R help - Oct 2009 - How apply a function to a list while maintaining list name?

I use lapply to apply a function to the list 'L'. But of course, the
list names in 'X' is not maintained. I'm wondering if there is a
function that can maintain the list names as well as apply the
function.

$ Rscript lapply.R
> L=list(x=c('a','b'), y=c('a','b'))
> L
$x
[1] "a" "b"

$y
[1] "a" "b"
> X=lapply(1:length(L),function(x){paste(L[[x]],collapse='')})
> X
[[1]]
[1] "ab"

[[2]]
[1] "ab"
> names(X)=names(L)
> X
$x
[1] "ab"

$y
[1] "ab"

Hi Peng,

Try

lapply(L, paste, collapse="")
$x
[1] "ab"

$y
[1] "ab"


HTH,
Jorge


On Sat, Oct 24, 2009 at 12:02 PM, Peng Yu <> wrote:
> I use lapply to apply a function to the list 'L'. But of course,
the
> list names in 'X' is not maintained. I'm wondering if there is
a
> function that can maintain the list names as well as apply the
> function.
>
> $ Rscript lapply.R
> > L=list(x=c('a','b'), y=c('a','b'))
> > L
> $x
> [1] "a" "b"
>
> $y
> [1] "a" "b"
>
> > X=lapply(1:length(L),function(x){paste(L[[x]],collapse='')})
> > X
> [[1]]
> [1] "ab"
>
> [[2]]
> [1] "ab"
>
> > names(X)=names(L)
> > X
> $x
> [1] "ab"
>
> $y
> [1] "ab"
>
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