In R, match function for rows or columns of matrix

Question

The value matching function in R is very useful. But from my understanding, it does not sufficiently support two or high dimensional inputs.

For examp

Answer 1

You can use asplit to create a list which can be used by match. But the manual says lists are converted to character vectors and Matching for lists is potentially very slow and best avoided except in simple cases.

match(asplit(x, 1), asplit(y, 1))
#[1] NA  1  2

So maybe using interaction or paste is an option.

match(interaction(data.frame(x)), interaction(data.frame(y)))
#[1] NA  1  2

match(apply(x, 1, paste, collapse =" "), apply(y, 1, paste, collapse =" "))
#[1] NA  1  2

Data:

(x <- matrix(1:9, 3))
#     [,1] [,2] [,3]
#[1,]    1    4    7
#[2,]    2    5    8
#[3,]    3    6    9

(y <- matrix(2:10, 3))
#     [,1] [,2] [,3]
#[1,]    2    5    8
#[2,]    3    6    9
#[3,]    4    7   10