[R] Alternative to list()

[Petr Pikal]

On 15 Mar 2001, at 19:33, Ko-Kang at xtra.co.nz wrote:

> Hi,
> 
> Suppose I have a dataset with 10 columns, let's call it "foo".
> 
> Now if I want to extract out only column 2 ~ 8, then I know I can use
> either:
>      foo[ ,2:8]
> or
>      fooNew <- list( foo[ ,2:8] )
Hm. Why do you bother with list. I assume foo is either matrix or data 
frame and for this I usually use

fooNew_foo[,2:8]

> 
> (Is there any other alternative, just out of curiosity?)
> 
> But, if I only want, say, column 1, 4 and 7, I tried:
>      fooNew <- list( x = foo[ ,1], y = foo[ ,4], z = foo[ , 7]  ) then
> when I type 
>      fooNew
> I got a list of:
>   $x
>    ....
>    ....
>   $y
>    ....
>    ....
>   $z
>    ....
>    ....
> 
> However what I really want is for them to be in vector/column form. 
> How would I do this?

again 

fooNew_foo[,c(1,4,7)]

can probably do what you want.
> 
> Thanks in advance!
> 
> 
> Kevin
> 
> -------------------------------------------------
> Ko-Kang Kevin Wang
> Statistical Analysis Division Leader
> Software Developers' Klub
> University of Auckland
> New Zealand
> 

Hi.

Petr Pikal
Precheza a.s.
Nabr.Dr.E.Benese 24
tel: 00420 641 25 2257
     +420 (0)724 008 364
     petr.pikal at precheza.cz
     p.pik at volny.cz

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