1、 > a <- c(2,3,4,2,3,4,2,2,4) > b <- as.data.frame(table(a)) > b a Freq 1 2 4 2 3 2 3 4 3 相关文章: 2021-10-22 2022-01-02 2021-07-21 2021-09-17 2022-12-23 2022-01-18 2021-11-15