repeating rows or columns within a matrix
Juhana Vartiainen wrote:
Hello Spse I have a matrix, say 1 2 3 4 5 6 7 8 9 and I would like to expand it by repeating rows within the matrix, to get, if the repeating factor is 2, say: 123 123 456 456 789 789 (or columnwise as well) . There must be a smart way of doing that?
You could do something like that:
R> mymatrix <- matrix(1:9, ncol=3)
R> myindex <- rep(1:nrow(mymatrix), rep(2, nrow(mymatrix)))
R> mymatrix[myindex,]
[,1] [,2] [,3]
[1,] 1 4 7
[2,] 1 4 7
[3,] 2 5 8
[4,] 2 5 8
[5,] 3 6 9
[6,] 3 6 9
Best,
Z
Many thanks Juhana Vartiainen juhana.vartiainen at labour.fi -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
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