[R] Combine by columns a vector with another vector that is constant across rows

Jeff Newmiller jdnewm|| @end|ng |rom dcn@d@v|@@c@@u@
Tue Jul 3 17:21:47 CEST 2018


Gabor's solution seems to optimize 'simpler'.

More efficient is to learn that in R a vector is not a matrix, but a matrix is just an ornamented vector.

fastWolfgang <- function( v, vec ) {
  matrix( c( v, rep( vec, length( v ) ) )
         , now = length( v ) )
}

On July 3, 2018 6:28:45 AM PDT, "Viechtbauer, Wolfgang (SP)" <wolfgang.viechtbauer using maastrichtuniversity.nl> wrote:
>Hi All,
>
>I have one vector that I want to combine with another vector and that
>other vector should be the same for every row in the combined matrix.
>This obviously does not work:
>
>vec <- c(2,4,3)
>cbind(1:5, vec)
>
>This does, but requires me to specify the correct value for 'n' in
>replicate():
>
>cbind(1:5, t(replicate(5, vec)))
>
>Other ways that do not require this are:
>
>t(sapply(1:5, function(x) c(x, vec)))
>do.call(rbind, lapply(1:5, function(x) c(x, vec)))
>t(mapply(c, 1:5, MoreArgs=list(vec)))
>
>I wonder if there is a simpler / more efficient way of doing this.
>
>Best,
>Wolfgang
>
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-- 
Sent from my phone. Please excuse my brevity.




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