Randomly insert NAs into dataframe proportionaly

Question

I have a complete dataframe. I want to 20% of the values in the dataframe to be replaced by NAs to simulate random missing data.

A <- c(1:10)
B <- c(1         


        

Answer 1

If you are in the mood to use purrr instead of lapply, you can also do it like this:

> library(purrr)
> df <- data.frame(A = 1:10, B = 11:20, C = 21:30)
> df
    A  B  C
1   1 11 21
2   2 12 22
3   3 13 23
4   4 14 24
5   5 15 25
6   6 16 26
7   7 17 27
8   8 18 28
9   9 19 29
10 10 20 30
> map_df(df, function(x) {x[sample(c(TRUE, NA), prob = c(0.8, 0.2), size = length(x), replace = TRUE)]})
# A tibble: 10 x 3
       A     B     C
     
1      1    11    21
2      2    12    22
3     NA    13    NA
4      4    14    NA
5      5    15    25
6      6    16    26
7      7    17    27
8      8    NA    28
9      9    19    29
10    10    20    30