Select specific column(s) via various ways. One can select columns by their column names, indexes or regular expression recognizing the column name(s).
select_dt(.data, ..., cols = NULL, negate = FALSE)
select_mix(.data, ..., rm.dup = TRUE)data.frame
List of variables or name-value pairs of summary/modifications functions. It can also recieve conditional function to select columns. When starts with `-`(minus symbol) or `!`, return the negative columns.
(Optional)A numeric or character vector.
Applicable when regular expression and "cols" is used.
If TRUE, return the non-matched pattern. Default uses FALSE.
Should duplicated columns be removed? Defaults to TRUE.
data.table
iris %>% select_dt(Species)
#> Species
#> <fctr>
#> 1: setosa
#> 2: setosa
#> 3: setosa
#> 4: setosa
#> 5: setosa
#> ---
#> 146: virginica
#> 147: virginica
#> 148: virginica
#> 149: virginica
#> 150: virginica
iris %>% select_dt(Sepal.Length,Sepal.Width)
#> Sepal.Length Sepal.Width
#> <num> <num>
#> 1: 5.1 3.5
#> 2: 4.9 3.0
#> 3: 4.7 3.2
#> 4: 4.6 3.1
#> 5: 5.0 3.6
#> ---
#> 146: 6.7 3.0
#> 147: 6.3 2.5
#> 148: 6.5 3.0
#> 149: 6.2 3.4
#> 150: 5.9 3.0
iris %>% select_dt(Sepal.Length:Petal.Length)
#> Sepal.Length Sepal.Width Petal.Length
#> <num> <num> <num>
#> 1: 5.1 3.5 1.4
#> 2: 4.9 3.0 1.4
#> 3: 4.7 3.2 1.3
#> 4: 4.6 3.1 1.5
#> 5: 5.0 3.6 1.4
#> ---
#> 146: 6.7 3.0 5.2
#> 147: 6.3 2.5 5.0
#> 148: 6.5 3.0 5.2
#> 149: 6.2 3.4 5.4
#> 150: 5.9 3.0 5.1
iris %>% select_dt(-Sepal.Length)
#> Sepal.Width Petal.Length Petal.Width Species
#> <num> <num> <num> <fctr>
#> 1: 3.5 1.4 0.2 setosa
#> 2: 3.0 1.4 0.2 setosa
#> 3: 3.2 1.3 0.2 setosa
#> 4: 3.1 1.5 0.2 setosa
#> 5: 3.6 1.4 0.2 setosa
#> ---
#> 146: 3.0 5.2 2.3 virginica
#> 147: 2.5 5.0 1.9 virginica
#> 148: 3.0 5.2 2.0 virginica
#> 149: 3.4 5.4 2.3 virginica
#> 150: 3.0 5.1 1.8 virginica
iris %>% select_dt(-Sepal.Length,-Petal.Length)
#> Sepal.Width Petal.Width Species
#> <num> <num> <fctr>
#> 1: 3.5 0.2 setosa
#> 2: 3.0 0.2 setosa
#> 3: 3.2 0.2 setosa
#> 4: 3.1 0.2 setosa
#> 5: 3.6 0.2 setosa
#> ---
#> 146: 3.0 2.3 virginica
#> 147: 2.5 1.9 virginica
#> 148: 3.0 2.0 virginica
#> 149: 3.4 2.3 virginica
#> 150: 3.0 1.8 virginica
iris %>% select_dt(-(Sepal.Length:Petal.Length))
#> Petal.Width Species
#> <num> <fctr>
#> 1: 0.2 setosa
#> 2: 0.2 setosa
#> 3: 0.2 setosa
#> 4: 0.2 setosa
#> 5: 0.2 setosa
#> ---
#> 146: 2.3 virginica
#> 147: 1.9 virginica
#> 148: 2.0 virginica
#> 149: 2.3 virginica
#> 150: 1.8 virginica
iris %>% select_dt(c("Sepal.Length","Sepal.Width"))
#> Sepal.Length Sepal.Width
#> <num> <num>
#> 1: 5.1 3.5
#> 2: 4.9 3.0
#> 3: 4.7 3.2
#> 4: 4.6 3.1
#> 5: 5.0 3.6
#> ---
#> 146: 6.7 3.0
#> 147: 6.3 2.5
#> 148: 6.5 3.0
#> 149: 6.2 3.4
#> 150: 5.9 3.0
iris %>% select_dt(-c("Sepal.Length","Sepal.Width"))
#> Petal.Length Petal.Width Species
#> <num> <num> <fctr>
#> 1: 1.4 0.2 setosa
#> 2: 1.4 0.2 setosa
#> 3: 1.3 0.2 setosa
#> 4: 1.5 0.2 setosa
#> 5: 1.4 0.2 setosa
#> ---
#> 146: 5.2 2.3 virginica
#> 147: 5.0 1.9 virginica
#> 148: 5.2 2.0 virginica
#> 149: 5.4 2.3 virginica
#> 150: 5.1 1.8 virginica
iris %>% select_dt(1)
#> Sepal.Length
#> <num>
#> 1: 5.1
#> 2: 4.9
#> 3: 4.7
#> 4: 4.6
#> 5: 5.0
#> ---
#> 146: 6.7
#> 147: 6.3
#> 148: 6.5
#> 149: 6.2
#> 150: 5.9
iris %>% select_dt(-1)
#> Sepal.Width Petal.Length Petal.Width Species
#> <num> <num> <num> <fctr>
#> 1: 3.5 1.4 0.2 setosa
#> 2: 3.0 1.4 0.2 setosa
#> 3: 3.2 1.3 0.2 setosa
#> 4: 3.1 1.5 0.2 setosa
#> 5: 3.6 1.4 0.2 setosa
#> ---
#> 146: 3.0 5.2 2.3 virginica
#> 147: 2.5 5.0 1.9 virginica
#> 148: 3.0 5.2 2.0 virginica
#> 149: 3.4 5.4 2.3 virginica
#> 150: 3.0 5.1 1.8 virginica
iris %>% select_dt(1:3)
#> Sepal.Length Sepal.Width Petal.Length
#> <num> <num> <num>
#> 1: 5.1 3.5 1.4
#> 2: 4.9 3.0 1.4
#> 3: 4.7 3.2 1.3
#> 4: 4.6 3.1 1.5
#> 5: 5.0 3.6 1.4
#> ---
#> 146: 6.7 3.0 5.2
#> 147: 6.3 2.5 5.0
#> 148: 6.5 3.0 5.2
#> 149: 6.2 3.4 5.4
#> 150: 5.9 3.0 5.1
iris %>% select_dt(-(1:3))
#> Petal.Width Species
#> <num> <fctr>
#> 1: 0.2 setosa
#> 2: 0.2 setosa
#> 3: 0.2 setosa
#> 4: 0.2 setosa
#> 5: 0.2 setosa
#> ---
#> 146: 2.3 virginica
#> 147: 1.9 virginica
#> 148: 2.0 virginica
#> 149: 2.3 virginica
#> 150: 1.8 virginica
iris %>% select_dt(1,3)
#> Sepal.Length Petal.Length
#> <num> <num>
#> 1: 5.1 1.4
#> 2: 4.9 1.4
#> 3: 4.7 1.3
#> 4: 4.6 1.5
#> 5: 5.0 1.4
#> ---
#> 146: 6.7 5.2
#> 147: 6.3 5.0
#> 148: 6.5 5.2
#> 149: 6.2 5.4
#> 150: 5.9 5.1
iris %>% select_dt("Pe")
#> Petal.Length Petal.Width
#> <num> <num>
#> 1: 1.4 0.2
#> 2: 1.4 0.2
#> 3: 1.3 0.2
#> 4: 1.5 0.2
#> 5: 1.4 0.2
#> ---
#> 146: 5.2 2.3
#> 147: 5.0 1.9
#> 148: 5.2 2.0
#> 149: 5.4 2.3
#> 150: 5.1 1.8
iris %>% select_dt(-"Se")
#> Petal.Length Petal.Width Species
#> <num> <num> <fctr>
#> 1: 1.4 0.2 setosa
#> 2: 1.4 0.2 setosa
#> 3: 1.3 0.2 setosa
#> 4: 1.5 0.2 setosa
#> 5: 1.4 0.2 setosa
#> ---
#> 146: 5.2 2.3 virginica
#> 147: 5.0 1.9 virginica
#> 148: 5.2 2.0 virginica
#> 149: 5.4 2.3 virginica
#> 150: 5.1 1.8 virginica
iris %>% select_dt(!"Se")
#> Petal.Length Petal.Width Species
#> <num> <num> <fctr>
#> 1: 1.4 0.2 setosa
#> 2: 1.4 0.2 setosa
#> 3: 1.3 0.2 setosa
#> 4: 1.5 0.2 setosa
#> 5: 1.4 0.2 setosa
#> ---
#> 146: 5.2 2.3 virginica
#> 147: 5.0 1.9 virginica
#> 148: 5.2 2.0 virginica
#> 149: 5.4 2.3 virginica
#> 150: 5.1 1.8 virginica
iris %>% select_dt("Pe",negate = TRUE)
#> Sepal.Length Sepal.Width Species
#> <num> <num> <fctr>
#> 1: 5.1 3.5 setosa
#> 2: 4.9 3.0 setosa
#> 3: 4.7 3.2 setosa
#> 4: 4.6 3.1 setosa
#> 5: 5.0 3.6 setosa
#> ---
#> 146: 6.7 3.0 virginica
#> 147: 6.3 2.5 virginica
#> 148: 6.5 3.0 virginica
#> 149: 6.2 3.4 virginica
#> 150: 5.9 3.0 virginica
iris %>% select_dt("Pe|Sp")
#> Petal.Length Petal.Width Species
#> <num> <num> <fctr>
#> 1: 1.4 0.2 setosa
#> 2: 1.4 0.2 setosa
#> 3: 1.3 0.2 setosa
#> 4: 1.5 0.2 setosa
#> 5: 1.4 0.2 setosa
#> ---
#> 146: 5.2 2.3 virginica
#> 147: 5.0 1.9 virginica
#> 148: 5.2 2.0 virginica
#> 149: 5.4 2.3 virginica
#> 150: 5.1 1.8 virginica
iris %>% select_dt(cols = 2:3)
#> Sepal.Width Petal.Length
#> <num> <num>
#> 1: 3.5 1.4
#> 2: 3.0 1.4
#> 3: 3.2 1.3
#> 4: 3.1 1.5
#> 5: 3.6 1.4
#> ---
#> 146: 3.0 5.2
#> 147: 2.5 5.0
#> 148: 3.0 5.2
#> 149: 3.4 5.4
#> 150: 3.0 5.1
iris %>% select_dt(cols = 2:3,negate = TRUE)
#> Sepal.Length Petal.Width Species
#> <num> <num> <fctr>
#> 1: 5.1 0.2 setosa
#> 2: 4.9 0.2 setosa
#> 3: 4.7 0.2 setosa
#> 4: 4.6 0.2 setosa
#> 5: 5.0 0.2 setosa
#> ---
#> 146: 6.7 2.3 virginica
#> 147: 6.3 1.9 virginica
#> 148: 6.5 2.0 virginica
#> 149: 6.2 2.3 virginica
#> 150: 5.9 1.8 virginica
iris %>% select_dt(cols = c("Sepal.Length","Sepal.Width"))
#> Sepal.Length Sepal.Width
#> <num> <num>
#> 1: 5.1 3.5
#> 2: 4.9 3.0
#> 3: 4.7 3.2
#> 4: 4.6 3.1
#> 5: 5.0 3.6
#> ---
#> 146: 6.7 3.0
#> 147: 6.3 2.5
#> 148: 6.5 3.0
#> 149: 6.2 3.4
#> 150: 5.9 3.0
iris %>% select_dt(cols = names(iris)[2:3])
#> Sepal.Width Petal.Length
#> <num> <num>
#> 1: 3.5 1.4
#> 2: 3.0 1.4
#> 3: 3.2 1.3
#> 4: 3.1 1.5
#> 5: 3.6 1.4
#> ---
#> 146: 3.0 5.2
#> 147: 2.5 5.0
#> 148: 3.0 5.2
#> 149: 3.4 5.4
#> 150: 3.0 5.1
iris %>% select_dt(is.factor)
#> Species
#> <fctr>
#> 1: setosa
#> 2: setosa
#> 3: setosa
#> 4: setosa
#> 5: setosa
#> ---
#> 146: virginica
#> 147: virginica
#> 148: virginica
#> 149: virginica
#> 150: virginica
iris %>% select_dt(-is.factor)
#> Sepal.Length Sepal.Width Petal.Length Petal.Width
#> <num> <num> <num> <num>
#> 1: 5.1 3.5 1.4 0.2
#> 2: 4.9 3.0 1.4 0.2
#> 3: 4.7 3.2 1.3 0.2
#> 4: 4.6 3.1 1.5 0.2
#> 5: 5.0 3.6 1.4 0.2
#> ---
#> 146: 6.7 3.0 5.2 2.3
#> 147: 6.3 2.5 5.0 1.9
#> 148: 6.5 3.0 5.2 2.0
#> 149: 6.2 3.4 5.4 2.3
#> 150: 5.9 3.0 5.1 1.8
iris %>% select_dt(!is.factor)
#> Sepal.Length Sepal.Width Petal.Length Petal.Width
#> <num> <num> <num> <num>
#> 1: 5.1 3.5 1.4 0.2
#> 2: 4.9 3.0 1.4 0.2
#> 3: 4.7 3.2 1.3 0.2
#> 4: 4.6 3.1 1.5 0.2
#> 5: 5.0 3.6 1.4 0.2
#> ---
#> 146: 6.7 3.0 5.2 2.3
#> 147: 6.3 2.5 5.0 1.9
#> 148: 6.5 3.0 5.2 2.0
#> 149: 6.2 3.4 5.4 2.3
#> 150: 5.9 3.0 5.1 1.8
# select_mix could provide flexible mix selection
select_mix(iris, Species,"Sepal.Length")
#> Species Sepal.Length
#> <fctr> <num>
#> 1: setosa 5.1
#> 2: setosa 4.9
#> 3: setosa 4.7
#> 4: setosa 4.6
#> 5: setosa 5.0
#> ---
#> 146: virginica 6.7
#> 147: virginica 6.3
#> 148: virginica 6.5
#> 149: virginica 6.2
#> 150: virginica 5.9
select_mix(iris,1:2,is.factor)
#> Sepal.Length Sepal.Width Species
#> <num> <num> <fctr>
#> 1: 5.1 3.5 setosa
#> 2: 4.9 3.0 setosa
#> 3: 4.7 3.2 setosa
#> 4: 4.6 3.1 setosa
#> 5: 5.0 3.6 setosa
#> ---
#> 146: 6.7 3.0 virginica
#> 147: 6.3 2.5 virginica
#> 148: 6.5 3.0 virginica
#> 149: 6.2 3.4 virginica
#> 150: 5.9 3.0 virginica
select_mix(iris,Sepal.Length,is.numeric)
#> Sepal.Length Sepal.Width Petal.Length Petal.Width
#> <num> <num> <num> <num>
#> 1: 5.1 3.5 1.4 0.2
#> 2: 4.9 3.0 1.4 0.2
#> 3: 4.7 3.2 1.3 0.2
#> 4: 4.6 3.1 1.5 0.2
#> 5: 5.0 3.6 1.4 0.2
#> ---
#> 146: 6.7 3.0 5.2 2.3
#> 147: 6.3 2.5 5.0 1.9
#> 148: 6.5 3.0 5.2 2.0
#> 149: 6.2 3.4 5.4 2.3
#> 150: 5.9 3.0 5.1 1.8
# set rm.dup to FALSE could save the duplicated column names
select_mix(iris,Sepal.Length,is.numeric,rm.dup = FALSE)
#> Sepal.Length Sepal.Length Sepal.Width Petal.Length Petal.Width
#> <num> <num> <num> <num> <num>
#> 1: 5.1 5.1 3.5 1.4 0.2
#> 2: 4.9 4.9 3.0 1.4 0.2
#> 3: 4.7 4.7 3.2 1.3 0.2
#> 4: 4.6 4.6 3.1 1.5 0.2
#> 5: 5.0 5.0 3.6 1.4 0.2
#> ---
#> 146: 6.7 6.7 3.0 5.2 2.3
#> 147: 6.3 6.3 2.5 5.0 1.9
#> 148: 6.5 6.5 3.0 5.2 2.0
#> 149: 6.2 6.2 3.4 5.4 2.3
#> 150: 5.9 5.9 3.0 5.1 1.8