如何在列表列表中获取不同列表的频率

Question

Suppose i have the following list:

test<-list(c("a","b","c"),c("a,c"),c("a,c"),c("a","b","c"),c("a"))

I want this as result:

("a","b","c") = 2
("a,c")=2
("a")=1

I tried with

> table(test)
Error in table(test) : all arguments must have the same length

Answer 1

Here is a one-liner. The upper row of numbers are the vector's names.

table(match(test, unique(test)))
#1 2 3 
#2 2 1 

Answer 2

What's wrong with sapply and toString :

> table(sapply(test, toString))

      a a, b, c     a,c 
      1       2       2 
>