[R] Pairwise combination

[chen jia]

Thanks, everyone.

combn function works pretty well for me.

Best,
Jia

On Tue, May 11, 2010 at 5:12 PM, Henrique Dallazuanna <wwwhsd at gmail.com> wrote:
> Or:
>
> combn(1:4, 2, paste, collapse = ' and ')
>
> On Tue, May 11, 2010 at 5:54 PM, Ista Zahn <istazahn at gmail.com> wrote:
>>
>> On Tuesday 11 May 2010 4:27:01 pm David Winsemius wrote:
>> > On May 11, 2010, at 1:45 PM, chen jia wrote:
>> > > Hi there,
>> > >
>> > > I am looking for a function that takes a vector as input and generates
>> > > all pair wise combination of the elements of the input vector.
>> >
>> > ?combn
>> >
>> > > For example, the input vector is c(1,2,3,4). The output vector is c(1
>> > > and 2, 1 and 3, 1 and 4, 2 and 3, 2 and 4, 3 and 4).
>> >
>> > That's not a vector.
>>
>> True, although it is possible the OP wanted paste(combn(1:4, 2)[1,],
>> "and",
>> combn(1:4, 2)[2,])
>>
>> -Ista
>>
>> >
>> > > The
>> > > representation here is generic.
>> > >
>> > > I can use a for loop to do it, but it gets slow when the number of
>> > > elements of the input vector is large.
>> > >
>> > > Best,
>> > > Jia
>> >
>> > David Winsemius, MD
>> > West Hartford, CT
>> >
>> > ______________________________________________
>> > R-help at r-project.org mailing list
>> > https://stat.ethz.ch/mailman/listinfo/r-help
>> > PLEASE do read the posting guide
>> > http://www.R-project.org/posting-guide.html and provide commented,
>> > minimal, self-contained, reproducible code.
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
>
>
> --
> Henrique Dallazuanna
> Curitiba-Paraná-Brasil
> 25° 25' 40" S 49° 16' 22" O
>



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