How to generate specific number of specific integers within a range?

2 views (last 30 days)
I want to generate a random array of 8 integers within [1,4] where each integer appears exactly twice. Examples:
1 1 2 2 3 3 4 4
4 2 1 2 3 1 3 4
2 4 1 2 3 4 3 1
I know randi(4,8,1) gives a random array of 8 integers within [1,4] but it does not specify how many come from which integer. Is there a built in matlab function that does this? If not, what should I do?

Accepted Answer

Stephen23
Stephen23 on 28 Apr 2017
Edited: Stephen23 on 28 Apr 2017
This is easy with randperm:
>> vec = repmat(1:4,1,2);
>> out = vec(randperm(numel(vec)))
out =
2 3 2 4 1 1 4 3
>> out = vec(randperm(numel(vec)))
out =
1 4 2 3 2 1 3 4
>> out = vec(randperm(numel(vec)))
out =
2 1 2 4 3 3 4 1

More Answers (0)

Categories

Find more on Creating and Concatenating Matrices in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!