Question

What code in R will do the following:

Given a list 1, 2, …, M create a list of N random entries from that list. Furthermore, obtain the complement list.

example:
N = 5
M = 10
list = [1,4,3,9,2]
complement = [5,6,7,8,10]

Answer 1

?sample

samp_range <- 1:M
out <- sample(samp_range, N)
compliment <- samp_range[!samp_range %in% out]

or as per Joran’s comment:

compliment <- setdiff(samp_range, out)

Also, as a rule, avoid using things like list as variable names since they are internal R functions.