# [R] Combinations with two part column

Sofyan Iyan sofyan.iyan at gmail.com
Tue May 17 22:24:24 CEST 2005

```Thanks for you quick answer.
Could I extend my question?
How to make the result for each rows with comma ",";
> library(gtools)
> comb8.5 <- t(apply(combinations(8,5), 1, function(x) c(x,setdiff(1:8, x))))
> comb8.5[,1:5]
[,1] [,2] [,3] [,4] [,5]
[1,]    1    2    3    4    5
[2,]    1    2    3    4    6
[3,]    1    2    3    4    7
[4,]    1    2    3    4    8
[5,]    1    2    3    5    6
[6,]    1    2    3    5    7
...

I mean like:
1,    2,    3,    4,    5
1,    2,    3,    4,    6
1,    2,    3,    4,    7
1,    2,    3,    4,    8
1,    2,    3,    5,    6
1,    2,    3,    5,    7

> comb8.5[,6:8]
[,1] [,2] [,3]
[1,]    6    7    8
[2,]    5    7    8
[3,]    5    6    8
[4,]    5    6    7
[5,]    4    7    8
[6,]    4    6    8
...

this below like:
6,    7,    8
5,    7,    8
5,    6,    8
5,    6,    7
4,    7,    8
4,    6,    8

Best,
Sofyan

On 5/17/05, Gabor Grothendieck <ggrothendieck at gmail.com> wrote:
> On 5/17/05, Sofyan Iyan <sofyan.iyan at gmail.com> wrote:
> > Dear R-helpers,
> > I am a beginner using R.
> > This is the first question in this list.
> > My question, Is there possible to make combinations with two part column?
> > If I have a number 1,2,3,4,5,6,7,8. I need the result something like below:
> >
> > 1,2,3,4,5     6,7,8
> > 1,2,3,4,7     5,6,8
> > 2,3,4,5,6     1,7,8
> > 1,2,3,6,7     4,5,8
> > 1,2,3,4,8     5,6,7
> > 3,4,6,7,8     1,2,5
> > ....
> >
>
> Try this:
>
> library(gtools)
> t(apply(combinations(8,5), 1, function(x) c(x,setdiff(1:8, x))))
>

```