q**j
发帖数: 10612 | 1 如果有两个data frame, 可以match on two key variables. then how to select a
subset that is in one data frame but not in the other. i learned how to do
it when there is only one key variable. but i do not know what to do when
there are two or more.多谢。 | q**j
发帖数: 10612 | 2 re了就能看到了吧？
when
【在 q**j 的大作中提到】
: 如果有两个data frame, 可以match on two key variables. then how to select a
: subset that is in one data frame but not in the other. i learned how to do
: it when there is only one key variable. but i do not know what to do when
: there are two or more.多谢。
| q**j
发帖数: 10612 | 3 自己顶一下。好像比较棘手。
【在 q**j 的大作中提到】
: re了就能看到了吧？
:
: when
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