You can try something like: mtx <- matrix(1:4, ncol = 2)
mtx.rep <- t(apply(mtx, 1, rep, r)) mtx.rep <- cbind(mrx.rep, new.column) where r is your desired number of replications . Hope it helps, Boyko Joshua Wiley-2 wrote: > > Hello Wendy, > > The simplest solution that comes to mind is to just use cbind. > > For instance: > >> x <- matrix(1:4, nrow=2) > >> x > [,1] [,2] > [1,] 1 3 > > [2,] 2 4 > >> cbind(x,x,x,c(2,5)) # repeat x here as many times as needed > > [,1] [,2] [,3] [,4] [,5] [,6] [,7] > [1,] 1 3 1 3 1 3 2 > > [2,] 2 4 2 4 2 4 5 > > I hope that helps. Admittedly, this is not the best solution if you need > to > replicate a matrix many times. > > Best, > > Joshua > > On Sat, Feb 20, 2010 at 6:58 PM, wendy <wendy.q...@utoronto.ca> wrote: > >> >> Hi all, >> >> I have a matrix, for example >> [,1] [,2] >> [1,] 1 3 >> [2,] 4 6 >> >> I want to replicate the matrix twice and add an extra column at the end, >> which is >> [,1] [,2] [,3] [,4] [,5] [,6] [,7] >> [1,] 1 3 1 3 1 3 2 >> [2,] 4 6 4 6 4 6 5 >> >> I found 'rep' only works for vector. Does anyone know how to replicate a >> matrix, and append the matrix? >> >> Thank you in advance, >> Wendy >> >> >> -- >> View this message in context: >> http://n4.nabble.com/replicate-matrix-tp1563337p1563337.html >> Sent from the R help mailing list archive at Nabble.com. >> >> ______________________________________________ >> R-help@r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide >> http://www.R-project.org/posting-guide.html<http://www.r-project.org/posting-guide.html> >> and provide commented, minimal, self-contained, reproducible code. >> > > > > -- > Joshua Wiley > Senior in Psychology > University of California, Riverside > http://www.joshuawiley.com/ > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > > -- View this message in context: http://n4.nabble.com/replicate-matrix-tp1563337p1563360.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
