R help - Dec 2010 - How can i select a set of element in a list ?

How can i select a set of element in a list ?

x<-list(1,2,3,4,5)

How can I create a new list which only have the last 4 elements of x.
I can do it with a loop, but I want to avoid that. Thanks!

example :
y<-vector("list",4)
for ( i in 1:length(y) )
    y[[i]] <- x[[ i + length(x) - length(y) ]]
> y
[[1]]
[1] 2

[[2]]
[1] 3

[[3]]
[1] 4

[[4]]
[1] 5

Regards,
Julian

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at
r-project.org]
> On Behalf Of Julian TszKin Chan
> Sent: Wednesday, December 08, 2010 2:39 PM
> To: r-help at r-project.org
> Subject: [R] How can i select a set of element in a list ?
> 
> How can i select a set of element in a list ?
> 
> x<-list(1,2,3,4,5)
> 
> How can I create a new list which only have the last 4 elements of x.
> I can do it with a loop, but I want to avoid that. Thanks!
> 
> example :
> y<-vector("list",4)
> for ( i in 1:length(y) )
>     y[[i]] <- x[[ i + length(x) - length(y) ]]
> 
> > y
> [[1]]
> [1] 2
> 
> [[2]]
> [1] 3
> 
> [[3]]
> [1] 4
> 
> [[4]]
> [1] 5
> 
> Regards,
> Julian
> 
Julian,

You use standard indexing to do that.

y <- x[-1]

Hope this is helpful,

Dan

Daniel Nordlund
Bothell, WA USA