CODEWITHSUNDEEP
rcomparisonrankingrank
ilmatic9000
ilmatic9000

Reputation: 51

How do I compare the order of two lists in R?

Hi I'm trying to determine the change in ordering of two lists in R.

e.g. Comparing rankings of tennis players from two different months.

Feb <- c("A", "B", "C", "D")
Mar <- c("D", "B", "C", "A")

orderChange(Feb, Mar)

I would like to get a result which shows the difference in ordering/ranking.

(-3, 0, 0, 3)

I've tried which() but that only tells me whether an element is present and doesn't compare the ordering.

which(Mar %in% Feb)
[1] 1 2 3 4

Upvotes: 0

Views: 176

Answers (1)

GKi
GKi

Reputation: 39667

You can use seq_along and subtract match.

Feb <- c("A", "B", "C", "D")
Mar <- c("D", "B", "C", "A")
Apr <- c("C", "B", "D", "A")

seq_along(Feb) - match(Feb, Mar)
#[1] -3  0  0  3

seq_along(Feb) - match(Feb, Apr)
#[1] -3  0  2  1

and can pack this in a function if needed.

orderChange <- function(x, y) seq_along(x) - match(x, y)

Upvotes: 3

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