permutations in R

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.
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