The Simplest Way to Convert a List with Various Length Vectors to a Data.Frame in R

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

We can use

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

Or using tidyverse

library(dplyr)
library(tibble)
library(tidyr)
enframe(aa) %>%
    unnest(value)

convert list with vectors of different length into data frame

df =  data.frame(col1 = unlist(lapply(ex.list, paste, collapse = ", ")))
> df
           col1
1 Tom, Ron, Joe
2      Ron, Joe
3           Tom

To get the unique names you'd have to run something like this

> unique(unlist(strsplit(as.character(df[ , 1]), ", ")))
[1] "Tom" "Ron" "Joe"

You're not going to be able to look at the levels of the factor with the way you want your data.frame setup.

Convert a list to a data frame

Update July 2020:

The default for the parameter stringsAsFactors is now default.stringsAsFactors() which in turn yields FALSE as its default.

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Assuming your list of lists is called l:

df <- data.frame(matrix(unlist(l), nrow=length(l), byrow=TRUE))

The above will convert all character columns to factors, to avoid this you can add a parameter to the data.frame() call:

df <- data.frame(matrix(unlist(l), nrow=132, byrow=TRUE),stringsAsFactors=FALSE)

Convert a list of vectors of different lengths to a data frame

expand.grid should work in this case -

expand.grid(ll)

#  f1 f2 f3
#1  a  d  f
#2  b  d  f
#3  c  d  f
#4  a  e  f
#5  b  e  f
#6  c  e  f

Another similar alternative would be purrr::cross_df.

purrr::cross_df(ll)

List of different length character vectors into data frame

The easiest would be stri_list2matrix

library(stringi)
df <- as.data.frame(stri_list2matrix(folders, byrow = TRUE), stringsAsFactors=FALSE)
names(df) <- paste0("Level", seq_along(df))
df
#   Level1 Level2 Level3
#1   Main   <NA>   <NA>
#2   Main    Mid   <NA>
#3   Main    Mid    Sub

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But, this can also be solved with base R

m1 <- max(lengths(folders))
d1 <- as.data.frame(do.call(rbind, lapply(folders, `length<-`, m1)), stringsAsFactors= FALSE)
names(d1) <- paste0("Level", seq_along(d1))

how to convert a list with different length of lists to a dataframe in r

We use mtabulate and transpose the output

library(qdapTools)
t(mtabulate(data))

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Or if we are using base R, then stack into a data.frame with 2 columns and apply the table

table(stack(data))

Assuming that there are no duplicates for each entry. If there are duplicates, then we may need a logical vector coerced to binary

+(table(stack(data)) >0)

How to convert a list consisting of vector of different lengths to a usable data frame in R?

try this:

word.list <- list(letters[1:4], letters[1:5], letters[1:2], letters[1:6])
n.obs <- sapply(word.list, length)
seq.max <- seq_len(max(n.obs))
mat <- t(sapply(word.list, "[", i = seq.max))

the trick is, that,

c(1:2)[1:4]

returns the vector + two NAs

How do you convert large list with vectors of different lenght to dataframe?

You could do:

t(as.data.frame(lapply(lst, "length<-", max(lengths(lst)))))

#    [,1] [,2] [,3] [,4] [,5]
#a      1    2    4    5    6
#c      7    8    9   NA   NA
#c.1   10   11   NA   NA   NA

Or as @Andrew pointed out, you can do:

t(sapply(lst, "length<-", max(lengths(lst))))

#  [,1] [,2] [,3] [,4] [,5]
#a    1    2    4    5    6
#c    7    8    9   NA   NA
#c   10   11   NA   NA   NA

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