将不同名称的向量列表转换为R中具有唯一列名的数据框

Question

The title is wordy, but i couldn't find a solution to this problem and wanted to be as specific as possible. Is there an easy way to do the following:

test3 <- list('Row1'=c(a='a',b='b',c='c'), 'Row2'=c(a='d',var2='e',var3='f'))

desired dataframe
     a    b    c var2 var3
Row1 a    b    c <NA> <NA>
Row2 d <NA> <NA>    e    f

This article - https://www.r-bloggers.com/converting-a-list-to-a-data-frame/ - seems to claim I can just use as.data.frame(test3), however when I do it, I obtain:

> as.data.frame(test3)
  Row1 Row2
a    a    d
b    b    e
c    c    f

t(as.data.frame(test3))
     a   b   c  
Row1 "a" "b" "c"
Row2 "d" "e" "f"

neither of which are right...

Thanks in advance for help!

Answer 1

Here is a solution with rbindlist() from data.table :

library("data.table")
test3 <- list('Row1'=c(a='a',b='b',c='c'), 'Row2'=c(a='d',var2='e',var3='f'))
rbindlist(lapply(test3, as.list), fill=TRUE)
#    a  b  c var2 var3
# 1: a  b  c   NA   NA
# 2: d NA NA    e    f

The elements of your list test3 are named character vectors - so first coercing to lists.
If you want the rownames you can do:

result <- setDF(rbindlist(lapply(test3, as.list), fill=TRUE))
rownames(result) <- names(test3)
result
#        a    b    c var2 var3
#   Row1 a    b    c <NA> <NA>
#   Row2 d <NA> <NA>    e    f

This will coerce the data.table to a dataframe and then sets the rownames.
For a data.table result you have to define an extra column for the rownames:

result <- rbindlist(lapply(test3, as.list), fill=TRUE)
result[, rowna := names(test3)]
result
#    a  b  c var2 var3 rowna
# 1: a  b  c   NA   NA  Row1
# 2: d NA NA    e    f  Row2