[R] Odd subsetting behaviour

[Peter Alspach]

Tena koe

Compare

1:3%/%2

and 

1:(3%/%2)

HTH ...

Peter Alspach

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of math_daddy
> Sent: Wednesday, 7 July 2010 5:57 a.m.
> To: r-help at r-project.org
> Subject: [R] Odd subsetting behaviour
> 
> 
> Hello. I've observed some odd behaviour. Most likely, it is already
> known and
> explained somewhere, but I can't find an explanation anywhere, so I
> would
> appreciate being pointed in the right direction.
> 
> The issue with the following code is self explanatory:
> 
> > mat <- matrix(c(c(1,1,1),c(2,2,2)),nrow=3)
> > mat[,c(1:3%/%2)]
>      [,1] [,2]
> [1,]    1    1
> [2,]    1    1
> [3,]    1    1
> > n <- 3%/%2
> > mat[,c(1:n)]
> [1] 1 1 1
> 
> What I want to know is, why does it give the first column twice when
> 3%/%2
> is computed within the subset call, and just the first row when it is
> computed outside?
> 
> Thanks very much in advance.
> --
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> subsetting-behaviour-tp2279957p2279957.html
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> 
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