I can specify a range of columns in data.table using: first_col:last_col and can subset the data.table using that syntax. But if I want to set the same columns to NULL, data.table says it can't 'find' the columns (see below).
Why is that? And how can I delete a range of columns using "first_col:last_col" syntax?
library(data.table)
d <- data.table(a = 1:3, b = 4:6, c = 7:9)
# a b c
# <int> <int> <int>
# 1: 1 4 7
# 2: 2 5 8
# 3: 3 6 9
d[, b:c ]
# b c
# <int> <int>
# 1: 4 7
# 2: 5 8
# 3: 6 9
d[, b:c := NULL ]
#Error in eval(lhs, parent.frame(), parent.frame()) : object 'b' not found