[R] Integer Sample with Mean Dependent on Size

[Richard O'Keefe]

I don't know why I thought you wanted a *random* sequence..
The 'rep' function can do more than you realise.

generate_k <- function (N, n3) rep(1:3, c(n3+2, N-2-n3*2, n3))



On Thu, 1 Aug 2019 at 22:48, Lorenzo Isella <lorenzo.isella using gmail.com>
wrote:

> Yes, you are right (and yours is one of the possible cases).
> I think this works (I resorted to pen and paper for once)
>
>
>
> generate_k <- function(N, n3){
>
>     n1 <- 2+n3
>     n2 <- N-n1-n3
>
>
>     out <- c(rep(1, n1), rep(2, n2), rep(3, n3))
>
>     return(out)
> }
>
> where N is the length of the sample, n3 is the number of times I have the
> number 3 in the sample (n1 and n2 are the same for 1 and 2, respectively).
> So far it holds!
>
> L.
>
> On Thu, Aug 01, 2019 at 12:37:47PM +0200, Gerrit Eichner wrote:
> >n_1 + ... + n_N = 2(N-1) is requested for integers n_i >= 1.
> >
> >What about c(rep(2, N-2), 1, 1))?
> >
> >but I'm afraid that this was not what you really wanted. ;-)
> >However, you didn't say if your sample should be random. :-)
> >
> > Best regards  --  Gerrit
> >
> >---------------------------------------------------------------------
> >Dr. Gerrit Eichner                   Mathematical Institute, Room 212
> >gerrit.eichner using math.uni-giessen.de   Justus-Liebig-University Giessen
> >Tel: +49-(0)641-99-32104          Arndtstr. 2, 35392 Giessen, Germany
> >http://www.uni-giessen.de/eichner
> >---------------------------------------------------------------------
> >
> >Am 01.08.2019 um 12:27 schrieb Lorenzo Isella:
> >>Dear All,
> >>I cannot unfortunately provide any R code, otherwise I
> >>would not need to post this in the first place.
> >>I need to generate a sample of N positive non-zero
> >>integers such that their mean is *exactly* 2(N-1)/N,
> >>i.e. the mean depends on the length of the sample.
> >>For a start, we can assume that every integer in my
> >>sample can assume only the values 1, 2 and 3.
> >>Any suggestion is appreciated.
> >>Cheers
> >>
> >>Lorenzo
> >>
> >>______________________________________________
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> >>PLEASE do read the posting guide
> >>http://www.R-project.org/posting-guide.html
> >>and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
>

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