Elegant way to create two different random integers

Question

I want to create two random integers on the interval [1,n] which are guaranteed to be different from each other. I feel like

ri(1)=randi([1 n]);
ri(2)=randi([1 n]);
while ri(1)==ri(2)
  ri(2)=randi([1 n]);
end

is not really the smoothest thing you can do.

Answer 1

One method is to use randperm so that you generate a random permutation of n values that are enumerated from 1 up to and including n, and only return the first two elements of the result:

ri = randperm(n, 2);

Older versions of MATLAB do not support calling randperm this way. Older versions only accept the one input variant, which by default returns the entire permutation of the n values. Therefore, you can call randperm using the one input version, then subset into the final result to return what you need:

ri = randperm(n);
ri = ri([1 2]);