[R] how to make list() return a list of *named* elements

[Berwin A Turlach]

G'day Hans,

On Mon, 4 Oct 2010 11:28:15 +0200
Hans Ekbrand <hans at sociologi.cjb.net> wrote:

> On Thu, Sep 30, 2010 at 09:34:26AM -0300, Henrique Dallazuanna wrote:
> > You should try:
> > 
> > eapply(.GlobalEnv, I)[c('b', 'my.c')]
> 
> Great!
> 
> b <- c(22.4, 12.2, 10.9, 8.5, 9.2)
> my.c <- sample.int(round(2*mean(b)), 4)
> 
> my.return <- function (vector.of.variable.names) {
>   eapply(.GlobalEnv, I)[vector.of.variable.names]
> }

Well, if you are willing to create a vector with the variable names,
then simpler solutions should be possible, i.e. solutions that only
operate on the objects of interest and not on all objects in the global
environment (which could be a lot depending on your style).  For
example:

R> my.return <- function (vector.of.variable.names) {
  sapply(vector.of.variable.names, function(x) list(get(x)))
}
R> str(my.return(c("b","my.c")))
List of 2
 $ b   : num [1:5] 22.4 12.2 10.9 8.5 9.2
 $ my.c: int [1:4] 7 5 23 4

Cheers,

	Berwin

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