Hi, If I have a matrix like 1 2 3 4 5 6 7 8, how can I repeat two rows as whole, to be like 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8? Since I have more two rows in a matrix and I need to repeat many times, I wonder whether there is a convenient command to do so. Thanks! [[alternative HTML version deleted]]
> a <- matrix(1:8, 2, 4, byrow=TRUE) > a[,1] [,2] [,3] [,4] [1,] 1 2 3 4 [2,] 5 6 7 8> a[c(1,2,1,2),][,1] [,2] [,3] [,4] [1,] 1 2 3 4 [2,] 5 6 7 8 [3,] 1 2 3 4 [4,] 5 6 7 8>On Wed, Apr 25, 2012 at 8:32 PM, Rebecca <rebecca0420@yahoo.cn> wrote:> Hi, > If I have a matrix like > 1 2 3 4 > 5 6 7 8, > how can I repeat two rows as whole, to be like > 1 2 3 4 > 5 6 7 8 > 1 2 3 4 > 5 6 7 8? > > Since I have more two rows in a matrix and I need to repeat many times, I > wonder whether there is a convenient command to do so. > > Thanks! > [[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<http://www.r-project.org/posting-guide.html> > and provide commented, minimal, self-contained, reproducible code. > >[[alternative HTML version deleted]]
Yes, integer vector indexing. You haven't provided R code to work with so I will just refer you to read the pdf "An Introduction to R" included with most R installations for more details. --------------------------------------------------------------------------- Jeff Newmiller The ..... ..... Go Live... DCN:<jdnewmil at dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go... Live: OO#.. Dead: OO#.. Playing Research Engineer (Solar/Batteries O.O#. #.O#. with /Software/Embedded Controllers) .OO#. .OO#. rocks...1k --------------------------------------------------------------------------- Sent from my phone. Please excuse my brevity. Rebecca <rebecca0420 at yahoo.cn> wrote:>Hi, >If I have a matrix like >1? 2? 3? 4 >5? 6? 7? 8, >how can I repeat two rows as whole, to be like >1? 2? 3? 4 >5? 6? 7? 8 >1? 2? 3? 4 >5? 6? 7? 8? >? >Since I have more two rows in a matrix and I need to repeat many times, >I wonder whether there is a convenient command to do so. >? >Thanks! > [[alternative HTML version deleted]] > >______________________________________________ >R-help at 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.
Hi what about rbind(a,a) [,1] [,2] [,3] [,4] [1,] 1 2 3 4 [2,] 5 6 7 8 [3,] 1 2 3 4 [4,] 5 6 7 8 Regards Petr> > > a <- matrix(1:8, 2, 4, byrow=TRUE) > > a > [,1] [,2] [,3] [,4] > [1,] 1 2 3 4 > [2,] 5 6 7 8 > > a[c(1,2,1,2),] > [,1] [,2] [,3] [,4] > [1,] 1 2 3 4 > [2,] 5 6 7 8 > [3,] 1 2 3 4 > [4,] 5 6 7 8 > > > > On Wed, Apr 25, 2012 at 8:32 PM, Rebecca <rebecca0420 at yahoo.cn> wrote: > > > Hi, > > If I have a matrix like > > 1 2 3 4 > > 5 6 7 8, > > how can I repeat two rows as whole, to be like > > 1 2 3 4 > > 5 6 7 8 > > 1 2 3 4 > > 5 6 7 8? > > > > Since I have more two rows in a matrix and I need to repeat manytimes, I> > wonder whether there is a convenient command to do so. > > > > Thanks! > > [[alternative HTML version deleted]] > > > > > > ______________________________________________ > > R-help at 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. > > > > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guidehttp://www.R-project.org/posting-guide.html> and provide commented, minimal, self-contained, reproducible code.