[R] changing a list element's name during execution in lapply - possible?

[Gabor Grothendieck]

Try this:

# same args as lapply.  FUN must return named components.
lapplyWithRename <- function(...) {
	x <- lapply(...)
	names(x) <- sapply(x, names)
	lapply(x, function(x) { names(x) <- NULL; x })
}

# test function - if x is "A" then f returns c("Name A" = "A")
f <- function(x) structure(x, .Names = paste("Name", x))

L <- list(a="A", b="B")
lapplyWithRename(L, f)

Output looks like this:
> lapplyWithRename(L, f)
$`Name A`
[1] "A"

$`Name B`
[1] "B"


On Fri, Jan 1, 2010 at 8:21 AM, Mark Heckmann <mark.heckmann at gmx.de> wrote:
> Happy New Year, all!
>
> I want to do calculations on each element of a list l, but i want the
> returned list element to be named differently after the calculation.
> Is it possible to do the renaming somehow within the lapply call?
>
>        l <- list(a=NA, b=NA)
>        lapply(l, function(x) {names(x) <- "new name";  return(x) })
>
> This does not work, any ideas?
> TIA
>
> –––––––––––––––––––––––––––––––––––––––
> Mark Heckmann
> Dipl. Wirt.-Ing. cand. Psych.
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