Replicate same data.frame n times and save them into a list

Question

I just need to replicate my data.frame n times (e.g. 100) and save all the outputs into a list.

It should be quite easy and straightforward but I could not find any solution yet.

Fake data.frame:

df = read.table(text = 'a b
1 2
5 6
4 4
11 78
23 99', header = TRUE)

yes, exactly.....I need it because I want to manipulate them eventually in n different ways — aaaaa, May 08 '17 at 18:17

score 13 · Accepted Answer · answered May 08 '17 at 17:34

13

With lapply:

df_list <- lapply(1:100, function(x) df)

answered May 08 '17 at 17:34

Sraffa

1,658
12
27

This solved a similar problem for me as well. I am curious about the syntax. Why does this result in basic replication? Is the function(x) basically a non-function, so you are repeating "df" 1:100 times but without doing anything to it? – PortMadeleineCrumpet Nov 16 '21 at 00:11

score 9 · Answer 2 · answered May 08 '17 at 17:33

9

We can use replicate

n <- 100
lst <- replicate(n, df, simplify = FALSE)

answered May 08 '17 at 17:33

akrun

874,273
37
540
662

If this helped, you should mark the checkbox beside it. – Arya McCarthy May 08 '17 at 18:18

score 2 · Answer 3 · answered May 08 '17 at 17:50

You can use rep if you wrap it in list, as rep tries to return the same type of object you pass it:

df_list <- rep(list(df), 100)

str(df_list[1:2])
#> List of 2
#>  $ :'data.frame':    5 obs. of  2 variables:
#>   ..$ a: int [1:5] 1 5 4 11 23
#>   ..$ b: int [1:5] 2 6 4 78 99
#>  $ :'data.frame':    5 obs. of  2 variables:
#>   ..$ a: int [1:5] 1 5 4 11 23
#>   ..$ b: int [1:5] 2 6 4 78 99

Replicate same data.frame n times and save them into a list

3 Answers3