

Source: R/colwise-group-by.R

These scoped variants of group_by() group a data frame by a selection of variables. Like group_by(), they have optional mutate semantics.

group_by_all(.tbl, .funs = list(), ..., .add = FALSE,
  .drop = group_by_drop_default(.tbl))

group_by_at(.tbl, .vars, .funs = list(), ..., .add = FALSE,
  .drop = group_by_drop_default(.tbl))

group_by_if(.tbl, .predicate, .funs = list(), ..., .add = FALSE,
  .drop = group_by_drop_default(.tbl))

Arguments

.tbl

A tbl object.
.funs

A function fun, a quosure style lambda ~ fun(.) or a list of either form.
...

Additional arguments for the function calls in .funs. These are evaluated only once, with tidy dots support.
.add

See group_by()
.drop

When .drop = TRUE, empty groups are dropped. See group_by_drop_default() for what the default value is for this argument.
.vars

A list of columns generated by vars(), a character vector of column names, a numeric vector of column positions, or NULL.
.predicate

A predicate function to be applied to the columns or a logical vector. The variables for which .predicate is or returns TRUE are selected. This argument is passed to rlang::as_function() and thus supports quosure-style lambda functions and strings representing function names.

Grouping variables

Existing grouping variables are maintained, even if not included in the selection.

See also

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

Examples

# Group a data frame by all variables:
group_by_all(mtcars)
#> # A tibble: 32 x 11
#> # Groups:   mpg, cyl, disp, hp, drat, wt, qsec, vs, am, gear, carb [32]
#>      mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear  carb
#>  * <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#>  1  21       6  160    110  3.9   2.62  16.5     0     1     4     4
#>  2  21       6  160    110  3.9   2.88  17.0     0     1     4     4
#>  3  22.8     4  108     93  3.85  2.32  18.6     1     1     4     1
#>  4  21.4     6  258    110  3.08  3.22  19.4     1     0     3     1
#>  5  18.7     8  360    175  3.15  3.44  17.0     0     0     3     2
#>  6  18.1     6  225    105  2.76  3.46  20.2     1     0     3     1
#>  7  14.3     8  360    245  3.21  3.57  15.8     0     0     3     4
#>  8  24.4     4  147.    62  3.69  3.19  20       1     0     4     2
#>  9  22.8     4  141.    95  3.92  3.15  22.9     1     0     4     2
#> 10  19.2     6  168.   123  3.92  3.44  18.3     1     0     4     4
#> # … with 22 more rows

# Group by variables selected with a predicate:
group_by_if(iris, is.factor)
#> # A tibble: 150 x 5
#> # Groups:   Species [3]
#>    Sepal.Length Sepal.Width Petal.Length Petal.Width Species
#>           <dbl>       <dbl>        <dbl>       <dbl> <fct>  
#>  1          5.1         3.5          1.4         0.2 setosa 
#>  2          4.9         3            1.4         0.2 setosa 
#>  3          4.7         3.2          1.3         0.2 setosa 
#>  4          4.6         3.1          1.5         0.2 setosa 
#>  5          5           3.6          1.4         0.2 setosa 
#>  6          5.4         3.9          1.7         0.4 setosa 
#>  7          4.6         3.4          1.4         0.3 setosa 
#>  8          5           3.4          1.5         0.2 setosa 
#>  9          4.4         2.9          1.4         0.2 setosa 
#> 10          4.9         3.1          1.5         0.1 setosa 
#> # … with 140 more rows

# Group by variables selected by name:
group_by_at(mtcars, vars(vs, am))
#> # A tibble: 32 x 11
#> # Groups:   vs, am [4]
#>      mpg   cyl  disp    hp  drat    wt  qsec    vs    am  gear  carb
#>  * <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
#>  1  21       6  160    110  3.9   2.62  16.5     0     1     4     4
#>  2  21       6  160    110  3.9   2.88  17.0     0     1     4     4
#>  3  22.8     4  108     93  3.85  2.32  18.6     1     1     4     1
#>  4  21.4     6  258    110  3.08  3.22  19.4     1     0     3     1
#>  5  18.7     8  360    175  3.15  3.44  17.0     0     0     3     2
#>  6  18.1     6  225    105  2.76  3.46  20.2     1     0     3     1
#>  7  14.3     8  360    245  3.21  3.57  15.8     0     0     3     4
#>  8  24.4     4  147.    62  3.69  3.19  20       1     0     4     2
#>  9  22.8     4  141.    95  3.92  3.15  22.9     1     0     4     2
#> 10  19.2     6  168.   123  3.92  3.44  18.3     1     0     4     4
#> # … with 22 more rows

# Like group_by(), the scoped variants have optional mutate
# semantics. This provide a shortcut for group_by() + mutate():
d <- tibble(x=c(1,1,2,2), y=c(1,2,1,2))
group_by_all(d, as.factor)
#> # A tibble: 4 x 2
#> # Groups:   x, y [4]
#>   x     y    
#>   <fct> <fct>
#> 1 1     1    
#> 2 1     2    
#> 3 2     1    
#> 4 2     2    
group_by_if(iris, is.factor, as.character)
#> # A tibble: 150 x 5
#> # Groups:   Species [3]
#>    Sepal.Length Sepal.Width Petal.Length Petal.Width Species
#>           <dbl>       <dbl>        <dbl>       <dbl> <chr>  
#>  1          5.1         3.5          1.4         0.2 setosa 
#>  2          4.9         3            1.4         0.2 setosa 
#>  3          4.7         3.2          1.3         0.2 setosa 
#>  4          4.6         3.1          1.5         0.2 setosa 
#>  5          5           3.6          1.4         0.2 setosa 
#>  6          5.4         3.9          1.7         0.4 setosa 
#>  7          4.6         3.4          1.4         0.3 setosa 
#>  8          5           3.4          1.5         0.2 setosa 
#>  9          4.4         2.9          1.4         0.2 setosa 
#> 10          4.9         3.1          1.5         0.1 setosa 
#> # … with 140 more rows