Re: [R] accessing dimension names

From: Petr PIKAL <petr.pikal_at_precheza.cz>
Date: Tue, 18 Dec 2007 14:54:56 +0100


Hard to help as i do not have "y" and it definitelly is not a matrix as you tried to pretend.

  1. Try to look at structure of your y object by str(y)
  2. Try to learn about how to extract parts of objects e.g. by reading ?"["
  3. Try to use what you learned on your y object
  4. If you still does not get what you want then make some example which can be reproduced and ask again

> mat<-matrix(rnorm(12),3,4)
> dmat<-data.frame(mat)
> dimnames(dmat)

[[1]]
[1] "1" "2" "3"

[[2]]
[1] "X1" "X2" "X3" "X4"

> dimnames(dmat)[1]

[[1]]
[1] "1" "2" "3"

> dimnames(dmat)[1][1]

[[1]]
[1] "1" "2" "3"

> dimnames(dmat)[[1]][1]

[1] "1"

Regards

Petr
petr.pikal_at_precheza.cz

born.to.b.wyld_at_gmail.com napsal dne 18.12.2007 14:25:06:

> Thanks. Actually, I need something else as well.
>
> I need to get as.numeric(dimnames(y)$x93[1]), which in this case is 1. I
tried
> as.numeric(dimnames(y)$paste('x',idx,sep='')[1]), and it did not work.
>
> Please help.
>
>
>

> On Dec 18, 2007 6:26 AM, Petr PIKAL <petr.pikal_at_precheza.cz> wrote:
> Hi
>
> r-help-bounces@r-project.org napsal dne 18.12.2007 12:01:41:
>
> > I have a matrix y:
> >
> > > dimnames(y)
> > $x93
> > [1] "1" "2"
> >
> > $x94
> > [1] "0" "1" "2"
> > .................. so on (there are other dimensions as well)
> >
> >
> >
> > I need to access a particular dimension, but a random mechanism tells
me
> > which dimension it would. So, sometimes I might need to access
> > dimnames(y)$x93, some other time it would be dimnames(y)$x94.. and so
> on.
> > Now let that random dimension be idx, then
> dimnames(y)$paste('x',idx,sep='')
> > doesn't work.

> Why not
>
> dimnames(y)[idx]
>
> Regards
> Petr
>
>
> >
> > Can anyone help?
> >
> > 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.



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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. Received on Tue 18 Dec 2007 - 14:00:45 GMT

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