Use Object Names as List Names in R

Use object names as list names in R

Find the names, then call mget.

If there is a pattern to the names of each individual variable, then this is straightforward.

var_names <- paste0("df", 1:3)
mget(var_names, envir = globalenv())  #or maybe envir = parent.frame()

If the naming system is more complicated, you can use regular expressions to find them, using something like

var_names <- ls(envir = globalenv(), pattern = "^df[[:digit:]]+$")

How to name a list object in R

If you want to name the lists while creating them you can use tibble::lst

my_df1 <- mtcars[1:10,]
my_df2 <- mtcars[11:20,]
my_df3 <- mtcars[21:30,]
my_list <- tibble::lst(my_df1, my_df2, my_df3)

If the list is already created you can use names or setNames to name the list.

names(my_list) <- c('list1', 'list2', 'list3')

setNames(my_list, c('list1', 'list2', 'list3'))

Naming list elements in R

The first case is the correct usage. In the second case you are sending filList[i] to names<- which is only exists as a temporary subsetted object.

Alternatively, you could just do everything outside the loop with:

names(filList) <- names(Fil)

Can lists be created that name themselves based on input object names?

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.

Give name to list variable

Since @akrun doesn't need any more points, here is an example showing how you can assign names to a list:

lst <- list(a="one", b="two", c=c(1:3))
names(lst)
[1] "a" "b" "c"
names(lst) <- c("x", "y", "z")

> lst
$x
[1] "one"

$y
[1] "two"

$z
[1] 1 2 3

How can I make a named list or vector from environment objects, using the object names?

You can use match.call to retrieve the names of the arguments being passed in

name_list <- function(...){
  vnames <- as.character(match.call())[-1]
  return(setNames(list(...), vnames))
}
a = 1; b=c(1,2)
name_list(a, b)

Get the name of the list object then add that name as a new column of the each list

If I've understood you correctly, I'd probably use the purrr library. imap_dfr will pass both your matrix and its name to the function, and then bind the results into a single dataframe.

library(purrr)

new_list <- imap_dfr(mylist, function(mat, name) {
  result <- as.data.frame(mat)
  result$name <- name
  result
})

gives

> new_list
  Analyte_Mean SDBetweenGroup SDWithinGroup replicates NumSamples    FValue    PValue FCritical  name
1       5.1210    0.008363944    0.01994994          5         10 1.8788386 0.0836504  2.124029  SiO2
2       2.0812    0.005310367    0.01590597          5         10 0.4426877 0.9032892  2.124029 Al2O3

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