[R] assign a list using expression?

[Gabor Grothendieck]

This still isn't clear.  In your post, values is already
a list with the required names and values in it so the
whole exercise is pointless -- you are starting
out with the answer.

Just guessing, but maybe your setup is a set of variables
in your workspace and a vector of their names with the
output being a named list of them:

a <- 1:2; b <- 1:3
nms <- c("a", "b")
sapply(nms, get, simplify = FALSE)


On Mon, Jan 12, 2009 at 10:58 AM, Skotara <nils.skotara at uni-hamburg.de> wrote:
> Thank you Patrick and Gabor!
> Sorry, I think I have not explainend it well.
> The purpose is as follows:
>   names <- letters[1:3]
>   values <- data.frame(a = 1:3, b = 4:6, c = 7:9)
> With more complicated objects similar to 'names' and 'values' I wrote the
> following line to assign the elements of the list:
>   mycommand <- parse(text = paste(names, " = values[\"", names, "\"]",
> sep="") )
> However,
>   list(eval(mycommand))
> does not do what I want.
> whereas
>   list(a = values["a"], b = values["b"], c = values["c"])
> does.
>
> I can not tell why...
> I try to understand, what expression and eval do. I know that many times
> there are other ways to achieve the same goal.
> So here, too. But I think there should be a reason why it does not work that
> way.
>
> Best regards!
> Nils
>