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

[Boris Steipe]

That would be the "each" argument to rep()...
n <- 5
rep(1:n, each=4)
 [1] 1 1 1 1 2 2 2 2 3 3 3 3 4 4 4 4 5 5 5 5

Cheers,
B.


On Apr 19, 2015, at 9:44 AM, 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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