Analogous function for mutate and transmute in dplyr.

mutate_dt(.data, ..., by)

transmute_dt(.data, ..., by)

Arguments

.data

data.frame

...

List of variables or name-value pairs of summary/modifications functions.

by

(Optional) Mutate by what group?

Value

data.table

See also

Examples

iris %>% mutate_dt(one = 1,Sepal.Length = Sepal.Length + 1)
#> Sepal.Length Sepal.Width Petal.Length Petal.Width Species one #> <num> <num> <num> <num> <fctr> <num> #> 1: 6.1 3.5 1.4 0.2 setosa 1 #> 2: 5.9 3.0 1.4 0.2 setosa 1 #> 3: 5.7 3.2 1.3 0.2 setosa 1 #> 4: 5.6 3.1 1.5 0.2 setosa 1 #> 5: 6.0 3.6 1.4 0.2 setosa 1 #> --- #> 146: 7.7 3.0 5.2 2.3 virginica 1 #> 147: 7.3 2.5 5.0 1.9 virginica 1 #> 148: 7.5 3.0 5.2 2.0 virginica 1 #> 149: 7.2 3.4 5.4 2.3 virginica 1 #> 150: 6.9 3.0 5.1 1.8 virginica 1
iris %>% transmute_dt(one = 1,Sepal.Length = Sepal.Length + 1)
#> one Sepal.Length #> <num> <num> #> 1: 1 6.1 #> 2: 1 5.9 #> 3: 1 5.7 #> 4: 1 5.6 #> 5: 1 6.0 #> --- #> 146: 1 7.7 #> 147: 1 7.3 #> 148: 1 7.5 #> 149: 1 7.2 #> 150: 1 6.9
# add group number with symbol `.GRP` iris %>% mutate_dt(id = 1:.N,grp = .GRP,by = Species)
#> Sepal.Length Sepal.Width Petal.Length Petal.Width Species id grp #> <num> <num> <num> <num> <fctr> <int> <int> #> 1: 5.1 3.5 1.4 0.2 setosa 1 1 #> 2: 4.9 3.0 1.4 0.2 setosa 2 1 #> 3: 4.7 3.2 1.3 0.2 setosa 3 1 #> 4: 4.6 3.1 1.5 0.2 setosa 4 1 #> 5: 5.0 3.6 1.4 0.2 setosa 5 1 #> --- #> 146: 6.7 3.0 5.2 2.3 virginica 46 3 #> 147: 6.3 2.5 5.0 1.9 virginica 47 3 #> 148: 6.5 3.0 5.2 2.0 virginica 48 3 #> 149: 6.2 3.4 5.4 2.3 virginica 49 3 #> 150: 5.9 3.0 5.1 1.8 virginica 50 3