## Hi, I'm having trouble understanding how the cbind function decides what
method to apply to its arguments. Easy cut and paste code below.
>
>
>
> ## create two columns
> c1 <- c("A","A","B","B")
> c2 <- 1:4
>
> ## cbind outputs a matrix with elements that are characters, seems
reasonable
> out <- cbind(c1,c2)
> out
c1 c2
[1,] "A" "1"
[2,] "A" "2"
[3,] "B" "3"
[4,] "B" "4"
> class(out)
[1] "matrix"
> mode(out)
[1] "character"
>
>
> ## there are two methods associated with cbind. so i assume that
> ## cbind is calling the data.frame method, because neither of my
> ## arguments are of ts class
> methods(cbind)
[1] cbind.data.frame cbind.ts*
Non-visible functions are asterisked
>
>
> ## now i explicitly tell cbind to use the data.frame method
> ## (which is what i assumed it was doing automatically in the last
example)
> ## but this produces something very different from before, a data.frame
> out2 <- cbind.data.frame(c1,c2)
> out2
c1 c2
1 A 1
2 A 2
3 B 3
4 B 4
> class(out2)
[1] "data.frame"
> mode(out2)
[1] "list"
>
>
> ## can someone explain why these outputs are different. Thanks, James.
>
c1 <- c("A","A","B","B")
c2 <- 1:4
out <- cbind(c1,c2)
out
class(out)
mode(out)
methods(cbind)
out2 <- cbind.data.frame(c1,c2)
out2
class(out2)
mode(out2)
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