I want to select rows with duplicated id but keep both rows in the resulting dataset. Here is the original dataset:
dd <- data.frame(id=c(1,1,2,2,3,4,4,5,6,7,7),
coder=c(1,2,1,2,1,1,2,1,1,1,2)
)
dd
id coder
1 1
1 2
2 1
2 2
3 1
4 1
4 2
5 1
6 1
7 1
7 2
In the end, I want this:
id coder
1 1
1 2
2 1
2 2
4 1
4 2
7 1
7 2
I tried subset(dd, duplicated(id)) but it only kept one row:
id coder
1 2
2 2
4 2
7 2
How to achieve that?
