How to create new column in a data.table when the name of column must be a string or character?
For example:
library(data.table)
DT = data.table(v1=c(1,2,3), v2=2:4)
new_var <- "v3"
DT[, new_var:=v2+5]
I Get
DT
#> v1 v2 new_var
#> 1: 1 2 7
#> 2: 2 3 8
#> 3: 3 4 9
But, I want
#> v1 v2 v3
#> 1: 1 2 7
#> 2: 2 3 8
#> 3: 3 4 9