# [R] binary order combinations

Dimitri Liakhovitski ld7631 at gmail.com
Fri Sep 5 17:23:20 CEST 2008

```I am not sure it can do it. Besides, I ran a test of combos from quantreg:

library(quantreg)
H<-1:3
test.combos<-lapply(1:3,function(x)
{combn(H,x)
})

Every time I tried it crashed my R...

:(

Dimitri

On 9/5/08, roger koenker <rkoenker at uiuc.edu> wrote:
> Does ?combos in the quantreg package do what you want?
>
>
> url:    www.econ.uiuc.edu/~roger            Roger Koenker
> email    rkoenker at uiuc.edu            Department of Economics
> vox:     217-333-4558                University of Illinois
> fax:       217-244-6678                Champaign, IL 61820
>
>
>
>
> On Sep 5, 2008, at 9:58 AM, Dimitri Liakhovitski wrote:
>
> >
> > Dear all!
> >
> > I have a vector of names
> > names<-("V1", "V2", "V3",....., "V15")
> >
> > I could create all possible combinations of these names (of all
> > lengths) using R:
> >
> > combos<-lapply(1:15,function(x)
> > {combn(names,x)
> > })
> >
> > I get a list with all possible combinations of elements of 'names'
> > that looks like this (just the very beginning of it):
> >
> > [[1]] - the first element contains all combinations of 1 name
> >    [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10] [,11] [,12] [,13]
> [,14]
> > [1,] "V1" "V2" "V3" "V4" "V5" "V6" "V7" "V8" "V9" "V10" "V11" "V12" "V13"
> "V14"
> >    [,15]
> > [1,] "V15"
> >
> > [[2]] - the second element contains all possible combinations of 2 names
> >    [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9]  [,10] [,11] [,12] [,13]
> > [1,] "V1" "V1" "V1" "V1" "V1" "V1" "V1" "V1" "V1"  "V1"  "V1"  "V1"  "V1"
> > [2,] "V2" "V3" "V4" "V5" "V6" "V7" "V8" "V9" "V10" "V11" "V12" "V13" "V14"
> > .
> > .
> > .
> > etc.
> >
> > My question is: Is there any way to re-arrange all sub-elements of the
> > above list (i.e., all possible combinations of names such as V1,
> > V1:V3, V1:V2:V4:V5) in a binary system order. More specifically,
> > according to this system:
> > V1=1
> > V2=2
> > V3=4
> > V4=8
> > V5=16, etc....
> >
> > So, I'd like those combinations to be arranged in a vector in the
> > following order:
> > 1. V1 (because V1=1)
> > 2. V2 (because V2=2)
> > 3. V1:V2 (because V1=1 and V2=2 so that 1+2=3)
> > 4. V3 (because V3=4)
> > 5. V1:V3 (because V1=1 and V3=4 so that 1+4=5)
> > 6. V2:V3 (because V2=2 and V3=4 so that 2+4=6)
> > 7. V1:V2:V3 (because V1=1 and V2=2 and V3=4 so that 1+2+4=7)
> > 8. V4 (because V4=8)
> > etc.
> >
> > Is it at all possible?
> > Or maybe there is a way to create the name combinations in such an
> > order in the first place?
> >
> > Thank you very much!
> > Dimitri Liakhovitski
> >
> > ______________________________________________
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