Exporting Items from List into Single .csv File R - r

Question

I have a list which contains vectors that I would like to export as a single .csv file containing all vectors as named colums.
For instance, if I have, simply, four vectors containing ten items from hypothetical cluster analyses of four models containing a variable number data points created by
veglist=list.files(pattern="TXT") #create list of files
veg=lapply(veglist,read.csv,header=T,row.names=1) #read list of files
vegbc=lapply(veg,vegdist,method="bray") #create dissimilarity matrix from each file
av=lapply(vegbc,agnes,method="average") #do clustering analysis with each dissimilarity mat
av2=lapply(av,cutree,k=2) #cut the hierarchical analysis at 2 groups level
when I type in fix(av2) I would see:
list(c(1,1,1,1,1,1,2,2,2,2,2,2),c(1,1,1,1,1,2,2,2,2,2),c(1,1,1,2,1,2,2,2,2,2),c(1,1,1,1,2,1,2,2,2,2,2,2,2))
If I type in av2 I see
[[1]]
[1] 1 1 1 1 1 1 2 2 2 2 2 2
[[2]]
[1] 1 1 1 1 1 2 2 2 2 2
[[3]]
[1] 1 1 1 2 1 2 2 2 2 2
[[4]]
[1] 1 1 1 1 2 1 2 2 2 2 2 2 2
I have tried following this example How to read every .csv file in R and export them into single large file. This did not work.
I think the underlying problem is that my vectors are not the same size. What I want to do is output the vectors into a single table that looks something like:
a b c d
1 1 1 1
1 1 1 1
1 1 1 1
1 1 2 1
1 1 1 1
1 2 2 2
2 2 2 2
2 2 2 2
2 2 2 2
2 2
2 2
2
Where a,b,c,d are in place of my actual names. Preferably it would look prettier than this, but I could work with it.
I apologize for the very long question, but I was trying to provide enough of an example to go by. I am also sorry if this has a very easy answer, but I am not yet good with R. Thanks in advance.

Answer 1

Here is one way you can do:
l <- list(c(1,1,1,1,1,1,2,2,2,2,2,2),c(1,1,1,1,1,2,2,2,2,2),c(1,1,1,2,1,2,2,2,2,2),c(1,1,1,1,2,1,2,2,2,2,2,2,2))
maxlength <- max(sapply(l, length))
df <- data.frame(sapply(l, function(x) c(x, rep(NA, (maxlength - length(x))))))
df
X1 X2 X3 X4
1 1 1 1 1
2 1 1 1 1
3 1 1 1 1
4 1 1 2 1
5 1 1 1 2
6 1 2 2 1
7 2 2 2 2
8 2 2 2 2
9 2 2 2 2
10 2 2 2 2
11 2 NA NA 2
12 2 NA NA 2
13 NA NA NA 2

Answer 2

You would first need to extend each vector to the length of the maximum length-ed vector and then you could cbind them together so that write.csv would send them out as "columns":
> maxlength <- max(sapply(l, length))
> mat <- cbind(sapply(l, `length<-`, maxlength))
> mat
[,1] [,2] [,3] [,4]
[1,] 1 1 1 1
[2,] 1 1 1 1
[3,] 1 1 1 1
[4,] 1 1 2 1
[5,] 1 1 1 2
[6,] 1 2 2 1
[7,] 2 2 2 2
[8,] 2 2 2 2
[9,] 2 2 2 2
[10,] 2 2 2 2
[11,] 2 NA NA 2
[12,] 2 NA NA 2
[13,] NA NA NA 2
> write.csv(mat, file="mycsv.csv")
Which looks like this in a text editor (and would get imported into Excel properly.):
"","V1","V2","V3","V4"
"1",1,1,1,1
"2",1,1,1,1
"3",1,1,1,1
"4",1,1,2,1
"5",1,1,1,2
"6",1,2,2,1
"7",2,2,2,2
"8",2,2,2,2
"9",2,2,2,2
"10",2,2,2,2
"11",2,NA,NA,2
"12",2,NA,NA,2
"13",NA,NA,NA,2

Answer 3

This can be done with stri_list2matrix from stringi
library(stringi)
m1 <- stri_list2matrix(l)
mode(m1) <- "integer"
m1
# [,1] [,2] [,3] [,4]
# [1,] 1 1 1 1
# [2,] 1 1 1 1
# [3,] 1 1 1 1
# [4,] 1 1 2 1
# [5,] 1 1 1 2
# [6,] 1 2 2 1
# [7,] 2 2 2 2
# [8,] 2 2 2 2
# [9,] 2 2 2 2
#[10,] 2 2 2 2
#[11,] 2 NA NA 2
#[12,] 2 NA NA 2
#[13,] NA NA NA 2