The simplest way to convert a list with various length vectors to a data.frame in R

Question

Here I have a list with different length vectors. And I\'d want to get a data.frame. I\'ve seen lots of posts about it in SO (see ref), but none of them are as simple as I e

Answer 1

Make this function:

listToDF <- function(aa){
  sapply(aa, "length<-", max(lengths(aa)))
 }

Then use it, simply:

listToDF(aa)

Answer 2

We can use

data.frame(lapply(aa, "length<-", max(lengths(aa))))

Answer 3

Using tidyverse packages. Place the list in a nested data frame. Extract the name for each vector in the list. Unnest the data frame. Give a row index i for each element in each vector, spread the data in wide format

    aa <- list(A = c(1, 3, 4), B = c(3, 5, 7, 7, 8))
    library(tidyverse)
    data_frame(data = aa) %>% 
        group_by(name = names(data)) %>% 
        unnest() %>%
        mutate(i = row_number()) %>% 
        spread(name, data)
    # A tibble: 5 x 3
          i     A     B
    * <int> <dbl> <dbl>
    1     1     1     3
    2     2     3     5
    3     3     4     7
    4     4    NA     7
    5     5    NA     8