How to sort a list alphabetically?-CodePudding

It is necessary to create a list of random letters of the alphabet. And then sort it alphabetically. To create such a list, I use the following code:

# Creating a random vector of letters
random_text_data = sample(letters, 10)
random_text_data

# Convert to list
list_text_data = as.list(random_text_data)
list_text_data

In the console I get the following:

> random_text_data
 [1] "h" "m" "q" "b" "z" "i" "y" "f" "d" "e"
> # Convert to list
> list_text_data = as.list(random_text_data)
> list_text_data
[[1]]
[1] "h"

[[2]]
[1] "m"

[[3]]
[1] "q"

[[4]]
[1] "b"

[[5]]
[1] "z"

[[6]]
[1] "i"

[[7]]
[1] "y"

[[8]]
[1] "f"

[[9]]
[1] "d"

[[10]]
[1] "e"

Now I need to sort it alphabetically. I have tried the following:

# Sort list alphabetically
sort_data = sort(list_text_data)

But get error:

> sort_data = sort(list_text_data)
Error in sort.int(x, na.last = na.last, decreasing = decreasing, ...) : 
'x' must be elementary

How should you sort?

CodePudding user response：

Here's a method that do not need to unlist(). After making the list with random letters, assign names to the list with the content of the list. Then order the names within the list.

Input

random_text_data = sample(letters, 10)

[1] "c" "v" "m" "g" "h" "l" "d" "i" "u" "y"

Original solution

list_text_data = as.list(random_text_data)

list_text_data <- setNames(list_text_data, list_text_data)

list_text_data[order(names(list_text_data))]

$c
[1] "c"

$d
[1] "d"

$g
[1] "g"

$h
[1] "h"

$i
[1] "i"

$l
[1] "l"

$m
[1] "m"

$u
[1] "u"

$v
[1] "v"

$y
[1] "y"

Updated solution

Inspired by @zx8754's answer, you don't actually need to change names of the list, you can use setNames within order, then the output will be an unnamed list.

list_text_data[order(names(setNames(list_text_data, list_text_data)))]

[[1]]
[1] "c"

[[2]]
[1] "d"

[[3]]
[1] "g"

[[4]]
[1] "h"

[[5]]
[1] "i"

[[6]]
[1] "l"

[[7]]
[1] "m"

[[8]]
[1] "u"

[[9]]
[1] "v"

[[10]]
[1] "y"

CodePudding user response：

Convert character to integer, then order:

# reproducible example data
set.seed(1); random_text_data = sample(letters, 3)
list_text_data = as.list(random_text_data)
# [[1]]
# [1] "y"
# 
# [[2]]
# [1] "d"
# 
# [[3]]
# [1] "g"


# sort
list_text_data[ order(sapply(list_text_data, utf8ToInt)) ]
# [[1]]
# [1] "d"
# 
# [[2]]
# [1] "g"
# 
# [[3]]
# [1] "y"

CodePudding user response：

We may have to flatten the list first before sorting the elements. We can try the sort unlist like below

relist(sort(unlist(list_text_data)), list_text_data)