It would be very helpful to me to be able to create an R list object without having to specify the names of each element. For example:
a1 <- 1
a2 <- 20
a3 <- 1:20
b <- list(a1,a2,a3, inherit.name=TRUE)
> b
[[a1]]
[1] 1
[[a2]]
[1] 20
[[a3]]
[1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
This would be ideal. Any suggestions?
The tidyverse package tibble has a function that can do this as well. Try out tibble::lst
tibble::lst(a1, a2, a3)
# $a1
# [1] 1
#
# $a2
# [1] 20
#
# $a3
# [1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Coincidentally, I just wrote this function. It looks a lot like @joran's solution, but it tries not to stomp on already-named arguments.
namedList <- function(...) {
L <- list(...)
snm <- sapply(substitute(list(...)),deparse)[-1]
if (is.null(nm <- names(L))) nm <- snm
if (any(nonames <- nm=="")) nm[nonames] <- snm[nonames]
setNames(L,nm)
}
## TESTING:
a <- b <- c <- 1
namedList(a,b,c)
namedList(a,b,d=c)
namedList(e=a,f=b,d=c)
Copied from comments: if you want something from a CRAN package, you can use Hmisc::llist:
Hmisc::llist(a, b, c, d=a, labels = FALSE)
The only apparent difference is that the individual vectors also have names in this case.
deparse() will generate a vector of length >1, and sapply() will make a list instead of a character vector.A random idea:
a1<-1
a2<-20
a3<-1:20
my_list <- function(...){
names <- as.list(substitute(list(...)))[-1L]
result <- list(...)
names(result) <- names
result
}
> my_list(a1,a2,a3)
$a1
[1] 1
$a2
[1] 20
$a3
[1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
(The idea is stolen from the code in data.frame.)
Another idea ,
sapply(ls(pattern='^a[0-9]'), get)
$a1
[1] 1
$a2
[1] 20
$a3
[1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
