Subsetting data.table using variables with same name as column
Solution 1:
For now, a temporary solution could be,
`..` <- function (..., .env = globalenv())
{
get(deparse(substitute(...)), env = .env)
}
..(a)
## [1] "b"
dt[a==..(a)]
## a b c
## 1: b a 15
## 2: b a 11
## 3: b b 8
## 4: b b 4
## 5: b c 5
## 6: b c 12
Though this looks elegant, I am still waiting for a more robust solution to such scope issues.
Edited according to @mnel's suggestion,
`..` <- function (..., .env = sys.parent(2))
{
get(deparse(substitute(...)), env = .env)
}
Solution 2:
Now it's simple (since ..()
syntax introduced in data.table):
dt[eval(dt[, a %in% ..a])]
or even simpler in your particular case (since a
is a 1st column):
dt[eval(.(a))] # identical to dt["b"]