... and moreover, note that the assignment can even be shortened to:
> for ( i in 1:10 ) l[[c(i,1)]] <- 5
?"[[" contains details, but the relevant point is:
"[[ can be applied recursively to lists, so that if the single index i
is a vector of length p, alist[[i]] is equivalent to
alist[[i1]]...[[ip]] providing all but the final indexing results in a
list."
For a less terse version, see any good online R tutorial. Lists are
extremely useful in R, and indexing is fundamental. If you haven't
spent the time to learn about these constructs, you should now before
posting further. You'll save yourself a lot of grief and perhaps even
some embarassment.
Cheers,
Bert
Bert Gunter
"The trouble with having an open mind is that people keep coming along
and sticking things into it."
-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
On Sun, Apr 30, 2017 at 8:48 AM, peter dalgaard <pda...@gmail.com> wrote:
> assign(paste("list_", i, "[[1]]", sep = ""), 5) creates a new variable with a
> funny name.
>
> You'd have to parse() and eval() to make that work, something like
>
> eval(parse(text=paste("list_",i,"[[1]]<-",5, sep="")))
>
> However,
> -------
>> fortunes::fortune("parse")
>
> If the answer is parse() you should usually rethink the question.
> -- Thomas Lumley
> R-help (February 2005)
> -------
>
> It is much easier to handle this using a data structure containing a list of
> lists:
>
> l <- rep(list(list()), 10)
> for ( i in 1:10 )
> l[[i]][[1]] <- 5
>
>> On 30 Apr 2017, at 17:17 , Jinsong Zhao <jsz...@yeah.net> wrote:
>>
>> Hi there,
>>
>> I have a problem with assign(). Here is the demo code:
>>
>> for (i in 1:10) {
>> # create a list with variable name as list_1, list_2, ..., etc.
>> assign(paste("list_", i, sep = ""), list())
>> # I hope to assign 5 to list_?[[1]], but I don't know how to code it.
>> # list_1[[1]] <- 5 # works, however
>> assign(paste("list_", i, "[[1]]", sep = "", 5) # does not work
>> }
>>
>> How to do? Is there any alternatives? Many thanks!
>>
>> Best,
>> Jinsong
>>
>> ______________________________________________
>> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
> --
> Peter Dalgaard, Professor,
> Center for Statistics, Copenhagen Business School
> Solbjerg Plads 3, 2000 Frederiksberg, Denmark
> Phone: (+45)38153501
> Office: A 4.23
> Email: pd....@cbs.dk Priv: pda...@gmail.com
>
> ______________________________________________
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
