# Re: [R] Combinations with two part column

From: Sofyan Iyan <sofyan.iyan_at_gmail.com>
Date: Wed 18 May 2005 - 06:24:24 EST

[,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@gmail.com> wrote:
> On 5/17/05, Sofyan Iyan <sofyan.iyan@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))))
>

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