[R] rbind for matrices - rep argument

[Dimitris Rizopoulos]

you can use indexing, e.g.,

mat <- matrix(rnorm(20), 4, 5)

mat
mat[rep(1:nrow(mat), 3), ]


I hope it helps.

Best,
Dimitris


Niccolò Bassani wrote:
> Dear R users,I'm facing a trivial problem, but I really can't solve it. I've
> tried a dozen of codes, but I can't get the result I want.
> The question is: I have a dataframe like this one
> 
> [,1] [,2] [,3] [,4] [,5]
> [1,]    1    2    3    4    5
> [2,]    2    5    5    4    9
> [3,]    1    6    8    1    2
> [4,]    8    6    4    1    5
> 
> made up of decimal numbers, of course.
> I want to append this dataframe to itself a number x of times, i.e. 3. That
> is I want a dataframe like this
> 
> 
> [,1] [,2] [,3] [,4] [,5]
> [1,]    1    2    3    4    5
> [2,]    2    5    5    4    9
> [3,]    1    6    8    1    2
> [4,]    8    6    4    1    5
> [5,]    1    2    3    4    5
> [6,]    2    5    5    4    9
> [7,]    1    6    8    1    2
> [8,]    8    6    4    1    5
> [9,]    1    2    3    4    5
> [10,]    2    5    5    4    9
> [11,]    1    6    8    1    2
> [12,]    8    6    4    1    5
> 
> I'm searching for an "authomatic" way to do this (I've already used the
> rbind re-writing x times the name of the frame...), as it must enter a
> function where one argument is exactly the number x of times to repeat this
> frame.
> 
> Any ideas??
> Thanks in advance!
> 
> Niccolò
> 
> 	[[alternative HTML version deleted]]
> 
> 
> 
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-- 
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus Medical Center

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