[SOLVED] In R, how to get the results of combn() from a matrix into a vector without losing data?

In R, how to get the results of combn() from a matrix into a vector without losing data?

I know that combn() can give me all the unique combinations across a vector. However, it gives me a matrix output, and I want it as a vector. Wrapping the output in as.vector() makes every value individual, losing the purpose of running combn() in the first place. Imagine my dataset was c("a", "b", "c"), how can I use combn() (or some other function), to get a vector where my output would be:

my_data <- c("a", "b", "c")

#natural output with combn()

#output with combn()
combn(my_data, 2, simplify = TRUE)

#output with as.vector() wrapped
as.vector(combn(my_data, 2, simplify = TRUE))

#desired output
answer <- c("ab", "ac", "bc") #I don't care about order

Solution

You can paste each column of the result together using apply

my_data <- c("a", "b", "c")

apply(combn(my_data, 2), 2, paste, collapse = "")
#> [1] "ab" "ac" "bc"

^{Created on 2023-01-25 with reprex v2.0.2}