From: Peter Dalgaard <p.dalgaard_at_biostat.ku.dk>

Date: Sat 16 Jul 2005 - 20:20:35 EST

Date: Sat 16 Jul 2005 - 20:20:35 EST

(Ted Harding) <Ted.Harding@nessie.mcc.ac.uk> writes:

> On 16-Jul-05 Mauro Gasparini wrote:

*> >
**> > Dear users,
**> >
**> > I have a list of several matrices with the same number of columns,
**> > how do I rbind them all with a vectorized command?
**> >
**> > A related simpler question is, how do I vectorize the instruction
**> > that rbinds together several copies of the same matrix?
**>
**> Didn't you simply try:
**>
**> > A<-matrix(c(1.1,1.2,1.3,1.4,1.5,1.6),ncol=3)
**> > B<-matrix(c(2.1,2.2,2.3,2.4,2.5,2.6),ncol=3)
**> > C<-matrix(c(3.1,3.2,3.3,3.4,3.5,3.6),ncol=3)
**> > A
**> [,1] [,2] [,3]
**> [1,] 1.1 1.3 1.5
**> [2,] 1.2 1.4 1.6
**> > B
**> [,1] [,2] [,3]
**> [1,] 2.1 2.3 2.5
**> [2,] 2.2 2.4 2.6
**> > C
**> [,1] [,2] [,3]
**> [1,] 3.1 3.3 3.5
**> [2,] 3.2 3.4 3.6
**> > rbind(A,B,C)
**> [,1] [,2] [,3]
**> [1,] 1.1 1.3 1.5
**> [2,] 1.2 1.4 1.6
**> [3,] 2.1 2.3 2.5
**> [4,] 2.2 2.4 2.6
**> [5,] 3.1 3.3 3.5
**> [6,] 3.2 3.4 3.6
**> > rbind(A,A,A)
**> [,1] [,2] [,3]
**> [1,] 1.1 1.3 1.5
**> [2,] 1.2 1.4 1.6
**> [3,] 1.1 1.3 1.5
**> [4,] 1.2 1.4 1.6
**> [5,] 1.1 1.3 1.5
**> [6,] 1.2 1.4 1.6
**>
**> If there's an exception under which the above does not work,
**> I'd be interested to hear of it!
*

If the matrices literally are in a list, you might need

do.call("rbind", l)

which for multiple copies (5, say) of the same matrix might be done via

M <- matrix(1:4,2)

MM <- do.call("rbind",replicate(5, M, simplify=FALSE))

although it might be more efficient with

MM <- matrix(t(M),5*2,2,byrow=T)

-- O__ ---- Peter Dalgaard ุster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - (p.dalgaard@biostat.ku.dk) FAX: (+45) 35327907 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.htmlReceived on Sat Jul 16 20:24:24 2005

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