Create a cartesian product of k vectors in R

Question

suppose I have a vector and I want to create a cartesian product of k same vectors, How do I implement this in R.

Like, my vector is

m
[1] 1 2

and k is 3,

how do I get a result like a cartesian product of 3 m.

Answer 1

The cartesian product is implemented in R as outer, or its infix version %o%. Thus:

m %o% m %o% m

# , , 1
# 
#      [,1] [,2]
# [1,]    1    2
# [2,]    2    4
# 
# , , 2
# 
#      [,1] [,2]
# [1,]    2    4
# [2,]    4    8

or in a more easily expandable form,

Reduce(outer, rep(list(m), 3))

which returns the same thing.