tidyfst (version 1.8.1)

select_dt: Select column from data.frame

Description

Select specific column(s) via various ways. One can select columns by their column names, indexes or regular expression recognizing the column name(s).

Usage

select_dt(.data, ..., cols = NULL, negate = FALSE)
select_mix(.data, ..., rm.dup = TRUE)

Value

data.table

Arguments

.data

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.

cols

(Optional)A numeric or character vector.

negate

Applicable when regular expression and "cols" is used. If TRUE, return the non-matched pattern. Default uses FALSE.

rm.dup

Should duplicated columns be removed? Defaults to TRUE.

See Also

select, select_if

Examples

iris %>% select_dt(Species)
iris %>% select_dt(Sepal.Length,Sepal.Width)
iris %>% select_dt(Sepal.Length:Petal.Length)
iris %>% select_dt(-Sepal.Length)
iris %>% select_dt(-Sepal.Length,-Petal.Length)
iris %>% select_dt(-(Sepal.Length:Petal.Length))
iris %>% select_dt(c("Sepal.Length","Sepal.Width"))
iris %>% select_dt(-c("Sepal.Length","Sepal.Width"))
iris %>% select_dt(1)
iris %>% select_dt(-1)
iris %>% select_dt(1:3)
iris %>% select_dt(-(1:3))
iris %>% select_dt(1,3)
iris %>% select_dt("Pe")
iris %>% select_dt(-"Se")
iris %>% select_dt(!"Se")
iris %>% select_dt("Pe",negate = TRUE)
iris %>% select_dt("Pe|Sp")
iris %>% select_dt(cols = 2:3)
iris %>% select_dt(cols = 2:3,negate = TRUE)
iris %>% select_dt(cols = c("Sepal.Length","Sepal.Width"))
iris %>% select_dt(cols = names(iris)[2:3])

iris %>% select_dt(is.factor)
iris %>% select_dt(-is.factor)
iris %>% select_dt(!is.factor)

# select_mix could provide flexible mix selection
select_mix(iris, Species,"Sepal.Length")
select_mix(iris,1:2,is.factor)

select_mix(iris,Sepal.Length,is.numeric)
# set rm.dup to FALSE could save the duplicated column names
select_mix(iris,Sepal.Length,is.numeric,rm.dup = FALSE)