On Jan 4, 2012, at 10:32 AM, jeremy wrote:
> Hi all,
>
> I'm trying to combine exhaustively several character arrays in R like:
> x=c("one","two","three")
> y=c("yellow","blue","green")
> z=c("apple","cheese")
>
> in order to get concatenation of
>
> x[1] y[1] z[1] ("one yellow apple")
> x[1] y[1] z[2] ("one yellow cheese")
> x[1] y[2] z[1]("one blue apple")
> ...
> x[length(x)] y[length(y)] z[length(z)] ("three green cheese")
>
> Anyone has a solution ?
> Thank in advance
See ?expand.grid and ?paste
DF <- expand.grid(x, y, z)
> DF
Var1 Var2 Var3
1 one yellow apple
2 two yellow apple
3 three yellow apple
4 one blue apple
5 two blue apple
6 three blue apple
7 one green apple
8 two green apple
9 three green apple
10 one yellow cheese
11 two yellow cheese
12 three yellow cheese
13 one blue cheese
14 two blue cheese
15 three blue cheese
16 one green cheese
17 two green cheese
18 three green cheese
> with(DF, paste(Var1, Var2, Var3))
[1] "one yellow apple" "two yellow apple" "three yellow apple"
[4] "one blue apple" "two blue apple" "three blue apple"
[7] "one green apple" "two green apple" "three green apple"
[10] "one yellow cheese" "two yellow cheese" "three yellow cheese"
[13] "one blue cheese" "two blue cheese" "three blue cheese"
[16] "one green cheese" "two green cheese" "three green cheese"
HTH,
Marc Schwartz