How to Split a Vector into Equal Parts in R

We will show you how to split an R vector into n parts of equal size. Bear in mind that sometimes is not possible to create chunks of equal size. For example, if we want each part to consist of 3 elements and our vector has 21 elements, then it is possible to create 7 chunks of 3 elements. But if the vector has 23 elements, then we will need to create 7 chunks of 3 elements and 1 chunk of 2 elements. Let’s get our hands dirty.

# set a random seed
set.seed(5)

# elements of each part
k<-3

# generate 23 values from poisson distribution 
# with parameter lambda = 20
x<-rpois(23, lambda = 20)

# split the vector 
split_vector<-split(x, ceiling(seq_along(x)/k))

# print
split_vector

$`1`
[1] 16 17 20

$`2`
[1] 27 17 20

$`3`
[1] 16 20 25

$`4`
[1] 16 19 28

$`5`
[1] 27 22 24

$`6`
[1] 24 26 23

$`7`
[1] 23 18 26

$`8`
[1] 26 17

As we can see, we generated 8 chunks, where the last one is of 2 elements and all the rest of 3. Finally, since the output is a list, we can retrieve each chunk as follows.

# get the third chunk
split_vector[[3]]

[1] 16 20 25