CODEWITHSUNDEEP
r
ashim
ashim

Reputation: 25560

R. how to make matrix which have equal rows

I have row f. I want create matrix R such that every row of it is equal f. What is the most efficient way to do it in R?

Upvotes: 7

Views: 5908

Answers (3)

IRTFM
IRTFM

Reputation: 263342

R <-  matrix(f, 1)[rep(1,n), ]
     [,1] [,2] [,3] [,4] [,5]
[1,]    1    2    3    4    5
[2,]    1    2    3    4    5
[3,]    1    2    3    4    5
[4,]    1    2    3    4    5
[5,]    1    2    3    4    5

Or even more compact:

R <- rbind(f)[rep(1,n), ]
  [,1] [,2] [,3] [,4] [,5]
f    1    2    3    4    5
f    1    2    3    4    5
f    1    2    3    4    5
f    1    2    3    4    5
f    1    2    3    4    5

Note that rownames of matrices do not need to be unique, unlike the case with data.frames.

Upvotes: 5

Greg Snow
Greg Snow

Reputation: 49640

Here is one possibility:

mymat <- do.call( rbind, rep(list(f), 10) )

Upvotes: 3

Seth
Seth

Reputation: 4795

with a row

f=c(1,22,33,44,55,66)

get its length

lf=length(f)

Then make the matrix

R=matrix(rep(f,lf),
         ncol=lf,
         byrow=T)

Gives:

R
     [,1] [,2] [,3] [,4] [,5]
[1,]    1   33   44   55   66
[2,]    1   33   44   55   66
[3,]    1   33   44   55   66
[4,]    1   33   44   55   66
[5,]    1   33   44   55   66

Upvotes: 9

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