How do I get the logicals of shared rows of two data frames?
如何获得两个数据帧共享行的逻辑?
> a <- data.frame(x = 1:5, y = 7:11)
> b <- data.frame(x = c(4, 2, 6, 3, 3, 1), y = c(10, 16, 7, 9, 9, 7))
> a
x y
1 1 7
2 2 8
3 3 9
4 4 10
5 5 11
> b
x y
1 4 10
2 2 16
3 6 7
4 3 9
5 3 9
6 1 7
> a.indices <- c(TRUE, FALSE, TRUE, TRUE, FALSE)
> b.indices <- c(TRUE, FALSE, FALSE, TRUE, TRUE, TRUE)
I would like to return a.indices or b.indices.
我想退货。指数或b.indices。
1 个解决方案
#1
2
You can do a combinaton of what merge and %in% does
您可以对merge和%in%做一个组合
a.indices <- match(
do.call(paste, c(a, sep="\r")),
do.call(paste, c(b, sep="\r")), nomatch=0
)>0
You combine the rows into a single value and then use match to compare one set to the other. You could also do
将行合并为一个值，然后使用match将一个集合与另一个集合进行比较。你也可以做
b.indices <- Reduce(function(vprev,vnow) vprev & !is.na(vnow),
Map(match, b,a), init=T)
(for both these methods you can swap a and b to get the opposite result). You may wish to test to compare performance in your specific scenario.
(对于这两种方法，你可以交换a和b以得到相反的结果)。您可能希望测试在您的特定场景中比较性能。
#1
2
You can do a combinaton of what merge and %in% does
您可以对merge和%in%做一个组合
a.indices <- match(
do.call(paste, c(a, sep="\r")),
do.call(paste, c(b, sep="\r")), nomatch=0
)>0
You combine the rows into a single value and then use match to compare one set to the other. You could also do
将行合并为一个值，然后使用match将一个集合与另一个集合进行比较。你也可以做
b.indices <- Reduce(function(vprev,vnow) vprev & !is.na(vnow),
Map(match, b,a), init=T)
(for both these methods you can swap a and b to get the opposite result). You may wish to test to compare performance in your specific scenario.
(对于这两种方法，你可以交换a和b以得到相反的结果)。您可能希望测试在您的特定场景中比较性能。