LambdaVu LambdaVu - 1 month ago 8
R Question

Copying multiple columns from one data.frame to another

Is there a simple way to make R automatically copy columns from a data.frame to another?

I have something like:

>DF1 <- data.frame(a=1:3, b=4:6)
>DF2 <- data.frame(c=-2:0, d=3:1)


and I want to get something like

>DF1
a b c d
1 -2 4 -2 3
2 -1 5 -1 2
3 0 6 0 1


I'd normally do it by hand, as in

DF1$c <- DF2$c
DF1$d <- DF2$d


and that's fine as long as I have few variables, but it becomes very time consuming and prone to error when dealing with several variables. Any idea on how to do this efficiently? It's probably quite simple but I swear I wasn't able to find an answer googling, thank you!

Answer

The result from your example is not correct, it should be:

> DF1$c <- DF2$c
> DF1$d <- DF2$d
> DF1
  a b  c d
1 1 4 -2 3
2 2 5 -1 2
3 3 6  0 1

Then cbind does exactly the same:

> cbind(DF1, DF2)
  a b  c d
1 1 4 -2 3
2 2 5 -1 2
3 3 6  0 1