识别 R 中两个变量之间未共享的索引

Question

I would like to identify the indices for which there is not a match between two variables. The following code identifies the matches rather than the mismatched:

x <- c("a", "b", "c")
y <- c("a", "z", "c")
which(unique(as.character(x))%in% unique(y))

Thoughts on how to get this to identify the False indices (or in this example, 2)?

Answer 1

which(!(unique(as.character(x))%in% unique(y)))

cdeeterman 基本上是正确的，只需要确保 not (!) 适用于整个关系 unique(as.character(x))%in% unique(y)

Answer 2

You could also try using two equal signs where "x == y" basically says "x is exactly equal to y"

x = c("a", "b", "c")
y = c("a", "z", "c")

z = x == y
which(z == FALSE)

Answer 3

What about setdiff?

> which( y %in% setdiff(y,x)  )
[1] 2