[R] permutations in R

Stavros Macrakis macrakis at alum.mit.edu
Mon Mar 16 23:43:07 CET 2009


Greg,

Thanks for helping this user.

I assume you mean the permn function in the combinat package? For a
new user (including me), it is not obvious how to get from "the
permutations function in the Combinations package" to that.

I see there is also a function gtools::permutations.  The gtools
package seems to be more recent than combinat, but I don't know if it
is better.  You might expect a utils::permn since there is a
utils::combn, but there isn't one....

I'm not bringing this up because I am bloody-minded, but because I
think it's a serious issue with the R libraries -- there is no obvious
way to find relevant functions, and no way of knowing which one to use
if there is more than one.  Or am I missing some trick?

Thanks,

              -s


On Mon, Mar 16, 2009 at 3:26 PM, Greg Snow <Greg.Snow at imail.org> wrote:
> Look at the permutations function in the Combinations package.  Using the "fun" argument may accomplish what you want.  If not, there are references on the help page to other code that may work for you.
>
> Hope this helps,
>
> --
> Gregory (Greg) L. Snow Ph.D.
> Statistical Data Center
> Intermountain Healthcare
> greg.snow at imail.org
> 801.408.8111
>
>
>> -----Original Message-----
>> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
>> project.org] On Behalf Of onyourmark
>> Sent: Friday, March 13, 2009 7:09 PM
>> To: r-help at r-project.org
>> Subject: [R] permutations in R
>>
>>
>> Hi. Does anyone know of a function which will take as input a number n
>> (or a
>> set of n letters) and will give out, one at a time, the permutations of
>> n
>> (or of those n letters) as a vector?
>> So that I can use the permutations one at a time. And such that it will
>> exhaust all the permutations with no repeats.
>>
>> For example if n is 3, I would want a function which I could use in a
>> loop
>> and the first time I use it in the loop it may give the vector
>> 123
>> and then the next time in the loop it may give
>> 132
>> and so on until after 6 iterations through the loop I would get all 6
>> permutations of 123.
>>
>> Thank you.
>> --
>> View this message in context: http://www.nabble.com/permutations-in-R-
>> tp22507989p22507989.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
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>> and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-help at r-project.org mailing list
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>




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