[R] accessing dimension names

[Petr PIKAL]

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 at 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]]
> >
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