Message-ID: <OFB34B1756.53ABB58B-ONC1257551.00581C4F-C1257551.0058516F@precheza.cz>
Date: 2009-02-02T16:05:10Z
From: PIKAL Petr
Subject: Odp: Matrix
In-Reply-To: <21792064.post@talk.nabble.com>
Hi
r-help-bounces at r-project.org napsal dne 02.02.2009 16:52:06:
>
> Hi,
>
> I have a very basic question on merging two matrices by alternating the
> rows. For illustration, assume two matrices -
>
> A looks like:
>
> 10 10
> 10 10
>
> B looks like:
>
> 20 20
> 20 20
>
> How do I combine them such that I get alternating rows from A and B? My
> final result should be C which looks like:
>
> 10 10
> 20 20
> 10 10
> 20 20
I would rbind both matrices and then indexed the resulting matrix.
x<-rep(10,4)
y<-rep(20,4)
dim(x)<-c(2,2)
dim(y)<-c(2,2)
z<-rbind(x,y)
> z
[,1] [,2]
[1,] 10 10
[2,] 10 10
[3,] 20 20
[4,] 20 20
ind<-c(seq(1,4,2), seq(2,4,2))
z[ind,]
> z[ind,]
[,1] [,2]
[1,] 10 10
[2,] 20 20
[3,] 10 10
[4,] 20 20
Regards
Petr
>
> Thanks very much, and I am sorry for such a newbie question.
>
> Shruthi
> --
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http://www.nabble.com/Matrix-tp21792064p21792064.html
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>
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