Fast selection of data.table columns

Present since hutils 1.2.0.

selector(DT, ..., cols = NULL, preserve.key = TRUE, shallow = FALSE)

Arguments

DT	A data.table.
...	Unquoted columns names.
cols	Character vector of column names.
preserve.key	(logical, default: TRUE) Reapply the key (if DT has one)?
shallow	(logical, default: FALSE) Should the result be a shallow copy of DT's columns or should the columns be assigned by reference? If TRUE, any modification to the result also modifies the selected columns in DT.

Value

DT with the selected columns.

Examples

RQ("nycflights13", no = {
 library(nycflights13)
 library(data.table)
 fs <- as.data.table(flights)
 fs1 <- selector(fs, year, month, day, arr_delay)
 fs1[, arr_delay := NA]
})
#>         year month day arr_delay
#>      1: 2013     1   1        NA
#>      2: 2013     1   1        NA
#>      3: 2013     1   1        NA
#>      4: 2013     1   1        NA
#>      5: 2013     1   1        NA
#>     ---                         
#> 336772: 2013     9  30        NA
#> 336773: 2013     9  30        NA
#> 336774: 2013     9  30        NA
#> 336775: 2013     9  30        NA
#> 336776: 2013     9  30        NA