基于两列的子集重复

Subset duplicates based on two columns

我的数据是这样的:

A   B
1   2
1A  2
1A  2
2   3
2   4
2   4
3A  0
3A  0
4A  1
4A  1
5   5

我想根据两列的值对数据进行子集化,并提取所有重复的记录。我尝试使用 cbind 和 unique,但它们仅提取唯一值。如果有帮助的话,我找不到反向子集函数。 谢谢

你可以试试

 df1[duplicated(df1)|duplicated(df1, fromLast=TRUE),]
 #    A B
 #2  1A 2
 #3  1A 2
 #5   2 4
 #6   2 4
 #7  3A 0
 #8  3A 0
 #9  4A 1
 #10 4A 1

数据

 df1 <- structure(list(A = c("1", "1A", "1A", "2", "2", "2", "3A",
 "3A", 
 "4A", "4A", "5"), B = c(2L, 2L, 2L, 3L, 4L, 4L, 0L, 0L, 1L, 1L, 
 5L)), .Names = c("A", "B"), class = "data.frame", row.names = c(NA, 
 -11L))