我有一个大型数据框(1616610行,255列),我需要根据一个键将每列的唯一值粘贴在一起.
例如:
> data = data.frame(a=c(1,1,1,2,2,3),
b=c("apples", "oranges", "apples", "apples", "apples", "grapefruit"),
c=c(12, 22, 22, 45, 67, 28),
d=c("Monday", "Monday", "Monday", "Tuesday", "Wednesday", "Tuesday"))
> data
a b c d
1 1 apples 12 Monday
2 1 oranges 22 Monday
3 1 apples 22 Monday
4 2 apples 45 Tuesday
5 2 apples 67 Wednesday
6 3 grapefruit 28 Tuesday
我需要的是聚合255列中每一列中的每个唯一值,并为每个唯一值返回一个带逗号分隔符的新数据框.像这样:
a b c d
1 1 apples, oranges 12, 22 Monday
2 2 apples 45, 67 Tuesday, Wednesday
3 …