[R] generate a list as follows: 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, . . . . ., n, n, n, n

[SOUVIK BANDYOPADHYAY]

Hi,
You can use the apply group of functions

n<-5
k<-4

unlist(lapply(1:n,rep, each=k)) # For vector output:
sapply(1:n,rep, each=k) # For a matrix output

Hope this helps
Souvik

On Sun, Apr 19, 2015 at 7:14 PM, John Sorkin <JSorkin at grecc.umaryland.edu>
wrote:

> Windows 7 64-bit
> R 3.1.3
> RStudio 0.98.1103
>
>
> I am trying to generate a list of  length 4n which consists of the
> integers 1 to n repeated in groups of four, i.e.
>
> 1,1,1,1,  2,2,2,2,  3,3,3,3, . . . . , n,n,n,n
>
> (The spaces in the list are added only for clarity.)
>
>  I can generate the list as follows, but the code must be modified for any
> value n, and the code is UGLY!
>
> c(rep(1,4), rep(2,4), rep(3,4), . . . ,c(n,4))
>
> Can anyone help me?
>
> Thank you,
> John
>
> John David Sorkin M.D., Ph.D.
> Professor of Medicine
> Chief, Biostatistics and Informatics
> University of Maryland School of Medicine Division of Gerontology and
> Geriatric Medicine
> Baltimore VA Medical Center
> 10 North Greene Street
> GRECC (BT/18/GR)
> Baltimore, MD 21201-1524
> (Phone) 410-605-7119410-605-7119
> (Fax) 410-605-7913 (Please call phone number above prior to faxing)
>
>
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>
> John David Sorkin M.D., Ph.D.
> Professor of Medicine
> Chief, Biostatistics and Informatics
> University of Maryland School of Medicine Division of Gerontology and
> Geriatric Medicine
> Baltimore VA Medical Center
> 10 North Greene Street
> GRECC (BT/18/GR)
> Baltimore, MD 21201-1524
> (Phone) 410-605-7119410-605-7119
> (Fax) 410-605-7913 (Please call phone number above prior to faxing)
>
>
>
>
> John David Sorkin M.D., Ph.D.
> Professor of Medicine
> Chief, Biostatistics and Informatics
> University of Maryland School of Medicine Division of Gerontology and
> Geriatric Medicine
> Baltimore VA Medical Center
> 10 North Greene Street
> GRECC (BT/18/GR)
> Baltimore, MD 21201-1524
> (Phone) 410-605-7119
> (Fax) 410-605-7913 (Please call phone number above prior to faxing)
>
>
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