Group by one or more variables

Group by one or more variables

# S3 method for FDF
ungroup(x, ...)

ungroup(x, ...)

# S3 method for FDF
group_by(.data, ..., add = FALSE)

group_by(.data, ..., add = FALSE)

Arguments

x	A FDF.
...	Not used.
.data	A FDF.
add	When add = FALSE, the default, group_by() will override existing groups. To add to the existing groups, use add = TRUE.

Examples

(test <- FDF(datasets::iris))
#> # A Filebacked Data Frame with 150 rows and 5 columns.
(test2 <- group_by(test, Species))
#> # A grouped Filebacked Data Frame with 150 rows and 5 columns.
test2$groups
#> # A tibble: 3 x 2
#>   Species    ind_row   
#>   <chr>      <list>    
#> 1 setosa     <int [50]>
#> 2 versicolor <int [50]>
#> 3 virginica  <int [50]>
group_by(test, starts_with("Sepal"))$groups
#> # A tibble: 117 x 3
#>    Sepal.Length Sepal.Width ind_row  
#>           <dbl>       <dbl> <list>   
#>  1          4.3         3   <int [1]>
#>  2          4.4         2.9 <int [1]>
#>  3          4.4         3   <int [1]>
#>  4          4.4         3.2 <int [1]>
#>  5          4.5         2.3 <int [1]>
#>  6          4.6         3.1 <int [1]>
#>  7          4.6         3.2 <int [1]>
#>  8          4.6         3.4 <int [1]>
#>  9          4.6         3.6 <int [1]>
#> 10          4.7         3.2 <int [2]>
#> # ... with 107 more rows
group_by(test2, Sepal.Length, add = TRUE)$groups
#> # A tibble: 57 x 3
#>    Species Sepal.Length ind_row  
#>    <chr>          <dbl> <list>   
#>  1 setosa           4.3 <int [1]>
#>  2 setosa           4.4 <int [3]>
#>  3 setosa           4.5 <int [1]>
#>  4 setosa           4.6 <int [4]>
#>  5 setosa           4.7 <int [2]>
#>  6 setosa           4.8 <int [5]>
#>  7 setosa           4.9 <int [4]>
#>  8 setosa           5   <int [8]>
#>  9 setosa           5.1 <int [8]>
#> 10 setosa           5.2 <int [3]>
#> # ... with 47 more rows