R语言去重复数据

>test <- data.frame(
  x1 = c(1,2,3,4,5,1,3,5),
  x2 = c("a","b","c","d","e","a","b","e"),
  x3 = c("a","b","c","d","e","a","c","e"))
> test
  x1 x2 x3
1  1  a  a
2  2  b  b
3  3  c  c
4  4  d  d
5  5  e  e
6  1  a  a
7  3  b  c
8  5  e  e

> test[!duplicated(test),] #删掉所有列上都重复的
  x1 x2 x3
1  1  a  a
2  2  b  b
3  3  c  c
4  4  d  d
5  5  e  e
7  3  b  c

> test[!duplicated(test[,c(2,3)]),]
  x1 x2 x3
1  1  a  a
2  2  b  b
3  3  c  c
4  4  d  d
5  5  e  e
7  3  b  c